Pennsylvania Crusher
®
The Most Choices, The Most Experience
HANDBOOK OF CRUSHING With Posimetric® Feeders
INTRODUCTION We specialize in the manufacture of size reduction and feeding equipment and have pioneered many basic designs. Pennsylvania® produces more types and sizes of crushers and breakers than any other firm in the world and is known for offering, "The Most Choices, The Most Experience". Established in 1905, our equipment is used by numerous basic industries such as power generation, mining, cement plants, food & chemical processing, the glass industry and many others. In the U.S. in fact, a high percentage of the coal needed to generate electric power is crushed using our equipment. Our application expertise is second to none, and we invite you to take advantage of our help in solving your reduction or feeding problems.
THE TECHNOLOGY OF CRUSHING The ability to crush material is governed by the laws of physics involving mass, velocity, kinetic energy, and gravity. However, it is impractical to reduce the process of selecting and sizing a crusher to a series of formulas. The selection process is largely based on experience and testing: experience with actual field applications and laboratory tests that show how a given material will be reduced by a given crusher type. The main purpose of this handbook is to explain the principles that govern the technology of crushing and also to impart the practical knowledge gained by Pennsylvania Crusher over the past century.
Pennsylvania Crusher
®
The Most Choices, The Most Experience
600 Abbott Drive • Box 100 • Broomall, PA 19008-0100 U.S.A. Phone: (610) 544-7200 • Fax: (610) 543-0190 E-Mail:
[email protected] www.penncrusher.com
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Table of Contents THE TECHNOLOGY OF CRUSHING Introduction .................................................................................................................................................................. Table of Contents ........................................................................................................................................................ Glossary of Terms ........................................................................................................................................................ Mechanical Reduction Methods .................................................................................................................................. Crusher Selection Criteria / Development of Job Specifications ................................................................................ Application Analysis Form ............................................................................................................................................ Typical Screen Analysis .............................................................................................................................................. Crushing Tests ............................................................................................................................................................ How to Take Samples .................................................................................................................................................. Measuring Crushing Resistance .................................................................................................................................. Measuring Relative Abrasiveness ................................................................................................................................ Index of Abrasiveness .................................................................................................................................................. Definitions of Material Characteristics.......................................................................................................................... Physical Characteristics of Materials .......................................................................................................................... Power Requirements.................................................................................................................................................... Closed Circuit Crushing .............................................................................................................................................. Hammer Technology ....................................................................................................................................................
2 3 4 5 7 8 9 10 10 10 10 11 12 12 13 13 14
FACILITIES Facilities and Organization .......................................................................................................................................... Parts and Service ........................................................................................................................................................
PRODUCTS
15 21
Complete brochures with specifications on individual products are available upon request.
BRADFORD BREAKERS • Roller Mounted Breakers .......................................................................................................................................... • Tri-Mounted Breakers ................................................................................................................................................ • Bradpactors................................................................................................................................................................
23 23 24
CAGE MILLS ..............................................................................................................................................................
25
GRANULATORS..........................................................................................................................................................
26
HAMMERMILLS • Reversible Hammermills for Coal .............................................................................................................................. • Reversible Hammermills for Fluid Bed Boiler Applications........................................................................................ • Reversible Hammermills for Rock, Limestone, Minerals and Chemicals .................................................................. • Non-Reversible Hammermills .................................................................................................................................... • Non-Clog Hammermills..............................................................................................................................................
27 28 29 29 30
IMPACTORS • Coalpactors................................................................................................................................................................ • Aluminum Dross Impactors / Metallic Slag Crushers ................................................................................................ • Reversible Impactors ................................................................................................................................................ • Reversible Impactors, Small ...................................................................................................................................... • Twin Rotor Impactors ................................................................................................................................................
31 32 33 34 34
JAW CRUSHERS ........................................................................................................................................................
35
GRINDING MILLS • Brad-Multi-Roll Crushers ..........................................................................................................................................
36
ROLL CRUSHERS • Clinker Crushers ........................................................................................................................................................ • Single Roll Crushers .................................................................................................................................................. • Double Roll Crushers ................................................................................................................................................ • Frozen Coal Crackers................................................................................................................................................
37 38 39 40
SIZERS ........................................................................................................................................................................
41
POSIMETRIC FEEDERS ............................................................................................................................................
42
Trademarks of Pennsylvania Crusher Corporation PENNSYLVANIA BRADFORD HAMMERMILL®
FROZEN COAL CRACKER®
PENNSYLVANIA REVERSIBLE IMPACTOR®
KOAL KING® U.S. Patent Number 4,343,438
BRADPACTOR® U.S. Patent Numbers 3,931,937; 4,009,834
FBR®
COALPACTOR®
BMR BRAD-MULTI-ROLL®
POSIMETRIC® FEEDER
PENNTECHNIC®
PENNSYLVANIA®
©Pennsylvania Crusher Corporation 2000, 2002, 2003
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GLOSSARY OF TERMS Angle of Nip The angle formed between the moving surface of a crusher roll or jaw plate and the stationary plate surface, at which point the material will be pinched. Angle varies with machine size and material lump size. Bond Work Index (BWI) KW hr. per short ton required to reduce the material to 80% passing 100 microns. Breaker Block (Breaker Plate) The steel anvil surface of a crusher against which material is crushed by impact or pressure. Bridging Blocking of crusher opening by large pieces of material. Burbank Abrasion Test A standard method of comparing the relative abrasiveness of rocks, minerals and ores. Cage
A screening device, fixed or adjustable, made of precisely spaced bars or slotted plate, where final sizing is accomplished within the crusher.
Choke Feed Operating the crusher with a completely filled crushing chamber. Choke Point Place in the crushing chamber having the minimum cross section. All compression type crushers have choke points, but this does not necessarily mean that choking is likely to occur. Choking Stoppage of the flow of material through the crusher, usually the result of wet and sticky material clogging exit points. Circulating Load The amount of oversize returned to the crusher from a screen in a closed-circuit system. Closed-Circuit Crushing A system in which oversize material is screened from the output and returned for another pass through the crusher. D50
Denotes that output size is 50% smaller than the size indicated.
Feed
Input to the crusher.
Feeder A device that regulates and distributes material into the crusher.
Hopper The area of the crusher preceding the crushing chamber. Also, an external bin that holds the feed material. MOH Scale Relative hardness of material compared to 1-Talc, 2-Gypsum, 3-Calcite, 4-Fluorite, 5-Apatite, 6-Feldspar, 7-Quartz, 8-Topaz, 9-Corundum, and 10-Diamond. Nominal Describes product size (output size), usually denoting that at least 90% of product is smaller than size indicated. Oversize Material too large to pass through a specific size of screen or grizzly opening. Plugging Restriction of material flow through a crusher. Primary Crusher The first crusher in a crushing system into which material is fed. Succeeding crushers in the system are referred to as secondary or tertiary crushers. Product Output from the crusher. Reduction Ratio The ratio of the top size of input material to the top size of crusher discharge. Reversible Crushers Hammermills and impactors with rotors that can be run both clockwise and counterclockwise. ROM
Run Of Mine — Material from a mine that has not been crushed or screened.
ROQ
Run Of Quarry — Material from a quarry that has not been crushed or screened.
Rotor
Rotating assembly of shaft, discs, and hammers within a crusher which imparts the crushing forces to the material.
Scalping Removing all sizes smaller than output top size from the crusher input material.
Material with particle size smaller than a specified opening.
Screen Bars The bars in the cage of a hammermill or granulator, spaced to control the output size. Also called “cage bars” or “grate bars”.
Finished Product (Output) The resulting material after it has been processed.
Slugger Teeth The large teeth on a single roll crusher which first strike the material.
Friable Material that breaks easily.
Sorbent Stone, usually containing calcium; used to capture sulfur in a fluid bed boiler.
Fines
Hammers Free-swinging or fixed metal impact surfaces attached to the rotor assembly of an impactor or hammermill crusher. Sometimes designated as “beaters”. Hardgrove Index (HGI) The grindability of a coal is expressed as an index showing the relative hardness of that coal compared with a standard coal of 100 grindability.
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Height of Drop Vertical, free fall distance from the lip of the feeding device to the inlet opening of an impactor or hammermill crusher. Normally applies to reversible machines.
Tailings
Refuse or residue material from a screening process.
Top Size The largest particle size in an input or output size. Tramp Iron Bolts, shovel teeth, picks, and other uncrushable metal that is often present in crusher input.
THE TECHNOLOGY OF CRUSHING MECHANICAL REDUCTION METHODS
There are four basic ways to reduce a material — by impact, attrition, shear or compression — and most crushers employ a combination of all these crushing methods
Impact In crushing terminology, impact refers to the sharp, instantaneous collision of one moving object against another. Both objects may be moving, such as a baseball bat connecting with a fast ball, or one object may be motionless, such as a rock being struck by hammer blows. There are two variations of impact: gravity impact and dynamic impact. Coal dropped onto a hard surface such as a steel plate is an example of gravity impact. Gravity impact is most often used when it is necessary to separate two materials which have relatively different friability. The more friable material is broken, while the less friable material remains unbroken. Separation can then be done by screening. The Pennsylvania Bradford Breaker employs gravity impact only. This machine revolves so slowly that for all practical purposes, gravity is the only accelerating force on the coal. Material dropping in front of a moving hammer (both objects in motion), illustrates dynamic impact. When crushed by gravity impact, the free-falling material is momentarily stopped by the stationary object. But when crushed by dynamic impact, the material is unsupported and the force of impact accelerates movement of the reduced particles toward breaker blocks and/or other hammers. Dynamic impact has definite advantages for the reduction of many materials and it is specified under the following conditions: — when a cubical particle is needed —when finished product must be well graded and must meet intermediate sizing specifications, as well as top and bottom specifications —when ores must be broken along natural cleavage lines in order to free and separate undesirable inclusions (such as mica in feldspars)
—when materials are too hard and abrasive for hammermills, but where jaw crushers cannot be used because of particle shape requirements, high moisture content or capacity
Dynamic impact is the crushing method used by Pennsylvania Impactors.
Attrition Attrition is a term applied to the reduction of materials by scrubbing it between two hard surfaces. Hammermills operate with close clearances between the hammers and the screen bars and they reduce by attrition combined with shear and impact reduction. Though attrition consumes more power and exacts heavier wear on hammers and screen bars, it is practical for crushing the less abrasive materials such as pure limestone and coal. Attrition crushing is most useful in the following circumstances: —when material is friable or not too abrasive —when a closed-circuit system is not desirable to control top size
Shear Shear consists of a trimming or cleaving action rather than the rubbing action associated with attrition. Shear is usually combined with other methods. For example, single-roll crushers employ shear together with impact and compression. Shear crushing is normally called for under these conditions: — when material is somewhat friable and has a relatively low silica content — for primary crushing with a reduction ratio of 6 to 1 — when a relatively coarse product is desired, usually larger than 1 1/2" (38mm) top size 5
Compression As the name implies, crushing by compression is done between two surfaces, with the work being done by one or both surfaces. Jaw crushers using this method of compression are suitable for reducing extremely hard and abrasive rock. However, some jaw crushers employ attrition as well as compression and are not as suitable for abrasive rock since the rubbing
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action accentuates the wear on crushing surfaces. As a mechanical reduction method, compression should be used as follows: —if the material is hard and tough —if the material is abrasive —if the material is not sticky —where the finished product is to be relatively coarse, i.e., 1 1/2" (38mm) or larger top size —when the material will break cubically
The bottom of the Pennsylvania Reversible Impactor is open and the sized material passes through almost instantaneously. Liberal clearance between hammers and the breaker blocks eliminates attrition, and crushing is by impact only.
When a Pennsylvania Non-Reversible Hammermill is used for reduction, material is broken first by impact between hammers and material and then by a scrubbing action (shear and attrition) of material against screen bars.
Single Roll Crushers reduce large input by a combination of shear, impact and compression. They are noted for low headroom requirements and large capacity.
The Pennsylvania Jaw crushes by compression without rubbing. Hinged overhead and on the centerline of the crushing zone, the swinging jaw meets the material firmly and squarely. There is no rubbing action to reduce capacity, to generate fines or to cause excessive wear of jaw plates.
CRUSHER SELECTION CRITERIA When selecting a crusher, the following criteria must be considered: 1. Will it produce desired output size and shape at the required capacity? 2. Will it accept the largest input size expected? 3. What is its capacity? 4. Will it choke or plug? 5. Can it pass uncrushable debris without damage to the crusher? 6. How much supervision of the unit is necessary? 7. Will it meet product specifications without additional crushing stages and auxiliary equipment? 8. What is the crusher’s power demand per ton per hour of finished product? 9. How does it resist abrasive wear? 10. Does it operate economically with minimum maintenance? 11. Does it offer dependable and prolonged service life? 12. Is there ready availability of replacement parts? 13. Does it have acceptable parts replacement cost? 14. Does it have easy access to internal parts? 15. Is the crusher versatile? 16. How does the initial cost of the machine compare with its long term operating costs? 17. Is experienced factory service readily available?
DEVELOPMENT OF JOB SPECIFICATIONS The initial steps in selecting the proper crusher require the development of complete job specifications, including the pertinent physical characteristics of the feed material. The Application Analysis Form that appears here is designed to simplify the task of collecting job specifications. In most cases, the completed form will enable the engineering staff of Pennsylvania Crusher to recommend the crusher best suited to meet the requirements.
On occasion, it may also be necessary to supply actual samples of the material for test crushing in the Pennsylvania Crusher test facilities. Refer to Page 8 for “How to Take Samples”. Additional copies of the Application Analysis Form (Page 6) may be obtained by photocopying or by request. If you have any questions regarding the completion of this form, please contact Pennsylvania Crusher Corporation. 7
APPLICATION ANALYSIS FORM Completion of this sheet will help our engineers select the crusher best suited to your requirements.
Pennsylvania Crusher
Box 100 Broomall, Pennsylvania 19008-0100, U.S.A. Telephone: 610-544-7200 Fax: 610-543-0190 E-Mail:
[email protected]
COMPANY: __________________________________________
DATE: ____________________________________________
ADDRESS: __________________________________________
PROJECT: ________________________________________
CITY: ________________________________________________
PROJECT LOCATION: ______________________________
STATE:______ ZIP:_____________ COUNTRY: ______________
______________________________________________________
NAME AND TITLE: ____________________________________
______________________________________________________
PHONE: ______________________________________________
PROJECT REFERENCE NUMBER: ____________________
FAX: ________________________________________________
______________________________________________________
E-MAIL:______________________________________________
1. MATERIAL DESCRIPTION
2. APPLICATION REQUIREMENTS
3. GENERAL INFORMATION
4. OTHER INFORMATION WHICH MAY BE OF VALUE
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a. b. c. d. e. f. g.
Material: ________________________________________________________________________________ Bulk Density: _____________________________________________________________________________ Moisture:_______________________________%Total_______________%Surface _____________________ Compressive Strength (PSI) _________________________________________________________________ MOH Hardness/Hardgrove Index:_____________________________________________________________ Material Temperature:___________________Degrees F:____________________Degrees C: _____________ Material is: Free-Flowing ( ) Sticky ( ) Non-Abrasive ( ) Mildly Abrasive ( ) Very Abrasive ( ) h. Other Characteristics: ______________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ a. b. c. d.
Mining Method or Process Source:____________________________________________________________ Feed Size (Maximum): _______________________ X________________________X___________________ Desired Product Size (State size and % passing): ________________________________________________ Is product size material removed from feed prior to crushing? ______________________________________ What percentage is removed? _______________________________________________________________ e. Are fines: ( ) desirable ( ) undesirable ( ) no preference If undesirable, at what size? _________________________________________________________________ f. Can external screens be used to return oversize to crusher (closed-circuit)? ___________________________ g. Capacity desired (tons per hour): _____________________________________________________________ a. Crusher will: b. Project is:
( ) replace existing equipment ( ) be used in new operation ( ) study for feasibility or budget purposes ( ) funded for purchase. Expected purchase date:________________________________ c. Delivery is required by: _____________________________________________________________________
_________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________
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CRUSHING TESTS When a new or unusual application is encountered, samples of the material may be crushed to determine which crusher is most suitable. This is done in the Pennsylvania Crusher Test Laboratory. By crushing samples of the material, significant facts can be learned for predicting the performance of full capacity machines with acceptable accuracy. Laboratory tests can prove or disprove the relative merits of various types of crushers. They also provide an opportunity to evaluate the effects of various crusher settings, speeds, feeding methods, height-ofdrop, and size or shape of hammers and breaker blocks. In the lab, one element at a time can be changed while all others are held constant. Under such conditions, any changes in crushing results can be isolated and evaluated by our application engineers. Testing Procedure The normal procedure is to test crush a representative sample of the material and to then determine the product size gradation. From this data, a graph is plotted showing the cumulative percentage of material passing each screen size. Page 7 illustrates a typical screen analysis derived in this manner. By comparing screen analyses and other criteria with those associated with familiar materials, an experienced crusher application engineer can estimate overall crushing performance as well as power requirements. The engineer can also detect characteristics that require special design considerations or auxiliary equipment.
Measuring Crushing Resistance A basic premise in equipment selection is that the crusher be stronger than the material that it must crush. How strong are rocks and ore? While there is no direct measurement of “resistance to crushing”, it is possible to measure compressive strength and the elastic properties of a material. The graph shows a typical plot of test results for different materials, and it demonstrates the relationship between compressive load and resulting displacement. The material exhibiting twice as much displacement under compression will normally require twice as much power to be crushed. A.S.T.M. Method C-170-50 is used to obtain the highest accuracy in measuring compressive strength. However, the Pennsylvania Crusher laboratory has developed a procedure that is more practical for crusher selection. This procedure is fully described in an article by Benjamin B. Burbank, entitled “Measuring the Crushing Resistance of Rocks and Ores”. Copies are available from Pennsylvania Crusher Corporation.
70 9
60
50 11
1 Cement rock, NY 2 Colorado oil shale, CO
40
3 Feldspar, NH COMPRESSIVE LOAD (x 1,000 psi)
4 Cement rock, Thomaston, ME 5 Dolomite, NY
10
30
6 Sandstone, AZ 7 Iron ore, Ozark Mts., AR
Deciding Factors Tests may show that two or more types of crushers will perform equally well on a particular material. But other factors must still be considered such as headroom, desirability of fines, product shape, economics of maintenance and operations, and the adaptability of the crusher to future plant expansions.
8
8 Graphic granite (feldspar), NY
20
9 Chert, Picher, OK 7
10 Granite, Winterport, ME
6
10
5 4
11 Quartzite, VT 3
2
1
0 .004"
.008"
.012"
.016"
.020"
.024"
DISPLACEMENT (Inches)
HOW TO TAKE SAMPLES To ensure meaningful results from the Pennsylvania Crusher Test Laboratory, it is important that a truly representative sample of material be provided. Care must be taken to ensure that the sample is collected from a true cross section of the material and that it is packed to retain its original characteristics (moisture, size, shape, etc.). A 55-gallon steel barrel of material will usually be an adequate amount for testing.
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Measuring Relative Abrasiveness It is difficult to predict the abrasive action of rocks, minerals, and ores. Often, rocks belonging to the same geological classification will vary widely in abrasiveness from one locality to another. Therefore, in order to select the proper crusher, we must have some reliable measurement of the abrasiveness of the specific material. Abrasiveness can be determined either from prior experience or by testing in semi-production plants, but a simpler method has been developed by Pennsylvania Crusher Corporation. This involves
testing, and it is a reliable way to establish relative abrasiveness by using four 400-gram samples of the material to be crushed. Each sample of material is rotated for 15 minutes in a drum with a steel paddle. After the four separate batches are run, the average milligrams of weight loss by the paddle is measured. This will serve as a relative index of abrasive action. The higher the index, the greater the abrasiveness.
This test provides the most practical index of abrasiveness available today. Such test data has been collected for many years on numerous samples of rocks and ores. Typical scales of relative abrasiveness derived from this testing procedure are shown in the table below. A more complete description of the method and equipment for obtaining these abrasiveness indices is contained in our publication entitled, “Measuring the Crushing Resistance of Rocks and Ores.”
INDEX OF ABRASIVENESS MATERIAL AND SOURCE
ABRASIVENESS INDEX
Highly Abrasive Manganese Ore, Georgia ............................................................................................................................................................................ 32,946 Aluminum Oxide, New York......................................................................................................................................................................... 14,114 Sandstone, Pennsylvania ............................................................................................................................................................................ 13,121 Oxygen Furnace Slag, Ontario.................................................................................................................................................................... 10,828 Chert, Missouri ............................................................................................................................................................................................ 9,829 Stone and Bauxite Clinker, Indiana ............................................................................................................................................................. 9,489 Gravel, Mississippi....................................................................................................................................................................................... 8,888 Stone, Virginia ............................................................................................................................................................................................. 7,969 White Quartz, Maine.................................................................................................................................................................................... 7,000 Calcined Alumina, Louisiana ....................................................................................................................................................................... 6,879 Open Hearth Pot Slag, New York................................................................................................................................................................ 6,830 High-Silica Limestone, Pennsylvania .......................................................................................................................................................... 4,838 Granite, Puerto Rico .................................................................................................................................................................................... 4,517 Feldspar, Virginia ......................................................................................................................................................................................... 3,650 Burned Brick and Tile, Pennsylvania........................................................................................................................................................... 3,491 Sintered Ore, Alabama ................................................................................................................................................................................ 3,065 Trap Rock, Pennsylvania............................................................................................................................................................................. 2,928 Feldspar, New Hampshire ........................................................................................................................................................................... 2,871 Tungsten Ore, California ............................................................................................................................................................................. 2,253 Cement Clinker, Pennsylvania..................................................................................................................................................................... 2,206
Abrasive
(Wear can be minimized by design and materials of construction)
Iron Ore, Missouri ........................................................................................................................................................................................ Transvaal Chrome Ore, South Africa .......................................................................................................................................................... Coke Breeze, Alabama................................................................................................................................................................................ Calcined Bauxite, Missouri .......................................................................................................................................................................... Red Limestone, Vermont ............................................................................................................................................................................. Scoria Volcanic Cinder ................................................................................................................................................................................ Cement Clinker, Quebec ............................................................................................................................................................................. Grog, New Jersey........................................................................................................................................................................................ Amorphous Silica, Illinois............................................................................................................................................................................. Travertine, Australia..................................................................................................................................................................................... Phosphate Nodules, Tennessee.................................................................................................................................................................. Cement Clinker, Kentucky ........................................................................................................................................................................... Hematite, Venezuela ................................................................................................................................................................................... Barite, Arkansas .......................................................................................................................................................................................... Limestone, Indiana ...................................................................................................................................................................................... Dolomitic Clinker, Ohio ................................................................................................................................................................................ Cement Rock, Brazil.................................................................................................................................................................................... Ferro-Phosphorous, Oklahoma ................................................................................................................................................................... Dolomite, West Virginia ...............................................................................................................................................................................
Low in Abrasion
1,992 1,755 1,690 1,671 1,452 1,352 1,231 1,052 978 838 813 695 620 550 526 494 444 443 417
(Parts wear is not critical)
Shale, Virginia ............................................................................................................................................................................................. Antimony Ore, New Jersey.......................................................................................................................................................................... Oil Shale, Colorado ..................................................................................................................................................................................... Chamotte, Michigan..................................................................................................................................................................................... Zinc Sinter, Pennsylvania ............................................................................................................................................................................ Limestone, Ohio .......................................................................................................................................................................................... Extruded Zircon, New Jersey ...................................................................................................................................................................... Weathered Shale, Virginia........................................................................................................................................................................... Zinc Oxide, Pennsylvania ............................................................................................................................................................................ Diatomaceous Shale Clinker, England ........................................................................................................................................................ Dolomite, Alabama ...................................................................................................................................................................................... Sandstone, California .................................................................................................................................................................................. Red Flux, Australia ...................................................................................................................................................................................... Shale, Virginia ............................................................................................................................................................................................. Clay, Pennsylvania ...................................................................................................................................................................................... Cement rock, Pennsylvania......................................................................................................................................................................... Anhydrite, Kansas ....................................................................................................................................................................................... Limestone, Australia ....................................................................................................................................................................................
345 315 270 250 249 241 186 131 78 78 62 38 31 30 25 13 9 7
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DEFINITIONS OF MATERIAL CHARACTERISTICS Selection of the most appropriate crusher is greatly influenced by the precise nature of the material to be crushed. The listings that follow serve to illustrate how even the same basic materials can vary widely. Such variances will definitely influence the type of crusher that should be employed.
CLASS ABRASIVENESS
Low abrasiveness..................................................................................................................................... Mildly abrasive.......................................................................................................................................... Very abrasive............................................................................................................................................
1 2 3
FLOWABILITY
Very free flowing - angle of repose up to 30°........................................................................................... Free flowing - angle of repose 30°-45° .................................................................................................... Sluggish - angle of repose 45° and up.....................................................................................................
4 5 6
SPECIAL CHARACTERISTICS
Hygroscopic .............................................................................................................................................. Highly corrosive ........................................................................................................................................ Mildly corrosive......................................................................................................................................... Degradable when exposed to air ............................................................................................................. Very friable................................................................................................................................................ Mildly friable.............................................................................................................................................. Tough - resists reduction .......................................................................................................................... Plastic or sticky.........................................................................................................................................
A B C D E F G H
PHYSICAL CHARACTERISTICS OF MATERIALS Material Alumina Aluminum Oxide Bagasse Barite Bark (wood refuse) Basalt (broken) Bauxite (crushed) Bentonite Brick Carbon Electrodes (baked) Carbon Electrodes (unbaked) Cement Clinker Cement Rock Charcoal Clay (dry) Calcined Clay Coal - Anthracite Coal - Bituminous Coal - Sub-bituminous Coke - Petroleum Cryolite Cullet - Glass Diatomaceous Earth Dross - Aluminum Fluorspar Fullers Earth - raw Granite - broken Gravel Gypsum Rock
Class* 3-5-G 3-G 1-6-C 3-5 2-6-G 3-G 3-5-F 2-5 3-F 2-G 1-F 3-5-F 2-5-F 2-5-D-F 3-5 3-F 1-4-D-E 1-5-C-D-E 1-5-C-D-E 2-5 1-5-F 3-5-E 2 3-F-C 2-5-F 2-5 3-5-G-H 3-5-F 2-5-F
*Refer to table above for class description
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Average Weight in Lbs. Per Cubic Foot 60 70-120 7-8 140-180 10-20 10-20 75-85 40-50 100-125 — — 75-95 100-110 18-25 60-75 80-100 55-60 45-55 45-55 35-42 110 80-120 11-14 — 90-100 35-40 90-100 90-100 90-100
Material Lignite - Texas (ROM) Lignite - Dakota (ROM) Lime - Pebble Limestone - broken Manganese Ore Marble - broken Marl - raw & wet Middlings - Coal Phosphate – Rock - Ore Potash Ore Potash Ore Compactor Flake Quartz - broken Refuse - household Sand - dry bank Sand - foundry Sandstone - broken Shale - broken Shells - Oyster Diacalcium Phosphate Dolomite Slag - Open Hearth Slag - Blast Furnace Slate Soapstone (talc) Superphosphate Traprock - broken Triple Superphosphate Trona Ore Tungsten Carbide
Class* 1-5-D-E 1-6-D-F 1-5-E 2-5-F 3-5-G 2-5-F 2-6-E-H 2-5-G-F 2-5 1-E 1-E 3-5-E 2-G 3-5 3-5 3-F 2-5-F 2-5-E 2-5-E-H 2-5-F 3-G 3-4-F-E 2-E 1-F 2-6-F-H 3-5 2-6-F-H 2-5-F 3-4-G
Average Weight in Lbs. Per Cubic Foot 45-50 45-50 53-56 90-100 125-140 90-100 130-140 — — — — 85-95 45-50 90-110 90-110 85-90 90-100 70-80 43 90-100 160-180 80-90 85-95 40-50 50-55 105-110 50-55 90-100 —
POWER REQUIREMENTS In crushing, the useful or meaningful work is that expended to reduce the material to a given size. A number of theories have been expressed to define the relationship between work input and size reduction. Kick’s Law states that work done is proportional to the reduction in volume of particles, a theory which applies to the crushing of large particles. However, finer product sizes conform more closely to Rittinger’s Theory which concludes that work required is proportional to the new surface area formed, and inversely proportional to the product diameter. In any case, reduction ratio is not the only factor in determining power requirements. Nearly all crushing projects differ from one another in one or more aspects, and no hard and fast rule can be applied with regard to power consumption. However, through extensive experience in the field of mechanical reduction, some average values have been compiled regarding the power requirements of different types of crushers. Typical Horsepower Requirements It has been determined that a primary single roll crusher, reducing run of quarry medium-hard limestone to a 6" (150mm) product will require approximately 1/2 horsepower per ton per hour (HP per TPH). However, when crushing medium-hard bituminous coal to the same specifications, the power demand is only 1/12 HP per TPH. Even on the hardest materials, single rolls do not require more than one full HP per TPH and may demand as little as 1/25 HP per TPH. Coalpactors for preparing coking coal for coke ovens are fed with 3" (75mm) and under bituminous coal. The product usually desired is 80-85% minus 1/8" (3mm). For this service, 11/2 to 2 HP per TPH is normally required. In cement plants, where hammermills or impactors are used for secondary crushing of cement rock, the feed is approximately 6-10" (150 - 250mm) and the product is a nominal 1/2 " (12mm). This reduction needs 11/3 to 11/2 HP per net TPH. Impactors generally require approximately 1 HP per TPH (gross load) to drive them. This may be slightly increased if an extremely fast rotor speed is required. Granulators (ring hammermills) are most often used in the coal handling facilities of power stations where they reduce run of mine coal to a nominal 3/4" (19mm) product. This typically requires 1/2 HP per TPH.
The Pennsylvania Jaw Crusher requires approximately 1/3 or less HP per TPH, depending upon the reduction ratio desired. Bradford Breakers and Bradford Hammermills require approximately 1/4 or less HP per TPH. Motor Selection The foregoing figures are averages, and each crushing problem should be carefully studied before selecting motors. We urge all prospective customers to consult us prior to selecting motors, since so many factors will affect power demand. Our experience with such diverse types of crushers will serve as a guide for proper motor selection.
CLOSED-CIRCUIT CRUSHING Closed-circuit crushing is a means of controlling product top size by screening the product and then returning oversize material to the feed end of the crusher for another pass through the machine. While it may be possible to obtain a specified top size from crushers without using a closed-circuit system, it is not always desirable. To control top size from a single crusher operating in an open circuit, material must remain in the crushing chamber until it is reduced. This results in overgrinding a percentage of the product, with a corresponding increase in fines and a loss of efficiency. In a typical multiple-stage crushing plant with the last stage operated in closed-circuit, the primary crusher operates at a setting which produces a satisfactory feed size for the secondary crusher, so that a balance exists for the work done by each crusher.
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CRUSHER HAMMER TECHNOLOGY Hammer design plays a significant role in crusher efficiency, because in most types of crushers, the hammers do most of the work. Early hammer designs were only concerned with mass and general shape of the hammer. Today the technology of Pennsylvania hammers is highly developed, and we give careful consideration to a great many factors: Location of the hammer’s center of gravity The center of gravity determines the focus of impact, which in turn helps to control the amount of impact and the general shape of the shattered particle. The center of gravity must be controlled to utilize the full mass of the hammer against the feed. Air paths created by hammer rotation The air paths created by the hammer sweep usually contain a certain amount of fines and other small particles which must be directed away from the hammer shanks and rotor discs; otherwise premature wear would occur. Pennsylvania hammers are designed so that the resulting air paths are directed toward open areas of the crushing chamber, away from vital parts.
Edge configuration of the hammer head The edges of each Pennsylvania hammer face are shaped to a special geometry in order to produce maximum hammer life with the lowest amount of friction. Heat treating Hammer hardness is the most essential factor in determining hammer life, for while the hammer head must be extremely hard and resistant to wear, the shank must be more ductile in order to absorb shock. To produce this on certain designs, Pennsylvania uses a special method of heat treating that creates a gradually varying hardness between the shank and the tip, without any abrupt changes. However, in cross section, the hardness extends for the full depth instead of merely the surface. Hammer hardness is normally gauged according to the Brinnel method. As a result of continued improvements, Pennsylvania hammer design plays a major role in producing high efficiency and in reducing maintenance problems. As the company introduces refinements to the hammers, users are provided with the latest designs as part of their normal resupply orders.
BASIC HAMMER TYPES
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BAR HAMMER
RING-TYPE HAMMER (plain)
T-HEAD HAMMER
RING-TYPE HAMMER (toothed)
FACILITIES AND ORGANIZATION
Pennsylvania Crusher Manufacturing Plant (top) in Cuyahoga Falls, Ohio, and Headquarters in Broomall, Pennsylvania.
Pennsylvania Crusher possesses the most modern facilities in the world devoted to the design and manufacture of crushers. Still, our company’s most valuable assets reside in the talents of the skilled professionals who staff our many departments. Design engineering, application engineering, field service, parts, production, finance, marketing, research and development — all work together to provide equipment that will perform best in your application, with full factory support throughout the operational life of your crusher. For an evaluation of your needs, please contact us at any time. We believe you will be impressed with the experience, the proficiency and the helpful attitude you find at every level within Pennsylvania Crusher.
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Our manufacturing facility is located in Cuyahoga Falls, Ohio, near Akron, and is adjacent to major rail and highway arteries. This facility contains every type of manufacturing equipment needed to produce the numerous types and sizes of crushers and feeders sold by Pennsylvania Crusher.
An exceptionally high percentage of our manufacturing specialists are qualified journeymen, with a minimum of 8,000 hours of on-the-job training, coupled with years of formal schooling.
In terms of hands-on experience, fully half of us have served under the same roof for over ten years, and many have over twenty and thirty years to our credit.
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We also handle the repair and remanufacture of Pennsylvania crushers, including rotor and cage assemblies and other components. This enables the customer to upgrade to a new design, in order to achieve current operating efficiencies, along with a new parts warranty.
Analyses of materials, equipment and parts by our testing laboratory constitute the basic data from which recommendations will be made for selection and sizing of crushers.
We operate a Crushing Test Laboratory, fully equipped with various models of crushers. Test crushing your material in advance of purchase enables us to determine which model and size of crusher will be the most suitable. It also enables us to determine wear rates, height-of-drop data and other valuable information.
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All operations of Pennsylvania Crusher are linked by an integrated, state-of-the-art management program that embraces advance planning, accounting, engineering, order entry, scheduling, manufacturing, shop floor reporting, and shipping. This has enhanced our ability to provide you with timely information regarding the status of your order, and to expedite manufacture to suit your schedule.
Our extensive use of computer-aided design (CAD) helps to speed the completion of new equipment designs.
Design Engineering. This group is the source of numerous innovations in crusher design . . . including some basic crushing methods that have been adopted by the entire industry.
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Communications Center. This group is responsible for our company’s contact with all points on the globe. The innovative equipment used here helps to enhance the speed and accuracy of communications.
Field Service. We can supply trained personnel to supervise the installation of Pennsylvania Crushers. Their practical and extensive experience helps to achieve significant cost savings.
Management Information Systems. Computer-based procedures have enhanced Pennsylvania’s customer service and order acknowledgment systems. They also help the company to achieve more accurate levels of inventory to meet changing customer needs.
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Sales and Applications Engineering. These groups possess unparalleled skill and experience with material reduction projects worldwide. To complement the high professional expertise of each member, the application department maintains one of the most extensive data bases of information about materials, equipment, and test results on tens of thousands of mineral samples from every continent.
Accounting and Finance Group. The significant financial strength of our company is enhanced by the efficiency and smooth operation of this department. This section is staffed by professionals who clearly understand the special requirements of the markets we serve.
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The Pennsylvania Crusher Parts and Service Group has forged a reputation for responsiveness, experience and versatility.
Parts & Service Group. This group goes far beyond the usual concept of simply supplying replacement parts. They operate under a philosophy of service completely oriented to the continuing needs of the customer, regardless of whether the customer is working with new Pennsylvania equipment or with equipment that was placed in service over ninety years ago. As part of this practice, there are three important areas in which this department is of practical service to customers:
modifications, service records and all other pertinent data. Complete drawings are kept on modifications as far back as ninety years, for there are numerous instances where such Pennsylvania equipment is still in productive service. The Parts Department operates almost as an extension of the customer’s maintenance department, since the objectives are similar, i.e., to keep the equipment operating effectively and economically. Parts and Service sales representatives are available for consultation with the customer on questions regarding parts, service, or modification work.
1. Basic supply requirements. 2. Refinements to older design equipment for improved performance. 3. Major modifications to equipment either for improved performance or for different applications than that for which it was originally designed.
For maximum effectiveness, the Pennsylvania parts staff maintains thoroughly detailed records on all machines shipped, including details of past
Electronic Data Interchange Our on-line system for electronic data interchange (EDI) speeds the flow of acknowledgments, RFQs, POs and invoices, using a standard, ready-toprocess form. If you already have such a system, please contact us about establishing a link directly to your company or to your consulting service.
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PENNSYLVANIA CRUSHER PRODUCTS BRADFORD BREAKERS These machines are used for crushing, sizing, and cleaning of run-of-mine coal and other friable materials. They are used to produce a product that is relatively coarse, with minimum fines, and that is 100% to size. Bradford Breakers crush by gravity impact only. A large cylinder made of perforated screen plates is fitted with internal shelves. As the cylinder rotates, the shelves lift the feed and, in turn, the feed slides off the shelves and drops onto the screen plates below, where it shatters along natural cleavage lines. The size of the screen plate perforations determines the product size. Sized product falls through these perforations but oversized pieces will again be lifted and dropped by the shelves until they too pass through the screen plates. Tramp iron, lumber, or other uncrushable debris that enters the breaker along with the feed is transported to the discharge end of the cylinder. There, these uncrushables are scooped out continuously by a refuse plow which channels this debris out of the cylinder and into a disposal bin.
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Often a Pennsylvania Bradford Breaker is used merely to clean debris from coal that has already been sized. This gives some indication of the economy of operation and versatility of this machine. Breaker cylinders rotate at slow speeds of 12 to 14 RPM depending upon cylinder diameter. Compared with most other crushers, Bradford Breakers are extremely long lived. Screen plates, for example, frequently last ten years or more, crushing millions of tons of coal, and there are numerous examples of Pennsylvania Bradford Breakers in continuous service for upwards of forty years. Pennsylvania has also designed the screen plates in the breakers to be interchangeable, so that the screen plates from the feed end, where wear is greatest, can be switched with screen plates from other areas of the cylinder where there is less wear. The profile of the perforations in the screen plates has been scientifically designed to obtain a maximum self-cleaning effect, without product bridging across the perforation itself.
ROLLER MOUNTED BRADFORD BREAKERS The roller mounted Bradford Breaker is suited for coal mines where the feed often includes unusually large pieces of coal. This model will readily accept these larger pieces of coal without blocking the entry.
Roller Mounted
TRI-MOUNTED BRADFORD BREAKERS (Not illustrated) Many prefer this model because its three support points provide a stable yet forgiving platform, minimizing the attention to wheel alignment needed with the roller mounted arrangement to compensate for shifting foundations. This model also features the design standards found on our other Bradford Breakers such as lapped
screen plates, adjustable feed plows, and roller chain drive. Longitudinal beams are bolted to the end cones — never welded — so that replacement can easily be accomplished at your job site. These, plus numerous other features, make this an extremely low maintenance breaker.
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PENNSYLVANIA BRADPACTORS
The Bradpactor is a highly successful innovation based on the Bradford Breaker design. In the Bradpactor, the breaker cylinder is equipped with a rotor that is mounted with a series of paddle hammers. The rotor runs the entire length of the cylinder and the speed of the rotor can be varied. This gives operators the ability to “tune” the Bradpactor to the type of friable material that is to be crushed. The paddles impact against the oversize material dropped into their path by the rotating cylinder. The paddles drive the material against the cylinder walls until the product is sized and screened out through the screen plate holes. By varying the rotor speed, impact force as well as fines can be controlled. Compared with a breaker, a Bradpactor gives greater capacity while occupying far less space than a conventional breaker.
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CAGE MILLS
This crusher is employed for size reduction of friable, dry bulk substances such as chemicals, grain, fertilizer, coal, slag, glass, soap and many others. It’s also used for beneficiation of materials that vary in hardness. In this model, material is reduced in size purely by impact. Feed enters the innermost cage where it is initially struck by the first row of sleeves. They scatter the shattered material toward the next row which rotates in the opposite direction. Further reduction occurs in that and each successive row until the material exits the final row, to be thrown against impact plates that line the crushing chamber. The sized material then discharges through the open bottom of the mill. For production of fine, medium or coarse sizes, the spacing between sleeves on each row can be selected. Product size can also be changed by varying the speed of the cages. We have improved the cage mill design in several ways. For example, the two motors used to drive the cages are on the same side, away from the feed area, so as not to interfere with access to the crushing chamber for maintenance. This arrangement also produces a smaller footprint than ordinary cage mills, thereby allowing use of a smaller, less costly foundation. Additionally, total access to the whole interior is provided by the hinged hopper door. It swings wide open, completely out of the way, and an integral cage hoist can be installed at our factory or added later. We normally recommend that your material be test crushed in the full-scale cage mill at our Crushing Test Facility in Broomall.
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GRANULATORS
Pennsylvania Granulators use rows of ring hammers which crush with a slow, positive rolling action. This produces a granular product with minimum fines. Offered in three models and nearly fifty sizes, Granulators are used for crushing coals, particularly for power plants. They are also used for gypsum, salt, chemicals and moderately hard materials. Granulators crush by a combination of impact and rolling compression, producing high reduction ratios at high capacities. Product size is determined by screen openings, and is adjusted by changing the clearance between the cage and the path of the ring hammers. All Pennsylvania Granulators possess an external adjustment for the cage assembly which is operable while the crusher is operating. Granulators also have a tramp iron pocket for continuous removal of uncrushables from the crushing zone.
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This series includes the Koal King® Granulator, a machine that crushes fuel for both pulverized coal boilers and fluid bed boilers. The Koal King Granulator will handle virtually any type of coal, including low quality coals that are wet, frozen, high in fines, or high in ash content, with virtually no clogging problems. It has a number of important servicing advantages. It opens like a clamshell to expose the inside of the machine for inspection or maintenance, without disturbing the feed system. The rotor can be removed through the opening quickly and easily, and rigging to open the rear quadrant is totally unnecessary when the optional hydraulic door opener is specified. The Koal King Granulator accepts feed sizes up to 12" (300mm). Product sizes of 100% minus 1/2" (12 mm) can be maintained when necessary.
HAMMERMILLS
Hammermills are among the oldest, yet still the most widely used crusher designs. Although recent years have witnessed the introduction of new types of crushers, many are a refinement of the basic hammermill design to serve more specialized purposes. Pennsylvania Hammermills crush material in two stages: First, the material is reduced by dynamic impact; crushing then occurs by attrition and shear in the second zone, where small clearances exist between hammers and screen bars. This second zone is the final sizing zone for the product. One of the advantages of Pennsylvania Hammermills is their ability to produce the specified top size without the need for a closed-circuit crushing
system. Hammermill crushing produces a cubical product with a minimum of flats and slivers, and is recommended when the material to be crushed is not unusually abrasive. In a Hammermill, large particles cannot escape the cage bars until sized, resulting in great product uniformity with a minimum of oversize. Hammermills have high reduction ratios and will produce high capacities whether used for primary, secondary or tertiary crushing. Cages can be adjusted to regulate product size, and a tramp iron pocket is standard on all models.
REVERSIBLE HAMMERMILLS Pennsylvania Reversible Hammermills are symmetrically designed crushers with a rotor that can be run clockwise or counter-clockwise. Reversal of the rotor permits the operator to utilize the opposite face of the hammer daily for maximum hammer sharpness. This ability to reverse totally eliminates the requirement of manual hammer reversal.
In addition to more effective use of the hammers, reversal also brings the opposing set of breaker blocks and screen bars into use. The user of a Reversible Hammermill virtually has two crushers in one machine, reversal being done with a simple motor switch.
REVERSIBLE HAMMERMILLS FOR COAL Pennsylvania builds this Reversible Hammermill specifically for the reduction of pulverizer coals, cyclone fuel and other finely crushed coal. To produce the smaller product sizes required, this model has more rows of hammers than are found in the Reversible Hammermills used for stone or rock. The internal configurations of the coal and rock models differ, though the crushing actions are similar.
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REVERSIBLE HAMMERMILLS FOR FLUID BED BOILER APPLICATIONS These units are specifically designed to reduce both fuels and sorbents in fluid bed boiler applications. They meet the needs of utility and cogeneration plants for crushers that perform effectively and efficiently. They are also suitable for similar reduction problems in other industries. Low investment cost and low power consumption have enabled these units to enjoy rapid acceptance. While they constitute the state-of-the-art of this technology, their design is based upon our company’s many decades of experience with reversible hammermills of many types. Pennsylvania’s exclusive high performance, forged steel hammers are supplied for most applications. Alloy steel is used for breaker plates, scrubber and screen sections.
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Both sides of these units open fully for complete access to the crushing chamber. Product sizing and wear compensation are accomplished by adjusting the cage, and a tramp iron pocket is included for protection of the rotor. Options include air sweeping and drying. As plant needs change in future years, this design readily allows for modifications that can be performed whenever needed without compromising the original investment in this equipment. Our extensive experience with fluid bed applications will allow us to determine the configuration and size that match the needs of your plant. We also provide peripheral equipment and systems as needed to ensure a fully integrated operation.
REVERSIBLE HAMMERMILLS FOR ROCK, LIMESTONE, MINERALS AND CHEMICALS In these machines, the breaker blocks and the cage bars are more massive than those used for crushing coal or other relatively friable materials. This type of Reversible Hammermill has fewer rows of hammers than the coal version, and the hammers themselves are of a different type and size.
NON-REVERSIBLE HAMMERMILLS These are used for primary or secondary reduction of dry, friable, low abrasive rocks, ores and chemicals, particularly when uniform product gradation is important. This type of crusher is often used for primary crushing of quarry-run feed to the final product size in a single pass. It is also used for secondary crushing when oversize must be controlled, but where a closed-circuit crushing system is not practical. Size reduction starts by impact when the hammer strikes the material as it enters the crushing zone. Shattered fragments are swept down into the final crushing zone for further reduction at the pinch points between the hammers and screen bars. Oversize material remains in the machine until it is reduced sufficiently to fit through the screen bar openings. Some of these models are available with adjustable cages, a feature that permits the user to make changes in the product size and compensate for wear. The tighter the clearance between the screen bars and hammers, the smaller the particle size of the crushed product. However, major product size changes are controlled by changing the individual screen bar openings. When the machine has no adjustable cage, hammer wear is compensated for by resetting the hammer suspension bars closer to the outside edges of the rotor discs, and by moving the breaker plate closer to the hammer circle. Large access doors provide entry for these adjustments. These crushers accept feed sizes up to 30" (750mm).
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NON-CLOG HAMMERMILLS
This type of hammermill will crush material that might build up within other kinds of hammermills. This would apply to any product that is very sticky or muddy, or that is simply too wet to be effectively crushed in other mills. In place of the fixed breaker plate, a traveling breaker plate revolves continuously and carries the incoming feed into the path of the hammers. This virtually eliminates any chance for feed to build up outside of the hammer sweep area. The combined forces of crushed particle velocity and gravity are normally sufficient to clear the product through the machine. However, if the feed is so sticky that it may accumulate, this machine can be equipped with an
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additional traveling rear element which is self-cleaning. Both the traveling breaker plate and the traveling rear element have a torque release mechanism that allows the V-belts to go slack and the motor to shut off in case of a jammed breaker plate. Because this type of hammermill is usually operated under extremely difficult conditions, the motor drives for the traveling breaker plate and for the rear element are mounted on the mill itself, above the working level. This arrangement is very compact and requires minimum floor space. Non-Clog Hammermills accept feed sizes up to 36" (900mm).
COALPACTORS
Coalpactors were originated by Pennsylvania Crusher to crush coking coals and to produce an optimum percentage of product below 1/8” (3mm), but with a minimum amount of fines (100 mesh or smaller). Coalpactors are also used for crushing coal and petroleum coke for fluid bed boilers which have similar output size requirements. This crusher permits coke plant operators to obtain high stability coke from various grades of coal. When coke is produced from a blend of petrographically differing coals, the coke strength is improved by control of the minus 1/8” (3mm) pulverization. A Pennsylvania Coalpactor is similar to an impactor. It has breaker plates that are fully adjustable from outside of the frame to enable operators to vary the degree of pulverization. This allows maintenance of a uniform product size throughout the life of hammers and breaker plates.
The Coalpactor rotor may be run either clockwise or counter-clockwise to provide for equal wear on both hammer faces. This helps to extend hammer life and to reduce maintenance problems. To facilitate servicing, all internal parts of the machine are readily accessible. Pennsylvania Coalpactors have largely replaced other types of crushers for crushing coking coals because the Coalpactor will maintain rated capacity even when the coal is wet, and it is not affected by uncrushables. When used to crush fuel for fluid bed boilers, the FB-design Coalpactors use an extended crushing path to further improve output size control.
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ALUMINUM DROSS IMPACTORS This is a special type of Impactor that takes large pieces of aluminum dross or slag and reduces the oxide, by impact, to approximately 8" (200mm) and under. The impact frees the more friable slag from the harder, uncrushable metal. Thus, the machine not only reduces the dross, but also beneficiates the aluminum. As dross enters the feed hopper, it slides down into the path of heavy rotating hammers. Upon impact with these hammers, the dross is driven up against the breaker bars. Additional reduction also takes place as material ricochets between the hammers and the breaker bars, until it is finally swept from the crushing chamber. This machine also incorporates a protective device for uncrushables.
METALLIC SLAG CRUSHERS In addition to the Aluminum Dross Impactor, Pennsylvania Crusher also offers other crushers which are used for crushing dross or slag. The Reversible Impactor (CF 9-50) was developed for reduction of open hearth, B.O.F. and blast furnace slag. This crusher takes 10" - 12" (250300mm) slag and reduces it to a minus 2" - 3" (50-75mm) product size in one pass. In this crusher, the impact breaks the more friable oxides from the metallic particles. The metallic particles are then separated magnetically and the oxide or slag body is used for aggregate. Pennsylvania Jaw Crushers are used to crush residue material from the zinc smelting process. The crushed material then goes back into the system for reclamation of usable zinc. Pennsylvania Jaw Crushers are also used to crush salt cake, which is a furnace slag containing a high amount of sodium chloride. To retrieve particles of aluminum, the Pennsylvania Jaw Crusher reduces the salt cake to minus 5" - 6" (125 150mm).
Jaw Crusher
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CF 9-50 Reversible Impactor
REVERSIBLE IMPACTORS Reversible Impactors are used for secondary and tertiary crushing, and occasionally for primary crushing. They are used for reduction of cement rock, gypsum, fertilizer, chemicals, lime and agricultural limestone, lightweight aggregate, ceramics and other materials. Reversible Impactors are normally recommended when certain requirements exist: high reduction ratio (35:1 or greater), high capacity, cubically shaped, well-graded product, and minimum fines. These crushers can be easily adjusted to produce a wide variety of product sizes. For coarser output sizes, Impactors are operated at lower speeds. When finer output sizes are required, higher speeds are used. It is also possible to change product size by making adjustments to the breaker block assemblies. Material drops through the centrally located feed chute directly into the rotor, where it is struck by the rotating hammers. The material then impacts against the breaker blocks and rebounds into the path of the hammers. There are no cage bars or screens,
therefore, impact and some shear are the methods of reduction. The bottom of the crusher is entirely open and the sized material passes out freely. When the product must be held to a specific top size, the machines should be operated in a closedcircuit system. When operating in closed-circuit, the mill discharge is carried to external screens or classifiers for separation, with the oversized particles being returned to the impactor for further reduction. The size of the feed may vary up to sizes produced by primary crushers. In some instances, these crushers will handle material directly from quarries or other sources. Pennsylvania Crusher originated the Reversible Impactor in order to eliminate manual turning of hammers. The Reversible Impactor is symmetrical in design, and by simply pushing the reversing button, the operator can change the direction of the rotor, presenting a fresh hammer face to the feed.
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SMALL REVERSIBLE IMPACTORS These smaller impactors have been designed for specialized crushing requirements at relatively low capacities. Typical applications for these units include: “green” brick, mill scale, foundry sand, gypsum, phosphate rock, flake frit, graphite ore, glass tubing, salt cake, brass skimmings and tungsten carbide chips. For servicing, the frame section on both ends of the machine may be removed to expose the breaker blocks, liners and rotor. The liners are made of carbonmanganese steel and are renewable.
The upper breaker blocks are made of cast alloy steel and are both reversible and interchangeable. The lower breaker blocks are supplied in fixed or adjustable configuration. These impactors are offered in several sizes.
TWIN ROTOR IMPACTORS The Pennsylvania Twin Rotor Impactor handles wet, sticky materials that would clog most other crushers. It produces a maximum of fines and is widely used in brick and clay plants as a secondary crusher. It can also be used as a primary tailings crusher. The crushing action in Pennsylvania Twin Rotor Impactors is accomplished solely by impact of the feed against two counter-rotating sets of manganese steel hammers. There are no impact blocks, screen bars or other stationary impact areas, and the product path is directly through the center of the crusher. This design
SMALL REVERSIBLE IMPACTOR
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demands relatively little power and it facilitates crushing of wet, sticky materials. The Twin Rotor Impactor has an inner lining, separated from the outer shell by a chamber or “plenum”. Hot waste gas can be directed into the plenum, heating the lining. This helps to prevent a major accumulation of material. Twin Rotor Impactors are available in three sizes; the largest can accept feed sizes up to 14" (350mm). Normally these units are operated in closed-circuit. Each rotor is driven by a separate motor.
TWIN ROTOR IMPACTOR
JAW CRUSHERS For crushing of hard, abrasive materials, Jaw Crushers are often preferred, since this type of machine will crush virtually any mineral. Jaw Crushers differ substantially from other types of crushers. There is no rotary motion in the crushing cycle, and all crushing is done by compression of the feed material between two massive jaws, which in effect are a type of breaker plate. Jaw plates can be either smooth or corrugated. While one jaw is fixed, the other jaw pivots about a top hinge. This moving jaw is shaped to move firmly and squarely against the material, at 250 to 400 strokes per minute. There is no rubbing or grinding, only compression, which produces a generally cubical product with minimum fines. The moving jaw is so balanced that fully 95% of the drive motor power is used for crushing, while only 5% of the power is needed to move the jaw itself. As a result of this high mechanical efficiency, smaller motors may be used, keeping power costs down.
Behind the stationary jaw are shims, used to compensate for plate wear and to adjust the closed side setting. For protection from uncrushables, there is also an automatic drive disengagement feature that acts instantaneously on the moveable jaw assembly. Pennsylvania Jaw Crushers accept feed sizes up to 48" (1200mm) and produce a nominal product size as small as 3/4" (19mm). Product size is determined by the distance between the lower end of the jaws. This gap dimension may be adjusted by shims behind the stationary jaw assembly. These crushers may be chokefed from hoppers or conveyors. Jaw Crushers for Glass Cullet The basic Jaw Crusher design is modified for glass crushing by changing to special corrugated plates, called “cullet plates”, on both jaws. These cullet plates meet and intermesh to provide complete crushing of the glass. The product is designated as glass “cullet”.
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BRAD-MULTI-ROLL CRUSHERS The Brad-Multi-Roll Crusher was introduced to produce material with output smaller than 1/4" (6mm) while producing a minimum of extreme fines. This produces a product having a very steep gradation curve, making it ideally suited for preparation of fuel and sorbents for fluid bed boilers and for other applications that require such a gradation. This machine is capable of handling moist materials when operated in open circuit. Drying is usually recommended when closed-circuit operation is needed to meet a specific gradation curve. The Brad-Multi-Roll Crusher is well suited to abrasive materials. To compensate for any reduction in charge level resulting from wear, additional charge can
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simply be added. This greatly simplifies maintenance, and provides a machine with exceptionally high availability. For some closed-circuit applications, integral screening can be accomplished. The great compactness of this design means that a smaller building is required, while minimizing the need for peripheral equipment. Optional sound housings can be provided to control noise emissions. When compared with other machines that require air classification to achieve specified product sizes, users of the Brad-Multi-Roll Crusher will enjoy significant and continuing savings in power costs.
CLINKER CRUSHERS The Clinker Crusher is used for handling of bottom ash, though it can readily be configured to handle other materials. It is now widely employed as a direct replacement for the most common makes and sizes of clinker grinders. Its efficient design improves maintainability and increases component life, thereby reducing both operation and maintenance costs. For example, the cast, high chrome roll segments are reversible to maximize their wear life. These segments can also be changed out with the unit in place by means of a large door in the rear of the frame. For retrofit, no changes to foundations are needed under normal circumstances.
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SINGLE ROLL CRUSHERS Single Roll Crushers are typically used as primary crushers. A single roll crusher has a roll assembly consisting of a roll shaft and a fabricated roll shell with integral fixed teeth. In the single roll crusher, three different methods of reduction occur: impact, shear and compression. Entering the crusher through the feed hopper, the feed material is struck by the teeth of the revolving roll. While some breakage occurs here by impact, the rotation of the roll carries the material into the crushing chamber formed between the breaker plate and the roll itself. As the turning roll compresses the material against the stationary breaker plate, the teeth on the roll shear the material. Sized material falls directly out through the discharge end of the crusher which is completely open. There are no screen bars, and consequently there is no recrushing of the sized materials, a factor that helps to reduce power demand while minimizing product fines.
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The clearance between the breaker plate and the roll determines the product size. This clearance is adjustable from outside the machine by a shim arrangement. Adding or removing shims causes the plate to pivot about its top hinge, moving it into or away from the roll. For protection against uncrushable debris, the breaker plate assembly is secured with an automatic release device. As pressure from the uncrushable is exerted against the plate, the device allows the entire breaker plate assembly to move away from the roll instantly. The uncrushable drops clear of the machine by gravity, and the breaker plate assembly immediately returns to its normal crushing position. Pennsylvania Crusher Corporation builds several types of Single Roll Crushers in a great number of sizes and capacities, with product sizes ranging from 3" (75mm) to 12" (300mm) depending on machine size. Applications include petroleum coke, coal with rock, coal, aggregate, limestone, chemicals, phosphate rock, shale and many other materials.
DOUBLE ROLL CRUSHERS These are typically used in situations in which fines are to be minimized. They are widely employed on friable materials such as coal, lime, limestone, petroleum coke, and chemicals. As the two rolls rotate toward each other, the material is pulled down into the crushing zone where it is grabbed and compressed by the rolls. Product size is determined by the size of the gap between the rolls, and this gap can be changed to vary product size or to compensate for wear. Since both rolls rotate at the same speed, there is no relative motion between the two roll surfaces, and crushing is primarily accomplished by compression. Compression crushing is extremely efficient, as energy is only used to crush those particles larger than the gap between the rolls. Fines are reduced because already sized material passes freely through the crusher with no further reduction. Usual feed sizes are up to 6" (150mm), though larger feed can be effectively handled in certain applications. Reduction ratios normally do not exceed 4 to 1.
Protection from uncrushables is provided by means of a retractable roll assembly. It retracts instantly when an uncrushable is encountered, then reverts to its original position once the uncrushable has cleared the crushing chamber with no stoppage of the crusher. Pennsylvania offers Double Roll Crushers in a number of sizes and roll tooth patterns.
ROLL TOOTH PATTERNS
TRAPEZOID
SLUGGER
TRAPEZOID
SMOOTH
Other tooth patterns also available.
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FROZEN COAL CRACKERS This type of machine is basically a single roll crusher. It differs from our other single roll crushers in the drive mechanism. Though it utilizes the basic single roll design and crushing actions, this particular machine has an extremely wide feed opening which permits the use of open-throated hoppers to choke feed large lumps of coal into the machine. It will reduce coal to a nominal 6" to 8" (150 to 200mm) product size. Freezing of the coal can occur in railcars and stockpiles, causing stoppages in handling or conveying. These frozen coal lumps will often fall from conveyors or become wedged in hopper throats. For this reason, Pennsylvania Frozen Coal Crackers have a low profile, so as to fit into existing
handling systems. The machine is often installed directly below the railcar delivery hoppers or at the outdoor stockpile. The breaker plate may be backed off during warmer weather to permit coal to flow directly through the unit unhindered. If desired, the entire roll assembly can be removed for warm weather operation without disturbing the feed system in the Model FCC. The FCCR Model allows easier removal of the roll by a screw mechanism. The roll assembly is then stored on the frame, fully aligned and ready to be re-inserted when freezing conditions recur.
Model FCC
Model FCCR
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MOUNTAINEER™ SIZERS
The Mountaineer Sizer crushes a wide variety of materials. It incorporates all of the features needed to do a better job than ordinary sizers, for primary or secondary sizing. For example, it sizes very accurately, produces extremely low fines and operates at low speed. Such low speed also helps to extend component life. It also uses relatively low horsepower, resulting in reduced equipment wear and energy costs as well as low noise levels. Made in U.S.A., its construction is modular and employs standard components, meaning that maintenance can be performed more quickly and at less cost than others. Low headroom, as low as 40 inches, enables it to fit most plant layouts. An extremely rugged, high capacity machine, its crushing chamber is lined with heavy duty liners, and all side liners are reversible. The sizing rolls are offered in a variety of tooth patterns to suit the application. The Mountaineer Sizer is offered in various lengths, with capacity dependent on many factors, the most important of which is the output size. The sizers are direct driven through a gearbox, and a fluid coupling is provided for tramp iron protection.
Wheels not shown
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POSIMETRIC FEEDERS
This unique feeder handles materials having an extraordinary range of characteristics, including wet, dry, lumpy, sticky, abrasive or granular. Virtually immune to jams, it will feed dry, light particles at 1,200 pounds per hour, or heavy sticky materials at 120,000 cubic feet per hour, with absolute consistency never before achieved in ordinary feeders. It delivers material with unvarying accuracy of up to 99.5 percent, with no need to recalibrate, unless the material changes. Regardless of moisture content, it delivers a constant rate of bulk solid material; each rotation delivers a fixed volume that cannot vary, meaning that it feeds at the desired rate, with no surges and no partial feeding. This feeder contains only a single moving part – the rotating duct. Because the feed material helps to
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turn this duct, only a small motor, usually under 10 hp., is required to drive it. Those factors result in very low stress and exceptionally low maintenance. In addition, wear is negligible because there is almost no abrasive action of material against the working parts. Some units have been in service for up to ten years, without needing a single replacement part.
Pennsylvania Crusher
®
The Most Choices, The Most Experience
Click on link below to obtain contact information for our company staff and for our sales representatives around the world. Application engineering assistance is available upon request. Requests for individual brochures on each of our crushers or feeders may be sent to our e-mail address or by writing or faxing to the address shown.
600 Abbott Drive • Box 100 • Broomall, PA 19008-0100 U.S.A. Phone: (610) 544-7200 • Fax: (610) 543-0190 E-Mail:
[email protected]
www.penncrusher.com
Printed in U.S.A.
Bulletin 4050-D
00-3-03R-1M
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