Procedure Template for Pulverized Fuel Bin Entry and Inspection

Originating Department: Technical Training

Classification: Procedure

Creation Date: May Date: May 2, 2008

Revision Date: N/A Review Date: N/A

Control Number: HC.11.103

Prepared By: AnnaLisa By: AnnaLisa Homan Title: Sr. Training Specialist

Approved By: Mark Morgan Title: Manager, Technical Training

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NA Portal > Holcim (US) > ISO Documents > Policies & Procedures > 11-Manufacturing 11-Manufacturing Performance Center

Subject:

Procedure Template for Pulverized Fuel Bin Entry and Inspection

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PURPOSE: The purpose of this procedure is to provide an overview of safe procedures to enter a pulverized fuel bin for the purposes of inspecting the bin. This procedure is a general guideline, general guideline, and is meant to guide the development of plant-specific entry procedures at each facility which address the site specific equipment layout, as well as any additional hazards associated with the installation.

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SCOPE: This procedure is for the preparation of a PULVERIZED FUEL BIN for BIN for entry in order to perform inspections. Several additional safety precautions are necessary when entering bins containing COMBUSTIBLE material (such as coal), due to the additional risks of ignition.

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DEFINITIONS: Automatic Fire Suppression System – System – a system designed to dump large amounts of liquid N2 or CO2 into an enclosed area in order to put out a fire Bin or Silo – Silo – an enclosed space used for storage Blank – to install install a physical physical isolation isolation device which which prevents prevents material material from flowing flowing past the location of the blank into the confined space. Combustible – Combustible – capable of catching fire, igniting and burning Confined Space – Space – An area or space which has the following characteristics: 1. Limited Limited or or restrict restricted ed mean means s of entry entry or exit exit 2. Large Large enough enough for an employe employee e to enter enter and perform perform assigned assigned work work 3. Not design designed ed for contin continuou uous s occupancy occupancy by by the employe employee e Fuel – Fuel – any pulverized, combustible material which will can used as an energy source Hot Work – Work – work that that produces produces a potential potential point point of ignition, ignition, either by heat or or spark. Hot work includes riveting, welding, flame cutting, grinding or other fire or spark-producing operations. Inerting System – System – a system designed to flood an enclosed area with gaseous (vapor) N 2 or CO2 in order to displace oxygen and prevent combustion or smoldering Intrinsically Safe – Safe – equipment and wiring which is incapable of releasing sufficient electrical or thermal energy under normal or abnormal conditions to cause ignition of a specific hazardous atmospheric mixture in its most easily ignited concentration – employed as a protection technique for safe operation of electronic equipment in explosive atmospheres.

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Procedure Template for Pulverized Fuel Bin Entry and Inspection LEL – LEL – Lower Explosive Limit – the lowest concentration of a material, gas, or vapor in air capable of producing a flash or fire in the presence of an ignition source. NDT – NDT – Non Destructive Testing – those test methods used to examine an object, material or system without impairing its future usefulness. Typically includes radiographic testing, ultrasonic testing, electromagnetic testing, eddy-current testing, magnetic particle inspection, dye-penetrant testing, pressure testing, infrared and thermal testing, etc. PEL – PEL – Permissible Exposure Limit – the level of air contaminants that represents an acceptable exposure level as specified in standards set by a national government agency; generally expressed as 8-hour time-weighted average concentrations. Permit Required Confined Space – refers to those spaces that meet the definition of a "confined space" and may pose health or safety hazards, thereby requiring a permit for entry . A permit required confined space meets the definition above for a confined space, and contains one or more of the following hazards: 

Contains or has the potential to contain a hazardous atmosphere,

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Contains a material that has the potential for engulfing the entrant,

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Has an internal configuration that might cause an entrant to be trapped or asphyxiated by inwardly converging walls or by a floor that slopes downward and tapers to a smaller cross section Contains any other recognized serious safety or health hazards

Pulverized Fuel Bin – Bin – an enclosed bin used to store fuel which has been ground and is ready for transport to the pyro-processing system Smoldering – Smoldering – the process of coal slowly self-heating. It can lead to spontaneous combustion and burning of coal.

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RESPONSIBILITY: 4.1

Corpor rpora ate Re Respon ponsibi ibiliti litie es

It is responsibility of the Manufacturing Performance Center Technical Training Group to provide the general document template, and to keep it updated with any changes and revisions.












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Procedure Template for Pulverized Fuel Bin Entry and Inspection

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PROCEDURE: 5.1 5.1

Safe Safety ty cons consid ider erat atio ions ns prio priorr to to sta start rtin ing g wor work k A pulverized fuel bin is a PERMIT REQUIRED REQUIRED confined space, requiring requiring all related confined space precautions. Potential safety hazards particular to this procedure include (but are not limited to): 

Coal or other fuels, which are combustible and present a risk of fire

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Coal dust, which is explosive, with an LEL as low as 50 g/m 3

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Coal dust, which has a PEL of 2.0 g/m 3

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Oxygen deficiency which can be caused by air displaced by the inerting or suppression systems installed (CO 2 or N2) Frostbite hazard due to liquid CO 2 or N2 Toxic fumes including methane, carbon monoxide, SO 2, or H2S or other decomposition products of coal or the bin lining materials .

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Entrapment hazard due to bin configuration

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Overhead material accumulation, buildup, and falling material or debris

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5.2 5.2

Asphyxiation Asphyxiation hazard hazard due oxygen oxygen deficiency deficiency within within the confined confined space space

Mechanical hazards related to moving parts of the bin discharge or flow promotion devices

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Use of high pressure water cleaning tools

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Use of sandblasting tools and equipment

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Slip, trip, and fall hazards including wet surfaces

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Fall hazards due to the height or location of the bin

Prep Prepar arat atio ion n of fire fire figh fighti ting ng proc proced edur ures es Ensure that an up-to-date fire fighting procedure is in place, and has been reviewed with all personnel involved. The procedure should include: 

Description of fire fighting equipment to be used for each situation (water hose, fire piercing rods, fire extinguishers, automatic fire fighting system, etc)












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Procedure Template for Pulverized Fuel Bin Entry and Inspection 5.3 5.3

Prep Prepar arin ing g the the pulv pulver eriz ized ed fuel fuel bin bin for for work work 5.3.1 5.3.1

Empty Empty the the bin throu through gh down downstrea stream m equipme equipment nt / norma normall means means

5.3.2 5.3.2

Thoroug Thoroughly hly clean clean the surrou surroundin nding g area (shove (shovel, l, sweep sweep and then then wash wash down) so that no fuel sources are present (coal, grease, debris, etc) CAUTION: Do not use compressed air to blow off or clean coal. The CAUTION: use of compressed air could cause a coal dust cloud which could explode.

5.3.3 5.3.3

Lock Lock and and Tag-ou ag-outt the the bin [following bin [following plant LOTO procedures] This should include 

Isolating the bin from upstream and downstream equipment

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Isolating any material inlet chutes including dust collector discharge

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Isolating any venting lines, piping or ducting

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Controlling all forms of energy in the bin including agitation, or other flow promotion devices

NOTE: Do not lock out the inerting and automatic fire fighting systems at this time 5.3.4 5.3.4

Remove Remove the insulati insulation on and and cladding cladding from from the the bin, bin, if necessa necessary ry

5.3.5 5.3.5

Clean Clean the exterio exteriorr of the bin bin by mecha mechanica nicall means means (non-spa (non-sparking rking scrapers or brushes), or water spray, or high pressure water blaster or sandblasting as necessary CAUTION: Sand blasting can cause a temperature rise on the surface CAUTION: of the fuel bin which could cause ignition of any remaining fuel deposits on the interior. 5.3. 5.3.5. 5.1 1 

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Sandb andbla last stin ing g Prec Precau auti tion ons s

Check the initial temperature of the walls prior to beginning sandblasting using a thermal imaging camera or a handheld pyrometer. Periodic checks (every 10 minutes) should be made of the wall temperature to ensure that excess temperature does not create a












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Procedure Template for Pulverized Fuel Bin Entry and Inspection 

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5.4 5.4

Provisions may be needed to collect and dispose of the media, depending on the type used [insert any other details of sandblasting procedures here]

Prel Prelim imin inar ary y insp inspec ecti tion on of the the pul pulve veri rize zed d fuel fuel bin bin 5.4.1 5.4.1

Inspect Inspect the the exterior exterior of the the bin for for any indicat indication ion of intern internal al heating heating,, which could indicate combustion of any remaining fuel deposits on the interior. This includes: 

Visual and touch inspection for hot spots

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Visual inspection for peeled or bubbling paint

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Use of a thermal imaging camera or hand-held pyrometer to detect hot spots

5.4.2 5.4.2

If hot spots spots are dete detected cted,, deploy deploy automat automatic ic fire suppre suppressio ssion n system system inside the bin

5.4.3 5.4.3

Check Check the atmosph atmospheric eric conditi conditions ons inside inside the bin, bin, with alread already-ins y-install talled ed instrumentation. instrumentati on. This includes temperature and CO.

5.4.4 5.4.4

When When the bin bin is absent absent of any any indicat indication ions s of combusti combustion on (heat, (heat, CO, CO, smoke), proceed to opening the bin

5.4.5 5.4.5

Open Open a smal smalll port port on the the bin bin [describe location of ports here] . CAUTION: Opening the bin provides a source of oxygen to an CAUTION: otherwise oxygen-deficient atmosphere. This oxygen may lead to combustion or even an explosion. CAUTION: Always open open a small small port before before opening opening the main main access hatch. Wear protective gloves and face/eye protection and stay clear of the port as it is opened.

5.4.6 5.4.6

Perform Perform limite limited d inspect inspection ion of the the interio interiorr of the the bin bin Using an intrinsically safe flashlight, safe flashlight, visually inspect for any indications of smoldering coal. If there are any indications of combustion inside the bin (red glowing or smoke), deploy automatic fire fighting system inside the bin












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Procedure Template for Pulverized Fuel Bin Entry and Inspection CAUTION: “Entry” includes breaking the plane of the bin with any part CAUTION: of your body. body. Using an intrinsically safe flashlight safe flashlight or droplight, visually inspect for any build-up or suspended material that could pose an engulfment or overhead hazard, and for any indications of smoldering coal. If there are any indications of combustion inside the bin (red glowing or smoke), deploy automatic fire fighting system inside the bin 5.5 5.5

Prep Prepar are e for for entr entry y int into o the the pulv pulver eriz ized ed fuel fuel bin bin [insert details of door location, procedure, etc.] If safe access platforms are not installed at the door location, ensure that adequate fall protection is used in accordance with plant fall protection procedures. 5.5.1 5.5.1

Check Check air air quali quality ty and and atmos atmosphe phere re inside inside the bin [give plant related detail here, and any air limits more strict than the limits stated, or additional] 

Oxygen (O2) – PEL is 19.5% to 23.5%

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Methane (CH4) less than 10% LEL

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Carbon Monoxide (CO) less than 35 ppm

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Hydrogen Sulfide (H 2S) less than 10 ppm

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Temperature less than 50°C (122°F)

If there are any indications of combustion inside the bin (elevated CO or temperatures), initiate fire fighting procedure 5.5.2 5.5.2

Compl Complete ete Confin Confined ed Spac Space e Entr Entry y [give plant related detail here, and any air limits more strict than the limits stated, or additional related plant safety procedures – done by entry supervisor] 5.5.2.1

Prepare Confined Space Entry Permit

5.5.2.2 .2.2

Ensure sure that emp emplo loy yees are are train raine ed an and aw aware of ha hazards rds relating to the specific confined space

5.5.2.3 .2.3

Fol Follow low pla plan nt lo lock-o ck-ou ut ta tag-ou -out pro proce ced dure for for co contro trol of of Hazardous Energy














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Procedure Template for Pulverized Fuel Bin Entry and Inspection 

Carbon Monoxide (CO)

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Carbon Dioxide (CO 2)

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Hydrogen Sulfide (H 2S)

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Temperature

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Dust

5.5.2.5 .2.5

Ensure sure that th there is adequate ven ventila tilati tio on (a (a mi minimu imum of of 12 air volume exchanges per hour)

5.5.2.6

Assign a qualified at attendant / “hole-wa -watch”

5.5.3 5.5.3

Provide Provide a mean means s for debri debris s to exit exit the the bin. bin. This could could involve involve removi removing ng a gate or spool-piece and providing a safe location for fuel deposits and/or fuel-laden water to be discharged away from downstream process equipment

5.5.4 5.5.4

Using Using access access ports and and hatches hatches,, clean clean the interio interiorr of the bin bin enough enough to gain safe entry to the confined space. This includes removal of overhead material or debris which could present a hazard upon entry. This can be done using 

Mechanical Cleaning using non sparking tools or brushes (for example - brass poking bar, bar, wooden rod, etc)

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Water wash-down

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High Pressure Water Wash












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Procedure Template for Pulverized Fuel Bin Entry and Inspection CAUTION: When coal deposits are dislodged, they may form a coal dust cloud which CAUTION: could explode. 5.6.1 5.6.1

Ensure Ensure all neede needed d entry entry safety safety equipme equipment nt is availab available le includin including g life harness and retrieval systems etc.

5.6.2 5.6.2

Have Have fire fighting fighting equipm equipment ent availab available, le, includin including g inert dust dust and/or and/or water hose and/or dry chemical fire extinguisher CAUTION: CO2 fire extinguishers can change the environment of the CAUTION: bin and should only be used if adequate ventilation is provided, due to the asphyxiation danger

5.6.3 5.6.3

Ensure Ensure the entran entrantt uses proper proper PPE PPE including including non-sy non-synthe nthetic tic clothes clothes that that are flame resistant and free of combustibles such as coal dust or oil CAUTION: Only intrinsically safe non-sparking equipment can be CAUTION: taken into the bin. This includes lighting, radio, tools, etc . CAUTION: Cell phones and all other electronic devices are CAUTION: prohibited inside the pulverized fuel bin unless a hot work permit is used, as they can be a source of ignition

5.6.4 5.6.4

Clean Clean fuel dust dust deposit deposits s using mecha mechanica nicall cleaning cleaning (non-sp (non-sparkin arking g brushes or scrapers), water washing, high pressure water, sand blasting, or other means of surface preparation. CAUTION: Sand blasting can cause a temperature rise on the surface CAUTION: of the fuel bin which could cause ignition of fuel deposits.












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Procedure Template for Pulverized Fuel Bin Entry and Inspection 5.6.5 5.6.5 5.7 5.7

If there there is fuel fuel that that can not not be remove removed, d, cover cover the fuel fuel comple completely tely with with limestone or other inert rock dust to prevent smoldering.

Insp Inspec ecti tion on of the the pul pulve veri rize zed d fue fuell bin bin Once the bin is clean of all fuel, inspection (including non-destructive testing) and hot work may be performed both on the exterior or interior of the bin NOTE: Use of non-destructive testing equipment (NDT) within the bin is considered hot work, work, unless the equipment used for the testing is intrinsically safe (electrically) and can be shown to not be a source of heat, spark or potential ignition. See procedure HC.11.104 regarding hot-work inside a pulverized fuel bin.

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COMMUNICATIONS: The MPC Technical Training Department is responsible for communicating this procedure to the plants. The [plant insert title here] is responsible for communicating this procedure to affected managers, supervisors and employees and ensuring that the procedure is adapted and used at the respective plant

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TRAINING REQUIREMENTS: None












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Procedure Template for Pulverized Fuel Bin Entry and Inspection XX.XX.XX Plant Fall Protection Procedure XX.XX.XX Plant Scaffolding Procedure XX.XX.XX Plant Hot Work Procedure XX.XX.XX Plant Emergency Action Plant XX.XX.XX Plant Standard Operating Procedures (for kiln or fuel grinding system) XX.XX.XX Other Related Plant Procedures

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REFERENCES: None

Procedure Template for Pulverized Fuel Bin Entry and Inspection

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