4-2350-01-00041-2_D

Weir Minerals Latin America San José 0815 San Bernardo Santiago de Chile T: +56 (2) 7542200 E: [email protected] W: www.weirminerals.com

Installation and operation manual, 800CVX x 10 Cyclone Cluster CERTIFICADOPOR VULCOS.A.

D - REVIEWER FOR INFORMATION ONLY Autorización para proceder no constituye aceptación ni aliviar el contratista/proveedor de su responsabilidad de su obligación bajo el contrato y/o orden de compra. Esta revisión no otorga garantías expresas o implícitas de ningún tipo.

Sierra Gorda Project PO:4-2350-01 Project Nº:$6QM11

MQCL-1.4.2350.01-VEN-0000-MAN-ME00-0041 Sub-2

WEIR SLURRY GROUP MANUAL FOR THE CAVEX CYCLONE CLUSTER

Contents 1

Introduction

4

2. 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9

Terminology Cyclone Cluster Cyclone Hidrocyclone CAVEX Pulp collecting tanks Radial Distributor Spigot / Apex Downloading Overflow

5 5 5 5 5 6 6 6 6 6

3. 3.1 3.2 3.3

General Description Building the cyclone Materials Cavex cyclone models

7 7 7 8

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10 4.10.1 4.10.2 4.11 4.11.1 4.11.2 4.11.3

Operational Principals Overview The kinetics of fluids and particles in the cyclone The effectiveness of separation Cyclone pump - well The theory of orbital balance The theory of time resistance The theory of packaging The theory of Bi-phase turbulent flow Numeric Modeling Operation Variables Concentration of solids by weight Pressure on cyclones Cyclone Variables Diameter of Entry Diameter for the vortex finder pipe Diameter of the Spigot

9 9 9 10 11 12 13 14 14 15 17 17 17 17 17 18 18

5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10 5.10.1 5.10.2 5.10.3 5.10.4 5.10.5 5.10.6 5.10.7

Installation Requirements General Supply Pump Supply Pipe Control Valve Pressure Gauge Overflow pipework Discharge Cyclone Cluster Checklist implementation Storage before installation End point determinant Temperature Humidity Light Oxygen, ozone Deformation Contact with liquids or semi-solid liquids or their respected Vapors

19 19 19 19 19 20 20 20 20 21 22 22 22 22 22 22 23 23

Page 1 de 40 5th Revision October 2003 Manual for the Operation and Maintenance of the CAVEX cyclone cluster



5.10.8 Contact with metals 5.10.9 Contact with powered materials 5.10.10 Contact with different rubbers 5.10.11 Items with both metal and rubber 5.10.12 Containers, packaging materials and packaging 5.10.13 Turnover 5.10.14 Cleaning

23 23 24 24 24 24 24

6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8

25 25 25 26 26 27 27 27 28

Hidrocyclone Maintenance General Lifting / assembling / disassembling Casings Coatings Vortex Finder Spigots Hidrocyclone Cluster Solutions to problems

7 Assembling the Cyclone Cluster 7.1 Assembly schematics 7.1.1 What are schematics 7.1.2 The importance of schematics 7.1.3 Assembly example 7.1.3.1 First step, the assembly of the legs 7.1.3.2 Second step, Assembling the second structure 7.1.3.3 Third step, Assembling the cyclone and distributor 7.1.3.4 Fourth step, Assembling the battery floor 7.2 Precautions taken during assembly 7.2.1 Precautions taken during building 7.2.3 Safety 7.3 Transporting large parts 7.3.1 Diameter of large parts 7.3.2 Transport drill

29 29 29 30 30 31 31 32 32 33 33 33 33 34 34

8 Getting started 8.1 Screw Tightening 8.2 Overall Performance Review 8.2.1 Valves 8.2.2 Pump 8.2.3 Maximum limit detectors 8.2.4 Control Panel 8.2.5 Visual Inspection 8.3 Tests with water 8.3.1 Pressure surges 8.3.1.1 Recommendations for controlling pressure surges 8.3.2 Checking Cyclones 8.3.3 Checking filtration 8.3.4 Pressure and number of cyclones 8.3.5 Discharge flow versus pressure

35 35 35 35 35 36 36 36 36 37 37 37 38 38

9

Recommended replacement parts

38

10

List of schematics

39

11

List of CAVEX cyclone codes

40




List of User Specifications Date of Order: Order number:

(

Contact:

Javier López

Client: 6LHUUD*RUGD6&0 Country:

CHILE

Description of use:

SAMPLE MANUAL

Cyclone Model: &9;




1. Introduction CAVEX cyclones are a WEIR-VULCO product; they were initially designed by Warman, which is a member of the WEIR SLURRY GROUP today. This manual is designed to be used as a reference for those who use CAVEX hidrocyclone cluster, and is also a guide for the proper operation and upkeep when it comes to handling hydrocyclone cluster. It is important to note that the correct operation of a hydrocyclone cluster is a result of well-planned preventive maintenance measures of both hydrocyclones and all other equipment that works with it. . The Cluster operation depends significantly on the automatic control strategy of the equipment in the circuit and / or lack of it, so this manual is not intended to cover all the scenarios but the most common, which will be added and periodically updated. CAVEX cyclones are a WEIR-VULCO product which is a member of the Weir Slurry Group. This manual has been put together specifically for CAVEX users.

This manuals objective is to: 1. Description of the CAVEX cyclone and its construction. Diagram 1: Cyclone Cluster. Where the different parts of it can be seen: the cyclone, tanks, structures, control panel, etc.

2. Description of hydrocyclone principles and methods of operation. 3. Description of how to keep the CAVEX cyclone in good condition More information can be found by contacting your local WEIR – VULCO representative.




2. Terminology 2.1 Cyclone Cluster A cyclone cluster is a group of equipment that have the tools needed to able to classify particle such as: cyclones, pulp collecting tanks for both gross and fine material; power supply pipes for the cyclone, a radial distributor, structure, stands, rails, stairs, power supply and overflow pipes; a gauge and inspection covers, if needed. Diagram 1: Drawing of a cyclone cluster, in which its different parts can be observed, such as: the cyclones, tanks, structures, control panel, etc.

2.2 Cyclone A cyclone is a simple container in a cylindrical-conical shape with a tangential inlet and two outlets on each end of its axis. Cyclones are machines that use centrifugal force to accelerate the rate of sedimentation. Diagram 2: Diagram shows a hydrocyclone with the overflow pipe.

2.3 Hydrocyclone A hydrocyclone is a subclass or a specific part of a pneumatic cyclone that usually uses a liquid that has solid particles, such as pulp to process material. The most common use of hydrocyclones is to separate or classify solid particles according to their size from the sieve. This manual will be using the Word cyclone when referring to a hydrocyclone for abbreviation purposes.

2.4 CAVEX CAVEX is the name used for a new variety of cyclones originally developed by Warman, now part of the Weir Group designed specifically for grinding circuit applications. Its design is based specifically on a shape which provides enhanced durability, and also a significant improvement in its classification efficiency and ability, minimizing the amount of cyclones needed. Diagram 3 CAVEX cyclone cluster, model number 650CVX13°.




2.5 Pulp Collecting Tanks The pulp collecting tanks are made up of two radial tanks made out of steel, covered in natural rubber or other abrasion resisting material. Both of these tanks collect the classified particles from the pulp in both gross and fine material, the tank found in the upper part of the overflow tank’s battery collects the fine materials; while the tank found on the bottom collects the grosser material found in the pulp that was supplied to the cyclones.

Diagram 4 Underflow, in this can be observed “cama de piedra” here ,which protects the coating from erosion, in the cyclone’s discharge.

2.6 The Radial Distributor The radial distributor or the manifold purpose is to create a homogenous distribution of the flow of pulp fed to the cyclones. Its shape is designed to minimize any segregation of cargo, giving all operating cyclones a flow of homogeneous pulp. This part also has a removable lid at the top, in order to be able to inspect the inside. This part is also coated to resist abrasion in the same way the cyclones are.

2.7 Spigot

Diagram 5 Manifold or radial distributor. The inspection cap can be seen.

Also known as by apex, the spigot is the outlet for the last apex in the cyclone. It is usually a short and simple cylindrical part, its inner diameter is changed in other to suit the machines needs for it. The density of the discharge is highly influenced by the size of the spigot. WEIR- VULCO S.A. has a variety of different apexes with different characteristics and strengths, ranging from natural rubber to ceramic coating.

2.8 Discharge The discharge is the liquid that comes out of the spigot. Cyclones generally function in an upright position. Therefore the spigot discharges in an upright position, in order to produce discharge. When pulp is used the discharge has thicker and denser solid material.

2.9 Overflow Diagram 6 Cyclone’s apex or spigot, and Apex carrier, The drawing shows a rubber part from model number 650CVX.

This corresponds to the liquid section, which discharges through the vortex finder at the cylindrical end of the cyclone’s body. When pulp is used, the overflow contains a finer solid product which is less dense.




3. General Description of CAVEX Cyclones 3.1 Building the cyclone Cyclones have an innovative design in which is in the shape of a spiral, which creates a natural flow without any turbulence inside. CAVEX Cyclones are designed especially to meet high demand and durability bringing together several key components such as: durable faceplates, with anti-abrasion material coated on the liners (refer to diagram components in section 8). The faceplates are bolted together using metric bolts and / or fast powered clamps.

Diagram 7 Drawing of the CAVEX cyclone design shows the reduction of turbulence, controlling the flow.

The coating system for the CAVEX cyclone is designed so that adhesive material is not needed to adjust the coating for the casing. Each shell portion is molded to fit precisely to each component of the housing. This design allows the plants personnel to change the worn parts without the delays that involve parts that need to be adhered which can delay the machine from working.

3.2 Materials CAVEX Cyclones have faceplates made out of carbon steel or ductile iron. The coatings are molded from specially formulated compounds of natural rubber. Different wear-resistant materials fulfill different wear environments, for which the rubber made by WEIR-VULCO has proven to be the best material in regards to the cost-wear resistance.

Erosion is typically higher in the lower section of the cyclone, particularly in the spigot. For some equipment, lower ceramic coated cones and ceramic spigots have been a cost effective substitute for rubber. A WEIR-VULCO representative can advise on the use of special wear-resistant materials available.

Diagram 8 Drawing of the inside of the CAVEX cyclone the coating inside the faceplate can be seen.

CAVEX revolutionary design reduces turbulence increases the longevity of the parts. In conventional cyclones pulp collides inside the coating without any flow control, and the resulting turbulence causes the premature puncturing of the linear walls lining the supply chamber.




The CAVEX cyclone reduces turbulence, thanks to its innovative one-piece design, which doesn’t have any corners or junctions. Its spiral shape in the supply chamber generates a natural flow that minimizes turbulence.

3.3 CAVEX Cyclone Models

Diagram 9 Shows the flaw of a cyclone with a conventional design, while most of the body remains undamaged

the "size" of the cyclone is usually defined by the diameter of the inside of its cylindrical section or supply chamber. CAVEX models are defined by the nominal diameter in millimeters. Our experience indicates that CAVEX cyclones have up to 25% more capacity than a conventional cyclone equivalent in size.

Table 1 Chart of the processing capacity CAVEX cyclones, indicating the type of hydrocyclone operating pressure needed.




4. Principals of Operation In order to operate a cluster correctly understanding of how the equipment works is necessary x x x

Hydrocyclone Well-Pump Mills

The intention of this manual is not to delve into the theoretical aspects associated with the equipment but to recommend additional information that complements the information given here and will allow the reader to better understand the theoretical or conceptual aspects associated with the unit processes and equipment.

Diagram 10 Normal cyclone cluster, designed using Solid Edge 3D software

Nevertheless we will go over some basic concepts that will help in understanding how hydrocyclones operate.

4.1 General A hydrocyclone is a simple device, commonly used for the separation or classification of solid particles in a liquid or pulp.

Unlike a sieve, which only allows a particle with a fixed dimensional limit of go through, the hydrocyclone separates particles according to their relative rate of settling. However, instead of using gravity as a settling basin, the action of separation in a hydrocyclone is induced by a centrifugal force created within the cyclone. Settling is natural in pulp. The rate at which it settles depends on the size and shape of the particles, and the liquid viscosity of the pulp; and most importantly on the density and concentration of solid particles in the pulp.

4.2 Flow and kinetic movement of the particles within the hydrocyclone

Diagram 11 Tridimensional drawing of the pulp flow al inside a hydrocyclone . Conical Model.

Aside from the area inside and just around the inlet duct, the fluid motion within the cyclone has a circular symmetry. Most of the incoming fluid moves in a helical around the inner walls of the cyclone towards the cone where it begins to move towards the center. Some of the fluid at the bottom gets out through the spigot, while most of it reverses its vertical direction component by an internal helical flow and is discharged through the vortex finder pipe. A comparatively smaller pattern will flow above the feed chamber and back through the outer vortex finder to join the rest of the fluid in the overflow.




The solid particles in the pulp are driven outwards toward the cyclones inner walls by centrifugal force. This force is higher with more massive particles (larger or higher in density). As a result, grosser and heavier solids migrate through the inner wall of the cyclone to come up with some fluid and pressure in the discharge. A group of particles in any size (equal to the ratio of separation of water) will also come out in the discharge and they are considered a bypass (shunt) or unclassified group. This group of fine particles (strips), hidden in the discharge, can be reduced by maximizing the density of the discharge.

4.3 Cyclone Separation Efficiency The common measurement used in the separation of gross and fine particles is D50, also known by the name of cut size. D50 is the diameter of the particle, of which 50% by mass comes out in the discharge. Solids that are larger than D50 have more than a 50% chance of being in the discharge. Another measure of separation in a cyclone is the ratio between the quantity of liquid in the discharge and the amount of liquid in the feed. This is known as the ratio of removal of water ("water split") and commonly denoted by 'Rf'. The separation efficiency is more useful when expressed as a graph of percent of solids discharged versus particle size, and is known as the Tromp curve or curve of actual efficiency (see Diagram 9). Diagram 12 Diagram shows the efficiency of Royal Classification of a hydro cyclone. It highlights the difference between a conventional cyclone and a CAVEX model. Data gotten from the plant..

The recovery curve is in the shape of an S, passing through the separation size and intersecting the Y axis (a % belonging to the discharge) to a value close to that of the ratio of water separation. This can be understood considering that very fine particles that are sufficiently different from water molecules will be separated at the same rate at which fluid is separated, defined by the ratio of water separation (Rf). The reason for the separation of water can vary considerably depending on the operating conditions and shape of the cyclone, therefore this can be manipulated. Thus, it is common to remove the effect of the ratio of water separation efficiency from the definition by correcting the recovery curve so that it passes through the origin.

The corrected efficiency curve is defined using the following equation:

R a െR f

R c ൌ

100 െR f

where R c represents the efficiency that was corrected




R f represents the reason for the water split R a represents the percentage of the amount that was recovered Recovery curves and the corrected Recovery curve differ in that the latter is corrected by the short circuit. Importantly, the efficiency curve also defines the corrected d50 value, represented by d50c. d50c is a useful value to use when comparing the performance of cyclones for a specific job

Diagram 13 The classification efficiency curve, shows the classification efficiency of a conventional hydrocyclone and a CAVEX.

4.4 Well – Cyclone Pump

Diagram 13 Picture of a Bajo Molino SAG centrifuge pump. Warman ASH model, model 550 MCH.




As described in the previous section, a hydrocyclone is a device with no moving parts with a snail-type entrance with either tangential or scroll entry, typically followed in the shape of a cylinder or a cone. Hydrocyclones also have two axial exits, one on top or an overflow and one on the bottom or discharge Kinetic energy which makes the pulp pump function, mainly linear speed, is transformed in the hydrocyclone in a downward rotational movement which drains out of the exit at the bottom, forming a vortex movement whose intensity allows the stabilization of an air core, which allows the pressure in the axial axis of the hydrocyclone to decrease passed atmospheric pressure and therefore air enters the exits that are connected to the atmosphere. The increase of movement in the vortex increases the hydrocyclone’s feeding rate, as does the core size by the decrease in air in the hydrocyclone’s bottom exit, so that successive increases in the flow made by the discharge end from the feed flow through the top axial outlet or overflow. This hydrocyclone characteristic is important to understand because it stems a problem that is not less common in hydrocyclone cluster, which is that there is a minimum flow at the hydrocyclone entrance which allows the stabilization of both streams coming out of the hydrocyclone, thus separating gross particles from the discharge and the fine for the overflow. The cyclones ability to classify materials depends on the capacity of the pump and the power level of the pump’s feeding tank, the correct flow and pressure is required. A theory which makes this action understandable is the orbital equilibrium theory described below. 4.5 Orbital Equilibrium Theory According to this theory that was originally proposed by Crimer and Driesen (1950, 1951), there is a locus inside the Hydrocyclone where particles of a certain size and density reach a balance in a specific orbital position.




This balance is achieved when the centrifugal forces acting on the particle is equal to drag forces (Diagram 11).

If the orbit shown in the diagram, represents the orbit of a particle that has the same probability of leaving Hydrocyclone either through the overflow or discharge, the particles that are located between the wall and this group of orbits have (Fc> Fd) more of a chance of exiting through the hydrocyclone’s discharge. Similarly, particles that are located from the orbit towards the center of the hydrocyclone (Fc
T he cent rif ugal f orce acti ng on t he hydrocycl one appli ed on a spheri cal di amet er of t he parti cl e "d" i s expressed by:

Ɏ d 3 ሺ ɏs െ ɏሻVt 2 Fc ൌ 6r Where: d Particle Diameter ɏs : Solid Density

ɏ: Density of fluid

Vt : Tangential Velocity On the other hand, if laminar flow is being considered instead, Stokes' law can be applied, in which the drag force can be expressed as:

Fd ൌ3Ɏd ɊVr Where: d : Particle Diameter Ɋ : Flow Viscosity

Vr : Radial Velocity At equilibrium and when the particle size is correct, the following expression can be obtained (Kelly and Sputiswood, 1982).

d 50 ൌ

18 ɊVɏ f r

ሺɏs െ ɏሻVt

4.6 Time Resistance Theory Those that support this theory (Rietema, 1961), argue that the residence time of particles in a hydrocyclone (few seconds) is not enough to achieve equilibrium conditions. When Rietema




(1961) suggested this theory, he assumed that there was a uniform distribution of particles at the entrance of the hydrocyclone (Diagram 9). Therefore the size of the cut is the size of that particle, if it is located precisely in the center of the entrance opening of the machine, the particle will succeed in reaching the hydrocyclone wall at the level of the discharge opening during its residence time. Therefore using the mathematical equation for the particles d = d50 for the paticles. They will travel a radial distance equal to half of the diameter of the discharge entrance during its time spent in the hydrocyclone t

‫׬‬V 0

r

d t ൌ12 Di

Where Vr is the radial velocity calculated from the previous equation.

Vr ൌ

d502 ሺ ɏs െ ɏሻVt 2 18 Ɋr

Finally Rietema obtained the following expression for d 50 :

d502 ሺ ɏs െ ɏሻL ȟP 18Vz Dc ൌ ɊɏQ ɎVt Di Diagram 15 . Drawing of the radial fluid lines, and the axil inside the hydrocyclone. hidrociclón. (Rietema, 1961).

Where:

d : Diameter of the particle Dc : Cyclone diameter Di : Diameter of the entrance opening L : Hiydrocyclone length Q : Diameter of the entrance opening r : Radius of the orbit T : Time of residence in the hydrocyclone Vz : Axial velocity in the hydrocyclone Vt : Tangential velocity hydrocyclone Vr : Radial velocity in the hydrocyclone Ɋ : Dynamic Viscosity ɏs : Density of the solid ɏ: Density of the flow ȟP : Loss of pressure

According to Rietema

‫ۇ‬V Z ‫ۊ‬ ‫ ۈ‬V‫ۋ‬ ‫ ۉ‬t ‫ی‬

Is practically constant

When using a Reynold number for a specific cyclone, therefore this equation can be expressed using a number that characterizes a hydrocyclone which is C y50 . Page 14 de 40 5th Revision October 2003 Manual for the Operation and Maintenance of the CAVEX cyclone cluster



2 d 50 ȟɏ L ȟP ൌC y50 ൌ constant ɊɏQ

4.7 Crowding Theory Fahlstrom (1960) suggested that the classification efficiency of a hydrocyclone is determined by the probability that particles have to be discharged through the discharge opening (apex). According to this theory the process of separation in the hydrocyclone is not just a matter of movement "forced sedimentation" but also "forced download" through the apex. Accordingly, the cut size is defined by the ability of the discharge port and the size distribution of the feed. If the apex is only under the influence of centrifugal forces, the probability of a particle passing through the discharge opening is determined by its mass and density. The grosser and heavier particles have a greater chance of going through than smaller and lighter ones.. According to Fahlstrom this probability, should increase with the increase in the amount of solids in the feed, therefore the probability that a given particle can get out of the hydrocyclone through the apex decreases.

Diagram 16 Drawing of the forces that act inside the hydrocyclone.

Therefore, a material’s cut size is simply a way to get the solids back towards the outlet.

d 50c ൌ f ሺRs ሻ Where:

Rs = recovery of solids in the discharge.

4.8 Theory of Bi-Phase Turbulent Flow A common concern with this theory was its attempt to explain the influence of turbulence on the performance of a hydrocyclone. In 1951 Driessen attacked this problem, but it was not until Rietema, that the effect of turbulence on hydrocyclone efficiency was studied in detail . Rietema, explained this action by introducing the concept of turbulent diffusion acting on particles as if they were a homogeneously distributed substance. Therefore, differences in concentration are almost eliminated. The turbulence is commonly characterized by a parameter called "turbulent viscosity" which can be estimated with the help of tangential velocity.




According to Rietema the following dimensional formula describes the flow in a hydrocyclone:

Vr R ɉ' ൌ 0 ɂ Where: Vr0 : Radial velocity in the hydrocyclone wall.

R : Hydrocyclone radius ɂ : Turbulent viscosity. Describing the Navier-Stokes equations for different values, Rietema derived the theoretical profiles of tangential velocity in the hydrocyclone, assuming that the turbulent viscosity is independent of radial position and there is a specific relationship between the radial velocity and the radius. Recently there has been a great deal of research done in this area, including research done by Bloor and Ingham, Rietema, Schubert and Neesse, Duggeris, Percleous, Rhodes and others.

4.9 Numeric Modeling Hydrocyclone modeling from the perspective of fluid-dynamic principles is very attractive, because it opens a wide range of possibilities for simulation and design. For example it allows the study the effect of the shape of the hydrocyclone in great detail and furthermore allows for the quantification of the effects of changes in the properties of the pulp and operating conditions. However, the solution of the Navier-Stokes and / or the equations of the moment, even for the simplest cases involving a group of nonlinear partial differential equations often cannott be solved formally. Therefore, it requires the use of "Numerical Methods" to solve this problem. Models using this technique are classified in this chapter as "Numerical Models"

Diagram 17 Window that is used to adjust a grinding circuit, using JkSimMeT software.

The first attempt to describe the path of the particles in the hydrocyclone, is due to Kelsall who measured the velocity of the particles in the hydrocyclone rigorous technique using an optimal. Rietema resolved Navier Stokes equations in 1962, to get the tangential component in order to analyze the effect of turbulence on tangential velocity profiles.

Bloor and Inghan (1973) also solved the Navier-Stokes but under the assumption that the flow was ¢inviscid ¢ and the viscosity due to turbulence was negligible. Shubert and Nesse (1980) presented a solution that takes into account diffusion due to turbulence. Pericleous and Rhodes (1984) solved the Navier Stokes equations in two dimensions using a computer software and called Phoenics and predicted, successful Kellsall experiments . Hsieh and Rajamani (1988) achieved some success in predicting their own experimental measurements using the phenomenological model gave velocity profiles were measured using a speedometer Loser Doppler He-Ne.han.




The solution to the modeling of the hydrocyclone by solving the Navier-Stokes equations is complicated not only because the partial differential equations are nonlinear, but also because there are multiple phases within the hydrocyclone. There are usually three phases present in the hydrocyclone: solid, liquid and gas. There are also a range of particle sizes in many other industrial applications that have different densities. On the other hand, it requires a lot of information on the rheological properties of the pulp, which unfortunately change with changes in concentration of the suspensions. This information is usually ignored and / or easy assumptions are made. Finally, the migration of particles within the hydrocyclone body make local changes to the rheological properties of the pulp and sometimes create small eddies (localized turbulence) which makes the problem more complicated. Diagram 18 Profile of speed inside a hydrocyclone.

When Feniftoff, Plitt and Turak addressed this issue in 1987 they also added: "There can be no doubt respecting the potential of theoretical models, but these studies are in their beginning phases and time is needed before they have an significant impact on the practical applications of technology when modeling hydrocyclones. " To this date empirical models and / or semi-empirical are the only ones that have been used with some success in solving engineering problems in the area of design and / or modeling of hydrocyclones. There are a vast number of such models available in Reading material, some of which are separately summarized in four categories: ‫ ׏‬Flow models ‫ ׏‬Cut size models ‫ ׏‬Recovery of water and / or pulp models ‫ ׏‬Efficiency curve models.




4.10 Operation Variables Operating variables are the external factors that may affect the cyclone performance. 4.10.1 Concentration of solids in the feed:

Diagram 19 Balance Flow Sheet Process, for conventional milling, using cyclone classifiers. JKSimMet.

Usually expressed as a percentage by weight of solid (abbreviated Cw), the proportion of solids in the feed has a substantial effect on the performance of a cyclone. In principle, a higher percentage of solids, the thicker the cut size (greater d50). For example, an increase in solids from 5% to 20% by volume, approximately double the value of the cutoff size of a cyclone. 4.10.2 Cyclone Pressure The pressure required for the correct operation of a cyclone varies depending on the size of the cyclone and the application for which it will be used. It is important that an accurate pressure sensor is located in the feed distributor or the supply pipe adjacent the entrance of the cyclone, in order to constantly indicate its operating pressure. The pressure detector should ideally read: Maintained, indicating a constant supply. Within the range of operation for which it was designed, usually 50 to 150 kPa depending on the application (7 - 22 psi). A change in the supply pressure will affect the performance of operation and the rate at| which the cyclone separates water. Generally the higher the pressure the finer the separation, also the value of the ratio of water will go down as well. 4.11 Variables of the Cyclone There are several variables in a cyclone and several options are available for each dimensional cyclone model including the following:

4.11.1 Diameter of Entry

Diagram 20 The figure represents the diameter of the area that has the entrance to the cyclone.

The entrance section is rectangular and is an integral part of the feeding chamber lining. The area of the rectangular section is equivalent to the area of a circle whose diameter is known as "equivalent diameter" entrance and denotes the size of the entrance. Some CAVEX models have a wide range of sizes to choose from, according to performance and capacity needed.




4.11.2 Diameter of the vortex finder pipe There are a variety of sizes available for each cyclone model. The size of the vortex finder has the greatest effect on the cyclone’s performance, the smaller it is, the finer the classification as well as lessening the cyclone’s capacity.

Table 2 Changes in the variables of operation and design of a regular hydrocyclone Increased variable on the left, shows the reaction of the horizontal variables.

4.11.3 Spigot Diameter The diameter of the spigot is generally the variable that is more convenient to adjust or change and can be regarded as "tuning" once the cyclone is installed. The diameter of the spigot has the most important effect on the density of the cyclone’s discharge. Generally, a decrease in the diameter of the spigot increases density and improves the efficiency of the discharge classification. However, note that the diameter of the spigot cannot be reduced to a condition prevailing cordon. This would indicate that the spigot is overloaded and that the volume of solids in the discharge is too high and therefore requires a larger diameter. Diagram 21 Outline of the correct operation of the hydrocyclone, with respect to the diameter of the apex and density of the pulp fed to cyclone.




5.

INSTALATION REQUIREMENTS

5.1 General The cyclone should be fixed using the mounting plate or mounting feet provided. Charges should not be applied outside the cyclone. The cyclone should be installed so as to provide access for maintenance, especially for the maintenance of the spigot. - DMC components (fiber reinforced polymer) of the cyclone body are not suitable for to be cut using oxyacetylene or any form of welding Cyclones are often installed with their axis facing vertically up. The capacity of a cyclone is affected when its inclination is greater than 45 ° measured from a vertical angle. For a horizontally inclined cyclone or cyclones, a minimum angle of 10 ° -15 ° is recommended from the horizontal and the axis of the cyclone, depending on the angle of the cone. To ensure that the storm drains by itself once the power is cut a minimum angle of 5 ° is recommended. 5.2 Feeding Pump Most cyclones are fed through a centrifugal pump connected to a drawer or a drawer pond which is high enough to be manipulated by gravity. The pump and the drawer should be designed to deliver a constant flow of pulp to maintain the pressure the cyclone needs. Fluctuations in the power of the cyclone will affect its performance.

5.3 Piping for the cyclone’s feeding The cyclone feed pipe must have the same diameter as the rim of the cyclone (or the corresponding component supply). The length of the feed pipe must be at least 10 diameters worth of piping. It is not recommended to have more than 5 diameters worth of piping in front of the cyclone.

5.4 Control Valve

Diagram 22 Picture, the valve that controls the feed to the cyclones can be observed.

A cyclone’s control valve should be of the on-off type, such as a pulp gate valve (eg valve WEIR-VULCO knife valve) or a Galigher type pinch valve. The valves should not be used to throttle the flow to the cyclone, as the resulting turbulence will affect the efficient performance of the cyclone and quickly wear out the valves.




5.5 Pressure Indicator It is recommended to install a pressure gauge on the main power distributor or power of the cyclone, adjacent to the entrance (see Section 4.4). The most commonly selected stainless steel is 100mm in diameter, with a full deflection 0250kPa. A shield assembly such as a diaphragm indicator with a large diameter (50mm) is essential for the effective use of the indicator. 5.6 Overflow Piping Overflow pipes need to have the diameter of the cyclone overflow connection and should contain only large radius curves for directing the flow downward. Usually, the overflow pipe is short, discharging directly into a tank to a level between the cyclone and the spigot. If an overflow pipe is longer than required for installation, then a siphon breaker needs to be installed. Diagram 23 Overflow pipe that is commonly found in cyclone cluster. Note that some CAVEX ciclones models use overflow chambers.

NOTE: The overflow pipe should not be reduced in diameter or directed upwards as this will create back pressure and therefore significantly affect the performance of the cyclone.

5.7 Discharge The cyclone’s discharge must end up in a tank or a collector. No restrictive plumbing system should be attached to the spigot. The discharge tanks design should allow easy visual observation of the discharge spigot so that the plant operator is not limited when checking the condition of the discharge as well as in detecting any blockage. Access to change the spigot lining should also be considered. The point of impact of the discharge spray on the tank walls is subject to high abrasion wear and should be avoided by using suitable material or the use of a or CAVEX spigot discharge shirt or deflector to deflect the downward spray.

Diagram 24 Common wear found in a hydrocyclone. The photograph shows the Apex holder, discharge shirt, and underflow tank.

5.8 Cyclone Cluster If more than two cyclones are required in parallel circuit, then the cyclones should be installed in a radial configuration around a central distributor of feed to ensure the even distribution of flow for each cyclone.




These set ups are what are called cluster (nests) and are usually integrated using common overflow and discharge tanks. Separate piping may cause distribution to be uneven and therefore usually only considered for use in fine, very diluted pulp.

A Proper design of cluster is an important element in the successful operation of the multiple physical facilities of the cyclone. WEIR-VULCO can design the cyclone cluster to fit the specific requirements of each installation. Typically, cluster have four mounts or feet attached to the overflow tank, in which the load is distributed to the whole group. ‫ ׏‬No external load must be applied to any part of the cyclone cluster, other

than what was proposed for installation purposes. ‫ ׏‬Typically, all surfaces that come in contact with the pulp are covered with

elastomer or other material that is resistant to wear. The welding above the outer steel will damage the internal linings. Diagram 25 Cyclone cluster. In the picture the cyclones, the inside of the distributor, tanks, structure, etc. can be observed.




5.9 Storage Prior to Installation 5.9.1 Scope CAVEX cyclones are coated with elastomers that require protection for prolonged periods (months) from direct exposure to sunlight while in storage. Similarly, the rubber cyclone battery tank linings should always be protected from sunlight by tarpaulins or other protective covers. The following breakdown is for the storage guide for Vulcanized Rubber, according to the Chilean Official Standard NCh1837. 5.9.2 Temperature Storage temperature should be at most 25 ° C and preferably below 15 ° C. If exposed to temperatures above 25 ° C, can be certain forms of deterioration can be accelerated, which can affect longevity or life span

Diagram 27 This cartoon of the hydrocyclone, shows that it is sensitive to high temperatures, and direct sunshine affects the duration of the linings.










The sources of heat in the storage locations should be arranged so that the temperature of a stored item does not exceed 25 ° C. The effect of low temperature in storage units is not always harmful to vulcanized rubber articles, but the items may become more rigid when stored at low temperatures and precautions need to be taken to avoid deforming them while handling at these temperatures. When items are stored at low temperatures and are taken out of them for immediate use, their temperature must be elevated to approximately 30 ° C before putting them to use.

5.9.3 Humidity Moisture should be avoided; storage conditions must be such that no condensation occurs. 5.9.4 Light Vulcanized rubbers should be protected from light, especially from direct sunlight and strong artificial light with a high content of UV ultra violet rays. Unless items are packed in opaque containers, it is advisable to cover all windows of the storage warehouse with a coating of red or orange screens.

5.9.5 Oxygen, and Ozone Whenever possible, the vulcanized rubbers must be protected from circulating air by wrapping, storing them in airtight containers or by any appropriate means, and this applies especially to items that have a large surface area in respect to their volume, for example, waterproof fabric and cellular rubber. The storage unit must not have any equipment in it capable of producing ozone as fluorescent or mercury vapor, high voltage electrical equipment, electric motors or other equipment that could cause sparks or electric shock. Combustion gases and organic vapors should also be excluded because they can be converted into ozone by photochemistry.

5.9.6 Deformation Vulcanized rubbers need to be stored, in conditions that are free of any tension, compression or other deformation to the rubber; the rubber should be kept at a minimal value in order to avoid deformation because any deformation can lead to deterioration and permanent changes in shape. When items are kept in their original packaging in such they will not be likely be subject to any deformation. When the material is delivered in rolls, the binding strings need to be cut off, in order for tension to be released. If there are any further questions ask the manufacturer for advice.




5.9.7 Contact with Liquids and Semi-Solid Material or Their Vapors Vulcanized elastomers should not be placed in contact with liquid material or semi-solids, especially solvents, volatile oils and fats at any time during storage. 5.9.8 Contact with Metals

Diagram 28 This hydrocyclone cartoon shows that it is sensitive to chemicals, such as solvents, and volatile material as well as grease.

Certain metals especially copper and manganese, are harmful to vulcanized elastomers, therefore, they not be stored in contact with these metals, if soring them together cannot be avoided then they need to be separated using wraping made of a suitable material; for example paper or polyethylene. IMPORTANT: Laminated films should not be used for wrapping.

5.9.9 Contact with Powered Materials The most suitable materials are powdered chalk, talc and mica. These materials must not contain any constituent that has a harmful effect on the vulcanized rubber.




5.9.10 Contact with Different Types of Rubber Avoid contact between vulcanized rubber that have different compositions. This is especially applicable with different colored vulcanized rubber.

5.9.11 Items that with both Rubber/Metal Vulcanized rubber that is attached to metal should not come in contact with more than the place of union between them any protective material on the metal cannot have any harmful effects on the rubber. 5.9.12 Containers, Wrapping and Packaging Material The materials used for making containers and packing materials and lining must not contain substances that are harmful to vulcanized rubber such as copper naphthenate, creosote, etc. 5.9.13 Stock Rotation Vulcanized rubber should stay in storage for the shortest time possible. Diagram 29 This cartoon of the hydrocyclone, shows that it is advisable to rotate stock of spare parts, since the duration of these is limited.

Therefore, items need to leave the storage unit in a certain order, so that most recent arrivals are the ones that leaving storage after the older ones. 5.10.14 Cleaning Cleaning vulcanized rubber should be done with great care, cleaning them with soap and water has proven to be the gentlest. Do not use abrasive, sharp objects, or solvents such as trichlorethylene, carbon tetrachloride and hydrocarbons. Items that have just been cleaned should be dried at room temperature.




6. HYDROCYCLONE MANTENEANCE 6.1 Overview CAVEX cyclones are designed for industrial-heavy tasks, especially where heavy wear requires regular checking and replacement of wear liners. Typically, in-situ experience will determine the frequency in which certain parts of the cyclone will require replacement. For example, it is normal for the lining of the spigot to wear faster than the one in the cone. Similarly, in closed circuit grinding the heavy material can prematurely damage the feed chamber’s lining. Any unusual or excessive wear should be reported to your WEIR-VULCO representative for consultation on different alternatives or options available. 6.2 Lifting, Assembling / Disassembling Generally parts that belong to small cyclone models can be handled without machinery. Although at all times people should make sure they have the physical ability to lift the parts involved. Larger CAVEX cyclone models have heavier parts than the smaller ones do so they will require the assistance of machinery to do the lifting. For the inspection of or replacement of individual linings, partial disassembly can be done with a cyclone that has already been installed. To carry out a full inspection, or the replacement of a lining, the cyclone should be taken to a convenient working area. Cyclones can be lifted using a soft sling put around the supply chamber and under the entry duct, or through the eye bolt, or through the lifting loop provided. The assembly and disassembly is easier when the cyclone is upside down, sitting on its "head". Each section can then be removed easily, starting with the spigot casing above.

Picture 30 Picture shows the assembly of CAVEX cyclone model number, 650CVX13°.

A cyclone’s housings are secured by different sized hex head Bolts, or fast powered tongs (refer to Diagram Component for sizes). Only tighten the flange bolts enough so that the parts can be held firmly in place as indicated by the bolt torques table below.




Size of Screw Recommended Torque M10 10 Nm M12 17 Nm M16 42 Nm M24 150 Nm

Torque Limit 2 Nm 4 Nm 10 Nm 39 Nm

Table 3 The table shows the recommended torque for the cyclone’s screws, according to the size of the screw and limit. To be used with ruffs under the head and nut.

Table showing the torque limits that are recommended for the parts of the DMC cyclone, screws and are to be used without ruffs: Size of Screw Recommended Torque M10 10 Nm M12 14 Nm M16 22 Nm M24 97 Nm

Torque Limit 2 Nm 4 Nm 6 Nm 24 Nm

Table 4 The table shows the recommended torque for the cyclone’s screws, according to the size of the screw and limit. To be used without ruffs under the head and nut..

6.3 Housings The DMC requires little maintenance. If it gets a little damaged, such as a small piece that has cut through the lining, the damaged area can be filled with a polyester-based filler. Since DMC parts cost much less than steel, the repair is usually not covered by a warranty. Structurally damaged components should be replaced.

6.4 Linings Each of the housing’s parts has its own molded elastomer coating, rubber commonly a natural, which fits confortably within the housing. The coatings can be easily inspected by dismantling and removing segments of the housing. CAVEX cyclone liners require no adhesive or special tools for replacement. All parts are labeled and their position in the cyclone is easily found in its user manual diagrams. Diagram 31 Drawing shows the lining of the CAVEX feeding tanks.




When replacing liners, a good amount of hand cream will help put the mating faces in place. Warning: 1. Don’t use tools with Sharp edges. 2. Don’t use any kind of grease or oil. 6.5 The Vortex Finder Initially the vortex finder pipe can be inspected by removing the overflow chamber. A thorough inspection requires the vortex finder to be pulled away from the cyclone’s cover. Usually the vortex is set so that it may be easier to remove the cover which also houses the vortex finder. 6.6 Spigot The spigot’s lining is exposed to a higher amount of wear and should be checked regularly. A gauge can be inserted into the spigot’s lining, or the lining can be easily removed by undoing the spigot’s handle. To a large extent, the discharge density is controlled by the spigot’s inner diameter lining. Excessive wear will cause a low density discharge (refer to Section 4.5, the diameter of the spigot). 6.7 Cyclone Cluster Diagram 32 Picture, shows the lining of the CAVEX cyclone apex.

Routine maintenance that a cyclone battery needs is minimal. About six monthly inspections are enough as well as repainting any chipped paint. The outer part of the cluster that is made of steel may damage the inner liner. The repair of the battery’s linings depends on the type of material and should only be changed be someone who was trained in the process. Also the cyclone’s control valves need to be checked, especially the fit deflector cones.




6.8 Solutions to Common Problems Important: e Cut power to the cyclone before any work is preforme don the equipment. e Security procedures are always a priority. ISSUE Spigot isn’t discharging correctly

CAUSE Spigot is stuck. For example: A forgein object got stuck inside. The cyclone’s entrance is blocked. The lining came undone and the system clasped. Not enough feed provided.

Discharge is very dense or is in the shape of a string.

The density of the feed is too high. The spigot is too small.

SOLUTION Take spigot out and clean it. Take the entry part apart and clean that as well. Remove the lining and change it or refit it.

Reduce the density of the feed by adding water to the sump. Change the spigot for a bigger one. Discharge coming out Density of the feed is too low. Reduce the amount of of spigot is not dense The spigot is too big. water that was added to enough. the sump Change the spigot for a smaller one. Intermittent discharge Vortex finder has collapsed Change the vortex (lost stiffness) Insufficient finder from the overflow. power. Cyclone entrance is Reduce the number of blocked. The Lining is loose cyclones in operation and therefore collasped and / or increase the The vortex finder is blocked. volume of food. Take apart the matching supply and clean. Release lining and change or adjust. Take apart and clean. Pressure indicator Feed pump runs with shows steep changes insufficient food. in pressure.

Close the cyclones and add more water to the sump.




7. Assembling the Cyclone Cluster CAVEX cyclone cluster are relatively easy to assemble if you follow the instructions provide for each of its parts. The properly following the assembly diagrams can save time and avoid problems when moving large pieces.

7.1 Assembly Schematics Lo The assembly schematics, are intended to help in the correct assembly of the CAVEX cyclone cluster. Please refer to assembly drawings in section 10 in this manual. 7.1.1 What are Assembly Schematics An assembly schematic, it is an exploded drawing of the position each of the pieces that forms a cyclone cluster, in addition to its weight and volume. It is designed in order to be able to follow the sequence outlined by the axes, so that each piece is can be put in the right place, avoiding the risk of having to redo the machine, considering that some of these pieces are very large. Each piece is properly labeled with a number.

Diagram 33 Conventional cyclone cluster schematic. It shows the overall cutting set.




7.1.2 The Importance of Assembly Schematics Using a schematic on how to assemble a cyclone cluster makes identifying each part and where it goes easier and it also cuts back on time needed to figure out how to put it together.

7.1.3 Example of Assembly The following diagram gives the correct order of assembly, based on a common example on how to assemble a medium sized cluster.

Diagram 34 Schematic on how to put a cyclone battery together, the axes indicate where to put on part in terms of another.




7.1.3.1 First Step, the Assembly of the Legs First you must assemble the lower section of the equipment. In order to do this the middle structure (5.1) needs to be on the underflow tank (8), but first make sure that the discharge is in the position given in the diagram in relation to the foundation. Once it is stabilized it should to the height of the legs (5.2) in order to fit it into its final position. The next step is to put braces or tensions (5.3) that will allow for checking the legs wheelbase.

Diagram 35 Schematic on how to put a cyclone cluster together, it shows the main structure on which the underflow tank is hung.

7.1.3.2 Second step, assembling the second structure Secondly you must assemble the upper section of the structure, where you install the overflow tank. Note that the position of the overflows exit pipe the structure that supports the cyclone has to be attached to the tank, while the main power to the battery is inserted into the overflow tank.

Diagram 36 Schematic on how to put a cyclone cluster together, it shows the intermediate structures, in which the building of the overflow tank can be seen, the railing, the stairs, and the piping the feeds the cluster




7.1.3.3 Third step, Assembling the Distributor and Cyclones The third step consists of putting together the upper section of the cyclone cluster, which consists of the distributor, valves and cyclones. Note the correct position of the cyclone, if eventually the battery has covered exits without cyclones.

Once the cyclone’s support is attached to the overflow tank, place the cyclone, attaching it to the cyclone’s mounting flange. Finally install the cyclone’s overflows.

S We recommend placing the distributor (3) on the supply pipe (7) with the valves (2) and feeding nipples (4) that have already been assembled.

Diagram 37 Schematic assembly of the cyclone cluster, shows the radial distributor, valve, pipe feed to the cyclone, cyclone overflow, note the Victaulic Brand joints. joints.

7.1.3.4 Fourth step, assembling the cluster floor Finally, the cyclone’s cluster floor is assembled (9), handrails (10) and flaps (17). We note that the floor is made up of radial parts such as Grating grills

Diagram 38 Schematic assembly of the cluster of cyclones, shows floor grates that make up the halls.




7.2

Precautions taken during assembly

There are only two very important precautions that need to be taken, and remembered when assembling a cyclone cluster:

Diagram 38 Diagram, shows a common cyclone cluster plant.

o

Check the position of the underflow and overflow tank exits, with respect to the supporting structure (beams).

o

Check the position and the steadiness of the cyclone, in respect to the support structure, the cyclones should fit between the beams. The same action should be taken in regards to the center of the cyclone in order to prevent it from tipping to one side of the structure.

7.2.1 Building Precautions In respect to to the construction of the cyclone cluster, there must be a visual inspection done on the different parts that make up the machine. o

Check the thicknesses of the linings, make sure that they are even, and that there are no protuberances or blowholes.

o

Check the quality of the welding make sure it is even, without any sign of slag, cracks or pores.

7.2.3 Safety Safety comes first when assembling this type of equipment, because of the size of a cyclone cluster, this job may be risky. The use of ropes and free fall precautions are essential. Diagram 39 Picture shows the building of a large CAVEX cyclone cluster, model 800CVX.

Caution: Rubber is highly inflammable; any application of excessive heat can lead to a tragedy of major proportions. Please make sure not to use welding or cutting tools containing fire or near anything containing elastomeric lining. 7.3

Transporting Large Pieces

The transportation of large parts is usually a problem that transportation companies solve. However, it is important to be aware of the problems that one can run into when assembling the equipment at the plant, for example: access, proximity to buildings, tunnels, etc.

Diagram 40 Photograph shows the transfer of a underflow tank that belongs to a larger cyclone cluster.




7.3.1 Dimensions of Larger Parts It is necessary to know the dimensions of larger parts, in order to make room for them, and to make sure that they can get to where they need to go in case there are narrow hallways. The largest parts of a cyclone’s cluster, which may exceed permitted limits are are in most cases:

Diagram 41 Photo shows cluster the transfer of a smaller cyclone cluster. In this case they are transported put together.

o

Underflow Tank.

o

Overflow Tank.

The rest of the parts, might be long, but aren’t as wide and have smaller diameters; there should be no problem when moving them.

7.3.2 Transport Drill It is always very useful to double check the size of large parts and the available Access of where they will be delivered and set up, taking into account the access, proximity to buildings, tunnels, etc. Setting up a route beforehand is very useful because it can show any dimensional problems that can be run into, such as: o o o o

width of bridges. bridges and tunnels proximity to electric wiring. width of tunnels.

There are cases in which the width of the bridge is too small for the machinery to go through; one option is to remove the railings while going over the bridge, for example.

Diagram 42 Schematic, shows the route used to transfer a large piece.




8 Getting Started At startup, it is necessary to double check some important factors having to do with a cyclone cluster. Checking the condition of the various parts, will allow for proper operation and of course a stable operation with optimal results. 8.1 Screw Tightening E First, you need to check that the screws are tight, according to the specifications in section 6.2 in this manual. If the tightness is correct, there should not be leaking connections. Eventually in some joints rubber-rubber closure may have small openings. The pulp operation, will allow for these openings to close, and seal any small leak. 8.2 Overall Performance Review As stated above, it is important to check the various parts of the cyclone cluster, given to verify in order to double check its proper operation prior to implementation. 8.2.1 Valves Shutoff valves are essential in the proper use of the cyclone cluster, since the correct shutoff will allow the cluster to operate without losing pressure or pulp, because of the cyclones that are not functioning at the time. We recommend checking the opening and closing of the valve, and seeing that the blade moves freely. It is necessary to check that the rubber is in good condition, without any cracks or burns. If the valves are triggered by air or hydraulically, it is advisable to double check this method and making sure that there are no air leaks in the lines going to the cylinder. 8.2.2 Pump Diagram 43 Photograph shows the valve for the pneumatically operated knife in a cyclones cluster .

As stated in Section 4.4, depending on the capacity of the pump and the power level of the tank to the pump, the correct flow and pressure is what is required for cyclones to reach desired performance. Both electrical and piping connections should be checked, as well as the proper rotation of the pump shaft, which is marked on the housing. 8.2.3 Maximum Limit Detectors In machinery where the parts are fundamental, it is important to verify that the position sensors or limit switches are marked indicating the status of these, such as: open and closed positions.




8.2.4 Control Panels With respect to the control panels, double check the proper electrical connections to the air actuated valves and tool connections. On the first go it is important to double check that the identification number on the control panel, corresponds to the number of the instrument in the cyclone cluster. The open – close drive is a good tool to use for this. 8.2.5 Visual Inspection A complete visual inspection is essential in the cluster pack. Double check that there are no foreign materials within the tanks especially after the assembly or any repair, double checking this will avoid the clogging of pipes and ducts. The condition that the linings are in that cover the cyclone cluster is essential to the life of equipment. Early detection of losses in the thickness of the linings, generates an enormous gain in time and repair costs. Checking the diameters of the Apex (spigot) and the cyclone’s vortex, is important to avoid having to fix things later, and is essential for the desired operation efficiency. Make sure that the manometer or the pressure sensor is assembled (if applicable). 8.3 Testing with Water The most common start-up test to be performed is the water test which is essential in determining the pressure, flow, and the charge distribution of cyclones, which will affect proper operation with pulp. The most important things to keep in mind will be mentioned below.

8.3.1 Pressure Surges A pressure surge is the sudden increase of water pressure which occurs inside the pipe.

Diagram 44 Picture, shows a cyclone when it is being tested with water.

A hydraulic pressure surge occurs in the pipe when a valve closes too quickly. The circulating water hits the closed valve and bounces back like a wave. This rebound continues until the water hits an impact point and the wave’s energy from the water is distributed more evenly in the piping system. The point of impact, which may be in the connection between two pipes or a piping system, causes a “loud” sound.




Note that valves are designed to function and withstand high pressure. This provides a safety margin against unexpected increases in pressure. However, pressure surges can damage valves, pipes and parts of the cluster, the improper tightening of screws, may cause the loosening of parts and the possible injury to people around the machine.

8.3.1.1 Recommendations for Controlling Pressure Surges. P To avoid pressure surges when testing the machine with water and in the operation itself, you should not abruptly close all valves that feed the cyclones. The use of air chambers minimizes this problem as well, although it doesn’t completely eliminate the risk to people and the equipment at risk.

8.3.1.2 Check that the Pump is Providing the Correct Flow and Pressure Needed. Double check that the pump is providing the correct flow and pressure, by double checking the instruments, pressure gauge, flow meter, engine power and revolutions per minute of the pump it is also a good idea to have the operating curve of the pump handy.

8.3.2 Checking Cyclones. Check that the cyclones are not obstructed and that visually that both the discharge and overflow have a similar spray and that the flow is constant and that there are no pressure pulses. Any impulse discharge flow may eventually mean a blockage in the cyclone, or operational problems of the pump. In circuits where the pump has an inverter sensor relative to the power level of the tank, you should check that the implementation is not scheduled to change sharply in a short period of time. 8.3.3 Checking Filters. When checking the machine with water, it is also a good time to check for any leaks, and if necessary, to tighten screws. As stated in 8.1 in some areas eventually rubber-rubber binding may be have little holes.




8.3.4 Checking Pressure and Number of Cyclones Check that the number of cyclones in operation corresponds to that of the pump and that it is providing the required pressure and flow needed to function.

8.3.5 Discharge Flow versus Pressure As pressure to the cyclones rises, it is necessary to check that the discharge the cyclone’s discharge flow decreases. When the cyclone’s pressure increases,the core diameter of air into the hydrocyclone increases as well, then the evacuation area through the apex is reduced. This tends to make the flow go through the cyclone’s overflow. When the pressure is such that the cyclone’s discharge flow is zero, this is what is called “critical pressure”.

Diagram 45 Image, shows the effect of the flow on the cyclone’s discharge as the pressure becomes higher in the cyclone.

9 Recomended Parts Recommended parts for the CAVEX cyclone cluster depend on the type of cluster with respect to a specific client. Refer to the annexed list of components and parts. E In the list of parts and components, each part will be found separately in the following categrories: o o o

Cyclones Valves Mills



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