Alfa Laval ALDEC 30 Operator's Manual
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Alfa Laval ALDEC 30 Operator's Manual

Alfa Laval ALDEC 30 Operator's Manual

Decanter centrifuge
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Alfa Laval
Alfa Laval
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Decanter Centrifuge
FRONT
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OPERATOR'S
MANUAL
OPERATION
SERVICE
MAINTENANCE
English EN

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Summary of Contents for Alfa Laval ALDEC 30

  • Page 1 Alfa Laval Alfa Laval Decanter Centrifuge FRONT English EN OPERATOR’S MANUAL OPERATION SERVICE MAINTENANCE...
  • Page 3 Decanter Centrifuge Data Sheet Decanter Specification, Type ALDEC 30 Machine No.: 5121559/60 Date of issue: 2008-05-05 Specification: 882012900-0 Process liquid: Min. 0°C (32°F) - max. 100°C (212°F) Max. density of compact wet cake at max. bowl speed: 1.2 kg/dm³ Bowl...
  • Page 4 Drives Power supply: 3 x 400 V / 50 Hz Gearbox, type: Planetary - 2-stage Gearbox, max. torque: 1.5 kNm Gearbox, ratio: 1:97.2 Back drive: Eddy Current Brake 132 Back drive parts: Operating main speed: 4400 rpm (IEC) Max. diff. speed and torque 39 rpm / 1.5 kNm (at operating speed): G-force at operating speed:...
  • Page 5 Alfa Laval Chapter Contents Page Safety Instructions 1.0-1 .............. Decanter Operating Principle 2.0-1 ........Main Drive ..................2.1-1 Back Drive ..................2.2-1 2.2.1 Eddy Current Brake ................2.2-2 contd... 0.0-1 EN910001.TOC+...

  • Page 6: Table Of Contents

    Alfa Laval Chapter Contents Page Operation and Routine Maintenance 3.1-1 ....Before First Start ................ 3.1-1 3.1.1 Noise and Vibrations ................ 3.1-2 Start/Stop procedures .............. 3.2-1 3.2.1 Inspect Bowl ..................3.2-1 3.2.2 Before Start ..................3.2-1 3.2.2.1 Checkpoints ..................3.2-1 3.2.2.2...
  • Page 7 Alfa Laval Chapter Contents Page Disassembling and Assembling 4.0-1 ........Rotating Assembly ..............4.1-1 4.1.1 Remove Bowl ..................4.1-1 4.1.2 Install Bowl ..................4.1-4 4.1.3 Remove Large End Hub ..............4.1-7 4.1.4 Install Large End Hub ..............4.1-7 4.1.5 Remove Small End Hub ..............
  • Page 9 The decanter delivered must not be used to separate flam- mable, toxic, corrosive, or radioactive process media without prior written approval from Alfa Laval. Read this manual and the Operator's Manual before at- tempting to install or operate the decanter equipment, and follow all recommendations.
  • Page 10 13. Do not attempt to use the decanter for any application or process material other than that stated on the original pur- chase documentation without first consulting Alfa Laval. 14. Follow all lubricating procedures and schedules. 15. Check periodically - at least once a year - for loose bolts on foundation and supporting structures, covers, hatches and pipe connections of decanter and motor.
  • Page 11 Alfa Laval Rev. 2005-05 21. If the decanter is fitted with a frequency inverter, make sure that the maximum possible frequency will not cause overspeeding of the decanter. At least two separate pro- tections against overspeed must be provided. See section 6.9.
  • Page 12 Alfa Laval. Failure to obtain this approval may result in failure of parts involved with possible serious damage to equipment, property, or personnel.
  • Page 13 Replace worn or damaged parts with only original Alfa Laval parts. Alfa Laval cannot be held responsible for any damage to property or for injury to persons if genuine parts are not used. Do not interchange bowl parts, since specific parts are bal- anced as a unit.
  • Page 14 If the process liquid or cleaning agents contain chlo- rides, check these bolts at least once a year and exchange them at least every three years. Contact Alfa Laval, if in doubt. Contact Alfa Laval regarding the repair or replacement of pit- ted bowl shells or other parts.
  • Page 15 Alfa Laval Rev. 1999-04 2 Decanter Operating Principle Figure 2.1 The feed enters the decanter at the intersection of the conical and the cylindrical part of the bowl through a central feed pipe in the hollow drive shaft. After leaving the feed pipe, the feed suspension is distributed into the rotating liquid in the bowl and smoothly accelerated to the full rotational speed.
  • Page 16 Alfa Laval Rev. 1999-04 Figure 2.2 Decanter with Baffle Disc The space in the cylindrical and conical parts of the bowl, with the baffle disc between them, act as two communicating ves- sels. The plate dams can be set to a smaller radius than that of the solids discharge (negative beach).
  • Page 17 Alfa Laval Rev. 2001-05 2.2 Main Drive The decanter is driven by an electric motor. The motor shaft carries a drive pulley, and motive power is transmitted through V-belts to the bowl pulley to drive the bowl. 2.2-1 NALL2101.EN0...
  • Page 19 Alfa Laval Rev. 2007-08 2.2 Back Drive The purpose of the back drive system is to make it possible to control the speed of the sunwheel shaft of the gearbox and consequently control the differential speed between bowl and conveyor.
  • Page 20 Alfa Laval Rev. 2007-08 2.2.1 Eddy Current Brake Figure 2.2.1 Key Features of ECB 1. Pinion Shaft 4. Poled Wheel Assembly 7. Magnetic Coil 10. Bowl Speed Sensor (when fitted) 2. Torque Tube 5. Stator 8. Tacho-generator 3. Flexible Coupling 6.
  • Page 21 Alfa Laval Rev. 2007-08 The minimum controllable speed of the rotor is in the order of 300 rpm, which represents approximately 90% of the fixed dif- ferential speed obtainable with the mechanical type of torque control, dependent upon the type of gearbox fitted.

  • Page 23: Operation And Routine Maintenance

    Alfa Laval Rev. 1994-01 4 Operation and Routine Maintenance 4.1 Before First Start ATTENTION Be sure the decanter has been properly lubricated according instruc- tions in section 3.8. If the decanter has been in stock for more than a few months, the grease in the main bearings might have stiffened, which makes it difficult to attain full speed.

  • Page 24: Noise And Vibrations

    Alfa Laval Rev. 1994-01 4.1.1 Noise and Vibrations In spite of the most accurate balancing a rotating body is al- ways slightly out of balance. As the bowl and the conveyor are two separately balanced units rotating at different speeds, the negligible unbalance of each unit will coincide, and a momen- tary increase of noise and vibration occurs in the machine.

  • Page 25: Start/Stop Procedures

    Alfa Laval Rev. 2000-03 3.2 Start/Stop procedures 3.2.1 Inspect Bowl A bowl which has not been cleaned, but left clogged by solids after operation must be cleaned before the decanter is restart- ed, because dried solids may cause severe unbalance and eventual generation of an overload condition.

  • Page 26: Start Decanter

    Alfa Laval Rev. 2000-03 3.2.3 Start Decanter Release EMERGENCY STOP (in most cases: pull out the EMERGENCY STOP knob - or turn it as indicated by arrows). Start the decanter motor. Wait 2-4 minutes for the decanter to attain full speed with star connected circuit before switching to delta connected circuit.

  • Page 27: Monitoring Operation

    Alfa Laval Rev. 2008-03 3.5 Monitoring Operation Make particularly sure that there is no increase in vibration. Check the surface temperature of the main bearing housings from time to time. A temperature rise may indicate a possible malfunction in the bearing.

  • Page 28: Causes Of Overload

    Alfa Laval Rev. 2008-03 3.5.1.1 Causes of Overload The causes of overload may be: • Too high throughput. • Too high feed concentration. • The properties of the solids (prestraining or grinding the process liquid before feeding it into the decanter may be necessary).

  • Page 29: Vibrations

    Alfa Laval Rev. 2008-03 3.5.2 Vibrations If excessive vibrations occur while the bowl rotates, stop the main motor immediately and supply liquid to soften the vi- brations. 3.5.2.1 Vibration Switch (Optional Equipment) To protect the decanter against damage due to heavy vibra-...
  • Page 30 Alfa Laval Rev. 2008-03 Robertshaw Vibration Switch (Fig. 3.5.1) Resetting This vibration switch is reset manually by pressing the reset button, see figure 3.5.1 below Adjusting To adjust this vibration switch to trip at the correct vibration level, proceed as follows: When the decanter is not operating, turn the adjusting screw clockwise until the vibraswitch trips.

  • Page 31: Cleaning Procedures

    Alfa Laval Rev. 2006-06 3.2 Cleaning Procedures Before starting a cleaning process, please note that the below procedure is not product specific and therefore is only intend- ed as a guide. Before the decanter is stopped, close the valve to the feed and raise the differential speed, if possible, in order to transport the last solids remains out of the bowl.

  • Page 32: Chemical Cleaning (Optional)

    Alfa Laval Rev. 2006-06 If item 3 and item 4 are not satisfactory, the decanter must be accelerated to operating speed again, and the proce- dure is repeated from item 1. If it is not possible to prop- erly clean the bowl according to the above procedure, the bowl must be disassembled and then cleaned.

  • Page 33: High Speed Cip

    Alfa Laval Rev. 2006-06 During the flushing, the piping, the inlet parts, the bowl's ex- terior and the casing of the decanter are cleaned. Cleaning of the bowl's exterior is done in connection with deceleration of the bowl, as both the main motor and the cleaning fluid con- tributes to slowing down the bowl rotation.
  • Page 34 Alfa Laval Rev. 2006-06 Low speed: In order to be able to run low speed CIP, it is a condition that the main motor is equipped with a frequency converter. Cleaning at low speed is executed with a bowl speed below 1 G at the bowl wall (see the bowl speeds in table 3.2.2).
  • Page 35 Note! Alfa Laval expects that storage, handling, cleaning and re- moval of the used CIP-fluids is executed in accordance with the legislation of the country concerned, in which the decanter is used.
  • Page 36 Alfa Laval Rev. 2006-06 3.2.2 High Speed CIP In the high speed phase the nozzles are activated in the casing at 3 bar, see the recommended flows in table 3.2.1. Sequence: (see diagram page 3.2-10) Step I, Flushing: Shut off the main motor and the feed. Redirect the by-pass sys-...
  • Page 37 Alfa Laval Rev. 2006-06 ATTENTION When the decanter rotates in opposite direction of the normal rota- tion, the solids are transported towards the small end and the solids outlet. This reversed rotation is especially important on decanters with paring disc in order to avoid solids from blocking the paring disc outlet.
  • Page 38 Alfa Laval Rev. 2006-06 Sequence: (see diagram page 3.2-10) Step V, Caustic soda: Now when the decanter runs backwards and the speed is be- low 1 G (see table 3.2.2 for speeds), hot caustic soda is added, which is sprayed through the feed tube and the radial hole of the feed tube.
  • Page 39 Alfa Laval Rev. 2006-06 Flushing with water will contribute to slow down the bowl. While the decanter decelerates the rotations, it is emptied for cleaning fluid. At the moment when the decanter’s bowl starts rotating at low speed, the rotation direction is changed back to negative rotations.
  • Page 40 Alfa Laval Rev. 2006-06 3.2-10 NALL3403.EN0...

  • Page 41: Performance Optimization

    Alfa Laval Rev. 1998-01 3.5 Performance Optimization The decanter can be adjusted to suit individual requirements by varying the following control parameters: Bowl Speed By varying the rotational speed of the bowl, the G-force can be adjusted to suit the application. The higher speed, the better separation.

  • Page 43: Main Drive

    Alfa Laval Rev. 2005-04 3.6 Main Drive ATTENTION Store spare V-belts in a dry and cool place. Never roll up the V-belts. Sharp bends will damage them. Before installing new belts, check the pulleys for wear, using, if necessary, a profile and groove gauge.

  • Page 45: Eddy Current Brake

    For this reason it is recommended to avoid their occur- rence near the brake if possible. If, however, exposing the brake to dust and/or oil mist proves inevitable, Alfa Laval rec- ommend that the brake be disassembled for cleaning once a year or more frequently as required.
  • Page 46 Alfa Laval Rev. 2005-04 Figure 3.8.1 1. Main Bearing Large End 2. Main Bearing, Small End contd... 3.8-0 N9103801.EN0...

  • Page 47: Lubrication

    Alfa Laval Rev. 2005-04 3.8 Lubrication (Fig. 3.8.1 shows where the lubricating nipples are located) The lubricants must be kept in a dry and cool location (15-20°C =59-68°F). The containers must be kept closed to prevent con- tamination of the lubricants by dust and moisture.
  • Page 48 Alfa Laval Rev. 2005-04 Figure 3.8.2 1. Main Bearing, Large End 2. Main Bearing, Small End 3. Conveyor Bearing, Large End 4. Conveyor Bearing, Small End 5. Discharge Opening, Large End 6. Discharge Opening, Small End 3.8-2 N9103801.EN0...

  • Page 49: Main Bearings

    Alfa Laval Rev. 2005-04 3.8.1 Main Bearings (Nipples 1 and 2 in Fig. 3.8.2) Always lubricate the main bearings while the decanter is run- ning, and preferably, just before stopping it for any prolonged period of time. This will ensure the best distribution of grease, which in its turn gives optimum lubrication condition and maximum protection against contamination of the bearings.

  • Page 50: Conveyor Bearings

    Alfa Laval Rev. 2005-04 3.8.2 Conveyor Bearings (Nipples 3 and 4 in Fig. 3.8.2) Lubricate the conveyor bearings with the decanter stopped and the power effectively disconnected from the main motor. Using the grease gun included in the standard decanter delivery, apply 40 g (1.4 oz) - 27 strokes - of grease to each...

  • Page 51: Gearbox

    Alfa Laval Rev. 2005-04 3.8.3 Gearbox (Fig. 3.8.3) Change the oil in the gearbox at the intervals given in table 3.9.1 ’Lubrication Table’. In the front face of the gearbox there are two plugs (drain plugs) screwed into two holes.

  • Page 53: Maintenance Tables

    Lubrication: In cases where no Alfa Laval lubricants are available, other types of lubricants acceptable by Alfa Laval may be used; refer to the table 3.9.2. The alternative lubricants are only to be used, if this does not result in an increased bearing temperature level.
  • Page 54 See table 3.9.1.1 See table 3.9.2 Bearings at each grease nipple*) †) first time. Check oil level Alfa Laval 61203671-10 (see section 3.8.3). Gearbox See table 3.9.1.1 2.9 litre (0.76 gallon) If necessary, add Statoil Mereta 320 oil.
  • Page 55 Alfa Laval Rev. 2006-08 Recommended Intervals for Maintenance Interval [hours] Item 8h Daily 24h Service Main Bearings Lubrication Product temperature < 60°C (140°F) 100 *) 300 *) Product temperature > 60°C (140°F) 50 *) 150 *) Conveyor Bearings Lubrication Product temperature < 60°C (140°F)
  • Page 56 ❑ Lubricants accepted by Alfa Laval Δ Lubricant accepted by Alfa Laval for sanitary decanters **) ATTENTION If changing from this grease type to another, it will be necessary to disassemble all bearings and remove old grease by washing the bear- ing itself in petrol or a similar detergent.

  • Page 57: Disassembling And Assembling

    Alfa Laval Rev. 2006-04 4 Disassembling and Assembling WARNING Do not make any disassembly/assembly operations on the decanter unless the main power is shut off, and the disconnected main switch is locked with a safety lock. Replacing parts To ensure trouble-free operation of the decanter, great care must be taken during replacement of parts: •...
  • Page 58 Always use the recommended special tools for removing, disassembling, assembling, and mounting the bowl. In case of negligence of this point, Alfa Laval accepts no liability for pos- sible damage to the parts. Alfa Laval supplies a variety of special tools and accesso- ries to facilitate maintenance of the decanter.
  • Page 59 Alfa Laval Rev. 2006-04 Spare Parts Kits Alfa Laval supplies three types of spare parts kits for the de- canter: The intermediate kit for main bearings and conveyor bearings, respectively, contain rubber parts for the main bear- ings and the conveyor bearings.
  • Page 60 Alfa Laval Rev. 2005-04 Figure 4.1.1 4.1-0 N9104101.EN0...

  • Page 61: Rotating Assembly

    Alfa Laval Rev. 2005-04 4.1 Rotating Assembly 4.1.1 Remove Bowl (Figs. 4.1.1, 4.1.2 and 4.1.3) WARNING Do under no circumstances loosen or remove the upper casing while the bowl is rotating. Remove the screws [1] holding the upper casing and open the casing.
  • Page 62 Alfa Laval Rev. 2005-04 Figure 4.1.2 4.1-2 N9104101.EN0...
  • Page 63 Alfa Laval Rev. 2005-04 Figure 4.1.3 Now remove the bowl assembly by means of the lifting sling as shown in Fig. 4.1.3. Carefully lift the bowl assembly off the lower casing and place it on a table or on two wooden trestles or the like.

  • Page 64: Install Bowl

    Alfa Laval Rev. 2005-04 4.1.2 Install Bowl (Figs. 4.1.1, 4.1.2 and 4.1.3) Place the lifting sling around the bowl as shown in Fig. 4.1.3. When installing the bowl, clean the pillow block contact sur- faces and the frame before lowering the bowl into place.
  • Page 65 Alfa Laval Rev. 2005-04 this page intentionally left blank 4.1-5 N9104101.EN0...
  • Page 66 Alfa Laval Rev. 2005-04 Figure 4.1.4 4.1-6 N9104101.EN0...

  • Page 67: Remove Large End Hub

    Alfa Laval Rev. 2005-04 4.1.3 Remove Large End Hub (Fig. 4.1.4) This procedure describes how to remove the large end hub with the gearbox assembled to it. For removal of the gearbox from the large end hub, see section 4.1.7.
  • Page 68 Alfa Laval Rev. 2005-04 Figure 4.1.5 4.1-8 N9104101.EN0...

  • Page 69: Remove Small End Hub

    Alfa Laval Rev. 2005-04 4.1.5 Remove Small End Hub (Fig. 4.1.5) Loosen the ten screws [12] and remove them. Loosen the six screws [A] and remove them. The hub can now be carefully pulled out. Use, if necessary, a plastic hammer on the edge of the hub to loosen it.

  • Page 70: Remove Gearbox

    Alfa Laval Rev. 2005-04 Figure 4.1.6 4.1.7 Remove Gearbox (Fig. 4.1.6) ATTENTION When removing or installing the gearbox, always suspend it from a hoist or the like to avoid excessive load to the splined shaft. Use the lifting sling* as shown in Figure 4.1.6.

  • Page 71: Install Gearbox

    Alfa Laval Rev. 2005-04 4.1.8 Install Gearbox (Figs. 4.1.6) Apply an ample amount of grease to the splined shaft and the splined hub in the conveyor. Push the gearbox assembly with splined shaft carefully into place. Rotate the sunwheel shaft a few turns, to make the splines engage.

  • Page 72: Fit New Wear Liners

    Alfa Laval Rev. 2005-04 Figure 4.1.7 4.1.9 Fit New Wear Liners (Fig. 4.1.7) When the small end hub has been demounted, it is possible to exchange the wear liners [1]. Do not expect to reuse the old wear liners after demounting as the material is very brittle and probably will break.
  • Page 73 Alfa Laval Rev. 2005-04 Mounting of new wear liners: Clean the surface for glue residues, and thoroughly clean all surfaces that are to be glued, on spokes and wear liners [1] with acetone. Apply Araldite 2014 zigzag-wise on the inner side of the wear liner [1].
  • Page 74 Alfa Laval Rev. 2006-08 Figure 4.2.1 4.2-0 N9104201.EN0...

  • Page 75: Main Bearings

    Alfa Laval Rev. 2006-08 4.2 Main Bearings (Fig. 4.2.1) 4.2.1 Disassemble Main Bearing Large End (Fig. 4.2.1) Prior to disassembling the large end main bearing, the gearbox must be removed according to instructions given in section 4.1.7. Remove the ten screws [6].

  • Page 76: Assemble Main Bearing Large End

    Alfa Laval Rev. 2006-08 4.2.2 Assemble Main Bearing Large End (Fig. 4.2.1) Insert the ball bearing [4] into the pillow block [3] and grease the balls. Fit the bearing cover [8] on the pillow block [3]. Insert the four screws [7] attaching the bearing cover [8] to the pillow block [3] and tighten them to a torque of 22 Nm (195 in- lbs).
  • Page 77 Alfa Laval Rev. 2006-08 this page intentionally left blank 4.2-3 N9104201.EN0...
  • Page 78 Alfa Laval Rev. 2006-08 Figure 4.2.3 4.2-4 N9104201.EN0...

  • Page 79: Disassemble The Main Bearing Small End

    Alfa Laval Rev. 2006-08 4.2.3 Disassemble the Main Bearing Small End (Fig. 4.2.3) Remove the eight screws [15]. Using two of them as jacking screws, pull off the V-belt pulley [12]. Place a standard two-armed puller as shown in Figure 4.2.4 and remove the complete bearing assembly, consisting of pil- low block [11], roller bearing [10], and bearing cover [13].

  • Page 80: Assemble Main Bearing Small End

    Alfa Laval Rev. 2006-08 4.2.4 Assemble Main Bearing Small End (Fig. 4.2.3) Fit the bearing cover [13] onto the pinion. Heat the roller bearing inner race [10] by means of an induc- tion heater or in an oven to approximately 80°C (175°F) and fit it onto the inner pinion;...
  • Page 81 Alfa Laval Rev. 2006-08 this page intentionally left blank 4.2-7 N9104201.EN0...
  • Page 82 Alfa Laval Rev. 2006-12 4.3y Figure 4.3.1 4.3-0 N9104301.en0...

  • Page 83: Conveyor Bearings

    Alfa Laval Rev. 2006-12 4.3 Conveyor Bearings (Fig. 4.3.1) 4.3.1 Disassemble Conveyor Bearing Large End Remove the large end hub according to instructions given in section 4.1.3. Remove the lock ring [4]. Remove the needle bearing inner race [3] by means of a stand- ard two-armed puller tool as shown in Figure 4.3.2.
  • Page 84 Alfa Laval Rev. 2006-12 Remove the snap ring ([2] in figure 4.3.1). Using the special puller* as shown in Figure 4.3.3, pull off the needle bearing outer race [3] . Alternative tool Figure 4.3.3 * For P/N, see Spare Parts Catalogue 4.3-2...

  • Page 85: Assemble Conveyor Bearing Large End

    Alfa Laval Rev. 2006-12 4.3.2 Assemble Conveyor Bearing Large End (Fig. 4.3.1) If the end flange [1] has been removed and disassembled, as- semble the parts in the following order: Fit the O-ring [7] in the end flange [1]. Fit the cover plate [9] and secure with the four screws [8].
  • Page 86 Alfa Laval Rev. 2006-12 Figure 4.3.4 4.3-4 N9104301.en0...

  • Page 87: Disassemble Conveyor Bearing Small End

    Alfa Laval Rev. 2006-12 4.3.3 Disassemble Conveyor Bearing Small End (Fig. 4.3.4) Remove the small end hub according to the instructions given in section 4.1.5. Remove the ten screws [14] and the ring [13]. Use a standard two-armed puller tool*, as shown in Fig.

  • Page 88: Assemble Conveyor Bearing Small End

    Alfa Laval Rev. 2006-12 4.3.4 Assemble Conveyor Bearing Small End (Fig. 4.3.4) Thoroughly clean the retaining ring [10] and insert the O-rings [102] and [103]. Grease the O-rings [102] and [103]. Place the retaining ring [10] on the conveyor pinion, and push it into place.

  • Page 89: Conveyor

    Alfa Laval Rev. 2005-04 4.4 Conveyor 4.4.1 Remove Conveyor from Bowl (Fig. 4.3.4) Remove the large end hub according to instructions given in section 4.1.3. Remove the small end hub according to instructions given in section 4.1.5. Carefully pull out the conveyor 4-500 mm by hand. Place a sling around the conveyor hub and connect the sling to a hoist.

  • Page 90: Insert Conveyor Into Bowl

    Alfa Laval Rev. 2005-04 4.4.2 Insert Conveyor into Bowl (Fig. 4.3.4) Place a sling around the conveyor hub and connect the sling to a hoist. Carefully insert the conveyor into the bowl until the sling hits the end of the bowl.
  • Page 91 Alfa Laval Rev. 2005-04 page intentionally left blank 4.4-3 N9104401.EN0...
  • Page 92 Alfa Laval Rev. 2005-04 Figure 4.5.1 4.5-0 N9104501.EN0...

  • Page 93: Main Drive

    Alfa Laval Rev. 2005-04 4.5 Main Drive This decanter can be equipped with a mechanical coupling, in order to reduce the starting current and avoid a star/delta re- lay. The motor should be connected in direct mode (delta cou- pled).
  • Page 94 Alfa Laval Rev. 2005-04 Figure 4.5.2 4.5-2 N9104501.EN0...

  • Page 95: Assemble Main Drive

    Alfa Laval Rev. 2005-04 4.5.2 Assemble Main Drive (Fig. 4.5.1) Fit the coupling onto the motor shaft. First install the snap ring [6] and the washer [7], then install the thrust plate* [26] by means of the centric screw [29]. Use the three M10x120 screws [28] to push the coupling in place on the shaft, and remove the centric screw [29].

  • Page 96: Tighten V-Belts

    Alfa Laval Rev. 2005-04 4.5.3 Tighten V-belts Using the tester illustrated in Figure 4.5.3 above, adjust the belt tension as follows: See how to hold the tension tester and choose one of the ways a, b, or c as shown in Figure 4.5.4.

  • Page 97: Disassemble Mechanical Coupling

    Alfa Laval Rev. 2005-04 Figure 4.5.5 For safe reading mark the spot of the upper side of the in- dicator with a thumbnail on the scale and then turn the tester sideways. Increase or decrease the belt tension depending on the measuring result until it is within the desired tension.

  • Page 98: Assemble Mechanical Coupling

    Alfa Laval Rev. 2005-04 4.5.5 Assemble Mechanical Coupling (Fig. 4.5.1) Fit the holders [10] onto the nave [9]. Fit the friction blocks [11] and secure with the screws [14]. Fit the ball bearings [5] and the ring [13], if it has been re- moved, and the snap ring [4].
  • Page 99 Alfa Laval Rev. 2005-04 this page intentionally left blank 4.5-7 N9104501.EN0...
  • Page 100 Alfa Laval Rev. 2005-04 Figure 4.6.1 4.6-0 N9104602.EN0...

  • Page 101: Disassemble Ecb/Vfd

    Alfa Laval Rev. 2005-04 4.6 Eddy Current Brake (ECB)/ Variable Frequency Drive (VFD) 4.6.1 Disassemble ECB/VFD (Fig. 4.6.1) Loosen the screw [9] and push the coupling part [B] onto the sunwheel shaft [A] of the gearbox so that the driving pins are free.

  • Page 103: Supplementary Documentation

    Alfa Laval Rev. 1994-09 5 Supplementary Documentation 5.0-0 NALL5001.EN0...
  • Page 105 Alfa Laval Differential Speed Control DSC2 English OPERATING INSTRUCTIONS...
  • Page 107 Alfa Laval Chapter Contents Page General Description ..............1-1 Installing a New DSC..............2-1 External Dimensions ..............2-1 Input Signals................. 2-1 Operation ..................3-1 Manual Mode................3-1 Automatic Mode ................3-2 Working Principle ............... 4-1 Torque Overload Protection ............5-1 Verification of Connections............

  • Page 109: General Description

    Alfa Laval Rev. 2006-11 1. General Description The purpose of the Differential Speed Controller (DSC) is to make it possible to optimize and monitor the operation of the decanter. This is achieved by making the differential speed between bowl and conveyor (Δn) automatically adjustable during op- eration, and by displaying and regulating the torque load on the conveyor.
  • Page 110 1: VFD back drive (Drive & Brake) for conventional planetary gearbox (VFD-Brake) 2: VFD for Alfa Laval Direct Drive gearbox (VFD-DD) Further information about the drive or backdrive system used on a particular machine can be found in the Decanter Opera- tors Manual.

  • Page 111: Installing A New Dsc

    Alfa Laval Rev. 2006-11 2. Installing A New DSC IMPORTANT! When installing a new DSC, make sure that the DIP switches on the rear have been set in accordance with table 5. W ARNING ! The ECB interface card is connected to high voltage and must...
  • Page 112 Alfa Laval Rev. 2006-11 Figure 1 DSC3.EN0...

  • Page 113: Operation

    Alfa Laval Rev. 2006-11 3. Operation (Figure 1) The DSC is operated by means of four “MODE”-keys and a pair of “UP/DOWN”-keys on the front panel (see fig. 1). The numeric display shows bowl speed (referred to as main speed on the panel) divided by 10, conveyor differential speed, con- veyor torque, and a setpoint.

  • Page 114: Automatic Mode

    Alfa Laval Rev. 2006-11 Automatic Mode The DSC has three automatic control modes, and it will auto- matically select the mode requiring the highest differential speed, depending on the torque. The three automatic control modes are as follows: Δ n-mode Constant differential speed.

  • Page 115: Working Principle

    Alfa Laval Rev. 2006-11 4. Working Principle (Figs. 1 and 2) Figure 2 Figure 1 above is a six-step illustration of how the DSC works when the solids load on the conveyor is varying. There is no momentary change in torque and differential speed on a change in the feed rate, and it may take several minutes before steady state conditions are reached.
  • Page 116 Alfa Laval Rev. 2006-11 When the feed rate is increased further, the differential speed and torque increases as before until the torque reaches the preset maximum value (MAX T). Then the DSC switches to T-mode, and the differential speed is in- creased further to keep the torque at the setpoint value.

  • Page 117: Torque Overload Protection

    Alfa Laval Rev. 2006-11 5. Torque Overload Protection To avoid problems of torque overload, the DSC setpoint for constant torque (max T) should be set in accordance with the gearbox type installed. See table 1. To avoid difficulties when turning on the feed, the setpoint for constant differential speed (min Δn) should not be set too low,...
  • Page 118 Alfa Laval Rev. 2006-11 Torque Alarms ECB & VFD, continuation... When the alarm condition is over, the display will stop blink- ing, and the internal relays will reset. The alarm code will con- tinue to be displayed until a key is pressed or a reset signal is received.

  • Page 119: Verification Of Connections

    Alfa Laval Rev. 2006-11 6. Verification of Connections At the initial startup of a new installation, the checks de- scribed below should be made according to the system used : VFD Direct Drive 1. Check direction of rotation of the sunwheel shaft.

  • Page 120: Vfd-Brake & Hydraulic Back Drives

    Alfa Laval Rev. 2006-11 Symptom : Possible Cause : Δn always equals bowl speed /gear ratio No signal from tacho generator or Brake unable to rotate Δn = --.- = out of range, N No signal from bowl speed sensor Bowl Δn higher than setpoint, Low torque (No feed) Torque too low to drive the brake...

  • Page 121: Special Functions

    Alfa Laval Rev. 2006-11 The two sensors are mounted side by side, and the first sensor encountered by the shaft when running in the same direction as the bowl should be the sensor for direction (Pin 16 on the DSC).

  • Page 122: D N Out Of Range

    Alfa Laval Rev. 2006-11 To enable inspection and/or modification of the setpoint which is not active, the DSC will alternate and display the oth- er setpoint whenever the Δn mode key is pressed. The DSC will always return to display the active setpoint when the keys have not been activated for app.

  • Page 123: Electrical Data

    Alfa Laval Rev. 2006-11 7. Electrical Data ELECTRICAL DATA Connector 25 pole male sub “D”-connector 24 VDC ± 10 % Use regulated power supply Power Supply 0 V normally connected to protective ground at supply Consumption: Max 0.2 Amp 0-50° C...
  • Page 124 Alfa Laval Rev. 2006-11 ELECTRICAL DATA Scaling of Analogue 4-20 mA Input Signals : Motor Torque : Planetary gearbox range : 0-20.4 Nm 2.5 kNm 0-36 3 kNm 0-71 3.5 kNm 0-40 6 kNm 0-36 10 kNm, i = 380...
  • Page 125 Alfa Laval Rev. 2006-11 ELECTRICAL DATA Pin Connections (25 Pole connector) : 1, 2 0 V Power & signal common 3, 4 24 VDC Power input Relay (Alarm or power off => contact open) 5, 6 ECB & VFD : Torque overload warning (PSH) Relay (Alarm or power off =>...
  • Page 126 Alfa Laval Rev. 2006-11 ELECTRICAL DATA ECB Interface Card 12 pole with screw terminals Connector Weidmüller type BLA 12 SN OR Power Supply 187-264 V 50-60 Hz Tacho Input Resistance 7.8 kohm max 200 V Output max 4.5 Amp 90 V...

  • Page 127: The Rear Of The Dsc

    Alfa Laval Rev. 2006-11 The Rear of the DSC (Fig. 1) Figure 1 1. DIP-switches (SW-1 to SW-8) 3. Pin connections (25 pole) 2. Serial I/O (RS 485) 4. EPROM DSC7.EN0...

  • Page 128: Setting Of Dip-Switches

    Alfa Laval Rev. 2006-11 Setting of DIP-switches In order to calculate the correct torque and differential speed the DIP-switches [Fig. 1, Pos. 1] must be set according to table 4: Gearbox Switch Setting Back Drive Size Ratio SW-6 SW-5 SW-4 SW-3 SW-2 SW-1 2.5 kNm...
  • Page 129 Alfa Laval Rev. 2006-11 SW-7 :Modifies the scaling of the bowl speed signal (see table 2). SW-8 :Normally set to 0 = Off : Only one Δn setpoint. If set to 1 = On : Two Δn setpoints (Special Δn for start-up).

  • Page 131: Regulator Parameters

    Alfa Laval Rev. 2006-11 8. Regulator Parameters When power to the DSC is turned on, all reg- The active parameter value is modified by us- ulator parameters are initialized to the stand- ing the Up/Down keys. ard values, which should normally always be Δ...

  • Page 133: Dsc Remote Setpoints

    Alfa Laval Rev. 2006-11 9 . DSC Remote Setpoints Software version 5.64 or later Δ This software version enables modification of the setpoints for differential speed ( ) and conveyor torque (T ) with a remote 4-20 mA signal. The 4-20 mA signal is connected on Pin 24 of the 25 pole connector.
  • Page 134 Alfa Laval Rev. 2006-11 Scaling of 4-20 mA signal (Pin 24) Δ Δ Δ Δ - 4 mA)/16mA, 0.5 RPM < < remote =Tx*(I - 4 mA)/16mA, 0.5 kNm < T < Tx remote Δ Back Drive Tx = Gearbox Size 2.5 kNm...

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