To describe standard operating procedure for breakdown rectification of centrifuge.
1.0 PURPOSE:
To describe standard operating procedure for breakdown rectification of centrifuge.
2.0 SCOPE:
The standard operating procedure describes in detail the method of breakdown rectification of the centrifuge.
3.0 RESPONSIBILITY:
The responsibility of breakdown rectification of centrifuge lies with the staff of rank not lower than the supervisor of maintenance department.
The responsibility of preparing, reviewing and approving the standard operating procedure lies with the Manager - Maintenance, Head of Production and Head of QAD respectively.
4.0 METHOD:
4.1 Failure of brakes:
4.1.1 The brake belt is fitted with brake liners which is below the cast Iron main base and connected to the brake handle. Initially the position of the brakes is to be adjusted, however in use the liner wears out and the positions should be adjusted from time to time.
4.1.2 Isolate the equipment electrically.
4.1.3 Check the gap between liners and drum when the brake is in engaged position.
4.1.4 If the gap is more and liners are not engaging on the drum, when the brake is applied and the thickness of the liners is found insufficient, readjust the brake spring by tightening the nut.
4.1.5 If the liners are wornout, loose the brake rod, open the spring. Take out the brake belt and change the brake liner as per SOP REPLACEMENT OF BREAKE LINERS OF CENTRIFUGE..
4.1.6 Place the liner belt in correct position on the brake drum.
4.1.7 Fix the spring to the rod.
4.1.8 Rotating the basket by hand, adjust the brake belt till it engages on the brake drum.
4.1.9 Ensure that the brake liner and brake drum are engaged properly.
4.1.10 Restore the power supply to the equipment, switch on the power supply and after a minute, switch off the power supply.
4.1.11 Apply the brakes slowly, check whether the brake is properly holding or not.
4.1.12 If necessary, the brake liner can further be adjusted by tightening the nut.
4.2 ABNORMAL SOUND AND VIBRATION:
4.2.1 Probable reasons are:
4.2.1.1 Uneven feeding of material.
4.2.1.1a Ensure that the rate of feeding of material is uniform.
4.2.1.2 If the cake formation in the basket is uneven follow the steps 4.2.1.2.1 to 4.2.1.2.5.
4.2.1.2.1 Switch off the centrifuge.
4.2.1.2.2 Open the centrifuge lid.
4.2.1.2.3 Adjust the cake which was formed using scoop.
4.2.1.2.4 Ensure that the material is uniformally distributed.
4.2.1.2.5 Close the centrifuge lid.
4.2.1.2.6 Switch-on the centrifuge.
4.2.1.3 DAMAGE OF BEARINGS:
4.2.1.3.1 Isolate the equipment electrically.
4.2.1.3.2 Loose the motor base bolts and pull the motor housing inwards and remove the belts.
4.2.1.3.3 Open the foundation bolts of the equipment, takeout the equipment from foundation and shift to the engineering workshop.
4.2.1.3.4 Place the equipment under a chain pulley block and open basket.
4.2.1.3.5 Slowly remove the basket by chain block.
4.2.1.3.6 Open the brake belt. Remove clutch unit from the shaft.
4.2.1.3.7 Remove the driven pulley from the shaft.
4.2.1.3.8 Remove the housing base bolts and nuts.
4.2.1.3.9 Remove the housing base completely with shaft, using chain pulley block.
4.2.1.3.10 Remove the shaft from the housing. Ensure that whenever hammering the shaft, one wooden piece must be kept on the end of the shaft.
4.2.1.3.11 Replace the bearings as per SOP REPLACEMENT OF BEARINGS OF PROCESS / UTILITIES / LABORATORY EQUIPMENT
.
4.2.1.3.12 Check the drive pulley bearings also.
4.2.1.3.13 If they are damaged replace as per SOP REPLACEMENT OF BEARINGS OF PROCESS / UTILITIES / LABORATORY EQUIPMENT.
4.2.1.3.14 Insert the shaft with bearings into the housing.
4.2.1.3.15 Fix the top and bottom covers of the housing.
4.2.1.3.16 Rotate shaft by hand. Ensure that it rotates freely.
4.2.1.3.17 Lift the housing along with the shaft using chain pulley block.
4.2.1.3.18 Place the housing in correct place.
4.2.1.3.19 Match the bolts.
4.2.1.3.20 Fix all the bolts and nuts.
4.2.1.3.21 Fix the clutch unit.
4.2.1.3.22 Fix the brake belt.
4.2.1.3.23 Fix the basket on the shaft using chain pully block.
4.2.1.3.24 Hammer the basket slowly on the cone by keeping a wooden block till the basket bottom sets in correct position.
4.2.1.3.25 Then lock the basket properly by tightening the lock nut.
4.2.1.3.26 Rotate the basket by hand. Apply brakes and check whether the brake is engaging or not.
4.2.1.3.27 Replace the V-belts as per SOP REPLACEMENT OF V-BELTS OF REACTORS, VACUUM PUMPS, COMPRESSORS, AIR COMPRESSORS, CENTRIFUGES, BLOWER ETC..
4.2.1.3.28 Shift the unit to the place of operation.
4.2.1.3.29 Place the centrifuge on the foundation and tighten the foundation bolts.
4.2.1.3.30 Restore the power supply to the equipment. Switch on the motor and ensure that the motor rotate in clockwise direction.
4.2.1.3.31 Run the machine for few minutes without load.
4.2.1.4 UNBALANCING OF BASKET:
4.2.1.4.1 The dynamic balancing of basket of centrifuge is to be done whenever required. Send the centrifuge basket for balancing as per SOP SENDING OUT EQUIPMENT FOR RECTIFICATION TO THE OUTSIDE AGENCY.
4.3 FAILURE OF CLUTCH:
The problem implecations of failure of clutch are
1) Equipment not attaining the required speed due to the clutch liners.
2) Abnormal sound from the clutch pulley due to the failure of bearings.
4.3.1 Failure of clutch liners.
4.3.1.1 Isolate the power supply to the equipment.
4.3.1.2 Remove the clutch pulley from the centrifuge motor.
4.3.1.3 Dismantle the clutch pulley.
4.3.1.4 Replace the clutch liners with new liners of same length and width.
4.3.1.5 Lubricate the bearings and assemble the clutch pulley.
4.3.1.6 Fix the clutch pulley to the centrifuge motor and restore the power supply.
4.3.2 Failure of bearings.
4.3.2.1 Isolate the power supply to the equipment.
4.3.2.2 Remove the clutch pulley from the centrifuge motor.
4.3.2.3 Dismantle the clutch pulley.
4.3.2.4 Replacing the bearings and assemble the clutch pulley.
4.3.2.5 Fix the clutch pulley to the centrifuge motor and restore the power supply.
5.0 RECORDING:
Responsibility of recording of breakdown rectification in the history card as per SOP lies with a person of rank not lower than the maintenance engineer.
Rectification of centrifuge, engineering, isolate
