Centrifugal pump transfers drilling fluids for some solids control equipment, such as desander, desilter, jut mud mixer. They are indispensable equipment in drilling fluids purification system.

There are some processing methods for centrifugal pump breakdown resulting from various reasons when they are in the process of drilling fluids solids control.

1. Pump can not start or load too big.

(1) Prime mover or power is not normal. The solution is to check the power and prime mover.

(2) Pump is stuck. The solution is to use hand shaft coupling to check and, if necessary, to eliminate static and dynamic parts faults.

(3) Gland is packed too tightly. The solution is to relax packing.

(4) Discharge valve has not been closed. The solution is to close discharge valve and then restart.

(5) Balance pipe is not unobstructed. The solution is to dredge the balance pipe.

2. Pump does not drain.

(1) Insufficient irrigation pump ( or inner pump gas is not thoroughly exhausted ). The solution is to infuse pump.

(2) Wrong pump rotating direction. The solution is to check rotating direction.

(3) Pump rotating speed is too slow. The solution is check rotate speed, faster it.

(4) Mesh plugging, bottom valve is ineffective. The solution is  to check mesh and eliminate sundry.

(5) Smoke height is too high, or suction liquid tank occurs vacuum. The solution is to reduce suction height and check the pressure in absorption liquid tank.

3. Pump breaks after draining.

(1) Inhaled pipeline leaks. The solution is to check inhaled side pipe joints and packing box sealing.

(2) The filling pump, suction side gas is not over. The solution is asked to infuse pump. 

(3) Inhaled side was suddenly blocked by foreign bodies. The solution is stop the pump for handling foreign bodies.

(4) It inhales certain amount of gas. The solution is to check the suction whether it has vortex and submerged depth whether it is too shallow.

4. Insufficient Flow

(1) Same with 2( 1 ), 3( 1 ). The solution is to adopt corresponding measures.

(2) System static head increases. The solution is to check liquid height and the system pressure.

(3) Resistance losses increase. The solution is to check piping and check valve obstacles.

(4) Shell and impeller wear-resisting rim wear is too big. The solution is to change or repair wear-resisting ring and impeller.

(5) Other part leaks. The solution is to check shaft sealing etc parts.

(6) Pump impeller jams, wears and corrodes. The solution is to clean, check and replace.

5. Insufficient head

(1) Same with the 2 ( 1 ), ( 2 ), ( 3 ), ( 4 ) and 3( 1 ), 4 ( 6 ). The solution is to adopt corresponding measures.

(2) Reverse installation of impeller ( double suction wheel ). The solution is to check impeller.

(3) Liquid density and viscosity does not conform to design conditions. The solution is to check liquid physical properties. 

4) The operating flow is too big. The solution is to reduce flow.
 

6. Large power consumption in operation

(1) Impeller and wear-resisting ring, impeller and shell has friction. The solution is to check and repair.

(2) Same with 5(4). The solution is to reduce flow.

(3) Liquid density increases. The solution is to check liquid density.

(4) Gland is packed too tightly or unlubricated. The solution is to relax packing, check water pipe.

(5) Bearing is damaged. The solution is to check, repair or replace bearing.

(6) Rotate speed is too fast. The solution is to check driver and power.

(7) Pump shaft is bent. The solution is to correct shaft.

(8) Axial force balance device fails. The solution is to check balance hole and return pipe whether they are blocked.

(9) Couplings centering is bad or axial gap is too small. The solution is to check centering circumstance and adjust axial clearance.

7. Pump vibration or abnormal noise

(1) Same with 3 (4), 6 (5), (8), (9). The solution is to adopt corresponding measures.

(2) Vibration frequency is 0~40% of working rotate speed. Excessive bearing clearance, axle bush loose, oil has impurities, oily (viscosity and temperature) bad, because air or process liquid make oil foam, bad lubrication, bearing damage. The solution is to examine and adopt corresponding measures, such as adjusting bearing clearance to remove oil impurities, replace new oil.

(3) Vibration frequency is 60% ~ 100% working speed. Relevant bearing problem same with (2), or is sealed large clearance, protect circle become loose, sealing wear. The solution is to check, adjust or replace the seal.

(4) Vibration frequency is twice working speed. No centering, couplings loose, sealing device friction, shell deformation, bearing damage, supporting resonance, thrust bearing damage, shaft bending, poor coordination. The solution is to check, adopt corresponding measures, repair, adjust or change.

(5) Vibration frequency is many times of working speed. Pressure pulsation, no centering, shell deformation, sealed friction, supporting or fundamental resonance, pipe, machine is resonant, processing method is same with (4), strengthening basic or piping.

(6) Vibration frequency is very high. Axis friction, seal and bearing, inaccurate, bearing hitter, bad contraction cooperate, etc. Treatment is same with (4).

8. Bearing heating

(1) Bearing pad scrape grind doesn't meet requirement. The solution is to repair bearing pad or replacement.

(2) Bearing clearance is too small. The solution is to readjust bearing clearance or blow grind.

(3) Lubricant volume is insufficient, oily adverse. The solution is to increase oil or replace lubricating oil.

(4) Bearing assembly is bad. The solution is to check according to requirement and eliminate factors not up to scratch.

(5) Cooling water open circuit. The solution is to check and repair.

(6) Bearing wear or loose. The solution is to repair bearings or scrap. If loose, tighten relevant bolt.

(7) Pump shaft is bent. The solution is to correctional pump shaft.

(8) Swinging oil ring deformation, swinging oil ring cannot turn, without oily. The solution is to update jilt oil ring.

(9) Couplings centering is bad or axial gap is too small. The solution is to check centering circumstance and adjust axial clearance.

9. Shaft sealing heating

(1) Packing gland too tight or friction. The solution is to relax packing, check water pipe.

(2) Water seal ring and water sealing pipe dislocation. The solution is to re-examine alignment.

(3) Flushing, cooling is good. The solution is to check flush cooling cycle tube.

(4) Mechanical seal has broken down. The solution is to check mechanical seal.

10. Rotor moves a lot

(1) Improper operation, operating conditions from pump design conditions. Solutions: strict operation, making pump always works near the design conditions.

(2) Balance weak. The solution is to dredge balance pipe.

(3) Balanced disc and balance seat material don't meet requirement. The solution is to changing the material to meet the requirements of balanced disc and balanced seat.

11. Produce water hammer

(1) Because suddenly power off, causing system pressure fluctuations, appear eduction system negative pressure, and dissolved fluid bubble escaped makes pump or pipeline exist gas. The processing method is exhausting the gas.

(2) High pressure fluid column because suddenly power fail rapid flow backward, impact on pump export check valve plate. The processing method is the pump's unreasonable eduction system piping, pipeline accessories decorated undertake reform.

(3) Outlet piping valve closed too fast. The processing method is slowly close the valve.

KOSUN is a leader in China solids control industry with experience of more than 20 years, it main solids control equipment include the shale shaker, decanter centrifuge, desander, drilling fluid mud cleaner, desilter, vacuum degasser and complete solids control systems, etc.