How To Rebuild Cooling Tower Water Pump

The cooling tower water pump is an important component of industrial cooling systems, responsible for maintaining the flow of circulating water and ensuring stable and efficient heat exchange processes. With long-term operation, the water pump may experience issues such as decreased efficiency, increased vibration, and water leakage, requiring renovation or major repairs. This article will introduce the contents usually involved in the overhaul of cooling tower water pumps from several aspects, including principles, common causes of wear and tear, key points of renovation process, and daily maintenance.

Working principle of cooling tower pump

The majority of cooling towers use centrifugal pumps, and their basic principle is:

1) The high-speed rotation of the impeller generates centrifugal force

2) Throw the imported water towards the outer edge of the pump body

3) Create a pressure difference to promote continuous circulation of water flow

The system relies heavily on the geometric accuracy, lubrication, and sealing performance of components such as impellers, shaft seals, and bearings, and therefore requires timely maintenance after wear and tear.

Common wear and failure types of water pumps

Common issues with cooling tower water pumps include:

1.Aging or leakage of shaft seal

Impurities in water quality, high temperatures, or chemical treatment agents can accelerate shaft seal wear.

2.Bearing wear leads to noise and vibration

Long term operation or insufficient lubrication can cause bearing damage.

3.Impeller corrosion or scaling

The water quality is too hard and contains chemical agents, which will reduce the efficiency of the impeller.

4.Corrosion of pump body or scaling on inner wall

Affects flow and head.

5.Motor issues (such as current exceeding limits, insulation degradation)

Pump refurbishment (major overhaul) usually includes the following contents

1. Equipment initial inspection and shutdown preparation

Check operating indicators such as noise, vibration, flow rate, and current

Check for leaks, abnormal temperature rise, and other phenomena

2. Disassembly inspection and component status assessment

The wear condition of the following components is usually evaluated:

Impeller (whether corroded or deformed)

Shaft seal (mechanical seal or packing seal)

Bearings (clearance, wear, lubrication condition)

Pump shaft (whether bent or surface worn)

gasket

Scale formation on the inner wall of the pump casing

3. Component repair or replacement

Depending on the status, it may be possible to:

Cleaning, rust removal, and necessary replacement of impellers

Mechanical seal component update

Bearing replacement

Straighten or replace the pump shaft

Update of gaskets and vulnerable parts

4. Reassembly and Calibration

Calibrate the coaxiality, pump shaft and motor coupling

Ensure that the bearing clearance and sealing preload meet the equipment requirements

5. Trial operation and performance testing

1) Check if the vibration and noise are normal

2) Test whether the flow rate and head have been restored

3) Confirm no water leakage or abnormal temperature rise

Maintenance suggestions for extending the service life of cooling tower water pumps

1.Regular maintenance of lubrication system

Add or replace lubricating grease according to the manufacturer's requirements.

2.Maintain stable quality of circulating water

Reduce corrosion and scaling of impellers and pump bodies.

3.Regularly check the status of the shaft seal

Especially for mechanical seals, if dripping occurs, it needs to be dealt with early.

4.Monitoring vibration and temperature

Abnormal vibration may indicate potential issues with bearings, couplings, or pump shafts.

5.Avoid long-term low load operation

The efficiency of centrifugal pumps may decrease and may cause hydraulic vibration.