Lubricating oil is widely used in industry, electric power, mining, mechanical equipment and other fields. Many oil users will choose to purify the lubricating oil and reuse it from the perspective of cost and environmental protection. The purification devices mainly used are roughly divided into three categories: coalescence separation oil purifier, separation oil purifier and mechanical filtration oil purifier. Below, from the technical principle, application effect, dehydration capacity, operating parts The performance comparison of these three types of lubricating oil purification devices in terms of temperature requirements is expected to be helpful to oil consuming enterprises in selecting lubricating oil purifiers.

 

1. Technical principle

 

Coalescence separation oil purifier: particle filtration reaches above nas6 level (moog3 level) by pre filtration and fine filtration; Dehydration is achieved by coalescing into large droplets through coalescing filter element and sinking under the action of gravity, and then the oil is dehydrated through oil loving and water repellent separation filter element.

 

Centrifugal oil purifier: the centrifugal separator uses the centrifugal force generated by the drum with metal discs to separate water, particles and oil. Dehydration and particle accuracy are not very high, which is generally used when there is a large amount of water and impurities.

 

Mechanical filter oil purifier: use dry filter medium to absorb water in oil and filter particulate impurities in oil at the same time.

 

2. Use effect

 

Coalescence separation oil purifier: coalescence separation technology represents the development direction of turbine oil filtration due to its simplicity, effectiveness and reliable operation. It is adopted by more and more users and oil purifier manufacturers.

 

Centrifugal oil purifier: suitable for primary filtration or coarse filtration, with mechanical or vacuum fine filtration at the back; Or when there is a problem with the shaft seal and there is a lot of water in the oil. This technology is a traditional way, which is gradually being eliminated with the higher and higher purification requirements of the unit.

 

Mechanical filter oil purifier: the purification degree is higher than that of centrifugal filter, but the oil containing a large amount of water and impurities often needs centrifugal separator or other oil purifiers for rough filtration. Coupled with frequent replacement of filter media, it is generally no longer used.

 

3. Dehydration effect

 

Coalescence separation oil purifier: it can remove free water and break all emulsion structures in the medium.

 

Centrifugal oil purifier: it can only remove free water, not emulsified water. (emulsified water is an important reason for the reduction or even failure of turbine oil lubrication effect)

 

Mechanical oil purifier: it can remove part of free water and part of emulsified water

 

4. Running parts

 

Coalescence separation oil purifier: oil pump

 

Centrifugal oil purifier: oil pump, high-speed centrifuge and drive motor

 

Mechanical filter oil purifier: oil pump

 

5. Temperature requirements

 

Coalescence and separation oil purifier: the separation effect of water and particles is not affected by temperature, and can operate the same when the steam turbine is shut down or no-load.

 

Centrifugal oil purifier: the oil temperature is very critical to the separation effect of water and particles. Therefore, the temperature is required to be controlled within a very narrow range, and the heater is one of the necessary components

 

Mechanical oil purifier: in order to ensure the dehydration effect, the temperature of oil purifiering is generally required to be about 40 ℃.

 

6. Operation and maintenance

 

Coalescence and separation oil purifier: fully automatic operation, which can realize unattended operation. Except for the oil pump, there are no other rotating parts, with few fault points and very low power consumption. The maintenance cost is to replace the coalescing filter element every 6-24 months, which is only equivalent to the power consumption of centrifugal high-speed motor.

 

Centrifugal oil purifier: when the speed of high-speed motor and centrifuge is above 8000 rpm, it is prone to wear, material fatigue and lax sealing, resulting in oil leakage, shutdown and other faults. In case of failure, which cannot be repaired, it must be transported back to the original factory for disassembly. The power consumption of the centrifuge is generally more than 10kW. If the steam turbine is shut down or running without load, the heater must be turned on, which greatly increases the power consumption and the complexity of the system.

 

Mechanical oil purifier: simple structure; The filter medium is changed frequently and the work intensity is high; While adsorbing water, it also adsorbs a certain amount of oil, so it is necessary to replenish oil frequently in this way; There is often oil leakage.