Cleaning and replacement of screw compressor cooler

Cleaning and replacement of screw compressor cooler

Screw compressor is a relatively advanced and mature technology. Because it is controlled by an integrated circuit, it is more sensitive to faults. Even if a fault occurs, it can be detected in time by an alarm, so the general failure rate is relatively low. For example, if the temperature or pressure exceeds the standard, or other technical indicators that can be touched by the sensing system are abnormal, they will alarm in time, and in serious cases, they can automatically shut down in time.

The screw compressor is composed of three main systems: circuit system, oil circuit system and cooling system, each system has its own main function. The circuit system mainly plays the role of a rotating motor, and the circuit system is also a system that consumes a lot of power, so the compressor is called "electric tiger". The oil circuit system mainly lubricates the mechanical parts, and also has the function of oil and gas separation, so that the compressed air can be delivered to the user in a pure air state after the oil and gas separation. When the air participates in the compression, it will be squeezed by the high-speed rotation of the screw rotor, generating a large amount of heat, and the temperature of the compressed air and the equipment can be reduced through the cooling system. If the discharge temperature is too high and the compressor shuts down, it is often caused by a cooling system failure.

The cooling of air compressors can usually be divided into two ways: air cooling and water cooling. Air cooling is to let the high-temperature oil of the compressor flow through the cooler, and then the cooling fan works to reduce the temperature; water cooling is that the external cold water exchanges heat through the cooler to cool down. Air cooling has certain requirements on ambient temperature, while water cooling has certain requirements on water pressure, water quality and pipeline.

Cooler cleaning and replacement

The air compressor cooler should be cleaned in time after being used for a long time. When cleaning, it is necessary to wait for the air compressor equipment to stop and confirm that the pressure has been released, and then pull down the main power switch. Open the air hood to clear the cover, or remove the cooling fan. Use compressed air to blow back the dirt, and then take the dirt out of the air hood; if it is dirty, spray some degreaser before blowing. When the air compressor cooler cannot be cleaned by the above method, it needs to be removed, soaked or sprayed with cleaning fluid and cleaned with a brush.

The equipment of our company's second air compressor station has been running for seven years, and it has reached the stage of frequent accidents. The last few faults were all caused by the high exhaust temperature alarm of No. 1 engine. In order to completely solve this problem, after research at Station 2, it was decided to replace the air cooler of Unit 1.

The replacement of the fan cooler of the No. 1 unit belongs to the middle repair project. Since the middle repair project is not outsourced, it can only be repaired by the staff of the air compressor station. Disassemble while researching.

The general fan cooling machine is installed on the side, but the fan cooling machine of the No. 1 machine is installed on the ceiling of the body, and the disassembly and assembly operation can only be done by looking up. Because the body is smaller than the others, the internal space is very narrow, and it is very inconvenient to operate. , to the maintenance personnel to a certain degree of difficulty.

Oil cooler cleaning and replacement

In the process of compressing air by the screw compressor, without the participation of lubricating oil, the friction between steel and steel will not only produce a huge friction sound, but also wear due to friction. Therefore, when compressing air, there must be lubrication. Oil lubricates equipment. However, the mixture of oil and gas must be separated before it can be used normally. Therefore, after the gas is compressed, it must be separated by an oil and gas separator. The air after separation enters the air cooler from the upper part, and the oil enters the oil cooler through the lower part of the oil-air separator for cooling. The cooling process of the oil cooler is that the circulating water flows in the copper tube, and the oil runs in the shell, so that the oil is cooled by the low temperature effect of the water, so that the oil can reach the standard of normal operation.

In the era of piston compressors, the oil cooler was often dredged, because the circulating water was used for production and shared cooling water. After using the screw compressor, in order to improve the quality of cooling water, we separated the circulating water of the air compressor station from the cooling water system of other equipment, the maintenance of the cooler is much simpler, and the cooling effect of the compressor is much better than before.

However, after a long time of use, the bicarbonate substances such as calcium and magnesium in the cooling water of the air compressor will still form scale in it, which will increase the inlet and exhaust temperatures of the air compressor, and the air cannot be cooled to a predetermined temperature. cause high temperature failure. At this time, the cooler needs to be cleaned.

When cleaning the water-cooled cooler, after confirming the shutdown and pressure relief and power outage, disassemble the cooling water inlet and outlet pipes, inject the cleaning solution to soak or use the pump to circulate and flush (the recoil effect is better). When the scale of the oil cooler is serious and the above methods are not ideal for cleaning, you can remove the oil cooler separately, open the end caps at both ends, and use a special cleaning steel brush or other tools to remove the scale.

When only cleaning the cooling medium side cannot effectively reduce the temperature, it is necessary to clean the oil side. The general method is to first make a dilute hydrochloric acid solution, add 5-10 kg of hydrochloric acid to 100 kg of water, and place the dilute hydrochloric acid tank at the bottom of the cooler. The leather pipe to the small water pump, the water pump and the cleaned cooler channel form a loop circulation. After the water pump is started, use dilute hydrochloric acid solution for circulating cleaning, generally cleaning for about 6 hours. If cleaning in winter, the solution can be heated to 70-80 degrees to speed up the cleaning speed and improve the cleaning effect. After cleaning with dilute hydrochloric acid solution, remove the liquid, then rinse with clean water. In order to prevent acid corrosion, it can be washed with 5% soda solution for 10 minutes, rinsed with clean water, then dried with dry air or dehydrated with dehydrated oil. Of course, it can also be cleaned with professional cleaning agent, the effect will be better, please refer to its product introduction for specific methods.

After prolonged use and multiple cleanings, the oil cooler also has an aging problem, so it also needs to be replaced. Due to its position at the bottom of the device, the space is small, and it is difficult to disassemble and assemble, but it is not impossible to solve.