Problems and Treatment Process of Screw Air Compressor

As a commonly used power source in factories, air compressors mainly supply pneumatic valves, instruments, cylinders and other equipment to provide effective protection for the normal operation of production. However, the air compressor system often has some problems, and even seriously affect the production. In this paper, some common problems of screw air compressor system are analyzed and dealt with for reference.

1. air compressor system

for the quality of the air compressor, the International Organization for Standardization (ISO8573-1) stipulates the cleanliness level of solid particles, water and oil in the air compressor

common Problems and Treatment Measures of Screw Air Compressor System

1) System flow

the air compressor system is mainly composed of air compressor station and air compressor pipe network. In the cement plant, the process is generally: air compressor & rarr; buffer tank & rarr; pre-filter & rarr; dryer & rarr; post-filter & rarr; gas storage tank & rarr; gas pipeline & rarr; gas point. As shown in the figure:

2) Equipment selection

for the general manufacturing enterprises mostly choose oil injection screw air compressor, if the use of oil-free screw air compressor more environmentally friendly. The choice of the dryer should be based on the local temperature and the user's demand for the quality of the air compressor.

For the pre/post filter, it is mainly to remove impurities and oil in the gas to ensure the quality of the air compressor. The air storage tank plays the role of buffering and air storage of the air compressor to ensure the stability of the system, and its volume should be calculated according to the total air compressor volume.

Analysis of Common Problems in 2. Air Compressor System and Treatment Measures

some problems in the air compressor system are mostly caused by unreasonable design and debugging. The following is a combination of some common problems in the operation of the plant system, part of the reason analysis: 1) frequent start and stop of the air compressor

cause analysis (1): the air compressor operating parameters are set incorrectly.

Treatment: The operating parameters of the air compressor should be reset.

Cause analysis (2): check valve is set on the external outlet pipeline of air compressor equipment.

Treatment measures: the outlet check valve outside the air compressor equipment should be canceled.

Cause analysis (3): buffer tank volume is too small.

Treatment measures: the volume of the buffer tank should be increased, and the total volume of the buffer tank can be selected according to 1/8~1/6 of the total displacement of the air compressor.

2) Air compressor high temperature alarm

cause analysis (1): If it is water-cooled, it should be considered that the cooling water cooling effect is not good, whether the water is not enough, or caused by pipeline scaling.

Treatment measures: first use the water meter to judge whether the cooling water meets the requirements; by analyzing the water quality of the cooling water, judge whether the cooling water is in a state of easy scaling, and timely add chemical treatment to the cooling water system.

Control of the Leyer Stability Index (RSI) of cooling water

cause analysis (2): The indoor temperature of the air compressor station is too high, and the ventilation system of the station may be unreasonable.

Treatment measures: if it is a negative pressure system, the exhaust air volume should be increased. For the positive pressure system, check whether the inlet filter of the positive pressure fan is blocked, resulting in reduced efficiency.

Cause analysis (3): temperature control switch control valve may be damaged.

Treatment measures: replace the new temperature control switch control valve.

3) The air compressor is not loaded

cause analysis: The sealing strip of the cylinder piston of the unloading valve is worn, which leads to the lax sealing of the control gas circuit and cannot be loaded.

Treatment measures: replace the unloading valve cylinder sealing strip.

4) The oil circuit system of the air compressor is rusted and the rotor is stuck.

Cause analysis: It is preliminarily judged that after the lubricating oil is emulsified, condensed water is generated in the oil circuit system, and the machine is still running continuously. After the lubricating oil is emulsified, it will slowly become thinner at first, and the oil and gas separator cannot be separated. The lubricating oil will gradually be discharged with the air compressor, and the remaining oil will become less and less. At the same time, it will be mixed with rust stains on metal parts, and the oil quality will become muddy.

Treatment measures: in order to avoid emulsification of lubricating oil, it is necessary to ensure that the outlet temperature of the rotor is above 75 ℃ when the air compressor is loaded, and the loading ratio accounts for at least 1/3 of the running time. If the rotor outlet temperature is too low or the loading ratio is low, the supply of cooling water can be reduced to increase the oil temperature.

5) Water leakage of air compressor oil cooler

cause analysis: the cooling water system is corrosive to the copper pipe of the cooler.

Treatment measures: It is recommended to test the composition of the cooling water. If the cooling water contains elements that are corrosive to copper, the cooling water must be treated immediately, otherwise it will cause damage to the cooler. If necessary, consider replacing the stainless steel tube cooler with stronger corrosion resistance. Refer to GB/T50050- 2017 Code for Design of Industrial Circulating Cooling Water Treatment for the water quality index of circulating cooling water of intercooled open system.

6) Air compressor cylinder wall corrosion

cause analysis: the cooling water temperature is too low. Air compressor cooling water temperature is too low, resulting in some heated expansion parts because the temperature is too low caused by expansion is not in place. If the temperature of the air compressor cylinder is too low, it will cause water vapor to condense on the cylinder wall, and then mix with impurities and lubricating oil in the air to easily generate corrosive substances, which will strongly corrode the cylinder wall and cause the surface metal structure to be loose.

Treatment measures: the inlet temperature of the cooling water of the equipment should be appropriately increased to ensure the normal operation of the equipment.

7) Pipe network contains water

cause analysis (1): The dryer is not running normally.

Treatment measures: check whether the pressure dew point of the dryer reaches the set operating parameters.

Cause analysis (2): Condensed water exists in the buffer tank or gas storage tank.

Treatment measures: timely vent the condensed water in the buffer tank and gas storage tank. Generally, an electronic drain valve is set up in the buffer tank for regular drainage to ensure that a large amount of condensed water in the system is discharged in time, thereby reducing the load of the dryer. A mechanical automatic drain valve is provided in the gas tank.