What Is a Rotary Vane Compressor?

Rotary vane compressors are also called sliding vane machines and rotary vane machines. As its name implies, it is a compressor that realizes the compression of gas by rotating the blades, and finally realizes the conversion of mechanical energy into wind energy. It belongs to a type of positive displacement compressor.

There are two types of cylinders for rotary vane compressors: circular and oval. In a circular cylinder, the main axis of the rotor is offset from the center of the cylinder by a close distance, so that the rotor is closely abutted between the suction and exhaust holes on the inner surface of the cylinder. In an oval cylinder, the main axis of the rotor coincides with the center of the oval.

The blades on the rotor divide the cylinder into several spaces. When the main shaft drives the rotor to make one revolution, the volume of these spaces continuously changes, and the volume and temperature of the refrigerant vapor in these spaces also change. Rotary vane compressors do not have suction valves because the vanes perform the tasks of sucking and compressing refrigerant. If there are 2 blades, there will be 2 exhaust processes during one revolution of the main shaft. The more blades, the smaller the compressor's exhaust fluctuations.

As the third-generation compressor, the rotary vane compressor can be very small in volume and weight, easy to arrange in a narrow engine compartment, coupled with the advantages of low noise and vibration, and high volumetric efficiency. It is also used in automotive air conditioning systems. Get a certain application. However, the rotary vane compressor requires high processing accuracy and high manufacturing cost. ^[1]

1) The moving blade is ejected by centrifugal force and forms a compression chamber with the inner wall of the casing.

2) A precise amount of lubricant is injected into the first compression chamber through the pores.

3) A thin oil film is formed between the side of the blade and the inner cavity of the shell and between the inner cavity of the shell and the blade. ^[1]

(1) Under the condition of 1500 rpm, it can effectively generate large flow of compressed air.

(2) The load on the two bearing points is extremely small.

(3) (self-centering of the rotor) There is a total force to allow the rotor to move upwards to compensate for the bearing clearance. Bearing wear or failure has no effect on the compressor.

(4) Replacement of bearings is limited to local.

(5) Oil-free operation is allowed in emergency.

(6) The generated compressed air is absolutely pulseless.

(7) Bearing lubrication is separate.

(8) The floating ring seal, the lip seal of the rotating shaft and the oil collecting ring with the oil inlet ring constitute the three combinations of seals. ^[1]

The sliding blade machine has a pressure range of 2bar-10bar and a flow range of 0.8-100m ³ / min. Generally speaking, the technical requirements within this range can be satisfied by the sliding blade machine. Specific fields include: glass products industry, cement building materials industry , Chemical industry, petroleum and petrochemical industry, textile industry, fiberglass industry, lighting industry, etc. ^[1]

	Slider	Screw machine
Bearing	2, less load	4, heavy load
Rotor	1	2
Axial force	No axial force	With axial force
Rotating speed	Below 1500	Up to 5000 and above
transmission	Direct connection with low energy loss	Belt drive, high energy consumption
maintain	Fewer spare parts and lower costs	Many spare parts and expensive
life	Design life 100,000 hours	Design life 35,000 hours
Energy consumption	Low energy consumption and low power consumption	Large energy consumption and large power consumption

According to the principle and structure of the sliding blade machine, it is known that the wear part of the sliding blade machine is only lubricating oil, and the lubricating oil of the sliding blade machine is only ordinary lubricating oil, which is relatively cheap; as for the blade is not in contact with the inner wall (there is a lubricating film in the middle ), So the blade is not a wearing part, and the use cycle is very long, so the maintenance of the sliding blade machine is simple and does not require too much cost. ^[1]

1. The larger the bearing design of the sliding blade machine, the longer the bearing life, so the life of the machine is also longer;

2. The speed of the sliding blade machine is lower, so the energy consumption is lower, so its running cost is lower; while the screw machine's rotation speed is high (determined by the design principle), so its energy consumption is bound to be high.

3. The sliding blade machine's exit efficiency is higher (flow rate: plus or minus 5%), while the screw machine's out-of-factory efficiency is low (flow rate: plus or minus 20%); and with the use of prolonged time, The running sum is more perfect, and the screw machine will lose efficiency after running for a period of time, so the energy consumption of the sliding plate machine must be lower than that of the screw machine on the premise that the two have reached the same air output; The power consumption of the tablet machine is lower.

4. In terms of maintenance, the sliding blade machine requires almost no maintenance and has a long service life. Therefore, within a limited service life (such as 10 years), the maintenance cost is not much; and the screw machine has many spare parts. Lubricants are also special and require major repairs every few years, so maintenance costs are quite expensive.

Disadvantages: The purchase cost of the sliding blade machine is relatively high. At present, high-flow models (such as models above 20m ³ / min) have not been domestically produced, and they are not widely used in China. Everyone has a limited understanding of it. ^[1]

As a high-speed rotating working part, the air-conditioning compressor has a high probability of failure. Common faults include abnormal sounds, leaks, and non-operation.

(1) Abnormal sound. There are many reasons for compressor abnormal noise. For example, the electromagnetic clutch of the compressor is damaged, or the internal wear of the compressor is severe, and the lack of lubricating oil can produce abnormal noise.

(2) Leak. Refrigerant leakage is the most common problem in air conditioning systems. The location of the compressor leak is usually at the junction of the compressor and the high and low pressure pipes. It is usually troublesome to check because of the installation location. The internal pressure of the air conditioning system is very high. When the refrigerant leaks, the compressor lubricant will be lost, which will cause the air conditioning system to not work or the compressor to be poorly lubricated. The air conditioner compressor has a pressure relief protection valve. The pressure relief protection valve is usually a one-time use. After the system pressure is too high for pressure relief, the pressure relief protection valve should be replaced in time.

(3) Does not work. There are many reasons why the air conditioner compressor does not work, usually because of related circuit problems. The compressor can be preliminarily inspected for damage by directly supplying power to the electromagnetic clutch of the compressor. ^[1]