The difference between centrifugal air compressor and screw air compressor!
Centrifuge and screw air compressor are currently the air compressors with a high market share. Today, I will tell you what are the differences between centrifuges and screw air compressors. I hope this article can help you.
The comparison of centrifugal and screw air compressors, namely their advantages and disadvantages, similarities and differences, and application occasions.
The basic principle of centrifugal air compressor:
Centrifugal air compressor is a machine that generates pressure and is a kind of turbo air compressor. Turbine is the English transliteration "TURBINE", that is, rotating impeller. In all low pressure air separation plants, centrifugal air compressors are widely used, and there is a trend of centrifugal air compressors replacing piston air compressors.
1 Centrifugal air compressor:
refers to the movement of gas in the air compressor along the radial direction perpendicular to the axis of the air compressor.
2 working principle:
means that during the rotation of the working wheel, due to the centrifugal force of rotation and the diffused flow in the working wheel, the pressure and speed of the gas are increased. Then the speed energy is further converted into pressure energy in the diffuser. It can increase the pressure of the gas.
3 Features:
Centrifugal air compressor is a speed type air compressor, compared with other air compressors:
advantages:
⑵High speed.
⑶ No lubrication is required inside the machine.
⑷ Good sealing effect, less leakage.
⑸ has a flat performance curve and a wide operating range.
⑹It is easy to realize automation and large-scale.
⑺ Few wearing parts, less maintenance, and long operation cycle.
Disadvantages:
⑴The adaptability of operation is poor, and the nature of the gas has a great influence on the operation performance. During the start-up, shutdown and operation of the unit, the load changes greatly.
⑵The air velocity is large, and the parts in the flow channel have a large friction loss.
⑶ There is surging phenomenon, which is extremely harmful to the machine.
4 Application scope:
Large and medium flow, medium and low pressure occasions.
5 categories:
⑴According to the type of shaft: single shaft multi-stage, several impellers connected in series on one shaft.
Two-shaft four-stage type, four impellers are cantilevered on both ends of two small gears, and the rotating* motor drives the small gears through the big gear.
⑵According to the type of cylinder: horizontal split type and vertical split type.
⑶ According to the type of cooling between stages:
External cooling, after each stage of compression, the gas exits the machine and enters the cooler.
In-machine cooling, the cooler and the casing are cast as a whole.
⑷ Classified by compression medium: air compressor, nitrogen compressor, oxygen compressor, etc.
Screw air compressor is a kind of positive displacement air compressor. The compression of air is achieved by the volume change of the tooth grooves of the female and male rotors which mesh in parallel with each other in the casing. The rotor pair rotates in the casing that is precisely matched with it, so that the gas between the rotor teeth continuously produces periodic volume changes and moves along the axis of the rotor from the suction side to the discharge side, completing suction, compression and exhaust. A working process.
Features of screw air compressor:
1) Screw air compressors are the same as piston air compressors, and both belong to positive displacement air compressors. In terms of the use effect, the screw air compressor has the following advantages.
2) High reliability. The screw air compressor has few parts and no wearing parts, so it runs reliably and has a long life.
Convenient operation and maintenance. The screw air compressor has a high degree of automation, and the operator does not need to go through long professional training, and can realize unattended operation.
3) Good power balance. The screw air compressor has no unbalanced inertial force, the machine can work smoothly and at high speed, and can realize no-base operation. It is especially suitable for mobile air compressors with small volume, light weight and less floor space.
4) Strong adaptability. The screw air compressor has the characteristics of forced air delivery. The volumetric flow is almost not affected by the exhaust pressure. It can maintain high efficiency in a wide range. It is suitable for a variety of industries without any changes in the structure of the air compressor. condition.
The main disadvantages of screw air compressor:
1) High cost. Because the rotor tooth surface of the screw air compressor is a spatial curved surface, it needs to be processed on expensive special equipment with special tools. In addition, there are also high requirements for the processing accuracy of the oil and gas barrels of the screw air compressor.
2) Cannot be applied to high pressure occasions. Due to the limitations of rotor stiffness and bearing life, screw air compressors can only be used in the medium and low pressure range, and the exhaust pressure generally does not exceed 3Mpa.
3) Not suitable for small displacement occasions. The screw air compressor relies on the gap sealing gas. At present, the screw air compressor has superior performance only when the volume flow rate is greater than 0.2M3/min.
