Is it better for the air compressor to have oil or no oil

Q: Is it better for an air compressor to have oil or no oil?

Answer: Firstly, we need to understand the application scenarios of oil and oil-free air compressors, and evaluate which one is better based on our own needs.

Oil injected air compressors are commonly used in environments with low gas requirements, such as pneumatic equipment, automotive maintenance, etc;

Oil free air compressors are commonly used in environments with high gas requirements, such as pharmaceuticals, electronics, chemicals, food, etc.

What are the compression methods for air compressors?

Q: What are the compression methods for air compressors?

Answer: Common compression methods for air compressors include screw type, which can be divided into dry screw air compressors, water lubricated screw air compressors, and oil injection screw air compressors; There is also a vortex type air compressor, commonly used in scenarios with low exhaust demand. The piston type air compressor is quite common, and it is used for car inflation and tire repair.

Regulations on the Quality Level of Compressed Air

According to GB/T13277-91, the quality of compressed air should meet the following requirements:

1. The dew point under working pressure is -40 ℃;

2. The dust particle size in the purified gas shall not exceed 1um, and the maximum mass concentration shall not exceed 1 mg/m3;

3. The maximum oil content shall not exceed 1 mg/m3.

Are air compressors and compressors the same thing?

Q: Are air compressors and compressors the same thing?

Answer: Air compressors and compressors are not the same product

Process compressors can compress various gas media, such as hydrogen, nitrogen, chlorine, oxygen, etc. Air compressors are mainly used to compress air, and they are used in many industries;

The application scope is even more widespread in industries and departments such as petroleum, chemical industry, metallurgy, power, machinery, light industry, textile, automotive manufacturing, electronics, food, medicine, biochemistry, scientific research, etc.

Compressor is a general term, and air compressor can be said to be a type of compressor. Air compressor is included in the compressor, and currently there are many types of compressors, including refrigerant compressor, hydrogen compressor, and air compressor.

Air compressors, also known as air compressors, are simply used to convert mechanical energy into pressure energy for operation. Air compressors are widely used in the power industry. In addition to being widely used in the power industry, they are also commonly used for cooling and separating gases, transporting gases, and other purposes.

What is the difference between a cold dryer and a vacuum dryer

Cold dryer is a method of dehumidifying by freezing, allowing water in compressed gas to condense into a liquid state and then discharge cooling water through a separator.

The suction dryer is based on the principle of pressure swing adsorption, which contacts the moisture in compressed gas with the desiccant through a certain pressure, causing most of the moisture to be adsorbed into the desiccant, achieving the purpose of water gas separation.

The cold dryer condenses water into liquid through cooling and then discharges it through an automatic drain. The loss of air volume during operation is negligible. The desiccant inside the suction dryer needs to be regenerated when it absorbs water to saturation, and there will be a certain loss of regeneration gas during the process.

Differences in water removal effects

The cold drying machine adopts a cooling principle. If the temperature is too low, internal icing may occur, causing ice blockage and affecting gas flow. Therefore, in general, the design dew point of the cold drying machine is between 2 and 10 ℃. The suction dryer uses a dryer that can perform deeper drying, with a designed dew point temperature below -20 ℃. So in terms of water removal effect, the suction dryer is better than the cold dryer.

Differences in energy consumption

The cold drying machine mainly achieves the purpose of removing water by cooling the refrigerant, with higher energy consumption. The vacuum dryer, on the other hand, uses a program inside the electric control box to control the valve, resulting in lower power consumption.

How to choose vortex and screw air compressors

Which is better, oil-free vortex air compressor or screw air compressor? Let’s first take a look at the disadvantages and then take a look at the advantages:

1、 Disadvantages of oil-free vortex air compressor:

(1) The surface of its moving parts is mostly curved, and the processing and inspection of these curved surfaces are relatively complex, some of which require specialized equipment, resulting in high manufacturing costs;

(2) The sealing between moving parts or between moving parts and fixed parts is often achieved by maintaining a certain movement gap, and gas leakage will inevitably occur through the gap. This limits the difficulty of achieving a high compression ratio for rotary compressors, so they are often used under air conditioning conditions;

(3) The screw air compressor is also a rotary displacement type machine, and the compression of air is achieved by the volume change of the teeth slots of the male and female rotors installed in parallel mesh within the casing.

2、 Advantages of oil-free vortex air compressor:

(1) The oil-free vortex air compressor belongs to volumetric rotary machinery, which utilizes the meshing of the vortex rotor and the vortex stator to form multiple compression chambers;

(2) There is no reciprocating motion mechanism, so the structure is simple, the volume is small, the weight is light, the parts are few (especially the vulnerable parts are few), and the reliability is high;

(3) Small torque variation, high balance, low vibration, smooth operation, making operation simple and easy to achieve automation;

(4) It has high efficiency within its applicable refrigeration capacity range;

(5) Low noise.

3、 Disadvantages of screw air compressors:

(1) The tooth surface of the rotor is a spatial curved surface that needs to be processed using specially designed cutting tools on expensive equipment. The machining accuracy of the body components also has high requirements, and high-precision equipment must be used.

(2) Due to the periodic connection between the volume between the teeth and the suction and exhaust ports, the compressor noise is relatively high.

(3) Due to limitations such as rotor stiffness and bearing life, the compressor can only rely on clearance sealing internally, so screw compressors can only be used in the medium and low pressure range and cannot be used in high-pressure situations.

(4) Due to the large amount of fuel injection and the complexity of the oil treatment system, there are many auxiliary equipment for the unit.

(5) Screw compressors rely on gap sealing gas seals and do not have superior performance in small volume ranges.

4、 Advantages of screw air compressor:

(1) The screw compressor is the same as the oil-free scroll air compressor, and both belong to the positive displacement compressor;

(2) High reliability: The screw compressor has fewer components and no vulnerable parts, so it operates reliably and has a long service life. The overhaul interval can reach 40000 to 80000 hours;

(3) Easy operation and maintenance: The screw compressor has a high degree of automation, and operators do not need to undergo long-term professional training to achieve unmanned operation;

(4) Good power balance: The screw compressor has no unbalanced inertia force, and the machine can work smoothly at high speed, achieving groundless operation. Especially suitable for mobile compressors, with small volume, light weight, and small footprint;

(5) Strong adaptability: Screw compressors have the characteristic of forced gas transmission, and the volumetric flow rate is almost unaffected by the exhaust pressure. It can maintain high efficiency within a wide range and is suitable for various working conditions without any changes to the compressor structure.