Generally speaking, the exhaust pressure is divided into: low pressure air compressor, exhaust pressure ≤ 1.0MPa; Medium pressure air compressor, 1.0MPa<discharge pressure ≤ 10Mpa; High pressure air compressor, 10MPa<discharge pressure ≤ 100MPa. High pressure air compressor is a safe and reliable supply system for breathing air and high pressure air, which compresses the air under free state, flows through the separator and filter in the unit, removes water, oil and impurities contained in the high pressure air, and makes the discharged gas clean and odorless. The gas quality meets the standard.

I、 Operating principle of high-pressure air compressor

High pressure air compressor is mainly composed of compressor host, driver (motor), interstage cooler, compressed air separation, purification and other processing devices, as well as pressure display, regulation and safety devices. When the drive machine drives the compressor through V-belt, the free air is drawn into the first stage cylinder through the intake filter, compressed to a certain pressure, and discharged into the first and second stage coolers and separators. After cooling and oil-gas separation, it enters the second stage cylinder, which is further compressed to a higher pressure, and then discharged into the second and third stage coolers and separators for cooling and filtering the oil and condensate in the compressed air, Then enter the third stage cylinder to compress to the final required pressure, and then enter the separator filter purifier to further remove the oil, condensate and oil vapor in the compressed air, so as to obtain cool, clean and odorless high-pressure air, which is filled into qualified high-pressure cylinders for use. The oil and condensate separated and filtered from the separator behind all cylinders are regularly discharged out of the machine or collected in the dirt tank through the drain valve.

II、 Operation process of high-pressure air compressor

The process of compressed air by high-pressure air compressor seems simple, but the whole process is uncontrollable, so each production step must be strictly controlled. The working process of high-pressure air compressor mainly includes the following steps:

1. The external air is sucked into the primary cylinder through the air filter and initially compressed to a certain pressure (low pressure);

2. The initially compressed pressure is discharged into the primary and secondary intercoolers and separators, and then enters the secondary cylinder after cooling and oil-gas separator.

3. It is compressed to a higher pressure (medium pressure) again, and then discharged to the second and third stage intercoolers and separators.

4. It is cooled and filtered again to further remove impurities such as oil and condensate in the compressed air.

5. It is discharged to the third stage cylinder for further compression (high pressure).

6. Enter the separator and filter purification equipment again, further remove the oil, condensate and oil vapor in the compressed air, and obtain the final clean and dry compressed air for relevant equipment.

From the whole work process, we know that the compressed air can be compressed and filtered three times at most in the medium and high pressure air compressor. Therefore, the compressed air after treatment is of very high pressure and quality, which is also a very important factor for selecting medium and high pressure air compressor in some occasions.

III、 Main components of high-pressure air compressor

We have a simple understanding of the main components of the high-pressure compressor.

1. Crankshaft and connecting rod components

The crank of the crankshaft is installed with connecting rod and rolling bearings at both ends of the crankshaft, and the big end of the crankshaft is installed with flywheel and connected with elastic coupling; a belt pulley is installed near the bearing at the small end to drive the cooling fan to rotate. The crankshaft is lubricated by the splashing of the lubricating rod of the connecting rod onto the crankshaft, piston pin and other parts.

2. Crankcase components

Both sides of the crankcase are equipped with side covers and oil windows for disassembly and inspection. The front section, namely the power coupling end, is equipped with bearing seats and front bearing caps. The fan bracket on the upper part of the rear bearing cap supports the fan components: the upper part is cast with a cylinder support plane that forms 90 ° with each other, the large side is equipped with primary cylinder and fourth cylinder components, the small side is equipped with secondary cylinder and third cylinder components, and the top surface is equipped with a respirator; the bottom of the crankcase is equipped with an oil pan, which contains special compressor oil.

3. Air inlet and exhaust valve components

The first and second stage air inlet valves and exhaust valves are of annular valve structure. There is a spring on the valve seat to support the annular valve plate. The valve plate and spring are made of imported high-quality materials. The third and fourth stages are 45 # steel air inlet and exhaust combined valves.

4. Cylinder components

There are first, second, third and fourth stage cylinder parts. The first, second, third and fourth stage cylinder heads are cast with many cooling fins to increase the heat dissipation area. The cylinder heads are respectively equipped with air inlet and exhaust valve parts, air inlet and exhaust pressure cylinders, and air inlet and exhaust glands.

5. Piston components

There are primary, secondary, tertiary and quaternary piston components. The primary piston is made of cast aluminum alloy, the secondary piston is made of cast iron, and the primary and secondary pistons are equipped with piston rings. The upper part is flat ring, the middle part is twisted ring, and the lower part is oil ring. The piston ring opening is staggered with the piston pin hole by more than 60 °, and each piston ring opening is staggered by 120 °. The third stage is equipped with 7 flat rings, and the fourth stage is equipped with 9 flat rings.

6. Cooler and fan components

It is divided into first, second and third stage coolers and aftercooling and cooling fans, which are connected between the first stage exhaust port and the second stage air inlet. The fourth stage is aftercooling. The stand is installed on the base, the upper part of the cooler is equipped with a safety valve, the lower part is equipped with a drain valve, the end toward the crankshaft is equipped with a wind guide cover and a protective cover, and the middle part is equipped with a suction type cooling fan. There is a fan bracket to install the fan components on the crankcase, and the crankshaft pulley at the end of the crankcase drives the fan to rotate through a V-belt.

IV、 Main applications of high pressure compressor

High pressure air compressor is a relatively small category product, which is mainly used in some special occasions. To sum up, it can be divided into the following categories:

1. Aerospace industry

Wind tunnel test gas supply, ground air supply support equipment, pressure bearing and air tightness test platform supply, such as various valve tests, nitrogen pressurization and other occasions;

2. Automobile industry

It is used for air tightness test of products, such as brake caliper, brake hose, GIT gas assisted molding, nitrogen spring filling, test of various pressure sensors on automobiles, protective performance test of air bags, and occasions where high-pressure air is required to pop out the frame and dummy instantaneously;

3. Petrochemical industry

Air passivation of urea reactor, nitrogen pressurization storage, nitrogen purging, nitrogen covering explosion-proof, pneumatic valve control in case of power failure, with the help of small volume and large storage volume of high-pressure gas, volume expansion in powder product production, breathing air supply in plant emergency system and other fields;

4. Energy industry

Airbag filling, emergency generator startup, turbine blowing out/spraying and other occasions;

5. Food industry

Volume increase/foaming of powder products, nitrogen packaging, purging and stirring of food grade oil-free gas, high-pressure gas supply in special packaging process, etc;

6. Production/machinery factory

Pressure test of vessels, pipelines and valves, gas required by the test bench, and high-pressure gas are also required for metal thermoforming;

7. Defense industry

High pressure supply of pneumatic system, pure gas supply of infrared thermal imaging cooler, ground and ship gas support system, etc;

8. Scientific research institutions

Helium recovery, argon recovery, research and development of air powered vehicles, high-pressure air for engine test platforms and other occasions;

9. Shipbuilding industry and navy

High pressure air supply and breathing air supply for diesel engine startup, port base maintenance and testing;

10. Gas industry

Filling of helium and argon, rare gas recovery, pipeline tightness test after gas engineering installation, etc. Of course, the application of high-pressure gas is far more than that. For example, some support air cushions used for life saving need to be filled with high-pressure air; In some hydraulic systems, high-pressure gas is also required for the pressure buffer of the system.