The effect of using different air compressors in the same industry

People who are often in contact with air compressors should know the basic difference between a piston machine and a screw machine. They have obvious differences in structure, moving parts, operating parts, life span and performance. Today we will take a look at the piston machine in detail. The difference with the screw machine.

   1. The differences between the two structures are as follows:

   Piston air compressor: The crankshaft drives the piston to reciprocate, changing the cylinder volume for compression.

  Screw type air compressor: The yin and yang rotors run continuously, changing the cavity volume for compression.

  2. Specific differences in operation:

   Piston machine: The operating procedure is complicated, and multiple data needs to be recorded manually. Such as running time, there is still time for refueling, oil filter, air intake filter, oil and gas separator time, need specialized personnel to operate.

   Screw machine: Because of the complete computer control, it can automatically start and stop, load and unload on time after the next setting. Automatically record a variety of parameters, automatically record the use time of consumables and prompt for replacement, and can also manage the inspection of the air compressor station.

  3. Common problems of damage and repair:

Piston air compressor: due to uneven reciprocating motion, it wears quickly and needs to be replaced frequently. The cylinder needs to be removed for repair within a month, and many sealing rings are replaced accordingly. There are dozens of cylinder liner springs that need to be replaced. Each part has continuous operation of multiple pistons, piston rings, valve parts, crankshaft bushes, etc. Due to the large number of parts, especially the vulnerable parts, the failure rate is very high, and several maintenance personnel are usually required. The replacement of consumables requires more than one person to complete, and the machine room needs to be equipped with lifting equipment, so the machine room cannot be clean without oil leakage.

  Screw air compressor: Only a pair of ordinary bearings need to be replaced. Its life span is 20,000 hours. It is replaced once every three years during 24 hours and annual operation, and only two sealing rings are replaced at the same time. Only a pair of rotors run continuously, the failure rate is very low, and no maintenance personnel are required.

   4. System configuration:

   Piston air compressor: compressor + after cooler + high temperature type refrigeration dryer + three-stage oil filter + air storage tank + cooling tower + water pump + water valve

   Screw air compressor: compressor + air tank + primary oil filter + refrigeration dryer + secondary oil filter

  5. Performance:

Piston air compressor: Exhaust temperature: 120 degrees or more, high water content, need to be equipped with an after cooler, can be cooled to about 80 degrees (water content of 290 g/m3), need to be equipped with a large high temperature cooling Dry machine. Oil content: An oil-free machine has no oil lubrication in the cylinder, but the reciprocating motion will bring the lubricating oil in the crankcase into the cylinder. Generally, the exhaust oil content is above 25ppm, and oil-free piston engine manufacturers will recommend the installation of additional oil filters, which is based on this.

  Screw type air compressor: Exhaust temperature: less than 40 degrees, water content 51g/m3, 5 times lower than piston engine, general cold dryer is enough. Oil content: less than 3ppm, the low oil content makes the additional oil filter have a long life.

   6. Installation aspect:

   Piston air compressor: The piston has large reciprocating shock and vibration, it must have a cement foundation, system equipment, and installation workload. The vibration is large, and the noise is above 90 decibels. Generally, another noise reduction equipment and materials are required.

   Screw-type air compressor: The air-cooled machine only needs to be placed on the ground to work. The noise is 74 decibels, without noise reduction. It is easy to install and move.

  7. Consumable life:

   Piston air compressor: Lubricating oil: 2000 hours; Intake filter: 2000 hours

   screw air compressor: lubricating oil: 4000 hours; intake filter: 4000 hours

   8. Cooling method:

   Piston-type air compressor: generally cold water, additional cooling system is required, such as cooling tower, water pump, valve, which increases the complexity of the system, there is the possibility of water leakage, and it is inconvenient to clean the water-cooled heat exchanger.

  Screw air compressor: air-cooled, water-cooled, air-cooled is recommended, no additional investment, heat exchanger cleaning only with compressed air blowing.

   Carrying out such an analysis, everyone should have some understanding of these two types of air compressors. Piston and screw compressors are essentially different.