Air compressor after-treatment equipment is broadly divided into three categories, of which the most commonly used equipment is the gas storage tank, dryer (refrigerated and adsorption), filters and other three.
1, storage tanks:
Storage tanks are used to store compressed air; eliminate pressure fluctuations, buffer pressure, to ensure the continuity of the output airflow, because the air compressor discharge air pressure fluctuations, the addition of storage tanks, the use of compressed air compressed air pressure at the end of the more stable; regulate the amount of air or to prepare for the occurrence of failures and temporary needs of the emergency; to further separate the moisture and oil compressed air, air part of the water and oil. And oil, part of the water vapor in the air compressed by the compressor has formed liquid water droplets, these water droplets through the tank when most of the tank will be deposited in the bottom of the tank, the bottom of the tank has a drain valve, can be manually or automatically discharged.
2, dryer (refrigerated and adsorption)
Dryer is to further absorb and exclude the compressed air in the moisture, oil, so that it becomes dry air for the quality of the air source for higher requirements of the pneumatic instrumentation, injection components of the system used. At present, China's production and use of compressed air drying device mainly adsorption and freezing two kinds of adsorption is the silica gel, aluminum gel, molecular sieve adsorbent filling in two dryer, when the gas passes through the dryer, adsorption of desiccant will be milled down, so as to achieve the purpose of drying. The freezing type utilizes the form of Freon cooling to separate out the water in the air after condensing, so as to achieve the effect of drying (water removal). The adsorbent of the adsorption drying device needs to be regenerated after work, and the form of regeneration is divided into two kinds: heatless (self-heating) regeneration and heat regeneration. Heating regeneration is divided into external heating regeneration, internal heat regeneration, residual heat regeneration, micro-heat regeneration and other forms.
3, the filter
Filter to remove the compressed air oil, water and dust and other impurities. Different use of different occasions on the air source filtration requirements, the filter is divided into a primary filter, secondary filter and high efficiency filters. Primary filter, also known as simple filter, placed in the air pressure station after the dryer, commonly used filter, felt, silica gel, coke and other materials to play the role of adsorption filtration, its ash filtering efficiency of 50% to 70%. The secondary filter, also known as water filter, is the most widely used in pneumatic system, and its ash filtration efficiency is 70% to 90%. High-efficiency filters are precision water-splitting filters with small pore sizes, commonly used in pneumatic sensors and detection devices, etc. They are installed after the secondary filter as the third level of filtration, and their ash filtration efficiency reaches 99%.
Filter requirements:
1, the filter gas dust particle size, the maximum diameter of solid particles that can pass through the filter under the specified experimental conditions, expressed in um (micron).
2, filtered gas oil content, the unit volume of compressed air contained in the oil (including oil droplets, suspended particles, oil vapor) of the mass, converted to the absolute pressure of 1bar, the temperature of 20 ℃ and relative humidity 65% of the value of the standard atmospheric conditions. The residual oil content of compressed air after filtration is expressed in ppm, 1 ppm ≈ 1.2 mg/ m3 (mg/cubic meter).
Principles of selecting air compressor after-treatment equipment
1, the rated volume of air compressor and pressure values as the basis for selecting the purification system.
2, based on the inlet temperature, rated air volume, rated pressure value and ambient temperature, to determine the dryer power.
3, to dryness, that is, the dew point value of the high and low as the basis for selecting the configuration of what type of dryer.
4, to the oil content indicators, dust content indicators based on the high and low, choose to configure several levels of filtration, and determine the type of filter.
5, dew point, oil content, dust content indicators to determine the configuration of the pipeline, and the choice of pipeline materials.
6, in the environment of a large amount of dust in the workplace, to install the inlet filter to protect the air compressor and ensure the purification effect.
7, other process standards to comply with the "air compressor station design standards" of the corresponding provisions.
8, in the whole compressed air system, the setting of the storage tank plays an important role, the storage tank has a stabilized airflow, cooling, drainage, storage of gas, so, between the air compressor and drying and purification equipment, drying and purification equipment and the end of the point of air should be set up between the storage tank.
9, compressed air drying and purification process is mainly drying, filtration process, but also a process of decreasing temperature. Temperature plays an important role in purification, inlet temperature, ambient temperature directly affects the drying, purification effect.