The suction gas dryer requires periodic regeneration, which usually requires about 15% compressed air to blow off. When the rotary vane vacuum pump is used, the amount of compressed air blowing can be reduced from 15% to 5%, so that 10% more compressed air can be produced. It can be used in all industries that need a lot of compressed air, such as pulp mills, steel mills, chemical plants and glass production. This is the application of rotary vane vacuum pump in compressed air.
How is compressed air produced?
Compressed air is the air that is compressed by mechanical movement of air compressor to reduce volume and increase pressure. Compressed air is an important power source, which has the advantages of no pollution, clear and transparent, convenient transportation, no harmful performance and no fire risk. Therefore, it is widely used in all aspects of production enterprises, such as the operation of processing machinery, transmission and control of pneumatic valves, cylinder and controller, transmission medium or purge gas, etc. In order to obtain dry, dust-free, oil-free and meet the requirements of clean compressed air, it must be purified. The filter system can eliminate oil and dust, and the dryer can dehydrate water. These need to use the rotary vane vacuum pump.
Because the impurities such as solid, liquid and gas contained in compressed air have their own characteristics, it is impossible to achieve the purpose with a single equipment, so how can compressed air be dried and purified?
Compressed air drying method:
1. Adsorption drying method
The adsorption drying method is to use the adsorption capacity of adsorbent for water, such as silica gel, activated alumina and molecular sieve, which have strong adsorption capacity for water. The moisture absorption process of adsorbent is a physical change, so this kind of adsorption is characterized by regeneration, adsorption under high pressure and desorption under low pressure, namely pressure swing adsorption (PSA); it can also be adsorbed under normal pressure and regenerated when heated, namely, variable temperature adsorption (TSA); or it can be adsorbed under high pressure and normal temperature and desorbed under normal pressure and high temperature, namely, temperature and pressure swing adsorption (PTC). The drying degree of this kind of adsorption drying can reach – 70 ℃.
2. Freeze drying method
The freeze-drying method is to cool the compressed air by using the cooling capacity produced by the rotary vane vacuum pump drying, so that the compressed air can reach the dew point temperature corresponding to its pressure, so that the water in the compressed air can be analyzed to achieve the purpose of drying. The drying degree of this kind of drying method can reach – 23 ℃ under atmospheric pressure.
3. deliquescence drying method
Deliquescence dryer also uses the adsorption characteristics of adsorbent to water, but the deliquescence adsorbent becomes liquid after absorbing water, and the deliquescent adsorbent can not be regenerated, and will cause pollution to the environment. This method is also called chemical method. This kind of drying device can reach the dew point of – 38 ℃.
Working principle of rotary vane vacuum pump applied in compressed air
1. The compressed air containing dust, oil, rust, moisture and other harmful substances is carried into the primary filtration device of gaspure compressed air filter.
2. When the compressed air passes through the first stage tubular mesh filter element, it will produce coalescence effect, the larger particles will be adsorbed on the filter material, and the water will condense into larger water droplets.
3. When entering the separation chamber, the speed of compressed air slows down, which makes the particles gather again, and the water mist condenses on a honeycomb water collector again.
4. The water carrying the impurity particles flows to the drainage device along the bottom and is discharged through the automatic or electric drain valve.
5. More than 95% of the water drops, oil and large particles in the compressed air have been filtered by the first filter element, and the compressed air after the first filtering enters the second filter element.
6. When the compressed air passes through the fiber filter screen made of special cotton in the second stage, thousands of small vortices will be generated. At the same time, the compressed air will be accelerated dozens of times. The vortex center will be like a tornado, forming a vacuum state. In the first stage, the water droplets that have not been filtered out are vaporized, converted and filtered again. At the same time, the particles as small as 5 microns are completely filtered by the second stage filter screen eliminate.
7. After two-stage filtration, clean and dry compressed air without dust, rust, oil and water drops is achieved to ensure the normal operation of pneumatic equipment and extend the service life of pneumatic equipment.