In grain processing plant, the typical compressed air system is composed of compressor, dryer, coarse filter, air storage tank, fine filter and various pneumatic working machinery.
1. Air compressor Air compressor can be divided into piston air compressor, screw air compressor, centrifugal air compressor and scroll air compressor according to its working principle. The first two are widely used in the grain processing industry. The maximum displacement of piston air compressor is 3m3/0.7MPa, with a large energy consumption ratio, power saving and low manufacturing cost. It is popular with users, especially air-cooled piston air compressor is better than water-cooled. However, this type of air compressor is not satisfactory in terms of noise and vibration performance, and the maximum displacement is limited. Screw air compressor has high precision, low noise, no vibration, and a large displacement range. It is very suitable for large grain processing plants, but its cost is very high and requires special types of lubricating oil. To ensure the normal production of the factory, the system is usually equipped with two air compressors, one of which is spare.
2. Compressed air dryer for air compressor The exhaust temperature of air compressor is generally above 100℃, and moisture and oil gas are mixed with compressed air in gaseous state and output. Compressed air in high temperature state contains a lot of oil and water, which undoubtedly brings overload burden to air source purification equipment, seriously affecting the normal operation of pneumatic machinery, and it is necessary to increase the drying process. Dryers are divided into refrigerated compressed air dryers, heatless regenerative compressed air dryers, and heatless micro-air volume regenerative compressed air dryers. Heatless regenerative compressed air dryers have the characteristics of stable performance, low investment, convenient operation and maintenance, and its use requires a gas-liquid separator.
3. Air compressor gas tank The gas tank is used for the air compressor pulse airflow to stay in the tank for a period of time, so that the airflow becomes stable, and through the collision of the flow in the tank, it condenses into larger water droplets and deposits and removes them. At the same time, it is filtered through the high-efficiency foam net at the outlet to separate part of the water. The volume of the gas tank should be greater than 1/4 of the air compressor exhaust volume per minute.
4. Compressed air filter for air compressor The filter is used to filter out dust, moisture, oil and deodorization in compressed air. According to the filter parameters, it can be divided into 40u pre-filter, 3u oil filter, 0.03u, 0.01u precision filter, etc. Compressed air in grain processing plants is generally required to be filtered through 40, 3, 0.03, 0.01 and activated carbon filters. 5. Other equipment The diameter of the pneumatic control valve is greater than or equal to the size of the pipe fittings of the air inlet of the pneumatic working machine. Each branch of the network should be equipped with an exhaust valve to discharge condensed water.