When producing and manufacturing freeze dryers, the compressor should be selected as such
1. In order to prevent the pressure in the front tank evaporator from rising due to the closing of the electromagnetic valve, the temperature adjustment effect is not guaranteed, and the technician adds a steam return pipe to the steam return line in front of the electromagnetic valve, and is connected to The two-stage compressed suction pipe of the refrigeration compressor proves that this treatment scheme is feasible through the practice on multiple freeze dryers. It can avoid the increase of the cost of adding the temperature control unit and solve the present problem. The commonly used capillary temperature regulation results in an unsatisfactory temperature regulation effect and a load shock to the compressor.
2. In order to meet the cooling capacity of the refrigeration compressor, add a cooling branch that can provide appropriate cooling capacity to the cooling system of the front of the refrigeration system to meet the cooling demand during temperature adjustment;
3. At the same time, due to the temperature adjustment, the refrigeration compressor supplies cooling to two evaporators with different evaporation temperatures. The difference in working conditions may cause a large impact on the refrigeration compressor due to the hysteresis of the expansion valve control. In severe cases, It will cause the liquid pressure of the refrigeration compressor to cause a failure, which requires a good grasp of the control of the return steam pressure. The technicians now add an electromagnetic valve to the steam return line of the front tank evaporator, and the electromagnetic valve is passed through the pressure controller. The monitoring of the differential pressure before and after to control the opening or closing of the valve reduces the load shock during the temperature adjustment to ensure the smooth operation of the compressor;
The choice of refrigeration system is very important for the quality of the freeze dryer, which is primarily the choice of compressor and evaporator. The refrigeration system can be said to be the core of the refrigerating dryer. When selecting the compressor, there will be a water-cooled refrigerating dryer, an air-cooled refrigerating dryer and an SMD refrigerating dryer.
Under normal circumstances, the water-cooled refrigerating dryer is mainly based on a fully enclosed compressor. Because the power of the fully enclosed compressor is small, the price is relatively cheap; the air-cooled refrigerating dryer generally adopts a semi-closed compressor; the air-cooled refrigerating dryer uses a semi-hermetic compressor, and when selected, ammonia can also be considered. Refrigeration compressors, because ammonia refrigeration compressors have high power and can be used in one machine, but installation and management are cumbersome.
In the selection of the evaporator of the refrigerating dryer, the high-temperature refrigerating dryer adopts the cooling fan as the evaporator, which is characterized by fast cooling speed, but it is easy to cause water loss of the cold collection; medium and low temperature refrigerating dryers are not used. The evaporation pipe made of the seam steel pipe is mainly composed of a constant temperature effect and can be stored in a timely manner. The refrigerating dryer plays a huge role in our factory equipment, especially for the industrial era of air compressors. The cold dryer has a good auxiliary equipment for the air compressor and has the post-processing function, which makes the air compressor efficiency. More perfect, give us a good working environment and work efficiency.