Guide About Freezer Air Dryers

Sep 14, 2024

1. What is a freeze dryer

The refrigerated dryer is a commonly used built-in dryer, which is compossed of an air storage cabinet and an air refrigerant storage cabinet. The locker removes the water from the compressed air through the water inside the condenser. This is essential to protect the compressed air system as well as the harmful effects of tower moisture on each piece of equipment that consumes compressed air. An important criterion is to keep the relative humidity of compressed air below 50%.

2. Working principle of the air dry machine

The working principle of freezer air dryer is based on the principle of low temperature condensation. First of all, the humid compressed air enters the precooler of the cold and dry machine, and the compressed air after cooling in the evaporator is heat exchange and cooling: the initially cooled compressed air enters the evaporator, and the refrigerant is heat exchange and cooled to 2-10℃. At a low temperature of 2-10 ℃, the water vapor in the air will condense into water droplets, and then enter the gas-water separator to separate and discharge the condensed water to complete the entire drying process.

3. What are the categories of commonly used air dryers?

Commonly used cold drying machine according to the cooling mode of condenser is divided into two types: air-cooled type and water-cooled type; According to the high and low intake temperature, there are high temperature intake type (below 80℃) and normal temperature intake type (about 40℃); According to the working pressure, there are ordinary types (0.3-1.0mpa) and medium and high pressure types (more than 1.2MPa). In addition, many special specifications of dry machines can be used to deal with non-air media, such as: carbon dioxide, hydrogen, natural gas, blast furnace gas, nitrogen and so on.

4. What are the characteristics of domestic air drying machines compared with imported cold drying machines?

At present, the hardware configuration of domestic dry machine parts is not much different from that of foreign imported machines, and refrigeration compressors, refrigeration accessories and refrigerants use a large number of international famous brands. At present, the gap between domestic and imported cold drying machines is mainly manifested in the production process level, especially in the refrigerant system pipeline cleaning, assembly and welding. In addition, the imported green and environmentally friendly refrigerant R134a or 407C, which has no damage to the atmospheric ozone layer, has been commonly used, and most of the domestic refrigeration dryers use R22, which is a refrigerant that destroys the atmospheric ozone layer.

5. How to evaluate the thermal efficiency of the air dryer?

As a kind of heat and mass exchange equipment, the thermal efficiency of the cold dryer should be paid attention to. Like all other thermal equipment, the thermal efficiency of the cold dryer is also defined as: “the ratio of effective energy to supply energy.” We know that the purpose of the work of the cold dryer is not to refrigeration, refrigeration is only to achieve the intermediate technical means of removing water to obtain relatively dry compressed air. Therefore, its effective energy can only be the cold amount consumed for the formation of condensate (Q effective), and other cold amount taken away by the reduction of exhaust temperature should be counted as “waste cold”. The supply energy of the cold dryer is the cold production capacity (Q supply) of the refrigeration compressor under specified working conditions, which is usually much larger than the calculated heat load of the evaporator. Use the formula to express the thermal efficiency η=Q effective /Q supply.