Current Location:Time: 2022-10-22 Views: 471 times
We often say that the cold dryer and suction dryer are compressed air drying equipment, they are widely used in industry, but there is no drying equipment suitable for all conditions, we mainly from the degree of drying, the use of costs to consider which equipment or equipment to meet the needs of users。
Freeze-drying method is to use the refrigerant to cool the compressed air to a certain dew point, precipitate the over-saturated water, and separate the liquid water through the steam separator, so as to achieve the purpose of drying, but the equipment outlet pressure dew point value can not reach the temperature below the freezing point of water。Outstanding features: continuous operation, no need for regeneration, low energy consumption。
Adsorption drying method
Adsorption drying method is the use of various adsorbents，Such as: silica gel, activated alumina, molecular sieve adsorption of water in the compressed air，So as to achieve the purpose of drying，This method can easily treat the pressure dew point of compressed air to the temperature below the freezing point of water，However, the adsorption capacity of the adsorbent itself is limited，Therefore, it is necessary to make the drying of compressed air continuous through the method of alternating adsorption of two or more towers。There are many kinds of drying machines on the market, but they all use the principle of dehydration by adsorbent, and the difference lies in the regeneration method。
So how do we choose？
In terms of performance requirements
Selection of the first and most important point: should be based on user needs to choose。
Refrigeration dryers have lower energy consumption and operating costs than adsorption dryers，However, it does not provide deep dry compressed air like adsorption dryers，The pressure dew point of freezer dryers is usually above 3℃td，For the general manufacturing process，Choosing a freeze dryer is sufficient;For some more demanding compressed gases that need to be drier, adsorption dryers should be selected。
From the installation environment
The adaptability of freezer dryers to the environment is weak，The ambient temperature is too high or too low is not conducive to the operation of the equipment: the ambient temperature is too high, resulting in an increase in the refrigerant condensing pressure of the air-cooled chiller，Reduce the cooling capacity，Increase the equipment outlet pressure dew point;The ambient temperature is too low. Procedure，Especially below 0℃，Ice blockage is easy to occur when condensate water is discharged from the cold dryer。
The adaptability of the adsorption dryer to the ambient temperature is relatively strong, but the influential factors of the high compressed air pressure dew point value caused by the high outlet temperature of the air compressor at the highest ambient temperature must be taken into account when the equipment is selected。
In terms of maintenance costs
Refrigerated dryers use a sealed refrigeration system where the refrigerant is not exposed to the atmosphere, so system maintenance costs are low。
The adsorption dryer involves frequent valve switching between the adsorption tower, and the thermal regeneration dryer also has high and low temperature switching, so the maintenance cost of the valve is relatively high。In addition, most of the front end of the adsorption dryer is configured with oil-lubricated compressors, and the compressor lubricating oil is easy to cause adsorbent "oil poisoning", and the adsorbent needs to be replaced regularly, resulting in higher maintenance costs。
In terms of acquisition costs
From the current sales price on the market, in the same brand of products, the price of adsorption dryers with the same processing volume will be higher than the price of frozen dryers。
In terms of running costs
The dew point values of the compressed air processed by the two devices are different and cannot be easily replaced, so the operating costs are not comparable。The difference between them is more in the comparison between the same type of equipment, such as the choice of different types of heat exchangers, different refrigerants, different vapor-liquid separation methods between the frozen dryer;Or a comparison between adsorption dryers of different regeneration forms。
Our advice
If the temperature in the area where pipes are arranged is lower than 2 ° C for a long time and the pressure dew point of the compressed air is higher than 5 ° C lower than the annual low temperature, you are advised to configure only a suction dryer。Clarify the user's demand for the actual dew point value when compressed air is used, and compare with the first point to take a lower value。Equipment selection should be based on meeting the dew point, and then consider the different energy-saving configurations between similar equipment, otherwise the gain is not worth the loss。
It is recommended to install a cold dryer before the drying machine. The cold dryer can remove most of the water and oil in the compressed air, reduce the water removal load of the drying machine, ensure its drying effect, reduce the selection of the drying machine, and reduce the pollution of oil impurities on the adsorbent, so that the drying effect can be maintained for a longer time and extend the replacement time of the adsorbent。
