Liquid dryer in automotive air conditioning system is indispensable, due to the constantly changing working conditions of automotive air conditioning unlike traditional commercial or household air conditioning system, which is relatively stable, is due to the condition at time of change, liquid refrigerant loss to be compensated, which requires liquid dryer play an important role in regulating at this time. The refrigerant flow increases at the beginning of the operation of the air-conditioning system due to the large system load, but after a period of work, due to the reduction of load, the refrigerant flow decreases accordingly. The liquid refrigerant in the tank is added to the system at high load to participate in the cycle, and the refrigerant is kept during load time. Automobile air conditioning system has been working under the condition of turbulence, it is inevitable that the refrigerant from the compressor and rubber air conditioning tube circulation of any part leakage, liquid refrigerant in the storage dryer can also play a role in the occurrence of trace leakage after the replacement of refrigerant. And these are liquid dryer "liquid" function, is called liquid drier, but also because it also has the function of filtration and drying, although all parts of the car air conditioning system including condenser are accord with the internal cleanliness requirements stipulated in the automobile engine factory, but after all, in the air conditioning system installation will have small foreign body into the system may also have the oxide or during the operation of the compressor within the debris and other sundry. The storage dryer is equipped with a filter that blocks the debris from entering the refrigerant cycle. And its drying function is more important, the car air conditioning system of liquid inside the dryer are equipped with the scientific name for silicon aluminate molecular sieve, its function is to absorb refrigerant cycle should not exist in the "water", also known as dry, drying system is not strict and air dissolve in refrigerant water, if the water into the refrigerant cycle will be formed in water vapor,