Q How to check the refrigerant leak in the refrigeration system of the air dryer
A Leak detection should be performed under the conditions of system working pressure or filling with a certain amount of refrigerant. There are several common methods for checking leaking refrigerant:
(1) Leak detection by visual method: In the refrigeration system, if oil leakage, dripping or oil leakage is found in a certain part, it can be concluded that there is refrigerant leakage in that part. This method is suitable for refrigeration systems that already have equipment in use.
(2) Halogen lamp leak detection: Halogen lamps are suitable for leak detection of refrigeration systems that have been filled with a small amount of refrigerant.
Halogen leak detection lamps are one of the more commonly used instruments. Because it is more accurate and less error detection. It consists of a portable propane or liquefied petroleum gas tank, a suction hose and a special burner containing copper. The gas is supplied to the burner and a small fire is ignited. The probe of the suction hose is near the leak point. When the leaked refrigerant vapor is sucked into the suction tube and sent to the burner with copper element, the flame of the halogen lamp Red turns green. When a large amount of refrigerant is burned, the flame is purple. When the burner is leaking, carefully observe the change in flame color. If experienced, even small leaks can be detected. Specific operation method, if the refrigerant in the system has been completely leaked. Then, the equipment must be refilled with refrigerant to make the refrigerant pressure reach about 35 Psi, and then pressurized to 175 Psi with inert gas (nitrogen), and then start leak detection of the equipment. Note: Pressurized gas cannot use oxygen or flammable gas.
(3) Halogen leak detector: The halogen leak detector is also called electronic leak detector. Its working principle is to use Freon ionization to generate ion current, deflect the pointer of the millimeter meter and emit a beep. When using, turn on the power first, and slowly move the probe to the leak detection part. If a Freon leak is encountered, the pointer will be deflected and a beep will sound. Halogen leak detectors have high sensitivity and are mainly used for fine inspection of refrigerant systems after they have been charged with refrigerant, to find hard-to-find leaks.
(4) Soap water leak detection: specific operation method, fill it with dry nitrogen, make the system pressure reach 200psi, and then wipe with soapy water on each joint, solder joint, if there is bubbling phenomenon, prove here If a leak occurs, such inspection can ensure foolproofness, and the method is simple and convenient.
When inspecting the equipment for leaking refrigerant, you should follow every step of the leak detection process, taking care to ensure that the fault point can be quickly found.
(5) Leak detection by filling pressure immersion method: immerse the equipment or parts that have been charged with working pressure in warm water as a whole, and observe carefully after the water surface is calm. This method is suitable for leak detection of single parts or small refrigeration equipment, and is simple and practical.