helium mass spectrometer leak detection technology in plate heat exchanger
Plate heat exchanger is a new type of widely used, efficient and compact heat exchanger, which is generally composed of heat transfer plate, sealing gasket and pressing device. Its structure is composed of a series of parallel thin metal plates with corrugated surface. Many stamping corrugated sheets are sealed by gasket at certain intervals, and are overlapped and pressed by frame and compression screw. The four corner holes of the sheet and gasket form the distribution pipe and collection pipe of the fluid. At the same time, the cold and hot fluid are separated reasonably so that they flow in the flow channels on both sides of each sheet, and heat exchange is carried out through the sheet. Plate heat exchanger has the advantages of high heat exchange efficiency, small heat loss, compact and light structure, small floor area, convenient installation and cleaning, long service life, etc.
The leakage is mainly the leakage. The main parts are the seal between the plate and the plate, the two-way seal leakage groove of the plate, and the seal between the end plate and the inner side of the compression plate.
The liquid flowing in series is mainly the medium on the side with high pressure flowing into the medium on the side with low pressure. If the medium is corrosive, it may also cause corrosion of other equipment in the circuit. Liquid flooding usually occurs in the diversion area or the second sealing area.
In order to avoid the occurrence of leakage, it is necessary to carry out helium mass spectrometer leak detection on the sealing part of plates and plates, the leakage groove part of the two-way sealing of plates and the inner sealing part of the end plates and the compression plates.
In order to avoid the occurrence of liquid string fault, it is necessary to carry out helium mass spectrometer leak detection in the diversion area and the second sealing area.
When vacuum method is used for leak detection, water ring vacuum pump, rotary vane vacuum pump, stainless steel bellows, ball valve and throttle valve are used to form a vacuum system. First, use the water ring vacuum pump to vacuumize, then fill in nitrogen, then use the water ring vacuum pump to vacuumize again, and repeatedly extract the water vapor and dust from the inside of the heat exchanger.
Use industrial vacuum cleaner to dust and dry the outer surface of heat exchanger. The inner part of the heat exchanger is further dried by vacuum pumping and nitrogen replacement. After drying, after vacuumizing the heat pipe, spray helium at the suspected leakage point, and observe the display of helium detector. Stop the leakage point.