Industrial equipment Brazed plate heat exchanger is a new type of high-efficiency heat exchanger made of a series of metal sheets with a certain corrugated shape stacked and brazed. Thin rectangular channels are formed between various plates, and heat is exchanged through the plates. Compared with the conventional shell and tube heat exchanger, its heat transfer coefficient is much higher under the same flow resistance and pump power consumption, and it has a tendency to replace the shell and tube heat exchanger within the applicable range. Applications: Refrigeration: used as condenser and evaporator b. HVAC: intermediate heat exchangers used in conjunction with boilers, intermediate heat exchangers in high-rise buildings, etc. c. Chemical industry: soda ash industry, ammonia synthesis, alcohol fermentation, resin synthesis cooling, etc. d. Metallurgical industry: heating or cooling of aluminate mother liquor, cooling of steelmaking process, etc. e. Machinery industry: cooling of various quenching fluids, cooling of reducer lubricating oil, etc. Design Parameters Flow range: 1-2000 m3/h Working pressure: vacuum-8.2MPa Operating temperature: -195-538C Interface size: 1"-DN300 welding, flange, thread and other connection forms Corrosion resistance: Welding seal without rubber gasket, choice of various metal and alloy materials, super corrosion resistance, longer service life. Application field: Crude oil, natural gas purification and chemical products; chemical industry; pharmaceutical and specific chemicals; injection control systems; HVAC, district heating, thermal power plants; food processing; cooling tower heat recovery Process requirements Pickling temperature: Raising the pickling temperature is conducive to improving the descaling effect. If the temperature is too high, it will aggravate the corrosion of the pickling solution to the heat exchanger plates. Through repeated tests, it is found that the pickling temperature should be controlled at 60. 2) Concentration of pickling solution: According to repeated tests, the pickling solution should be prepared according to the concentration of formic acid 81.0%, water 17.0%, buffer 1.2%, and surfactant 0.8%, and the cleaning effect is excellent. 3) Pickling method and time: The pickling method should be carried out by a combination of static soaking and dynamic circulation. The pickling time is static soaking for 2h first, and then dynamic circulation for 3~4h. During the pickling process, samples should be taken frequently to test the pickling concentration. When the difference between the two adjacent test concentrations is less than 0.2%, the pickling reaction can be considered to be over. 4) Passivation treatment: After pickling, most of the scale and metal oxides on the surface of the plate heat exchanger will be dissolved and fallen off, exposing new metal, which is very easy to corrode. The sheet is passivated.