Shandong heat exchanger maintenance, fixed tube plate heat exchanger characteristics are: 1. Bypass flow is small, low cost is not necessary 3, no internal leakage is not necessary. 4. The disadvantage of fixed tube plate heat exchanger is that the temperature difference between shell and pipe wall is large, temperature difference force is easy to produce; shell process cannot be cleaned; after pipe corrosion, the equipment life is low with shell scrapping; it is not suitable for case process easy to scale. 5 plate heat exchanger is a new type of effective heat exchanger which is made up of a series of metal sheets with certain corrugated shape. The heat exchange between plates is carried out by forming a thin rectangular channel through half plate. Plate heat exchanger is an ideal equipment for heat exchange between liquid liquid and liquid steam. It has the characteristics of high heat exchange efficiency, small heat loss, compact structure, small floor area, convenient installation and cleaning, wide application and long service life. The heat transfer coefficient of the tube heat exchanger is 3-5 times higher than that of the tube heat exchanger under the same pressure loss. The area of the heat recovery is more than 90% of the total area of the tube heat exchanger. 6. The plate and shell heat exchanger lamellaheatexchanger, which uses plate and tube as heat transfer element, is also called sheet heat exchanger. It is mainly composed of plate bundle and shell (in the figure). The contact of cold pressed pairs of slats is welded together tightly to form a plate tube drawing with multiple flat channels. Many tube plates with different width are arranged in a certain order. To keep the spacing between the plates and tubes, metal strips are inserted at both ends of adjacent plate pipes and welded with the plate pipes. The plate and tube state are formed at both ends of the plate and tube, which makes many plates and tubes firmly connected together to form the plate bundle for Shandong heat exchanger maintenance. The end face of the plate bundle shows a number of flat flow tube bundles assembled in the shell. It is used to eliminate the longitudinal expansion difference by sliding seal between the tube and the shell. The section of equipment is generally circular, and also has rectangle and hexagon. A fluid flows in the plate tube, while the B fluid flows between the plates and tubes in the shell. Plate and shell heat exchanger is a structure form between shell and tube heat exchanger. It takes into account the advantages of both: ① the plate is the heat transfer surface, and the heat transfer efficiency is good. The heat transfer coefficient is about twice that of shell and tube heat exchanger. ② Compact structure, small volume. ③ The temperature and pressure resistance working temperature can reach 800 ℃, and the working pressure of * * reaches 6.3 MPa. ④ The high speed flow of fluid in the flat channel and the smooth surface of the plate are not easy to scale. The plate bundle can be removed and cleaned easily. But the manufacturing process of this heat exchanger is more complex than that of shell and tube heat exchanger, and the welding quantity is large and the requirement is high, so its application is limited. Plate and shell heat exchanger is used in chemical industry, paper making, pharmaceutical industry and food industry. Typical products are mainly used in Shandong heat exchanger maintenance and processing industry, which requires good heat transfer efficiency and short residence time. 7. Plate fin heat exchanger defines the heat exchanger with plate and fin as the heat transfer element of plate and fin. The characteristics of this paper are that the heat transfer efficiency of the materials is high. Because the fins disturb the fluid, the boundary layer is constantly broken, so it has a large heat transfer coefficient. At the same time, the plate fin heat exchanger can achieve high efficiency because of the thin diaphragm and the fin with high thermal conductivity. The compact state of the material can reach 1000 m2 / m3 because of the expanded secondary surface condition of the plate fin heat exchanger. The light and light state of the material is mainly made of aluminum alloy because of its compact. The plate fin heat exchanger with strong adaptability can be used for the heat transfer between gas, gas, liquid, liquid, various fluids and the phase change of the concentration. Through the arrangement and combination of the runner, it can adapt to different heat transfer conditions such as the flow at the same time, the cross flow, the multi strand flow and the multi-pass flow. The combination of series, parallel and serial parallel between maintenance elements of single Shandong heat exchanger can meet the heat exchange needs of large equipment. In industry, it can be fixed and batch to reduce cost. The interchangeability can be expanded by building blocks. The manufacturing process of rare materials is strictly required. The process is complex. It is difficult to clean and repair the heat exchange medium in a clean, corrosion-free, scale-free, hard to deposit, and not easy to block. The structure is usually composed of diaphragm, fin, seal and guide plate. The sandwich is called channel state by placing fins, guide plates and seals between two adjacent diaphragms. The laminated layer is stacked according to different ways of fluid and brazed into a whole, and then the plate bundle is the core of plate fin heat exchanger. The plate fin heat exchanger is formed by necessary head, nozzle, support, etc. The manufacturing process of plate fin heat exchanger includes the following kinds of bonding, solvent bath brazing, solvent free vacuum brazing and gas protection brazing. The heat exchanger used in air separation equipment is not used in ethylene plant, ammonia plant, natural gas liquefaction and separation equipment of petrochemical industry. It is not necessary to use hydrogen, helium, refrigeration and liquefaction equipment in deep and low temperature for refrigeration and air conditioning. What is worth mentioning is that at present, it is necessary to use it in engineering machinery, general machinery, etc The plate fin heat exchanger, which is used in various oil, water and gas coolers, is widely used in Shandong heat exchanger maintenance.