Structural characteristics of plate heat exchanger
Plate heat exchanger is mainly composed of a certain number of flat plate heat exchanger (tens to hundreds of pieces), gasket, fixed frame and clamping device (compact screw and movable platen), etc.. The heat exchange plate is pressed or rolled into various shapes, and the surface of the heat exchange sheet is extruded with a specially designed corrugation. Turbulence effectively removed the sediment deposited on the surface, reduce the fouling, greatly improving the efficiency of heat transfer through the hot and cold medium thin metal siding. The corrugated form of the heat exchanger is very important, which determines the working characteristics of the heat exchanger. The main form of a corrugated, corrugated, flat corrugated folds of convex concave tumor board, zigzag corrugated plate, herringbone corrugated plate (V shape) and double corrugated plates (W shape) humanoid, corrugated inclined shape and different angle. The design and manufacture of corrugated plate is the key technology of plate heat exchanger. The heat exchanger is made of high quality stainless steel plate or aluminum plate, followed by aluminum and its alloy. Plate thickness 0.5 1.2m M. A liquid passage hole is arranged on the angle of the plate, and a circular groove is arranged on the periphery and the corner hole. The assembly first used adhesive gasket is stuck on the plate sealing groove, groove angle around the hole part according to the flow needs to be placed gasket, one hand to prevent fluid leakage, on the other hand to form a certain gap between the plates. When the metal plate pressed by the screw cover by pressing group, adjacent plate plate with a hole on the corner to form a continuous channel, the medium (in medium heat exchange process) drainage to the metal plate group from the inlet, and assigned to the narrow channel between the metal plate.
Plate type heat exchanger composed of heat transfer plate, sealing washer, clamping device and other components (such as nozzle shaft, etc.), the heat transfer plate is a key element of the heat exchanger, commonly used are the following: herringbone plate, horizontal straight corrugated plate, zigzag plate; sealing washer is a key parts of the heat exchanger, in order to prevent the leakage of fluid and the two fluid leakage, which is arranged in the sealing groove, the pressure and temperature in the operation, but also affected by the erosion of the working fluid; the compressing device comprises a compressing plate, and the fixed bolts, it is used to produce sufficient sealing gasket pressed the heat exchanger, leakage does not occur at work, to generate a pressing force by tightening bolts.
1, plate heat exchanger technical characteristics
The main characteristics of plate heat exchanger technology are: first, the plate heat exchanger unit and monolithic area. Second, the use of gasket without glue connection technology, the plate heat exchanger installation and maintenance time saving 80%. Third, the design of the plate by a different angle between the two different waveforms, in order to meet the requirements of different pressure drop occasions, thereby expanding the scope of application. Fourth, the sheet material diversification, has used the high chromium nickel alloy, stainless steel, Monel Hastelloy alloy, also introduced a graphite heat exchanger.
2, plate heat exchanger structure characteristics
The heat transfer efficiency is high, generally 4 times higher than that of the shell and tube heater, which is a factor of 2. The K value is generally up to 3500 5800KW/.K (3000-5000cal/m2.h. 9C), so the heat transfer area is small under the same conditions.
The utility model has the advantages of compact structure and small size, and is especially suitable for the technical transformation of the old factory to make full use of the original equipment to overcome the space limitation. Light weight, heat transfer plate is thin, less metal consumption, heating area per square meter about the consumption of metal 10kg. Only for tubular heater 1/3-1/4.
The heating material has a short residence time in the heater, less internal dead angle and good sanitary condition. Heating is suitable for heat sensitive materials, such as milk, monosodium glutamate solution etc..
The utility model has the advantages of flexible operation, wide application range, and can increase or decrease the number of plates to change the heating area or change the working condition. The size of the equipment is very large, the size of each piece of heat exchange, small to 0.5m2, up to 1.3 expansion, the heat exchange area of each device can be expanded in a 1000 between the two, the equipment is large margin of the big, the device can be extended to a maximum of 1.
It can use low temperature heat source to recover heat from low temperature heat source, so as to save energy. The heat transfer temperature difference between hot and cold materials can be reduced to 4 A / 5900
The motion of the fluid and plate heat exchanger in a channel between the fierce, and smooth surface, the formation of scale less, long working period, and facilitate the use of chemical cleaning method. The utility model can greatly reduce the manpower, material resources, financial resources, and the consumption of the evaporating tube brush tube in the small inspection or shutdown.
The plate heat exchanger is thin, the bearing capacity is low; especially for the corrugated plate is formed between the contact points, mutual support type heat exchanger, used in long, pressing dimensions beyond the installation requirements of size, easy to make contact pressure into the pit, and finally the formation of perforation, the plate scrapped.
The spacing between sheets (narrow gap width) (general heat exchanger 4 6mm "wide seam" of the heat exchanger in a thin film of 8 12mm), fast evaporation speed. If the high temperature steam and liquid materials as hot and cold medium heat, a sudden stop in the material case, prone to dry coking phenomenon, accelerate the sealing gasket between sheets damaged; coking material will cause the sheet material cooling channel blocked, affecting the use of equipment, causing losses to production. Therefore, the staff of plate heat exchanger device structure and working principle of understanding is the actual use of the difficulties.
