BR Plate Heat Exchanger

Plate heat exchanger has the following bit: (when compared with the tube shell heat exchanger)
1, heat transfer efficiency The corrugated sheet to the smaller flow rate of fluid formed in severe turbulence, when the Reynolds number Re is about 200 hours. That can produce turbulence. Therefore, the heat transfer efficiency, the heat transfer coefficient of shell and tube heat exchanger 3 to 5 times.
2, versatile Plate heat exchanger ability to adapt to conditions. Has been designed for good or used plate heat exchanger, only increase or decrease the number plate or change the combination plate, you can adapt to changes in production capacity and new condition requirements.
3, compactSmall footprint, shell and tube heat exchanger is only 1/5 to 1/0: light weight, shell and tube is only 1/5 or so.
4, low investment costsHigher heat transfer efficiency means less heat transfer area only. Especially in a corrosive condition, the device Xu Yong corrosion materials (such as industrial pure titanium), plate heat exchanger invest far less than the other heat exch- anger.
5, high heat recoveryThe end of shell and tube heat exchanger temperature difference of about 5 ℃, heat recovery is only around 50%; the plate heat exchanger end of the temperature difference can be less than 1 ℃, heat recovery rate of 90%.
6, lower water consumptionAs the plate heat exchanger with high thermal efficiency, thus greatly reducing the flow of cooling water, piping and valves to reduce investment, reduce operating costs.

Design principles and methods of selection:
1, plate heat exchanger type design principles
Selection process for the design of a plate heat exchanger, it is necessary to consider the design pressure and design temperature, media characteristics and economic factors.
(1) Veneer size selection
Veneer size too small, then the number plate over an area of large, pressure drop decreases; the contrary, Veneer too large, then the number of small plate, small footprint, pressure drop increased, but difficult to ensure proper flow between the board. Thus the general area of veneer can be pore flow rate of angular 6m/s about to consider.
(2) between the velocity of the selection board
Fluid flow between the plates affect the heat transfer performance and pressure drop. High velocity, high heat transfer coefficient, pressure drop also increased: rather, the opposite. Between the flow rate of the general board to take 0.2-0.8m/s, and as far as possible the speed of two fluids board asked the same. Flow rate is less than 0.2m / s, the turbulent fluid reach, and will form a large dead zone; flow rate is too high will lead to sharp increase in pressure drop, gas flow rate does not exceed cubicle 10m/s.
(3) The process of determining
Roughly the same on both sides of the flow of fluid when the process should be furnished by such: When the fluid flow on both sides of the disparity, then the flow on one side of a small arrangement or adopted by many processes ranging from cross-section channel plate heat exchanger. In addition, when a medium range of temperature or the temperature drop is larger, more processes can be applied. A phase change occurs on one side of a single process, generally, and under the interface mode for the upward mobility. In multi-process heat exchanger, generally on the same fluid in the process flow should be the same number of. Drop heat exchanger correction factor, when a single process to take 1.2 to 1.4,2 ~ 31.8 ~ 2.0,4 process take 5 process to take 2.6 to 2.8.
(4) the selection of the flow
Single-phase heat transfer, the counter has a maximum average temperature, usually in the design of plate heat exchanger fluid to the extent possible, arrangements for the counter. Fluid flow on both sides, etc., in order to counter; when both sides of fluid flow range, the downstream and upstream alternatively, the average temperature is less than when pure countercurrent.
2, plate heat exchanger selection calculation method
(1) heat exchanger selection formula: Q = K ? F ? tm, the formula: Q-heat flow (W), tm logarithmic mean temperature difference (℃), F-heat transfer area (m2) Plate heat exchanger in the actual operation, because of dirt, water affects inequality. Be introduced in the correction factor type (usually take 0.7 to 0.9). Therefore, the actual use, the formula is: Q = ? K ? F ? tm
(2) estimation method: according to the following estimates When the board between the flow rate of 0.3-0.5m / s when Water (steam) - Water K :3000-7000Water (steam) - Oil K = 400-1000Oil - Oil K = 175-400.