A detachable self-stretching falling film evaporator

Abstract

The invention discloses a detachable self-stretching falling film evaporator. The falling film evaporator comprises: the top of the shell of the evaporator is provided with a shell-side inlet and a shell-side steam outlet, the bottom is provided with a tube-side inlet, and the upper side wall and the lower side wall are respectively provided with a tube-side outlet and a shell-side outlet; The inner side of the tube pass inlet is provided with a lower tube sheet; the inner side of the tube pass outlet is provided with an upper tube sheet; the distributor is located in the falling film evaporator and connected to the shell pass inlet; heat exchange tubes, the tube bundle is located below the distributor, the lower end of the tube bundle is connected to the lower tube plate, the middle spiral part of the tube bundle is hung on a hanger, and the upper end of the tube bundle is bent and connected to the The upper tube plate is connected; the hanger is fixed on the shell wall inside the shell of the evaporator. The falling film evaporation effect of the falling film evaporator is good, and the problem of "dry evaporation of heat exchange tubes" will not occur. The sealing effect of the connection between the tube bundle and the tube sheet is convenient for disassembly and assembly.

Description

technical field [0001] The invention relates to a falling film evaporator, in particular to a detachable self-expandable falling film evaporator. Background technique [0002] At present, there are a large number of evaporation operations in industrial production, especially in the fields of chemical industry, pharmaceuticals, papermaking, sewage treatment, seawater desalination and so on. In the current large-scale industrial production, the evaporation operation usually adopts an evaporation system composed of a tubular falling film evaporator, using a high-temperature medium as a heat source to perform boiling evaporation heated by an indirect heat source. The tubular falling film evaporator is mainly composed of a shell, a tube bundle, a tube sheet, and a head. The shell is mostly circular, and parallel tube bundles are installed inside. Two fluids that exchange heat in the shell-and-tube evaporator, one flows inside the tube, and its stroke is called the tube side; the...

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Problems solved by technology

[0004] However, the above-mentioned vertical tube falling film evaporator has the following disadvantages: (1) When the tube box seals at both ends of the vertical tube falling film evaporator leak, it is necessary to extract the tube sheet and tube bundle from the shell as a whole, and then replace all the seals Heads and gaskets, resulting in cumbersome disassembly and assembly process and long maintenance time; (2) During work, especially in the start-up stage, the thermal expansion and contraction of the tube bundle will bring stress, causing the upper and lower tube sheets to bear very large bolts Tensile force, while the material of the tube sheet is generally soft material such as 10#, which can easily lead to the problem of bolt occlusion and difficulty in disassembly; (3) The feed liquid enters the heating tube from the top of the equipment, and its kinetic energy is relatively large, so it is easy to have a strong collision with the steam in the tube And produce a lot of foam; (4) The effect of liquid film formation on the inner wall of the tube is poor, the thickness of the liquid film is not uniform enough, and the heat exchange efficiency of the evaporator is low; (5) The black liquor scaling in the heating tube is on the inner surface of the heat exchange tube, which is ring-shaped Scale, more and more solid, not easy to fall off, when the scaling is serious, it needs to stop the machine for descaling, and the scale is located in the tube, it is difficult to clean, and even the tube bundle is scrapped

[0006] However, the above-mentioned horizontal tube falling film evaporator has the following disadvantages: (1) When the tube box seals at both ends of the horizontal tube falling film evaporator leak, it is necessary to extract the tube sheet and tube bundle from the shell as a whole, and then replace all the seals Heads and gaskets, resulting in cumbersome disassembly and assembly process and long maintenance time; (2) During work, especially in the start-up stage, the thermal expansion and contraction of the tube bundle will bring stress, causing the left and right tube sheets to bear very large bolts Tensile force, while the tube sheet material is generally 10# and other soft materials, which may easily cause the problems of bolts occluding and difficult to disassemble; (3) The material and liquid distribution of the horizontal tube falling film evaporator is not uniform, and it cannot be guaranteed that each heat exchange tube Can participate in heat transfer, especially the heat exchange tube at the bottom is prone to "heat exchange tube dry steaming" phenomenon, which reduces the service life of the heat exchange tube, makes the heat transfer coefficient of the horizontal falling film evaporator lower, and reduces the working efficiency

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