Gas-liquid contact type residual heat recovery device

Abstract

The invention discloses a gas-liquid contact type residual heat recovery device for recovering residual heat from flue gas and low-pressure steam. The residual heat recovery device is characterized in that a gas inlet pipe is arranged at the lower part of a shell and is connected with a gas input pipe; a plurality of spray heads are mounted in the shell and are connected with a cold liquid inlet pipe and a cold liquid conveying pipe; a plurality of annular liquid baffles are mounted in the shell; a liquid on the wall of the shell is intercepted and flows back to gas ascending space; a gas screw-out pipe is arranged at the upper part of the shell and is connected with a gas screw-in pipe; a gas distribution cone and a foam remover are mounted in the upper part of the shell, gas rotates at a high speed after entering a cyclone separator and then enters the foam remover through the gas distributor to separate the liquid from foam in gas flow; a liquid backflow outlet pipe is connected with a liquid backflow inlet pipe; a gas outlet pipe is connected with a gas emptying pipe; and a hot liquid outlet pipe is arranged at the lowest part of the shell and is connected with a hot liquid tank. The residual heat recovery device has the advantages of high heat exchange efficiency, capability of purifying flue gas, simple structure, reliability in working, convenience in mounting and the like.

Description

technical field [0001] The invention relates to a gas-liquid contact waste heat recovery device for waste heat recovery of flue gas and low-pressure steam (spent) steam. Background technique [0002] Small boilers and kilns that use gas, oil, and coal-water slurry as fuel will produce a large amount of flue gas, and processes that use steam as a heating medium or power will generate a large amount of low-pressure steam (exhausted) steam. These flue gases and Low-pressure steam (exhausted) steam contains a lot of heat. When it is discharged to the atmosphere, it will form a local "heat island effect". Waste and pollution of the environment. Due to their small power, the waste heat recovery of flue gas and low-pressure steam (exhausted) steam has not attracted enough attention, but they involve a wide range of areas and a large number. Research on how to recover and utilize flue gas and low-pressure steam (exhausted) steam The low-grade heat energy is an important topic of e...

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Problems solved by technology

[0003] At present, waste heat recovery from flue gas and low-pressure steam (spent) steam will encounter two problems: one is the use of tube-and-tube heat exchangers, steam (gas) goes outside the pipe, and water goes inside the pipe. Due to the low heat transfer coefficient, equipment investment The second is to adopt partition wall heat transfer. Due to the low heat transfer coefficient of the flue gas side, in order to prevent equipment corrosion, the outlet flue temperature should not be too low, and should be slightly higher than the flue gas dew point corrosion temperature. Therefore, small and medium-sized boilers, kilns The exhaust gas temperature of the furnace should be controlled at about 180°C, for this reason, the effect of flue gas waste heat recovery is not significant

Since the waste heat of flue gas and low-pressure steam (spent) cannot be recovered and utilized to the greatest extent, the emission of harmful gases such as carbon dioxide and sulfur dioxide in the flue gas cannot be reduced. At the same time, the equipment is expensive, which is not conducive to flue gas and low-pressure steam. Recovery and Utilization of Steam Waste Heat

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