Waste heat recovery device for moderate temperature flue gas containing high binding dust and method

Abstract

The invention provides a device which can be used for effectively recovering waste heat in moderate temperature flue gas high binding dust and a method. The waste heat recovery device provided by the invention adopts a flue which is horizontally arranged, a heat pipe is used as a heat exchange element, and a heat pipe heat absorption section is placed in the flue and can be used for absorbing heat of the flue gas; the heat pipe is perpendicularly placed, the lower section of the heat pipe is positioned in a free state, and a heat release section of the heat pipe is placed in a gas pipeline and can be used for transmitting heat to the gas; the outer side of the heat pipe contacted with the flue gas is provided with a scraping plate, the scrap plate can periodically do up-and-down movement, nodal ash of the outer surface of the heat pipe is scraped and drops in an ash collecting bin arranged below a heat exchanger. The waste heat recovery device and the method provided by the invention utilize the combination of the characteristic of the heat pipe and a special structure that the dust is removed by the scraping plate, and solve the dusting problem that the heat exchanger is difficult to perform ash removal when waste heat of the moderate temperature flue gas containing the high binding dust is recovered.

Description

technical field [0001] The invention relates to a flue gas waste heat recovery device and method in the industrial field, in particular to the waste heat recovery of medium-temperature flue gas with a temperature range of 350-150°C that produces a large amount of highly cohesive dust in kiln production. Background technique [0002] In some occasions in the industrial field, a large amount of flue gas will be produced. When the flue gas temperature is 350~150 °C, it is generally used to heat the combustion-supporting gas entering the furnace to achieve the purpose of saving fuel. At present, the waste heat recovery of high-temperature flue gas from rotary hearth furnaces in iron and steel plants mostly uses water-tube waste heat boilers, and the waste heat recovery of medium-temperature flue gas uses shell-and-tube gas preheaters. When iron and steel plants use rotary hearth furnaces to separate zinc from iron-containing dust, due to the strong cohesiveness of zinc oxide dus...

AI Technical Summary

Problems solved by technology

During the waste heat recovery process, the dust sticks to the metal heating surface, which gradually increases the scale, and finally causes the waste heat recovery system to be unable to absorb heat

The current traditional ash removal method cannot remove the ash on the heat exchange tube

Moreover, due to the huge amount of dust, the ash hopper will be full in a short period of time, causing the entire heat exchanger to be blocked and the equipment to be unusable

Therefore, at present, all zinc-separating rotary hearth furnaces in iron and steel plants cannot operate continuously, and they need to stop after about ten days of operation, and manually clean the ash on the heat exchange tubes and the ash bucket

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