Flue gas atomization evaporation process and system for high-salt wastewater based on ash waste-heat recovery

Abstract

A flue gas atomization evaporation process for high-salt wastewater based on ash waste-heat recovery comprises the following specific steps: the high-salt wastewater is treated by a deep filtration device; out-going water of the deep filtration device 1 is further treated by a pH adjusting device; out-going water of the pH adjusting device is softened by a softening device; out-going water of thesoftening device is introduced into the front section of an air-cooling mechanical slag removal device and a return type heating tube located at the bottom of a boiler through a waste-water conveyingpump, and is preheated by ash waste heat; and a spray nozzle sprays the preheated high-salt wastewater onto a horizontal flue between an air preheater and a dust catcher for flue-gas atomization evaporation. According to the invention, maximum preheating is carried out on the high-salt wastewater by recycling the ash waste heat and the characteristics of the return type heating tube, thereby not only greatly relaxing the use conditions of the flue gas atomization evaporation treatment technology, but also avoiding waste of high-level heat energy and improving the heat utilization efficiency ofpower plants.

Description

technical field [0001] The invention belongs to the technical field of environmental engineering wastewater treatment, and in particular relates to a high-salt wastewater flue gas atomization evaporation process and system based on waste heat recovery of ash and slag. Background technique [0002] Flue gas atomization and evaporation treatment technology has the advantages of simple system, low investment and operation cost, and no crystalline salt generation. The requirements for flue conditions are relatively high, and the amount of treated water is limited, which greatly limits its popularization and use. At present, the high-salt wastewater flue gas atomization and evaporation treatment processes used in coal-fired power plants mainly include the following types: [0003] ① High-salt wastewater → pretreatment → membrane concentration reduction treatment → main flue (or bypass flue) spray evaporation. For example, the two Chinese patents with the application number 2011...

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Problems solved by technology

[0007] In order to solve the problems existing in the existing flue gas atomization and evaporation treatment process, such as small range of operating conditions, waste of high-level heat energy, high investment and operating costs, etc., the present invention provides a high-salt wastewater flue gas atomization evaporation based on waste heat recovery from ash and slag. Process and System

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