Method for recycling heat energy in low-temperature smoke containing SO3 and dust

Abstract

The invention discloses a method for recycling heat energy in low-temperature smoke containing SO3 and dust. According to the method, electric precipitation is carried out on the low-temperature smoke containing the SO3 and the dust, and the smoke temperature after electric precipitation ranges from 290 DEG C to 310 DEG C; the smoke is fed into an acid and high temperature resisting heat exchange device, heat exchange is carried out on the smoke and soft water used in a waste heat boiler, and the temperature of the smoke obtained after heat exchange is 140 DEG C to 160 DEG C, the soft water obtained after heat exchange is used for the waste heat boiler, and the smoke obtained after the heat exchange passes through a smoke power wave purification device and a padding tower and then is discharged after the SO3 is absorbed, wherein the acid and high temperature resisting heat exchange device continuously operates for 12 hours to 36 hours and then is cleaned once by circulating dilute acid washing liquid of the smoke power wave purification device. According to the method, comprehensive recycling of the smoke heat energy can be achieved, the blocking and corrosion problems are solved, the cooling water evaporation capacity is reduced, the production cost is reduced, economic benefits are improved, and the method is suitable for being applied and popularized in the field.

Description

technical field [0001] The invention belongs to the field of waste heat utilization, in particular to a 3 A method for recovering and utilizing heat energy in dust and low-temperature flue gas. Background technique [0002] At present, my country's sulfuric acid production has surpassed that of the United States, becoming the world's largest sulfuric acid producer, with a sulfuric acid production of 84 million tons per year. The methods of producing sulfuric acid are divided according to the raw materials, mainly including sulfur acid production, pyrite (sulphur concentrate) acid production, smelting flue gas acid production, hydrogen sulfide acid production, gypsum acid production, etc.; Both gas acid production and gypsum acid production have dust removal and cooling equipment such as electrostatic precipitators and power wave scrubbers. The flue gas from the outlet of the electrostatic precipitator is about 300°C dust-containing (≤200g / Nm 3 ), including SO 2 , SO 3 ,...

AI Technical Summary

Problems solved by technology

Due to the characteristics of the flue gas: when the temperature is lower than the dew point temperature of 220°C, the SO in the gas 3 Combining with water will generate sulfuric acid mist, so some domestic manufacturers can only recover the heat energy of the flue gas with a temperature difference of about 50°C from 300°C to 250°C through heat pipe economizers or heat pipe boilers, but even so, the heat pipe equipment is still clogged , corrosion, and limited heat recovery