Method, process and equipment for recycling low-temperature afterheat generated in roasting process of producing sulfuric acid from iron pyrite

Abstract

The invention discloses a method, process and equipment for recycling low-temperature afterheat generated in a roasting process of producing sulfuric acid from an iron pyrite. In the invention, a three-room heat storage type heat exchanger is adopted, low-temperature afterheat in the roasting process of producing the sulfuric acid from the iron pyrite is subjected to the heat exchange of low-temperature raw material gas and furnace front air according to a designed operation process and is transferred to furnace inlet air, and then the furnace inlet air brings the afterheat into a roasting boiling furnace to achieve the purpose of recycling the low-temperature afterheat, which has significance to saving energy, reducing emission and developing low-carbon economy.

Description

technical field [0001] The present invention relates to a technology for recovering low-temperature waste heat in the roasting process of pyrite production of sulfuric acid, specifically a method for recovering low-temperature waste heat from roasting using a three-chamber regenerative heat exchanger. The present invention also relates to the process and equipment used in the method . technical background [0002] In the process of producing sulfuric acid with pyrite as raw material, the high-temperature sulfur dioxide raw material gas (referred to as raw material gas) at about 950°C coming out of the fluidized fluidized furnace passes through the waste heat boiler to recover waste heat to generate steam, and the temperature drops to about 350°C before entering the subsequent cyclone. Dust removal and purification equipment such as separators and electrostatic precipitators. Since the feed gas contains a small amount of sulfur trioxide (generally about 0.05% by volume), sul...

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Problems solved by technology

However, the classic double-chamber regenerative heat exchanger transfers the residual heat of the raw material gas from electrostatic precipitator to the air in front of the furnace, which cannot be carried out in the production operation: the raw material gas coming out of the fluidized fluidized furnace is a negative pressure system, and the regenerative heat exchange When the phase change in the vessel is exchanged with the air in front of the furnace, the air pressure in front of the furnace will change suddenly, which will affect the boiling state of the fluidized fluidized furnace. At the same time, the raw material gas will generate positive pressure, resulting in SO 2 Raw gas flows back out of the system, deteriorating the operating environment

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