Ammonia supply system and method for preparing sodium carbonate

Abstract

The invention provides an ammonia supply system for preparing sodium carbonate. The ammonia supply system comprises a heat exchange unit, a distillation unit, an ammonium chloride preparation unit anda calcium hydroxide preparation unit; the ammonium chloride preparation unit comprises an ammonium chloride dissolving tank, a cyclone separator and a tail gas washing tower; the distillation unit comprises a distillation tower, a reaction barrel and a flash evaporator, the distillation tower is provided with an ammonia outlet, and a raw material inlet of the distillation tower is communicated with the ammonium chloride dissolving tank through a pipeline; the heat exchange unit comprises a heat exchanger, the heat exchanger is provided with a refrigerant inlet, a heating medium inlet, a refrigerant outlet and a heating medium outlet, the heating medium inlet of the heat exchanger is communicated with the flash evaporator through a pipeline, and the refrigerant outlet of the heat exchangeris communicated with the washing water inlet of the tail gas washing tower through a pipeline; and the calcium hydroxide preparation unit is communicated with a raw material inlet pipeline of the distillation tower. The ammonia supply system for preparing sodium carbonate can be used for providing ammonia gas in an ammonia-method alkali-making process, accidents of a liquid ammonia storage tank are avoided, and the heat energy utilization efficiency is high.

Description

technical field [0001] The invention relates to the field of chemical equipment, in particular to an ammonia supply system and method for preparing soda ash. Background technique [0002] In the process of producing soda ash by the ammonia-soda method, ammonia does not participate in the product, but only participates in the chemical reaction as an intermediate medium, and is finally recovered through the distillation process. However, the actual production system is often accompanied by ammonia loss, such as waste liquid discharge, aeration of the filtration system, leakage of pipeline equipment, exhaust of exhaust gas, and equipment replacement. Therefore, the soda ash plant of the ammonia-soda method has an ammonia storage process, which replenishes liquid ammonia for the distillation process from time to time. The gaseous ammonia is pressurized to obtain liquid ammonia. Liquid ammonia is also corrosive and easy to volatilize. Ammonia is a toxic gas that is flammable, ex...

AI Technical Summary

Problems solved by technology

The gaseous ammonia is pressurized to obtain liquid ammonia. Liquid ammonia is also corrosive and easy to volatilize. Ammonia is a toxic gas that is flammable, explosive, poisonous, harmful and has a pungent smell. Therefore, the accident rate of liquid ammonia is quite high. High; in the process of storing and transporting liquid ammonia, due to various reasons or accidents, there may be serious potential risks such as leakage of liquid ammonia leading to fire and explosion, personnel poisoning, suffocation, scalding, etc.

Images