Steam self-supply system for producing sodium nitrate/sodium nitrite

Abstract

The invention discloses a steam self-supply system for producing sodium nitrate / sodium nitrite, which is suitable for preparing sodium nitrate / sodium nitrite. A desalination water tank is connected with a waste heat boiler through a coal economizer, and the waste heat boiler is connected with an ammoxidation reactor; the coal economizer is communicated with a crystallizer through an alkaline absorber, a preheater, an I-effect evaporator and an II-effect evaporator; the preheater is connected with the desalination water tank; a converter is respectively connected with the I-effect evaporator and a centrifugal machine; the II-effect evaporator is respectively connected with an alkaline dissolving workshop section and the crystallizer; the alkaline dissolving workshop section is connected with the centrifugal machine through a condenser and the crystallizer. The steam self-supply system is remarkable in energy saving benefit, convenient for process regulation and pollutant discharge reduction, high in degree of automation, remarkable in steam saving effect and high in recycling ratio.

Description

technical field [0001] The invention relates to the technical field of sodium nitrate / sodium nitrite preparation, in particular to a steam self-sufficient system in the production of sodium nitrate / sodium nitrite. Background technique [0002] The production of sodium nitrate / sodium nitrite mainly includes processes such as alkali dissolution, ammonia oxidation, alkali absorption, transformation, evaporation and post-treatment. The alkali-dissolving section is to dissolve soda ash to a qualified concentration, and provide the alkali absorption section for absorbing NO 2 , NO gas lye neutralization liquid; ammonia oxidation section to prepare NO, NO 2 Gas, de-alkali absorption section; Alkali absorption section uses lye to absorb NO 2 , NO gas; the conversion section reacts the sodium nitrate mother liquor from the centrifuge with dilute nitric acid to generate sodium nitrate solution; the evaporation section reacts the NaNO-containing solution from the alkali absorption s...

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Problems solved by technology

[0003] In this process, the evaporation process is divided into single-effect evaporation, double-effect evaporation or multi-effect evaporation. At present, due to the low utilization rate of heat energy in the domestic single-effect evaporation technology, the application is less, and the application of double-effect evaporation technology is more mature, but due to the nitrate Manufacturers in the industry have different processes, and the steam consumption is also very different. Generally speaking, the utilization of steam is not optimistic. The amount of self-supplied steam is small, and the demand for external steam is large. There is also a lot of pollution

[0004] On the other hand, a large amount of waste heat is generated in the production process. Due to the limitation of backward technology and other reasons, it has not been effectively recycled and lost through heat exchange. Some manufacturers use the flue gas from the waste heat boiler and the tail gas from the tail gas processor. Through heat exchange, although the temperature of the flue gas is reduced, the heat is discharged into the exhaust gas, which causes repeated consumption and waste of resources, and the low level of resource utilization leads to high energy consumption of the entire production

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