A kind of production device of sodium nitrite

Abstract

The invention provides a production device of sodium nitrite, comprising an alkali-dissolving pool, an alkali absorption tower, a crystallizer, a thickener, a centrifuge, a mother liquor tank, a conversion tower, and a heat exchange mechanism; the heat exchange mechanism includes a condenser, Ejector, circulating water tank, circulating pump and cooling tower, the outlet of the flash chamber of the crystallizer is communicated with the first inlet of described circulating water tank through condenser and injector, and the outlet of circulating water tank is connected with described circulating pump The top of the cooling tower is connected, and the outlet of the cooling tower is connected with the second inlet of the circulating water tank, and the outlet of the circulating water tank is connected with the inlet of the lye absorption tower through an alkali-dissolving pool; the present invention adopts a heat exchange mechanism, The circulating water tank pumps the vacuum circulating water into the upper part of the cooling tower through the circulating pump, and uses the fan to pump the air, so that the air directly contacts the water to dissipate heat. efficiency and quality, and make up for the disadvantages of the original heat exchanger.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a sodium nitrite production device. Background technique [0002] my country's two sodium products are produced by absorbing nitrogen oxides with lye. The new process of directly absorbing high-concentration disodium production with lye is the method adopted by large-scale disodium production enterprises. Due to the continuous improvement of national tail gas emission standards, increasing the operating pressure of the alkali absorption system is conducive to the positive reaction direction of nitrogen monoxide to nitrogen dioxide, further improving the absorption rate of nitrogen oxides, and reducing the emission of nitrogen oxides in tail gas. However, if the pressure is too high, the oxidation degree of nitric oxide in the gas will increase, thereby affecting the nitrous ratio of the neutralizing solution. With the depletion of global energy sources, the deteriorat...

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Problems solved by technology

[0004] At present, manufacturers in the same industry adopt indirect heat exchange for vacuum circulation cooling in the post-processing section. This method has extremely high requirements on the circulating water at the cold end. However, in the actual production environment, the heat exchange effect of this method is not ideal, and it cannot effectively reduce the heat load at the hot end Reduced, so that the evaporation vacuum cannot reach the ideal state, and the evaporation end temperature is high, which reduces the recovery rate of sodium nitrite and greatly affects the product quality

Moreover, this method also has the following disadvantages: 1. The area of ​​the required heat exchanger is large, which increases the purchase cost and maintenance cost; 2. The large flow rate and low temperature of the circulating water required for cooling the cold end, in the case of increasingly scarce groundwater, replenishment Deep well water will be difficult

3. The required circulating water at the cold end must maintain a good index to prevent scaling and blockage of circulating pipes and equipment. This requires a large amount of chemicals and fresh water supplementation, and at the same time increases the workload of equipment cleaning; 4. Heat exchange equipment There is a leakage and cross-linking situation, and the water containing a very small amount of material at the hot end is connected to the circulating water at the cold end, resulting in qualified water that cannot be processed

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