Crystallization apparatus of sulfur ammonium

Abstract

The present invention provides a crystallization apparatus of sulfur ammonium, comprising: a crystallization reactor, a prethickening device, a centrifuge and a drier. The crystallization reactor is equipped with an annular baffle plate, a guide shell, a gas balance pipe, an ammonia gas distributor, and an acid distributor. The crystallization reactor has different top and bottom diameters, wherein the top diameter is smaller than the bottom diameter, and the baffle plate extends to the middle part of the crystallization reactor vertically from the upper wall of the crystallization reactor; the gas balance pipe is arranged outside the crystallization reactor, the upper opening of the gas balance pipe is higher than the position of reaction liquid level and the lower opening of the gas balance pipe is at baffle area and lower than the bottom end of the baffle cover plate. Because the lower speed flow area at the top end of the rake section of the baffle plate is eliminated, aggregationand scab of sulfur ammonium crystals at the baffle plate and the gas balance pipes is avoided, the cycle environment of materials is improved, which facilitates the safe production. The acid distributor extends to the center of the guide shell and is equipped with a nozzle, thus making acid distribution more uniform, facilitating the generation of the large sulfur ammonium crystal grain, and improving the quality of the sulfur ammonium product.

Description

Technical field [0001] The invention is a crystalline separation device for the chemical industry, which specifically involves a device for the separation of ammonium sulfur crystals in the production process of hebramine. Background technique [0002] Crystal is an important unit operation process for chemical production and product separation. The crystalline reactor and its supporting equipment are important production devices for petrochemicals.In the production of hebramine, the ammonium sulfur crystalline device is the intermediate link of the production process of the 己 在 在. The main task is to neutralize the sulfuric acid in the acid group produced by the amide device to generate the sulfur sulfur sulfur sulfur.Belly separated, divided into ammonium sulfur crystals and amide oil.After drying, it is packed after drying, and the amine oil is refined after the ingenuamide is refined.The operating performance of the crystalline device determines the yield and quality of the 己...

AI Technical Summary

Problems solved by technology

The main problem that prior art ammonium sulfate crystallization device exists is: (1) the inclined part of baffle plate and gas balance pipe are close to liquid level, and the liquid velocity in this area is low, and turbulence is little, and ammonium sulfate crystal nuclei and tiny crystal grain are easily in its surface stays and attaches

The crystals gather on the upper part of the inclined part of the baffle and on the gas balance tube, causing scabbing and growing into giant scale, which hinders the circulation flow during the crystallization process and affects safe production and product quality; (2) due to the distribution of acid groups The outlet of the ammonia distributor and the ammonia gas distributor is located near the wall of the guide tube, and the acid group enters the guide tube from the opening of the feed pipe, resulting in uneven distribution of the acid group, fast local neutralization reaction speed, and supersaturation , there are many crystal nuclei formed, too many fine crystals are generated, and the particle size distribution range is wide, which affects the quality of ammonium sulfate, and will cause the centrifuge to stop shaking, affecting long-term safe production; (3) the metal on the surface of the stainless steel inner wall of the crystallization reactor Ions are negatively charged due to hydration, and the negatively charged inner wall surface will adsorb NH4+ ions in the solution, and induce ammonium sulfate in the adsorption layer under supersaturated conditions. Crystallization on the surface, which eventually aggregates into scale blocks, occupying the reactor space

(4) The slurry feed pipe in the pre-thickener sprays the slurry vertically downward, and the distribution of the slurry on the cross-section of the pre-thickener is uneven, which reduces the effective height of the elutriation section of the pre-thickener, resulting in wet ammonium sulfate crystals The entrainment of caprolactam oil (CPL) in the medium is high, the elutriation efficiency is low, and the loss of caprolactam is serious

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