Ammonium sulfate production process
Saturated process ammonium sulfate production process
1. Bubble Saturation
The coke oven gas from the blower is charged to the gas preheater after passing through the gas trap. In the preheater, the indirect gas is used to heat the gas to a temperature of 60 to 70 ° C or higher in order to allow the gas to enter the Ammonium Sulfate bubbling saturator to evaporate the excess water in the saturator to maintain the water balance in the saturator. The preheated gas enters the saturator along the saturator central gas pipe and is bubbled through the bubbling umbrella from the acidic mother liquor while the ammonia in the gas is absorbed by the sulfuric acid. Gas out of the saturator into the acid removal device, to capture the entrained acid mist, was sent to the crude benzene section.
After the bubbling saturator gas ammonia is generally less than 0.03g / m3. The ammonia gas obtained from the ammonia in the condensate section is directly fed into the saturator when the pyridine is not produced. When the pyridine is produced, the ammonia gas is introduced into the pyridine neutralizer. Ammonia in the neutralizer and the mother liquor in the free acid and pyridine sulfate role in the formation of ammonium sulfate, and with the neutralizer back to the saturator back to the saturator. Saturated mother liquor in the ammonium sulfate production, ammonium sulfate content in the above its solubility, the precipitation of crystals, and precipitation in the bottom of the saturator. The bottom of the crystal is pumped to the crystallization tank, in the crystallization tank to grow and precipitate in the bottom of the crystal. Crystallization of Ammonium Sulfate the bottom of the crystallization of ammonium sulfate into the centrifuge centrifuge separation, filter out the mother liquor, and washed with hot water to reduce the surface of ammonium sulfate on the free acid and impurities. Centrifuge the separated mother liquor with the crystallization tank out of the mother liquor together with the self-flow back to the saturator. The ammonium sulfate crystals separated from the centrifuge were passed through a screw conveyor, fed into a boiling drier, dried with hot air and fed into an ammonia sulphate bucket and packed into a finished product bag.
In order to make the gas in the saturator contact with the mother liquor is sufficient, it is necessary to make the coal bubble umbrella in the mother liquor have a certain liquid seal height, and to ensure that the saturation level inside the saturator, The overflow of the mother liquor through the full flow of the liquid flow into the full flow tank to prevent the gas escape. The lower part of the full flow tank is connected to the circulation pump and the mother liquor is continuously Ammonium Sulfate pumped to the injector at the bottom of the saturator. And thus a certain injection speed, so the satiator mother liquor is constantly circulating to improve the crystallization process. Gas into the saturator of the coal tar mist, in the saturator with the role of sulfuric acid to produce the so-called acid tar, bubble acid coal tar floating on the mother surface, and with the mother liquor into the full flow tank. The acid tar that floats on the full tank level should be removed in time or separated from the mother liquor by a separate separation device to recover the mother liquor. Saturated sulfuric acid in the saturator, sent from the sulfuric acid warehouse to the high trough, and then into the saturator, the normal production, should maintain the mother acid acidity of 4% to 6%, sulfuric acid into the amount of ammonia required; Production of coarse light pyridine, the sulfuric acid to increase the amount of some, but also with the ammonia into the Ammonium Sulfate saturator ammonia. Saturation of the saturator after a certain period of time, due to the deposition of crystals will increase its resistance, serious will cause the blocker of the saturation. So the operation must be regularly pickled and washed. When the regular large acid, replenishment, water rinse saturator and acid removal device, the formation of a large number of mother liquor flow tank full flow to the mother tank tank. In normal
The mother liquor is pumped back to the saturator for production. The saturator is a periodic continuous operation equipment, in order to prevent the crystal blockage, regular large acid and water, thus undermining the crystallization of the normal conditions, coupled with the crystallization of the saturator at the bottom of the residence time is short, and thus smaller crystal particles, the average diameter of 0.5 Mm.
To the ammonia in the gas. The gas and then into the tangent direction into the saturator in the acid removal device, remove the gas entrainment of acid mist droplets from the upper central outlet tube away from the saturator and then by the trap to capture the gas in the trace of acid mist to the final cold Wash the benzene section. Spray saturator gas after ammonia generally less than 0.05g / m3. The upper and lower sections of the saturator are connected by a downcomer. The mother liquor from the sprayed ammonia absorbs the solution from the downmix concept to the bottom of the crystallization chamber where the crystallization nucleus is pushed up by the saturated mother liquor and the