Urea granulation temperature reduction dust collection method and apparatus

Abstract

The invention discloses a urea granulating cooling and dedusting method and a device including the following steps: sending air from a blower outlet into a pan bottom air distributor in the bottom of a granulation tower, exchanging heat with urea granules with a temperature of 90-130 DEG C in the granulation tower through an air distribution cover on a pore plate of the air distributor; discharging the air with urea dust from an exhaust outlet on top of the granulation tower; removing the urea dust in the exhaust in a washing dust collector at the outlet of the granulation tower, wherein the upward exhaust and dust in the granulation tower are countercurrent contacted with atomizing drops which spray from an atomizing nozzle, and the urea dust is trapped and dissolved by the liquid drops. The invention has the advantages that the cooling effect of the urea particle is good, the dust generation quantity is low, and the apparent quality of the product is high; the urea dust content in the discharging tail gas is greatly reduced, and the product satisfies the environmental requirement.

Description

technical field [0001] The invention relates to a urea production method, in particular to a urea granulation cooling and dust removal method and device. It is suitable for the urea production process system using tower granulation. technical background [0002] At present, there are more than hundreds of urea production enterprises adopting tower granulation, and the design of the granulation section is relatively simple, and there are two problems. One is that after granulation, no cooling and dust removal treatment is carried out, the dust is heavy, the temperature is high, it is easy to agglomerate, it is inconvenient to store and use, it is less and less popular with farmers, and the market competitiveness is declining; If the top is emptied and not collected and utilized, it not only wastes resources and brings economic losses to the enterprise, but also pollutes the surrounding environment, which does not meet the national clean production requirements. [0003] The...

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Problems solved by technology

The advantage of using the wet dust recovery method introduced in the special issue is that the recovery efficiency is high, but the disadvantages are: large resistance, affecting the ventilation rate of the prilling tower, huge equipment, high recovery cost, and mist entrainment in the exhaust gas after washing, etc. question

[0004] In addition, due to the high granulation temperature, the ventilation volume of the granulation tower is limited, and the cooling rate of urea granules is low. When they fall to the bottom of the tower, the temperature is still high, and the strength of the particle structure is low. When they collide with the bottom of the tower, they are easy to break and pulverize. is the main cause of urea dust

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