Waste heat recovery system for table salt drying tail gas

Abstract

The invention relates to a waste heat recovery system for table salt drying tail gas. A hot blast heater is connected to a fluidized gas inlet of a fluidized bed dryer, a gas outlet of a cyclone separator is connected to a first water absorption tower through a first gas inlet pipe, a gas outlet of the fluidized bed dryer is connected to an induced draft fan, and a gas outlet in the top end of thefirst water adsorption tower is connected to an air preheater. A material preheating unit comprises a slurry conveying pipe, a slurry pump and a heat exchange spray tower, the slurry pump is arrangedon the slurry conveying pipe, and the slurry conveying pipe passing the heat exchange spray tower is connected to a material inlet of the fluidized bed dryer. The waste heat recovery system is scientific and reasonable in design, can remove corrosion of table salt drying tail gas to the wall of a heat exchange tube, reduce humidity and dust of tail gas, prevent scaling of the heat exchange tube,and improve the heat transfer efficiency. Meanwhile, the waste heat recovery system can recycle heat of the tail gas, so that the utilization ratio of energy source is improved.

Description

technical field [0001] The invention belongs to the technical field of chemical unit operation, and relates to salt drying, in particular to a system for recovering waste heat from tail gas of salt drying. Background technique [0002] In the existing tail gas waste heat recovery technology of the salt industry, the air at normal temperature enters the hot blast stove to heat up after the exhaust gas is preheated once, and the heated high-temperature dry air enters the fluidized bed dryer to be mixed with the salt in the fluidized state. Convective drying and taking away the water in it, the dehydrated salt is cooled and discharged, and the dried high-temperature tail gas is separated from dust by the cyclone dust collector, and then discharged after a heat exchange with normal temperature air in the air preheater. However, in the above-mentioned process, the exhaust gas after convection drying of hot air has relatively high humidity, contains more water vapor, and is mixed ...

AI Technical Summary

Problems solved by technology

However, in the above-mentioned process, the exhaust gas after convection drying of hot air has relatively high humidity, contains more water vapor, and is mixed with a large amount of sodium chloride and sodium sulfate. It is cooled by heat exchange with normal temperature air in the air preheater to reach its dew point. Finally, water droplets condense out to form a layer of liquid layer containing sodium chloride and sodium sulfate. If the dust separation efficiency is not high, it will mix and agglomerate with the condensed liquid layer, which not only hinders its heat exchange, but also the salt-containing liquid layer will last for a long time. Adhering to the tube wall will gradually corrode the heat exchange tube

[0003] Through the search of published patent documents, no published patent documents identical to this patent application have been found

Images