Circulating heat exchange multiple-effect evaporation system for high-concentration wastewater and evaporation process of evaporation system

Abstract

The invention discloses a circulating heat exchange multiple-effect evaporation system for high-concentration wastewater and an evaporation process of the evaporation system. A feeding barrel is connected with a submerged combustion evaporator through a feeding pipe; a steam exhaust pipeline of the submerged combustion evaporator is connected with one end of a thermal-insulation steam collecting tank; the other end of the thermal-insulation steam collecting tank is connected with an efficient heat exchanger; the thermal-insulation steam collecting tank is also connected with an idle steam heatsource; the feeding barrel is connected with one end of the efficient heat exchanger through a circulating pump. A low-temperature stock solution is pumped to the submerged combustion evaporator, combustible gas is directly sprayed to the evaporator after being ignited, so that the temperature of the solution in the evaporator is increased, and produced steam enters the thermal-insulation steam collecting tank, is mixed with the idle steam heat source and enters the efficient heat exchanger; the low-temperature stock solution in the feeding barrel enters the efficient heat exchanger, exchanges heat with high-temperature steam and returns to the feeding barrel, and the steam in the efficient heat exchanger is circulated again to enter the thermal-insulation steam collecting tank. The gas consumption is reduced by 60% or above through secondary utilization of the heat source and circulating heat exchange.

Description

technical field [0001] The invention belongs to the technical field of environmental protection treatment, and in particular relates to a high-concentration wastewater circulation heat exchange multi-effect evaporation system and an evaporation process thereof. Background technique [0002] Coking wastewater has the characteristics of high pollutant concentration, complex pollutant composition, high ammonia nitrogen concentration, high inorganic salt content, and serious scaling. The mainstream technical route of coking and chemical wastewater is to add nanofiltration membrane and reverse osmosis membrane after the biochemical treatment process. What comes is the problem that the concentrate is difficult to handle after passing through the membrane. [0003] At present, domestic high-concentration wastewater is mainly treated by evaporation. The commonly used evaporation technologies include partition heat exchange technology such as MVR and submerged evaporation technology...

AI Technical Summary

Problems solved by technology

However, both evaporation technologies have certain disadvantages. Fouling problems are prone to occur in technologies such as partitioned heat exchange MVR, resulting in frequent shutdown of the evaporator for cleaning, which greatly affects the treatment effect. At the same time, it leads to high energy consumption of the evaporation system, and there is no continuous stability in China. Successful cases running for more than 7 days

When the submerged evaporation technology is used, although it can operate stably and does not cause scaling problems, it is basically a single-effect atmospheric pressure evaporation at present, which consumes a lot of combustible gas fuels such as biogas or natural gas, and the evaporation efficiency is low. The heat is used in a single-effect in the evaporator Afterwards, it is directly discharged into the atmosphere, and the exhaust gas at 80°C is directly discharged into the air, causing energy waste

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