Method for pumping out incondensable gas between effects of multi-effect distillation system

Abstract

The invention discloses a method for removing incondensable gas from a multi-effect distillation system. The method comprises the following steps that: except a last effect evaporator, incondensable gas and uncondensed vapor in a tube pass of each effect evaporator are led to the shell side of the last effect evaporator by an incondensable gas channel on an incondensable gas pumping-out opening to be mixed with seawater vapor generated by evaporating seawater in the last effect evaporator, and then the mixed gas enters the tube pass of the next effect evaporator; and the incondensable gas and the uncondensed vapor in the tube pass of the last effect evaporator enter a condenser, which is arranged outside the system, from the incondensable gas pumping-out opening for enriching and then enter the atmosphere. The method has the advantages of simplifying the pumping process of the incondensable gas out of the multi-effect distillation system, simplifying a process flow and lowering production cost.

Description

technical field [0001] The invention relates to seawater desalination technology, in particular to a method and device for extracting noncondensable gas in a seawater multi-effect distillation system. Background technique [0002] Desalination is the desalination of seawater into fresh water. At present, seawater desalination mainly adopts thermal method to desalinate seawater, and the thermal method is based on the principle of evaporation and condensation. At present, the technologies for desalination of seawater by thermal method are mainly multi-stage flash evaporation and multi-effect distillation. Effect", the steam evaporated from the previous effect evaporator is used as the heat source of the next effect evaporator, and condensed into fresh water. The multi-effect distillation system generally includes a steam supply system, a water distribution system, and an evaporation tube bundle. [0003] When the multi-effect distillation system is used for seawater desalina...

AI Technical Summary

Problems solved by technology

In order to ensure the heat transfer and the establishment of vacuum, each effect evaporator of the multi-effect distillation system needs to extract the non-condensable gas. The condensed gas is extracted from the evaporator and discharged into the atmosphere. However, the disadvantage of this extraction method is that different pressure adjustments are required between each effect evaporator to ensure that the pressure difference between each effect evaporator remains the same as the design requirement. , and as the number of effects of the multi-effect evaporator increases, the suction port also increases, and the structure of the evaporator becomes more complicated, resulting in an increase in design, installation and operating costs

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