Low temperature multiple-effect distillation seawater desalination system and process flow thereof

Abstract

The invention discloses a low-temperature multieffect seawater distillation desalting system. The system comprises a plurality of multi-effect evaporator sets; each evaporator set is at least provided with a heater for preheating feeding seawater; an effect intermediate pump is arranged between two adjacent multi-effect evaporators; and one end of a condenser is connected with a raw material water pump, and the other end of the condenser is connected with the last evaporator set of the plurality of the multi-effect evaporator sets. The invention also discloses a process flow for utilizing the low-temperature multieffect seawater distillation desalting system to desalt seawater; the evaporators of the low-temperature multi-effect seawater distillation desalting system are divided into a plurality of sets; each set feeds in parallel; simultaneously, the front of the feeding seawater of the highest-temperature effect evaporator of each set is provided with a heater; residual strong brine of the front evaporator set is collected and beaten to the next evaporator set through the effect intermediate pump, and so on; a product water and strong brine flow in a ladder shape in a series of flash tanks and are gradually subjected to flash evaporation and cooling; steam obtained through flash evaporation enters the evaporator; and finally, the product of the cooled water and the strong brine are pumped out through a corresponding water pump respectively.

Description

technical field [0001] The invention relates to a low-temperature multi-effect distillation seawater desalination process used in the field of seawater desalination, in particular to a method of using pressure difference to flash steam to improve efficiency, and at the same time to use the flash steam to feed certain groups of materials The process of preheating the feed seawater of the effect evaporator. Background technique [0002] Low-temperature multi-effect distillation refers to operating below 70°C. Around 1981, this technology has been formally applied to industrial seawater desalination systems. It is characterized in that a series of horizontal tube spray falling film evaporators are connected in series. The steam input is through multiple evaporation and condensation, and the evaporation temperature of the latter effect is lower than that of the previous effect, so as to obtain distilled water that is multiple times the amount of steam. [0003] In low-temperatu...

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Problems solved by technology

[0012] In order to overcome the defect of low desalination efficiency in the typical seawater desalination process flow commonly used in the prior art, the present invention provides a low-temperature multi-effect distillation seawater desalination system and its corresponding process flow. The advantages of the two typical processes of low-temperature multi-effect distillation are combined, and the cost factor of the process device is fully considered

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