Double-effect Roots-type MVR (Mechanical Vapor Recompression) falling film evaporation system

Abstract

The invention relates to a double-effect Roots-type MVR (Mechanical Vapor Recompression) falling film evaporation system. The double-effect Roots-type MVR falling film evaporation system comprises double-effect falling film evaporators and a water vapor recompression system, wherein the double-effect falling film evaporators comprise a primary-effect evaporator and a secondary-effect evaporator which respectively comprises a heating chamber and a separation chamber; the water vapor recompression system is mainly formed by a Roots-type MVR compressor; a vapor outlet of a separation chamber of the secondary-effect evaporator is connected with a vapor inlet of the water vapor compressor, and a vapor outlet of the water vapor compressor is connected with a vapor inlet of the primary-effect evaporator. According to the double-effect Roots-type MVR falling film evaporation system, by recycling low-grade waste heat of the primary-effect evaporator and the secondary-effect evaporator and reutilizing all latent heat of secondary vapor generated in a solution evaporation process, primary energy is saved, the energy consumption in a solution evaporation process is greatly reduced, and the environmental pollution is reduced. The double-effect Roots-type MVR falling film evaporation system is simple in structure, small in occupied space and high in automation degree, only requires a small amount of vapor when being started, does not require live vapor after being started, is particularly suitable for heat-sensitive materials, has a wide application range and can be used on occasions of evaporation concentration, evaporation crystallization and low-temperature evaporation.

Description

technical field [0001] The invention relates to a double-effect Roots type MVR falling film evaporation system and an operation method, belonging to the technical field of heat pump evaporation. Background technique [0002] The full name of MVR is "Mechanical Vapor Recompression". The technology can be traced back to 1917 and was invented by Sulzer-EscherWyss Ltd in Switzerland. Mechanical vapor recompression technology can compress the secondary vapor to a higher pressure value, thereby increasing the internal energy, so as to realize the continuous cycle of this energy. [0003] Multi-effect evaporation is a mature technology, usually three-effect and four-effect, and the cost is low, but its energy saving is far from that of MVR technology. In the process of multi-effect evaporation, the secondary steam is usually used as the heat source for the secondary effect and the secondary effect. The difference between the MVR heat pump evaporator and the TVR heat pump evapora...

AI Technical Summary

Problems solved by technology

The difference between the MVR heat pump evaporator and the TVR heat pump evaporator is that the MVR can compress all the secondary steam, and the TVR can only compress part of the secondary steam.

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