MVR is the abbreviation of mechanical Vapor recompression.
It is to use the secondary steam and energy produced by the evaporation system itself to upgrade the low grade steam to the high grade steam heat source through the mechanical work of the compressor. An energy-saving technology that thus circulates heat to an evaporation system, thereby reducing the need for external energy.
But a lot of things we cannot directly use the compressor to compress the secondary steam evaporation, on the one hand, because the secondary steam is mixed gas, which contains a certain amount of incompressible gas is high, on the other hand, may contain high corrosive gas, corrosion of compressor impeller is larger, so in this case we still want to use the MVR system, Must be to transfer heat from the secondary steam feed water, that is to say, the evaporation of secondary steam was not directly into the evaporator, but into the circulating water heater, using the latent heat of vaporization secondary steam to circulating water temperature increased, and then enter the flash tank, flash off part of the water vapor, separation and then into the compressor, the compressor through the work, The temperature and pressure of the water vapor are raised, and it enters the heater again as heated steam, and so on. This not only solves the problem of incompressible gas, but also solves the direct contact between corrosive gas and compressor impeller. The corrosion of impeller is greatly reduced and the service life of compressor is improved.
Evaporation of secondary steam into the scrubber tower, wash incompressible gas and corrosive gas, the rest of the high purity water vapor into the compressor compression can also again, but scrubbing tower is not entirely remove want out of gas, only lower concentration, and expensive, so the heat transferred to the processed demineralized water is more suitable.
