MVR evaporator refers to a mechanical thermal compression evaporator, which is a new type of high-efficiency evaporation equipment developed internationally in the late 1990s. Its working principle is that the secondary steam generated by the evaporator is compressed by a mechanical compressor (similar to a blower), and the temperature is increased by 5-8 ℃, returning to the evaporator for heating the heat source. Fresh steam is only used to supplement heat loss and feed enthalpy, thereby greatly reducing the consumption of external fresh steam by the evaporator. In the TVR evaporator, only a portion of the steam is compressed, while in the MVR evaporator, all the steam is compressed, resulting in higher thermal efficiency. During boiling point feeding, there is no need to generate steam throughout the entire evaporation process except for start-up. In this way, the steam that was originally intended to be discarded is fully utilized, and the economy of steam production is equivalent to 30 effects of multi effect evaporation.
Currently, most MVR evaporation devices both domestically and internationally use single-stage centrifugal fans. The design of MVR fans is crucial as it will affect and determine the final evaporation capacity of the system. For materials with little difference in boiling point at different dry matter concentrations, a single fan can be used to meet the requirements; For materials with significant differences in boiling point at different dry matter concentrations, two fans can be connected in series or multi-stage compression fans can be used. MVR evaporation devices sometimes require a small amount of additional steam to be replenished according to different operating conditions, and sometimes the remaining steam needs to be condensed to maintain the overall thermal balance of the evaporator and ensure stable operating conditions.

Economic analysis of operation
Taking evaporation rate of 18 tons/h and glucose solution as an example

type	steam efficiency （kg/kg）	steam consumption （%）	power consumption （%）	cooling water （%）	operating cost （%）	invest （%）	investment recovery （yr）
4Efficient evaporation	3.6/1	100	100	100	100	100	-
5Efficient evaporation	4.6/1	78.8	114	79.4	79.1	112	4.4
1-MVR	200/1	1.8	686	1.8	13	175	1.7

Technical parameters of MVR:
Evaporation of one ton of water requires 15-50 kWh of electricity;
Can achieve low-temperature evaporation at 40 ℃ (without the need for a chilled water system)

The advantages of using MVR:
Low energy consumption and low operating costs, the energy consumption of MVR evaporation is comparable to that of a 30 effect evaporator.
Low temperature evaporation (suitable for heat sensitive materials) without the need for refrigeration equipment.
Simple structure, equivalent to a single effect device, without cooling equipment, boiler equipment, etc
Smooth operation and small footprint.