Reconstruction

Multi-effect Evaporator Reconstruction to MVR System

Features

■ Reduce the demand for fresh steam, reduce the energy consumption;
■ Make full use of existing evaporation equipment;
■ Maintain or increase evaporation capacity;
■ Maintain or improve evaporation process craft;
■ Low investment and fast modification cycle;
■ Low floor space requirement;
■ System after modification with high redundancy, operation safety factor increased;

In order to reduce the demand for fresh steam, reduce the energy consumption in the evaporation concentrating project and reduce the operation cost, the multi effect evaporator can be reconstructed to a MVR multi effect evaporator.

Required conditions:

■ Heat exchange temperature difference of the multi effect system cannot be too high. Generally, the total temperature difference should be within 40℃, and the single effect heat exchange temperature difference is not more than 15℃;
■ End effect temperature should not be too low (usually higher than 55℃); Low temperature will increase the cost of the compressor investment (Low temperature steam with large volume, require larger size steam compressor). Or the working temperature can be increased after MVR system modification;
■ Jobsite with sufficient power conditions or steam conditions which is required for the steam compressor;
■ Jobsite with certain installation space;

Case Analysis:

One biological company has one set Fructose four effect evaporator, with following technical parameters:

■ Evaporation capacity: 20tons/h
■ Temperature of fresh steam: 90℃
■ Steam temperature of end effect: 55℃
■ Handling material: Fructose

Reconstruction process by MVR Technology:

■ Add one set double stage steam compressor (with frequency convertor), power: 500kw, flow rate: 6tons/h, pressure rate: 4.4; Temperature rise: 35℃
■ Add the inlet pipeline and switching valve for compressor operation
■ Add the vacuum pump for MVR system operation

Energy Saving effect analysis:

S/N	Before modification (Four effect evaporator)	After modification (MVR Evaporator)
Steam cost	1875RMB/h (7.5tons/h, 250RMB/tons)	125RMB/h (0.5tons/h, 250RMB/tons)
Power cost	80RMB/h (100Kw.h, 0.8RMB/Kw.h)	480RMB/h (600Kw.h, 0.8RMB/Kw.h)
Cooling water cost	600RMB/h (200tons/h, 3RMB/tons)	60RMB/h (20tons/h, 3RMB/tons)
Total cost	2555RMB/h	335RMB/h
Total cost	1533million RMB (1years, about 6000hours)	201million RMB (1years, about 6000hours)

Energy saving effect

86%