MVR Technology Introduction

Qicai ECO has many successful projects involving multi-effect Evaporation and MVR systems. MVR is short for Mechanical Vapor Recompression. In the MVR system the secondary steam produced from the evaporation of the feed water is compressed to a higher pressure and enthalpy by a steam compressor and then used to heat the incoming feed water. MVR is therefore an energy efficient technology which greatly reduces the demand of energy. Since early 60’s, the technology has been successfully applied to various industries such as chemical, food, pharmaceutical, papermaking, seawater desalination and effluent treatment industries (first in France and Germany)

Technology Features

• MVR is suitable for companies which require building new evaporation equipment for the supply of steam but facing shortage of water. When chilled water condensation is required for the low temperature evaporation, the application of the technology would aid companies to achieve significant energy and investment savings simultaneously
• Materials that are suitable for single and multiple effect evaporation treatment would also be suitable for MVR evaporation treatment. MVR evaporator is however more energy-saving and environmental friendly
• The energy consumption and operation cost of the MVR system is lower than that of the multi effect system and it is easy to operate with high stability and level of automation
• Using low temperature negative pressure evaporation (40-100℃) can prevent the degeneration of materials under high temperature

Pretreatment + MVR for high-salt waste water
Our integrated technologies involve the use of the MVR system with one or more of our own advanced pretreatment technologies. Pretreatment may include wet catalytic oxidation, resin adsorption, complexation / liquid-liquid extraction, the iron carbon micro electrolysis, fenton oxidation, ozone oxidation, photocatalytic oxidation, electrocatalytic oxidation, physical adsorption etc. In these pretreatment stage the COD, ammonia bonded nitrogen and chroma are reduced, then the salt is separated from the waste water with MVR technology. The evaporation condensate can reach discharge standards or can ungergo biochemical treatment or utilized as process water.

Technology Features

• Solve problems of COD enrichment, evaporator coking etc. in operation which ensures long-term stable operation
• Small area required for MVR system, low running cost
• Simple operation, high automation, a key start
• High-quality industrial salt which can be recycled
• Evaporation condensate can be used as process water

Diagnosis and rectification of existing problems in evaporation system
In view of domestic and foreign factories the existing evaporator coking, the processing capacity does not meet the design requirements. The system could not be operated in an stable and continuous manner. Therefore by carrying out water quality analyses and providing on-site operation tracking, Qicai ECO provides personalized overall solutions.

Technology Features

• System upgrade based on the original process and equipment, resulting in investment cost savings
• The original system can achieve stable operation and acceptable target
• Upgrade of product or water quality standard with the pretreatment technology
• DCS is simple to operate and system has high level of automation and a key to start
• Safe and reliable operation, long equipment life and convenient maintenance

Energy-saving reconstruction of multi effect evaporation system
Most of the traditional evaporators are multi effect evaporator, such as three effects, four effects or five effects. In theory，the evaporation of 1 ton of water with single effect evaporator requires 1 ton of steam, two effect evaporator needs 0.5 ton of steam, three effect evaporator needs 0.33 ton of steam, and so on. Finally, the primary steam enters the condenser and is cooled by cooling water. If the second steam is compressed by MVR technology, then the temperature and pressure can be reused, and the latent heat of vaporization can be reused. In this way a lot of energy can be saved.

Technology Features

• To upgrade the system based on the originalequipment, saving the Investment cost.
• The use of electric driven steam compressor to replace the original steam, the operation cost is greatly reduced.
• DCS is simple operation, has high automationand a key to start.
• Safe and reliable operation, long equipment life, convenient maintenance

Engineering Case

One food company (Inner Mongolia)
This company is mainly occupied in the food processing industry and is one of the most influential companies in Inner Mongolia.
The daily processing capacity of waste water was 25000 tons. The operation cost before reconstruction was 60000 RMB/d. After the reconstruction of the system, the operation cost was 16000 RMB/d. The investment for reconstructing the system was 10 million RMB. In less than a year, the reconstruction investment was recovered, resulting in huge economic benefits.