Industrial processes often produce process vapors. These contain energy that in many cases is wasted. Mechanical vapor recompression is an efficient solution in this case: the vapors are compressed by an electrically operated compressor and reused to heat the evaporator. This process is advantageous in many respects, as it is cost-effective and also environmentally friendly, as it reduces the consumption of fossil fuels and CO2 emissions. Vapor recompressors help to sustainably improve the quality of industrial processes.
Vapor recompression Definition
Vapor recompression, also known as thermocompression, is a process in which process vapors are compressed by a compressor. This compressed vapor is then reused to heat the evaporator. Compression raises the energy in the vapor to a higher temperature and therefore a higher energy level so that it can be used more efficiently. This process is particularly relevant in industrial processes such as evaporation, distillation, fermentation, crystallization and drying.
A basic distinction is made between thermal and mechanical vapor recompression. In mechanical compression, the vapors are compressed by a compressor. The compressed vapor can then be used in a heat exchanger to transfer heat to a fluid or process. In contrast, a jet compressor is used for thermal vapor recompression, which uses steam to bring the vapor to a higher temperature level.
What is a vapor recompressor?
A vapor compressor is a machine designed for the compression of vapors or vapor condensate. These compressors typically work with an electric drive and compress the vapor to a higher temperature and energy level. These compressed vapors are then reused to heat the evaporator. Vapor recompressors can be single or multi-stage turbo compressors and are used in industrial processes.
Application areas of vapor recompressors
Vapor recompressors are used in a variety of areas. These include
- Food industry in the dairy sector for the concentration of milk and whey
- Thermal compaction for sugar and starch production
- Mechanical vapor recompression for salt extraction
- Purification and process plants
- Chemical industry
Vapor recompressors are also frequently used for the production of pectins, alcohols, citric and acetic acids as well as in meat production and for recycling oil.
Technology and function of vapor recompressors
The mode of operation of vapor recompressors differs depending on whether they are used for thermal or mechanical vapor recompression. Mechanical compressor technology is used in numerous industrial processes to generate large quantities of process vapor. The resulting process steam is compressed with a radial blower (mechanical vapor recompressor). This steam is then fed back into the system for heating so that no energy is lost.
Thermal vapor recompression works on a similar principle, except that the vapor is compressed in a steam jet pump or jet compressor. In contrast to mechanical vapor recompression, however, not all of the energy is fed back into the system in the thermal variant, as some of it – the so-called motive steam – is required to operate the compressor. The pressure to which the vapor is compressed is specified in bar.
Vapor recompressor advantages
- Low live steam requirement
- Low cooling water requirement
- Environmentally friendly
- Cost-efficient and flexible
- Low space requirement
- Low maintenance and little need for monitoring
- Reduced energy costs
Thermal vs. mechanical vapor recompression – the differences
Thermal vapor recompression (TVR) uses part of the vapor produced to heat the system, with the vapor being compressed in a steam jet pump for heat recovery. A certain amount of steam, also known as motive steam, is required to ensure the operation of a thermal vapor recompressor. One advantage of thermal vapor recompression is that the heating medium is available at the required temperature level and there is a moderate difference between the upper and lower temperatures. In addition, there are no moving parts, which results in low wear and high operational reliability. The investment costs are also generally lower.
In contrast, in mechanical vapor recompression, the vapors are compressed by an electrically operated compressor at high speed. The process vapor generated in industrial processes is raised to a higher temperature and energy level using a radial fan and fed back into the process as fresh heating vapor. The energy contained in the steam is not lost, but the additional energy required to raise the temperature must be applied. For compression, the turbocompressor can be either single-stage or multi-stage.
Despite certain differences, both compressors contribute to reducing the use of fossil fuels and CO2 emissions and are effective measures for saving energy and cutting costs in industrial processes.
Serafima: Your partner for efficient vapor recompressors
Serafima is your global expert for centrifugal fans and compressors and offers innovative solutions for efficient vapor recompression, individually adapted to your process conditions. With our state-of-the-art compressors and an experienced team of technicians, we support you in reducing your energy consumption and sustainably increasing the quality of your processes. We are at your side with our expertise and tailor-made solutions. Our goal: to meet your requirements and optimize your operations across the entire process chain.
As your global specialist for centrifugal fans and compressors, Serafima is at the forefront of innovation. We develop customized and innovative solutions for highly efficient vapour recompression, perfectly tailored to the specific requirements of your processes. Our portfolio not only includes state-of-the-art compressor technologies, but also the expertise of a team of experienced technicians. Together, we set ourselves the goal of minimizing your energy consumption and sustainably improving the efficiency and quality of your processes. Rely on our expertise and customized solutions to optimize your operations along the entire process chain. We are here to not only meet your expectations, but to exceed them.
Contact us today to find out more about the benefits of vapor recompressors for your industrial processes and arrange your no-obligation consultation.
Frequently asked questions (FAQ)
What is a vapor recompressor and how does it work?
A vapor recompressor is a machine that is used in industrial processes to compress process steam (vapors). Unlike positive displacement blowers, which usually compress air or gases, the vapor recompressor compresses and superheats vapor, which is then reused to heat the evaporator. The vapor recompression process can be carried out in two ways: thermally and mechanically. In thermal vapor recompression, the vapor is compressed using a vapor jet pump, while in mechanical vapor recompression, an electrically driven compressor is used. To activate the process, the required pressure difference is generated, which compresses the vapor and thus increases the thermal energy.
What are the advantages of vapor recompression?
Vapor recompression offers a number of advantages, including a lower live steam requirement, a low cooling water requirement, a moderate evaporation temperature and minimal operating costs. It also enables the reuse of low-pressure steam, has a small footprint and helps reduce the carbon footprint. Although efficiency varies depending on the type of compressor, energy savings of up to 95% can generally be achieved with a vapor recompressor.
Where is a vapor recompressor used?
A vapour recompressor is used in a wide range of industries, including the food industry (for the pre-evaporation of black liquor, milk, whey, starch, sugar, alcohols, pectins, citric and acetic acid, oil recycling, boiler feed water, meat and fish processing), the chemical industry (for distillation, crystallization and concentration) and the pharmaceutical and biotechnology industries (for the production of fertilizers and the recovery and purification of solvents).
How can a vapor recompressor optimize industrial processes?
Vapor recompressors, both thermal and mechanical variants, can reduce energy requirements and operating costs, improve product quality and reduce environmental impact.