Mechanical Vapor Recompression

Efficient blower and compressor technology

Centrifugal Blowers & Compressors for MVR Processes

The principle of mechanical vapor recompression (MVR) is used often in evaporators. It is an efficient solution to provide thermal energy for vaporization. Steam is compressed by a compressor, usually driven by an electric motor, and used for heating the evaporator column. Due to its low energy consumption, the MVR process is the most economical evaporation technology available.

In the past, complex turbo compressors, with speeds of more than 12,000 rpm, or positive displacement blowers were used in the MVR process. Since the 1980s PILLER has provided powerful blower solutions for these applications.


Today, PILLER is the technology and market leader in the field of steam compression, using single or multi-stage high-performance blowers.

Advantages of mechanical vapor Recompression

Efficiency, flexibility, and reliability for the process industry

PILLER Blowers achieve an efficiency of up to 86 percent. They are more flexible, more reliable, require less maintenance, are less sensitive to sub-optimal process conditions, and are more robust than conventional (steam) compressors.


The blower housing is also optimized to be particularly resistant to water and contaminated steam, and is largely maintenance-free. PILLER MVR Blowers are impressively powerful despite their compactness. They run with shaft powers of up to 5 megawatts at impeller speeds of up to 400 meters per second. Depending on the particular installation, steam can be compressed to a pressure of up to 20 bar.


Using patented bearing technology, engineered high-performance impellers, and a continuous product improvement process, PILLER manufactures high-quality MVR blowers that provide customers maximum efficiency and durability, resulting in cost savings and lower life cycle costs.

Our MVR blowers at a glance:
  • flexible and cost-effective integration into existing plants
  • compact and robust construction
  • long service life with low maintenance costs
  • efficiency up to 86 percent
  • several blowers can be connected in series to achieve more performance

Continuously improved MVR Blower technology

PILLER MVR Blowers have been used in industrial processes around the world for many decades. As industrial process requirements become more challenging, expertise must keep up with the pace. PILLER is always at the forefront of technology, looking for ways to improve durability and performance.


One result of this effort is our patented squeeze oil damper bearing, which combines the simplicity of antifriction bearings with the performance and reliability of hydrodynamic bearings. While providing the necessary damping when the critical speed is exceeded, it also reduces the bearing stiffness so that the critical speed is reduced well below the operating range of the blower.


In recent years, the performance range of our blowers has grown considerably, primarily with the addition of our VapoFan product line for small volume flows, and a current product line development to produce a temperature rise of up to 23K.

Customized MVR blowers for your requirements

What is so unique? All PILLER MVR Blowers are specifically developed and designed for steam applications. We serve a wide range of applications and specialize in customer-specific solutions for steam compression.


Our quality promise "Made by PILLER" means more than just quality components, materials, manufacturing, and final testing. It also stands for decades of experience and expertise in designing products for a wide range of process applications. We develop the best solution for your process requirements to ensure that our blower meets your specific needs.


All new developments and improvements to our machines are tested in our own MVR process plant.

The VapoLine

MVR Blowers for your application

The choice of a PILLER MVR Blower ultimately depends on operating conditions such as temperature differential and compression ratio.


The range of applications for MVR blower solutions is constantly expanding through implementation of new technology. Today, it is possible to produce a temperature rise (ΔT) of up to 23 K with a single-stage blower from PILLER.


Excellent performance and maximum efficiency are achieved with unique solutions. This is why PILLER specializes in customizing MVR blowers to your specific requirements: the VapoFlex.


With our MVR blowers, we draw on the entire portfolio and design the blower components to meet a wide range of requirements. With one hundred percent variability, no two steam compressors are alike. We design impellers, housings, materials, and bearings to accommodate the desired volume flow, required pressure and temperature rise, as well as general process conditions.


In addition to the variety of models, PILLER stands out from the competition with a modular, compact unit for steam compression in low mass flow MVR applications in the range of 200 to 5,000 kg/h. Where positive displacement compressors have often been used in the past, e.g. rotary lobe or Roots blowers, the VapoFan is a convincing alternative, employing unique technological advantages to provide a high-performance blower:

  • compact, vertically arranged, high-performance blower with direct-coupled drive
  • Temperature rise from 5 to 20 K
  • Non-critical gap dimension (clearances), continuous flow, and constant efficiency
  • completely constructed single-stage or two-stage solution


Our newest product line in the category of steam and vapor compressors lives up to the "Made by PILLER" reputation for durability and quality, but it also offers a new range of performance that competes with turbo compressors. Pressures of up to 20 bar and tip speeds of 400 m/s open new areas of application. Although specially designed to achieve maximum performance in steam applications, this compressor is also available for use with other industrial process gases.

What is mechanical vapor recompression?

The MVR process explained

Large quantities of process steam is required in numerous industrial applications. To achieve this, companies must use considerable amounts for energy. An effective measure to save energy – and to reduce the high consumptions of steam up until now – is the mechanical vapor recompression method, used in evaporation, distillation, crystallization and drying.

Reduced energy consumption

The temperature of the resulting process steam (vapor) is increased with a radial fan (mechanical vapor recompressor, MVR), and therefore to a higher energy level, and then fed back into the process as fresh heating steam. The energy contained in the steam is not lost; only the energy required to increase the temperature must be additionally raised.

Increased process efficiency

The closed process enables to evaporate temperature-sensitive fluids such as milk in high vacuum at approx. 60 °C and even blood plasma at 35 °C. Valuable components for the end product (e.g. milk powder) remain unaffected and thus increase the quality and value of the product.

Limitless applications for MVR blowers

Mechanical vapor recompression was initially used almost exclusively in the dairy industry. In the following years, its areas of application were expanded, and now include the dairy industry, brewing industry, sugar industry, saline industry, pulp industry, chemical industry, alcohol industry etc.

MVR blowers in thermal separation processes

Thermal separation is a widespread technology in many industries.

However, companies typically incur considerable energy costs due to the high demand for process steam. An effective measure to save energy, and to reduce high steam consumption, is the implementation of mechanical vapor compression. This technology is used in a wide variety of applications such as distillation, crystallization and concentration.


PILLER high-performance blowers are used as compressors in these processes and are precisely tailored to the application.


During distillation, liquid mixtures of substances with different vapor pressures and boiling temperatures are separated. Examples include distillation of alcohol, or the recovery and purification of solvents.


Evaporation produces a concentration of the substance being processed. In applications such concentrated milk or fruit juice production, evaporative systems are also used as a precursor to dryers in the food industry.


During the crystallization process, substances are separated from one another by using different solution equilibria. Applications include salt extraction and fertilizer production.

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