openPR Logo
Press release

Liquid ring vacuum pumps – Classic vacuum technology and yet still state of the art

07-30-2019 11:49 AM CET | Industry, Real Estate & Construction

Press release from: Busch Dienste GmbH

Two versions of Dolphin liquid ring vacuum pumps that are available with pumping speeds from 25 to 26,800 cubic metres per hour

Two versions of Dolphin liquid ring vacuum pumps that are available with pumping speeds from 25 to 26,800 cubic metres per hour

Vacuum technology has never stopped developing – not only in the recent past, but for decades it has continued to progress. Today, dry screw vacuum pumps are used in chemical processing technology and many other applications just as dry claw vacuum pumps have established themselves as standard vacuum generators in entire branches of industry. Oil-lubricated rotary vane vacuum pumps are also state of the art in many applications, not least due to their ongoing development. In their fields of application, they are generally the most used vacuum pumps. However, despite many improvements, new developments and further advancements, one principle of vacuum generation that has remained to this day in certain applications, and is still successfully applied, is the liquid ring vacuum pump.

The principle behind the liquid ring vacuum pump was already developed in 1890 as a “water ring pump”. Due to their simple and robust construction, liquid ring vacuum pumps are suitable for vacuum generation in applications in which damp gases or vapours are evacuated or those in which condensation inside the vacuum pump tends to take place during the compression process. They are therefore ideally suited to humid processes and are thus used for low vacuum generation in process technology, the chemical industry, during petroleum production and processing, for evacuating steam turbine condensers, also in the plastics industry, paper manufacturing, the food technology industry and many other industrial applications.

Operating principle
As an operating fluid, liquid ring vacuum pumps use water or a liquid compatible with the gas or vapour to be evacuated. Ethylene glycol, mineral oils or organic solvents are also used, as are other liquids that are already part of the process. The basic principle is the same in all sizes and versions.
An eccentrically mounted impeller rotates within a cylindrical housing. This housing is filled with operating fluid to the extent that the vanes of the impeller are immersed in the fluid. The rotary motion of the impeller and the resulting centrifugal force cause the liquid in the housing to form the so-called liquid ring. The gas is pumped in the spaces between the individual vanes and the liquid ring. Thanks to the eccentric arrangement of the impeller, the volumes of these spaces change with the result that gas is sucked in, compressed and discharged again. The liquid ring seals the individual spaces down to the cylinder. Therefore, it is sometimes referred to as the sealing fluid instead of the operating fluid.

Mechanism
Due to the operating fluid used, this mechanism can only be used in the rough vacuum range. The reason for this is that the achievable vacuum level depends on the vapour pressure of the operating fluid, which is constantly pumped through the vacuum pump. This allows a liquid ring vacuum pump to be operated at relatively low temperatures, and in addition, the temperature rise of the medium is kept to a minimum during the compression process. Therefore, liquid ring vacuum pumps are ideally suited for pumping vapours and gases with a high moisture content. The low temperatures in the vacuum pump are favourable for condensation of process vapours. To an extent, this means that the vacuum pump additionally functions as a condenser and because condensation takes place when the mixture enters the vacuum pump, the volume is drastically reduced. In addition to the condensation effect, this also achieves an increase in the nominal pumping speed.
The operating fluid absorbs the heat of compression and as liquid ring vacuum pumps are virtually isothermal, they offer advantages when pumping temperature sensitive products, such as polymers.
One significant advantage of liquid ring vacuum pumps is that the operating fluid and the materials used for the components can be adapted to fit the pumping medium. This also makes it possible to pump corrosive or explosive gases and vapours. Due to the low operating temperatures, pumping explosive materials can, in any case, be considered much less problematic than with other mechanical vacuum pumps.

Construction
Basic differentiation is made between single- and two-stage liquid ring vacuum pumps. In the single-stage version, the compression process described above is performed in one compression stage. In the two-stage vacuum pump, the pre-compressed pumping medium from the first stage is conveyed to a second compression stage and compressed again. Ultimate pressures of 130 hPa (mbar) can be realised with single-stage liquid ring vacuum pump versions, while two-stage versions can achieve up to 33 hPa (mbar).
Even the sizes vary significantly. Busch Vacuum Pumps and Systems has different series and versions of Dolphin liquid ring vacuum pumps in its portfolio, with pumping speeds that cover the range from 25 to 26,500 cubic metres per hour.

Variants
Supply and removal of operating fluid can happen in three ways:

1. Non-recirculating operation – once through operation
This is the simplest variant for operating a liquid ring vacuum pump and is used any time there is sufficient operating fluid available. The compression stage is constantly supplied with operating fluid. The fluid is then discharged together with the gas and the condensate.

2. Open fluid circuit – partial recirculation operation
In an open circuit, the operating fluid is diverted into a liquid separator together with the gas after it exits the vacuum pump. Liquid and gas are separated there. The gas is discharged or transferred while the operating liquid flows back to the pump. Additional fresh operating fluid is supplied through the liquid separator in the circuit. This guarantees that there is enough liquid in the circuit and that the temperature does not rise. This type of open circuit can save up to 50 percent of the fluid when compared to non-recirculating operation.

3. Closed fluid circuit – total recirculation operation
There is also a liquid separator downstream from the pump in a closed circuit. Gas is discharged from the separator, while the operating fluid is diverted using a heat exchanger before it enters the vacuum pump again. The operating fluid is thus maintained at a constant temperature. This means that only small amounts of fresh fluid need to be added via the liquid separator. We therefore recommend the closed circuit any time that sufficient operating fluid is not available or when as much operating fluid as possible should be conserved.

Tailored vacuum systems
Liquid ring vacuum pumps are exceptionally well suited for use as modules in vacuum systems and installations. Lower ultimate pressures can be realised in combination with gas, air or steam ejectors (jets) or Roots type vacuum boosters. Technically and economically optimum solutions can be found for vacuum systems that are directly tailored to the individual application. Busch Vacuum Pumps and Systems has decades of experience in designing, configuring and building these types of systems, which are used in economical and safe operation worldwide in chemical processing technology, petroleum production and processing, power generation and many other areas. The individual Dolphin liquid ring vacuum pump sizes from Busch are available in different ATEX-certified versions.

Jasmin Markanic

Busch Dienste GmbH
Global Marketing / Marketing Services
Coordinator Global Press & Media Relations

Schauinslandstraße 1
DE 79689 Maulburg
Phone: +49 7622 681 3376
Jasmin.Markanic@busch.de
www.buschvacuum.com

Busch Vacuum Pumps and Systems is one of the world’s largest producers of vacuum pumps, vacuum systems, blowers and compressors.
Its extensive product portfolio comprises solutions for vacuum and overpressure applications in all industries, including the chemical, semiconductor, medical technology, plastics, and food sectors. It also covers the design and construction of customized vacuum systems, as well as a global service network.
The Busch group is a family-owned company and is still managed by the Busch family. Busch Vacuum Pumps and Systems has 3,000 employees in more than 60 companies in over 40 countries worldwide. Busch is headquartered in Maulburg, in southwest Germany. This is the location of Busch SE headquarters, as well as the German production facility and German sales company. In addition to Maulburg, Busch also has its own production plants in Switzerland, the UK, Czech Republic, Korea and the USA.

Busch Vacuum Pumps and Systems was founded by Dr.-Ing. Karl Busch and his wife Ayhan Busch in 1963. Dr.-Ing. Karl Busch developed the “Huckepack”, which was the first vacuum pump that could be used for vacuum packaging of foodstuffs. The follow-up product, the compact “R 5” rotary vane vacuum pump, revolutionized food packaging. A further milestone represented the development of the “COBRA” screw vacuum pump. In 1971 the international expansion of the Busch group started with the founding of a sales company in the UK. The first production plant outside Germany was established in the USA in 1979.

This release was published on openPR.

Permanent link to this press release:

Copy
Please set a link in the press area of your homepage to this press release on openPR. openPR disclaims liability for any content contained in this release.

You can edit or delete your press release Liquid ring vacuum pumps – Classic vacuum technology and yet still state of the art here

News-ID: 1814272 • Views: 311

More Releases from Busch Dienste GmbH

Proven vacuum technology fit for Industry 4.0
Busch Vacuum Pumps and Systems enjoyed a great deal of interest from an audience of experts at the IFFA in Frankfurt. The vacuum technology specialist showcased its latest products for the vacuum packaging of meat and sausage products and for meat processing. Busch also premiered the new R 5 PLUS rotary vane vacuum pump, which is prepared for Industry 4.0. This innovative vacuum pump is based on proven rotary vane vacuum
Busch solutions for Industry 4.0 at ComVac
The Busch Vacuum Pumps and Systems trade show appearance received a great response from visitors to ComVac, the leading international trade show for compressed air and vacuum technology, held in Hanover, Germany. The interested trade show crowds were able to discover the topic of Vacuum 4.0 and the best-fitting innovative vacuum solutions at Busch. Numerous visitors took the opportunity to talk to the Busch vacuum experts. With Vacuum 4.0, Busch is
Busch presents new series of Dolphin liquid ring vacuum pumps
Busch Vacuum Pumps and Systems has now launched an entirely new series of liquid ring vacuum pumps. The new Dolphin LM/LT vacuum pumps have been completely redesigned but are based on proven liquid ring vacuum technology. With these new vacuum pumps, Busch has been able to optimize an existing product that has become an established part of many industrial processes, resulting in the development of extremely powerful, yet energy-efficient vacuum
Dry vacuum systems for centralization of vacuum supply
The concept, design and realization of central vacuum supplies is one of Busch Vacuum Pumps and Systems' core competencies. Thousands of such vacuum systems are in operation worldwide. A wide range of operating principles for generating vacuum in the individual pump modules are applied. In addition to oil-lubricated R 5 rotary vane vacuum pumps, dry-compressing vacuum modules can be used, for example in vacuum systems with COBRA NX screw vacuum

All 5 Releases


More Releases for Dolphin

Busch presents new series of Dolphin liquid ring vacuum pumps
Busch Vacuum Pumps and Systems has now launched an entirely new series of liquid ring vacuum pumps. The new Dolphin LM/LT vacuum pumps have been completely redesigned but are based on proven liquid ring vacuum technology. With these new vacuum pumps, Busch has been able to optimize an existing product that has become an established part of many industrial processes, resulting in the development of extremely powerful, yet energy-efficient vacuum
Travel Technologies Market Business Growth Statistics and Key Players Insights: …
QY Research Groups has announced the addition of "Global Travel Technologies Market Size, Status and Forecast 2019-2025" Market Research report to their database. Travel technologies are IT solutions used by airline companies, hotels, and OTAs to manage end-to-end travel solutions. IT solutions such as travel network management solution GDS, mobile solution, platform solutions, e-commerce software solution, data management solutions, and digital marketing solutions are primarily implemented in the travel industry. The increasing
Global Travel Agency Software Sales Market Qtech Software Dolphin Dynamics Toogo …
Researchmoz added Most up-to-date research on "Global Travel Agency Software Sales Market Report 2018" to its huge collection of research reports. In this report, the global Travel Agency Software market is valued at USD XX million in 2017 and is expected to reach USD XX million by the end of 2025, growing at a CAGR of XX% between 2017 and 2025. Geographically, this report split global into several key Regions, with sales
Busch presents new series of Dolphin liquid ring vacuum pumps
Busch Vacuum Pumps and Systems has now launched an entirely new series of liquid ring vacuum pumps. The new Dolphin LM/LT vacuum pumps have been completely redesigned but are based on proven liquid ring vacuum technology. With these new vacuum pumps, Busch has been able to optimize an existing product that has become an established part of many industrial processes, resulting in the development of extremely powerful, yet energy-efficient vacuum
Dolphin Tale made possible using new pool water treatment
The new blockbuster movie "Dolphin Tale" featuring "Winter" the dolphin, of the Clearwater Marine Aquarium, was a big hit at the movie theaters over the opening weekend. The movie finished in nearly a dead heat with another blockbuster movie "Moneyball" - featuring Brad Pitt. The top weekend grossing movie was the 3D release of "The Lion King", that came out the previous weekend. This
BATHROOM FIRM OFFERS LIFELINE TO STRICKEN DOLPHIN CUSTOMERS
A specialist bathing firm has offered a lifeline to stricken Dolphin customers by pledging to help elderly, infirm and disabled customers affected by Dolphin’s collapse into administration. Premier Care in Bathing has offered to waive any lost deposit placed on a bathroom adaptation order from the ‘Easy Bathing’ arm of Dolphin – and to carry out the important work so the customer will not lose money – or risk their safety. Premier