Industrial Utility Efficiency    

Atlas Copco Introduces AWS and AWD Liquid Ring Vacuum Pumps

Atlas Copco introduced its new AWS and AWD series standard liquid ring vacuum packages. These units are perfect for use in humid, dusty and dirty environments commonly found in industrial processes. The pumps have a simple sturdy design, and reliably deliver vacuum to a whole range of industries including food and beverage, dairy, mining, chemicals, oil, steel, cement, plastics, textiles and food processing.

Liquid ring pumps are equipped with a fixed blade impeller located eccentrically within a cylindrical casing. As the impeller rotates, liquid (usually water) is thrown out by centrifugal force to form a liquid ring around the circumference of the casing, sealing the tips of the impeller and creating separate enclosed gas chambers between each blade. As a result of the eccentric position of the impeller, these chambers vary in volume as the shaft rotates, having the effect of drawing in and compressing process gas.

“Liquid ring vacuum pumps combine a sturdy, reliable and low-maintenance design with highly-efficient performance and silent running,” says Adrian Sandham, Atlas Copco’s product manager. “These pumps are also extremely well-suited for humid, wet or corrosive process flows and even tolerate particles with ease. Users benefit from short lead times, minimum life-cycle costs and high reliability.”


The single-stage AWS360 liquid ring vacuum pump is a total fluid-recovery module.


Two Models, Three Configurations

Capacities range from 100 to 22,000 cfm. Lower capacity, below 3,237 cfm, units are available as single-stage AWS models or two-stage AWD models preconfigured with direct-drive options in 50 and 60 Hz. speeds. For larger installations, belt or gearbox transmission high capacity AWL pumps can often be the most appropriate selection. All AWS and AWD pumps achieve class-leading ultimate pressure levels as low as 29 in-HgV. Single stage AWS pumps have outstanding efficiency above 24 in-HgV, making them ideal for general process applications, such as filtration and dewatering, or pump down and evacuation duties.

The two-stage AWD pumps provide constant high-performance at operating pressures below 24 in-HgV. Two synchronized pump chambers work in series to achieve high-performance and improved efficiency on continuous process duties such as, drying, degassing, exhausting and solvent recovery.

The AWS and AWD vacuum pump series are offered in three pre-engineered modular configurations designed for once-through, partial recirculation or total recovery of the service water. In most cases all wetted system components are manufactured from stainless steel. “We try to make the customers life easy, so we offer all three configurations as pre-fabricated plug-and-play modules, including pump, motor and water recirculation system mounted on a compact skid,” Sandham explains. “Our customers receive a complete solution, which can be easily installed and commissioned with the minimum amount of work.”


Resource-Conserving Fluid Recovery

The once-through pump is the module with the simplest design. It consists of a pump with electric motor, drive system and skid. It is ideal for installations with an adequate supply of site water available so it can then be continuously drained from the pump for re-use. The pumping system adds no contaminates to the service water other than those coming from the process.

In the case of partial recovery, the discharge liquid-process gas mixture is collected in a vessel where it is mixed with fresh sealing liquid to ensure a constant temperature in the pump. Excess liquid is released from the system via an overflow. Compared with once-through operation, this mode of operation typically saves 50 percent of the fresh water required.

“With total recovery, liquid savings of up to 95 percent are possible,” Sandham explains. The recovered liquid is cooled via a high-efficiency heat exchanger before being returned to the pump chamber, “This configuration works with a closed liquid-cycle, and is recommended because it physically separates the cooling water circuit from possible process contaminates.”


Tailor-Made Solutions

Pre-engineered standard configurations allow for fast response to customers with proven technology solutions based on years of experience and best practice design. For more complex projects, the Atlas Copco applications teams develop systems tailored to meet the unique requirements of any customer. Atlas Copco experts can offer liquid ring packages adapted to most process conditions, including special materials and design of multi-stage systems.

“In addition, we can develop and design systems suitable for operation in potentially explosive atmospheres in accordance with ATEX,” adds Sandham. “We offer testing to Pneurop and HEI standards along with material certifications, project support and approved quality plans. Furthermore, our electrical engineers have experience with the design and installation of control systems for intelligent pump management.”


Atlas Copco is a world-leading provider of sustainable productivity solutions. The Group serves customers with innovative compressors, vacuum solutions and air treatment systems, construction and mining equipment, power tools and assembly systems. Atlas Copco develops products and services focused on productivity, energy efficiency, safety and ergonomics. The company was founded in 1873, is based in Stockholm, Sweden, and has a global reach spanning more than 180 countries. In 2016, Atlas Copco had revenues of BSEK 101 (BEUR 11) and about 45,000 employees. For more information, please visit

Atlas Copco’s Vacuum Technique business area provides vacuum products, exhaust management systems, valves and related products mainly under the Edwards, Leybold and Atlas Copco brands. The main markets served are semiconductor as well as a variety of industrial segments. The business area has a global service network and innovates for sustainable productivity in order to further improve its customers’ productivity. Principal product development and manufacturing units are located in the United Kingdom, Czech Republic, Germany, South Korea, China and Japan.

Industrial Vacuum is a division within Atlas Copco's Vacuum Technique business area. It develops, manufactures and sells sophisticated vacuum products and solutions for customers in the industrial process and rough vacuum sectors, for example steel, CPI (chemical process industries), metallurgy, petrochemical, food packaging and paper handling. The division markets products under the Atlas Copco, Edwards, Quincy and Leybold brands. The division's focus is to improve customers' productivity. The divisional headquarter is in Cologne Germany, the main production locations are in Cologne, Qingdao and Tianjin China, Lutin Czech, Valence France and Antwerp Belgium.