Environmental

  • Biogas production
  • Compressed air in wastewater treatment plants
  • Digester gas compression
  • Filtering
  • Fish and prawn pond aeration
  • Landfill site
  • Laminating solar modules
  • Soil gas extraction
  • Suction vehicles for wastewater cleaning
  • Vacuum priming
  • Wastewater purification/oxygenation of activated sludge tanks  
Environmental

Environmental


Biogas production

The biomass produced in activated sludge tanks and clarifying tanks is stabilized in the digestion tower and used to produce biogas. A thorough mixing of the sludge increases the gas yield and reduces its retention time in the reactor. In the process, the gas is withdrawn from the upper part of the digestion tower, compressed in the compressor and reintroduced through the nozzles at the bottom.

Example of Biogas application:

Example_Biogas_01
 


Compressed air in wastewater treatment plants

The digestion tanks in wastewater treatment plants are activated with oxygen by means of compressed air. A thorough mixing of the sludge with oxygen increases the gas yield and reduces its retention time in the tank. Even better results are achieved with warm compressed air.

G-Series – Side Channel

Digester gas compression

The pump's operating liquid cools the digester gas by absorbing the heat of compression, thus providing an almost isothermal mode of operation. This has a positive effect on the service life of downstream valves, gas burners and motors, and it reduces maintenance costs. The cooling function of the operating liquid simultaneously acts as a flame arrester and reduces expenditures for explosion protection. The contaminated raw gas is also cleaned in the water ring as though in a gas scrubber and is partially dried. The gas is thus oxygenated and returned to the wastewater treatment process.
 

L-Series – Liquid Ring

Filtering

The filtering process is accelerated by applying vacuum to a container which then pulls the liquid through a filter. The vacuum thus “helps“ gravity do its job.


Landfill site

The digestion of covered garbage under exclusion of oxygen produces landfill gas. The gas is collected in collection systems, removed from the landfill and compressed by gas compressors or gas blowers. The gas can be used as heating fuel, transformed into electricity or used as liquefied gas.


Laminating solar modules

Laminating is a cyclic process. A sandwich is typically made of the following layers

• cover film
• polymer film (usually ethylene vinyl acetate)
• solar cells
• polymer film (usually ethylene vinyl acetate)
• glass panel

These layers are taken into the laminator’s chamber where the air is evacuated using vacuum. In a second step, still under vacuum, the polymer films are baked using heat.


Soil gas extraction

Soil gas extraction is an approved method for the reclamation of soil polluted with aromatic hydrocarbons and volatile halogenated hydrocarbons. The operating range of the side channel blowers, depending on the amount and distribution of the substances, saturation pressure of the pollutant, air flow through the soil and vacuum applied, amounts to 10 – 80m. Disposal of the extracted air must be carried out in compliance with the Technical Instructions on Air Quality.

G-Series – Side Channel

Suction vehicles for wastewater cleaning

The suction pressure necessary for removing wastewater and cleaning sewer networks is provided by vacuum pumps. The contaminants in the wastewater are sucked in and can be flushed out periodically by means of pumps.
 


Vacuum priming

The extracted air may contain contaminating gases, vapours and particulates. We offer technical solutions that protect from these harmful inclusions and offer reliable continuous operation.

L-Series – Liquid Ring

Wastewater disposal

With the use of central vacuum systems the disposal of wastewater can be effected at the same place. The wastewater can be collected, drained and disposed of in complete housing areas at the same time. With the use of vacuum up to 97%  of the wastewater can be transported uphill.

L-Series – Liquid Ring

Wastewater purification-oxygenation of activated sludge tanks

To reduce the space requirements and costs of wastewater treatment plants, a growing number of activated sludge tanks are being set up. The introduction of oxygen is extremely important for purifying wastewater. Compressors supply the compression pressure required for maximum oxygen yield.


Further applications

Evacuation systems
Related Products: RadialRotary LobeClaw

Drying systems
Related Products: RadialRotary LobeClawScrew

Gas recirculation
Related Products: Rotary LobeClaw

Small domestic sewage plants
Related Products: Rotary Lobe


About Elmo Rietschle

Elmo Rietschle is part of Gardner Denver, Inc., a leading global manufacturer of highly engineered products. Gardner Denver is headquartered in Milwaukee, Wisconsin, USA and has facilities in more than 30 countries.

To learn more about Gardner Denver, Inc., please visit www.gardnerdenver.com.

© 2017 Gardner Denver, Inc.