At the beginning of the 20th century, biological wastewater treatment — more specifically, the activated sludge process — was developed and became widely accepted as the treatment method for municipal wastewater, helping to protect our lakes and rivers from pollutants and support public health. In 1947, the Committee on Development of Uniform Standards for Sewage Works was created by the group known as the Great Lakes – Upper Mississippi River Board of State and Provincial Public Health and Environment Managers.
When selecting a mixing technology, wastewater treatment plants (WWTPs) and their consultant engineers must consider numerous factors, balancing specific treatment demands with plant priorities and ultimately choosing the technology that best suits their needs and specifications. Compressed gas mixing (CGM) is often the best solution, allowing designers to circumvent many challenges that alternative technologies either create or cannot overcome.
Wastewater treatment processes have come a long way in the past century, but demand continues to grow for more reliable and efficient treatment technologies. As a result, industry professionals are searching for an all-encompassing solution to enhance their treatment plants and processes. One of the purest environmental aids on the market is oxygen.
As many well know, system measurement is essential to ensuring a compressed air system is running efficiently and effectively, with good air quality and adequate pressure. This is also well understood by a multi-national food company (name has been withheld to protect the innocent) who started a focused effort to measure and improve their compressed air systems in their many processing plants worldwide.
Air-operated double diaphragm (AODD) pumps are common to many manufacturing facilities. As estimated by veteran compressed air auditor Hank van Ormer of Air Power USA, approximately 85 to 90 percent of plants in the United States have AODD pumps. They are used for all kinds of liquid transfer applications, like those found in chemical manufacturing, wastewater removal, and pumping viscous food products.
Aeration tanks use bubble diffusers to distribute oxygen within the wastewater. Fine bubble diffusers, or those that produce a large amount of very small air bubbles, first began to become popular in the 1980s, as they had a much higher efficiency than coarse bubble diffusers. Fine bubble diffusers generally feature a membrane that allows airflow to pass from the piping system on the floor of the tank through the body of the diffuser and the membrane, providing oxygen into the wastewater for treatment.
The design of wastewater treatment plants is changing, and it has something to do with LEGO® bricks. More specifically, it has to do with how large and complex LEGO structures are built. If you follow the instructions carefully, you build module after module, eventually piecing them together to create a fully functional and cohesive unit.
A replacement strategy for air compressors and blowers integrated into a system-level approach towards energy efficiency can deliver significant energy savings and optimize equipment performance. At the Victor Valley Wastewater Reclamation Authority, a blower replacement project yielded annual energy savings of more than 928,000 kWh and \$98,000 in energy costs, while improving the reliability of its secondary treatment process. In addition, the agency qualified for important incentives from its electric utility — significantly improving the project economics and resulting in a 2.94-year payback.
High speed bearing technology is applicable for aeration blowers operating at much higher speeds than the typical 60Hz, 3600RPM for cast multistage units. High Speed Turbo (HST) units are usually single stage (though some utilize multiple cores) and rotate from 15,000 to 50,000RPM. At such high speeds, standard roller bearings cannot offer the industry standard L10 bearing life. Two types of bearing technologies have come to dominate the wastewater treatment market for these types of machines: airfoil and magnetically levitated. Often the two technologies are compared as equals, however, in many significant ways they are not.
Compressed Air Best Practices® Magazine interviewed Frank Mueller (President) and Stephen Horne (Blower Product Manager) from Kaeser Compressors.
Kaeser Compressors continues to grow both in the U.S. and internationally. We currently employ approximately 4800 people globally. In order to support the demand and maintain our superior quality and quality service levels, we continue to invest in people, facilities and technology.
Productivity is more reliable when equipment can be monitored to detect incipient failures and take corrective action before the plant goes down. But many devices, such as analog control valves, pneumatic valve terminals and field sensors, often do not offer diagnostic feedback, or it is not being used. This white paper describes how this problem is being addressed, and includes an example of pneumatic valve terminals that can monitor, among other things, open load or coil currents at the specific valve and pressure inside the valve terminal.