Industrial Utility Efficiency    

Aeration Blowers

Most blower applications for wastewater treatment are for conventional activated sludge aeration. The water level is typically constant, and pressure variations are usually less than one psi. There are other applications, however, that undergo significant variations in water level. These processes present challenges, but they can be accommodated with proper blower system design.
The 2017 WEFTEC Technical Exhibition and Conference was held October 2-4 at  McCormick Place in Chicago. The 2017 event made the list of the top five largest and best-attended events in the conference’s 90-year history. A total of 22,860 registrants and 1,011 exhibitors using a net of 305,600 ft2 of space attended WEFTEC. The event featured technical sessions, workshops, facility tours, and numerous other educational and networking events. WEFTEC is an enormous show. Both Blower & Vacuum Best Practices and Compressed Air Best Practices® Magazines were pleased to be in the literature bins at the 2017 WEFTEC!
Most-Open-Valve (MOV) can be a cost-effective way to optimize aeration energy. It can also be a confusing and troublesome addition to a process automation project. In my experience MOV is the least understood aspect of aeration control. This article will shed light on MOV, the process and energy impacts and why it’s worth the trouble.
Blower manufacturers are the source for the most accurate information on aeration blower power consumption. This includes the impact of various control technologies on the many types of blowers used for aeration. However, system designers often need to analyze several alternatives, making reliance on input from suppliers inconvenient. An understanding of the principles of operation will also enhance the designer’s ability to assess the data received from various sources.
The capacity and pressure requirements of blowers in a Water Resource Recovery Facility (WRRF) are determined by the aeration system. When systems are manually controlled blowers often operate at constant flow and pressure day in, day out. When the aeration system is automatically controlled to maintain a set dissolved oxygen (DO), however, the blower’s flow and system pressure vary constantly. Understanding these variations will help designers and suppliers optimize blower performance.
The Wastewater Association of Rheinfelden-Schwörstadt operates the wastewater treatment facilities in Schwoerstadt and Rheinfelden-Herten, Germany, as well as several rainwater overflow basins. This wastewater treatment facility now satisfies the highest requirements, and with a population of about 47,000, has reached a size that also guarantees sufficient disposal capacity for future generations.
Blower efficiency is a justifiable concern during the design and selection of aeration equipment. However, efficiency may not be the most important consideration in aeration blower applications. In many cases the blower with the highest efficiency will not provide the lowest energy consumption! Blower turndown is a parameter that is generally more important than efficiency in optimizing energy use.
Aeration blowers receive a lot of attention from design engineers, suppliers, and end users. That is understandable since blowers account for more than 50 percent of the energy used in a typical wastewater treatment plant (WWTP). They represent “low hanging fruit” for energy conservation measures in wastewater treatment!
Yeast fermentation is a vital process in the production of many food and beverage products. It is a common application within breweries, bakeries, and wineries, along with other facilities where biogas and ethanol are produced. In these facilities, fermentation tanks filled with a reaction liquid are often supplied with air from blowers. Recently, there has been a trend in the adoption of high-speed turbo blowers for yeast fermentation applications, as the blower technology can yield large energy savings if properly installed and controlled.
The Ilmajoki sewage treatment plant (STP) located in southern Finland was built in the mid-1970s during a boom of infrastructure construction. Over time, industrial presence in the Ilmajoki area grew, and the plant saw an increase in flow of industrial effluent—or liquid waste and sewage. As the amount of influent increased, the plant was no longer able to meet required performance criteria suffered from a severe lack of oxygen—particularly during peak loading times.
Hoffman & Lamson has been manufacturing multi-stage centrifugal blowers for a long time. Lamson was founded in 1880, and Hoffman was established in 1905. Now a single entity under the Gardner Denver Nash Division, the company has some serious resources to complement its 100-plus years of blower expertise.