Industrial Utility Efficiency
One definition of “calibrate” is “to determine, rectify, or mark the graduations of something”. An ammeter is an instrument for measuring electric current. Therefore the simple definition of a calibrated ammeter is a current measuring device marked with units of measure, presumably amperes. In the blower industry, however, the term has developed a specific meaning. A calibrated ammeter is an instrument that measures a blower motor’s current draw and converts the measurement to a display of blower airflow rate.
Different industries have differing levels of toxins and contaminants that need to be reduced before wastewater can be discharged. The company specializes in understanding those requirements and creating custom turbo blowers to customer specifications. Its leading industries are pulp and paper, poultry and food and beverage.
The ideal blower control matches the blower airflow to the process demand. The process demand, in turn, must be established by the aeration control system. This control strategy has become standard practice in most treatment facilities because of its proven effectiveness in reducing energy consumption and improving process stability.
The wastewater treatment plant for the City of Lafayette, Colorado, is a Class B biosolids facility. It meets grid regulations for volatiles reduction with at least a 38% reduction, and has a solids retention time (SRT) of at least 15 days at 95°F (35°C). Class B biosolids can be used as fertilizer for livestock feed and other applications that don’t directly lead to food for human consumption.
In order to properly identify the performance requirements of a blower it is necessary to identify the inlet and discharge pressures. The friction losses in the inlet and discharge piping must be calculated to determine the total pressure requirement. This article details a simplified procedure for calculating piping losses.
Many designers and operators believe that multistage centrifugal blowers are not suitable for variable speed control. They also feel that multistage centrifugal blowers are an inefficient option for wastewater aeration. Implementing VFD control of their aeration blowers allowed the plant to improve energy efficiency. The reduction in energy expense paid for the system upgrade in less than two years.
Supplying air to process equipment necessitates a system approach. Selecting the blowers is a critical design step, but far from the final one. The layout of the blower room and ancillary equipment is just as critical to project success as the blowers themselves.
The new solution also saves close to 90 percent of the annual maintenance costs. The side channel blowers required intensive repairs and were therefore a source of high costs. MINK MV claw vacuum pumps provide completely dry compression of intake air and thus work without operating fluids such as oil or water. This makes the vacuum pumps virtually maintenance-free.
Aerobic digestion is a common treatment technology used at small-to medium-sized wastewater treatment plants for the treatment of waste activated sludge (WAS). The objective of aerobic digestion is to treat the sludge for disposal, and for those trying to meet Class B biosolids, further reduce volatile solids (VS) and pathogens to ensure the sludge is suitable for land application.
When the plant’s original aeration blowers became costly to operate and newer technology offered the promise of energy-savings, Fuqua took decisive action and replaced the older blowers with high-speed turbo blowers. As a result, the plant saves ratepayers approximately $30,000 per year in energy costs and bolsters the plant’s ability to maintain uptime and achieve extremely clean effluent.
Leidos Engineering, LLC., is responsible for implementing the Wisconsin Focus on Energy® Large Energy Users (LEU) Program in Wisconsin. Blower & Vacuum Best Practices interviewed Leidos Engineering’s Joseph Cantwell, P.E., Senior Energy Management Professional, Focus on Energy – LEU Program, to learn how the firm works with Focus on Energy to help wastewater treatment facilities in the dairy state reduce energy consumption and save costs.
