Industrial Utility Efficiency
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.
In the absence of official third party specifications on energy efficiency, it is difficult to evaluate and compare blower technologies fairly and effectively. The lack of readily available evaluation tools leads to misinformation and unfair comparisons between technologies. Further, the performance verification process is difficult to prove.
Every municipality and utility is facing the reality of rising energy costs. In 2010, the Town of Billerica, MA, which is located 22 miles northwest of Boston with a population of just under 40,000 residents, engaged Process Energy Services and Woodard & Curran to conduct an energy evaluation of the Town’s Wastewater Treatment Facility (WWTF) and pump station systems sponsored by National Grid. The objective of the evaluation was to provide an overview of each facility system to determine how electrical energy and natural gas were being used at the facility and to identify and develop potential costsaving projects.
The right ingredients and processes are essential for manufacturing flavorful beverages that contribute to the company’s bottom line. But what happens to all those other “ingredients” that aren’t part of the recipe? Cleaning up those unwanted ingredients from bottling plant wastewater can consume large amounts energy, time and money—and become a distraction from the company’s primary goal of manufacturing beverages.
Aeration systems at wastewater treatment facilities present significant, cost-effective energy savings opportunities. Aeration—the introduction of air into the wastewater stream to support anaerobic bacteria and mixing—is a key function at the majority of wastewater treatment facilities in North America. Aeration accounts for 25-60 percent of total energy consumption at wastewater treatment facilities , and a significant piece of operating budgets sector-wide.
We have industrial accounts where we mix chemicals and acids. Our favorite is blending wine and spirits using compressed nitrogen. The old way to blend was to use “air rousing.” This was done by installing rows of perforated pipes in the bottom of the tank and attaching an air pipe to this grid. Since the typical mixing cycle was 45 minutes, copious amounts of air and energy were used.
In recent years, there have been many changes in wastewater treatment. Most modern processes control three cycles: DO, NH4, and NO3, and all of the processes require high volumes of air. Undeniably, the low pressure air system uses more electrical power than the rest of the wastewater treatment plant combined. The blower packages in these systems can be equipped with low noise enclosures, fixed speed or variable speed drives, and can include all the instrumentation needed for self-protection.
Blower & Vacuum Best Practices® Magazine interviewed Ms. Julie Gass P.E., Lead Process Mechanical Engineer, from Black & Veatch on trends in the wastewater treatment industry especially pertaining to new technology aeration blowers and energy efficiency.
The concept offers new possibilities for generating positive pressure or vacuum in a variety of applications. “By applying screw compressor technology to low-pressure air compression, we’ve greatly improved efficiency,” said Pierre Noack, President and CEO of Aerzen USA. The Delta Hybrid has seven patents or patent applications, making it one of the most innovative products in compression technology.
The Focus on Energy Water and Wastewater Program was developed to support the industry because of the enormous potential to reduce energy use without compromising water quality standards. Through the program, numerous water and wastewater personnel have learned that energy use can be managed, with no adverse effects on water quality. Most locations that have saved energy have found improved control and treatment.
The Hoffman U.S. Machinery Division was established in 1905 outside of East Syracuse, New York. The initial product was an exhauster for the dry cleaning industry — pulling a steam vacuum across the garments. The Company grew and soon after began discovering industrial applications for their technologies. After the war period, during which Hoffman manufactured ball bearings and operated it’s own foundry, the company began discovering new industrial markets for it’s products. A signiï¬cant part of their business was in the wastewater treatment industry.
