Technology

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.

Two years ago, sales were picking up and we began operating six extrusion lines on most days. We had to bring in some portable chillers, to keep up, and we started looking at buying a larger cooling system. We wanted to get rid of the portable chillers and have room to grow into four more extrusion lines. The new system we looked at was a 100-ton system that would have cost us around $150,000 in capital and installation and with a larger monthly electricity bill.

We were about to buy the new 100-ton chiller when our President, Abe Gaskins said, “Hold-on, can we replace the Liquid Ring pumps with something that doesn’t consume water”? That was our “Eureka!” moment.

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.

Using suction cups and air-driven vacuum pumps is a preferable gripping and handling method of corrugated cardboard materials and boxes in carton-machines like case/carton erectors and rotary cartoners. Robot based applications, like palletizing and de-palletizing, are other examples where the best practice technology for gripping and handling is by suction cups and air-driven vacuum pumps.

Energy efficiency and sustainability solutions are often associated with more obvious initiatives--such as installing compact fluorescent bulbs—but those solutions fail to dig deeper for the “hidden gems” that can have a much greater impact. For manufacturing and building engineers or anyone else dealing with high potential energy consumption and inrush current demands, compressed air systems are one of the first places to look for significant energy savings and greater sustainability.

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.

A large custom leather furniture manufacturer switches from rotary screw vacuum pumps to blowers for CNC router table hold down, and saves big on electricity, maintenance expenses and floor space.