Industrial Utility Efficiency    

Aeration Blowers

Finally, a test code has been created that will provide accurate performance comparisons for both positive displacement and dynamic (centrifugal) blowers. ASME PTC 13 provides procedures for determining the required total operating electrical power of a packaged blower system, termed the “wire-to-air” performance. Here’s a review of PTC 13 and considerations related to this important standard.
One of the most exciting technologies impacting the ability of end-users to optimize blowers at their wastewater treatment plants and manufacturing operations is controls. Blower & Vacuum Best Practices interviewed Tim Hilgart, of Howden America, to get his perspective on blower controls technology and its application.
The 2019 WEFTEC Technical Exhibition and Conference was held September 23-25 at McCormick Place in Chicago. The event featured 148 technical sessions, 27 workshops, 16 mobile sessions, seven local facility tours and 1,000+ exhibitors.  Both Blower & Vacuum Best Practices and Compressed Air Best Practices® Magazines were pleased to be in the literature bins at the 2019 WEFTEC!
In the first of this two-part series on the basics of aeration control valves we examined valve fundamentals and basic equations for analysis. Here, we look at interactions between valves and discuss new flow control technologies.
In 2010, the American Society of Mechanical Engineers (ASME) established the PTC 13 Committee to establish a power test code for all blower technologies. Blower & Vacuum Best Practices Magazine interviewed Committee Chair Jacque Shultz, HRO-Turbo Product Technical Leader, Howden North America, Inc., for an update on the new code.
Efficiency compares the inputs used by a system to the outputs produced. It is a commonly used concept, but one which is prone to a great deal of misuse in many industries. This article provides insight into the parameter known as “efficiency,” how it’s calculated, and importantly, it’s uses and limitations in predicting blower energy consumption and comparing alternate system designs.
After auditing and field-testing, the Sni-A-Bar Municipal Wastewater Plant in Blue Springs, Missouri, partnered with Inovair to replace 4 fixed-speed rotary lobe blowers on its aeration system with 4 Variable Frequency Drive (VFD), integrally geared centrifugal blowers. The new blowers, along with improvements in blower controls, reduces annual energy use by 442,664 kWh and peak electrical demand by 48.76 kW, which translates to an annual energy reduction of 37 percent and anticipated savings of $42,000 per year. Additionally, a rebate of $45,799 from the local utility resulted in a payback of less than six years.
Turndown designates the operating range of an aeration blower or a blower system – and it can often be the most important factor in determining the ability of a system to match process demand. It is also critical to the system’s energy optimization. Unfortunately, in designing blower systems and controls turndown is not always given the attention that its importance merits. Here’s a look at the critical nature of turndown in wastewater treatment plants and recommendations for ensuring adequate turndown when utilizing Positive Displacement (PD) and centrifugal blowers.
Originally built in 1958, the CMA wastewater treatment plant serves 14,000 residents, as well as businesses, in Clearfield Borough and surrounding portions of Lawrence Township, Clearfield County, PA. From the start, the plant consistently met water quality and effluent parameters as specified in its National Pollutant Discharge Elimination System (NPDES) permit throughout. However, new mandates in 2010 and the need for ongoing improvements drove the need for plant upgrades.  
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.