Blower replacement helps plant become more efficient

Problem

 A wastewater treatment facility in the Pacific Northwest had issues with an air-bearing blower. To prevent frequent starts/stops on a sequencing batch reactor, the staff left the blower running continuously and wasting energy. The plant needed a system both reliable in a start/stop environment and energy efficient.

Solution

 The plant switched to Inovair’s IM-30 Geared Centrifugal Blower (stacked option). It is efficient and designed to withstand multiple start/stops without limitation, while maintaining high shaft stability over its complete operating range. This application used unlimited-life, non-contact floating ring oil-film journal bearings and tapered-land thrust bearings in the gear box. That type of bearings has been used for decades in turbo-machinery; they operate on the same principles as the crankshaft bearings in most cars.

Result:

 After thousands of starts/stops, the blower has worked flawlessly with no unexpected maintenance or downtime. In addition to energy savings, the maintenance reduced schedule reduced operating costs significantly. Local service with quick turnaround gave plant personnel with peace of mind. 855-466-8247; www.inovair.com

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Screw pumps stand up to decades of abuse

Problem

 The Calhoun (Georgia) Wastewater Treatment Plant in 1988 installed two Lakeside Equipment 60-inch, 75 hp open screw pumps and two 72-inch, 50 hp screw pumps. Due to population growth, the plant needed more treatment capacity.

Solution

 Original concrete construction left an empty space for a third pump in each capacity. The space was filled in 2012 by a new 60-inch, 75 hp Lakeside Equipment screw pump. A year later one of the original 60-inch pumps was replaced; the other 60-inch pump was replaced the following year.

Result:

 John Banks, plant manager, observed, “The pumps were only beginning to wear out, but they were certainly not on their last legs. The original 60-inch pumps far exceeded their life expectancy and required very little maintenance. Once per week we check oil levels, and our operators also monitor the grease levels on the bottom bearing. All very simple, and with Lakeside’s stainless steel tubing, we don’t have to worry about corrosion. These routine checks have seen our screw pumps work very reliably for 25 years plus.” 630-837-5640; www.lakeside-equipment.com

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Plant selects a flexible solution for lift station pump controller upgrades

Problem

 A New Jersey wastewater treatment plant needed to replace outdated or obsolete pump control systems to ensure critical infrastructure resilience. A replacement controller would be easy to install and commission, flexible for a variety of pump system requirements, and future-proof, allowing the integration of new functions and capabilities as needed.

Solution

 The staff chose a PLCnext Pump Controller from Phoenix Contact as a “configuration-only,” prepackaged solution for controlling and monitoring up to four pumps while requiring no programming. The pre-designed configuration and operator screens are embedded in the controller and accessed via any HTML5-compatible device. The application runs on PLCnext Technology, an open control platform with new control system functionality needed to maximize efficiency and meet increased regulatory requirements.

Result:

 The utility solution was easy to implement, flexible, and capable of meeting future needs for availability and reliability of critical water systems. 800-888-7388; www.phoenixcontact.com

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Dewatering improvements needed at expanding plant

Problem

 The Sioux City (Iowa) Wastewater Treatment Plant (29 mgd average) had a solids treatment process installed in 2006 consisting of belt filter presses feeding a Schwing Bioset KSP-25 piston pump. The dewatered solids are pumped to a truck-loading sliding frame silo. As flow increased, more dewatering and pumping capacity became necessary. 

Solution

 A capital improvement project converted dewatering from belt presses to centrifuges; the process improvements required a technology able handle higher flow and drier cake solids. The plant selected a KSP-45 cake pump from Schwing Bioset, a technology familiar to the plant team, able to handle the increased flow, and reliable.

Result:

 The pump significantly increased cake pump capacity while handling the higher-solids cake. The second cake pump gave the system full redundancy plus capacity for the future. 715-247-3433; www.schwingbioset.com

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Bearing system keeps conveyor in operation long term

Problem

 A wastewater treatment plant in Florida was replacing conveyor screw ball-bearings much more rapidly than the OEM scheduled service interval, at great expense in downtime and maintenance labor. The conveyor uses a 4-inch shaft that drives the conveyor screw. Sludge would penetrate the pressurized grease-sealed ball-bearing cases and accelerate the wear, eventually resulting in a complete failure approximately nine months from the last rebuild.  

Solution

 SealRyt designed a PackRyt bearing from their own SR01081 material, along with a reconfigured housing that utilized a pressurized air flush system. The PackRyt BLR (bearing with integrated lantern ring) is designed with close clearances to eliminate shaft movement, allowing it to seal effectively. Once the shaft has been stabilized, the air flush system creates a pressure differential that keeps sludge from entering between the BLR bearing and sleeve - eliminating excessive wear. The design also eliminates any internal moving parts.

Result:

 The PackRyt BLR was installed over nine years ago (in September 2012) and continues to run today without replacement or adjustment. 413-564-5202; www.sealryt.com

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Wastewater treatment solution for a critical airport application

Problem

 To avoid the delay or cancellation of hundreds of flights, a European airport invested in de-icing cannons to spray airliners with heated glycol. The airport was concerned that wastewater from the process could contaminate waterways and harm wildlife. With up to 264 gallons of deicer required to clear an Airbus A380, and hundreds of flights departing daily, the pollution risk was significant.

Solution

 Water-treatment dosing and control specialist SEKO supplied an automated polymer batching system to separate pollutants and allow treated water to be safely discharged to a nearby watercourse. The PolyCendos polymer preparation unit automatically doses up to 53 gallons of wastewater per second with flocculant. The all-in-one system includes an IP65-rated electric control panel, dosing pumps and powder feeder. It has three chambers for dissolving, maturing and storage, interconnected by syphons, enabling formation of a high-quality solution. The chambers include inspection covers and emptying valves and are made entirely in PPH for chemical resistance and a low-friction surface.

Result:

 With the system in place, airport management can guarantee the quality of its discharged water and protect wildlife while enhancing its drive for sustainable growth. 215-945-0125; www.seko.com/us