Blowers decrease energy consumption and reduce noise, heat and maintenance costs
Problem: King County, Wash., wanted more energy efficiency in upgrading the aeration blowers at the South Plant in Renton. With the support of Puget Sound Energy and the Washington State Public Works Board, the plant secured incentives and a low-interest loan towards the retrofit. The county also needed to improve the working conditions for plant staff, increase operational reliability and reduce scheduled maintenance expenses.
Solution: The county replaced its blowers with APG-Neuros turbo blowers. The retrofit aligned with ongoing strategic efforts to protect water quality and decrease energy consumption in all county facilities by 20 percent by 2020.
Result: The county estimates the two new blowers will save $55,000 in annual energy costs and reduce the plant’s energy consumption by 782,268 kWh per year. 866/592-9482; www.apg-neuros.com.
Shredder pumps eliminate sump problems
Problem: A large meat processing plant in Michigan had continual problems with its non-clog submersible pumps installed in the main lift station that pumped from the factory’s wastewater pretreatment plant to the city’s force main sewer. Continual blockages made it necessary to have the pumps pulled at least once a week to be cleared, cleaned and reset. The added maintenance cost more than $20,000 annually.
Solution: Kerr Pump and Supply replaced the existing pump with two SK Series shredder pumps and rail systems from BJM Pumps. The units shred solids before passing the liquid, leaving solids slightly larger than if passed through a grinder pump. The retrofit used the existing control panel and upgraded the motor starters to handle the 15 hp motors.
Result: After 16 months in service, savings totaled over $22,400. Kerr has since replaced more non-clog pumps in the wastewater treatment plant with BJM shredder pumps. 877/256-7867; www.bjmpumps.com.
Solids-handling pump reduces grease and eliminates odor and clogs
Problem: The wet-well duplex station at WK North Medical Center in Shreveport, La., transfers kitchen and basement wastewater into a city manhole about 300 feet away. The station was outfitted with two 7.5 hp submersible pumps. The medical center’s maintenance engineering supervisor, Marty Cole, noticed odor and was experiencing two or more clogs in the station every six to eight months due to heavy grease buildup.
Solution: Crane Pumps & Systems distributor, Delta Process Equipment, installed two 4SHM Barnes Solids Handling Series pumps rated 400 gpm at 25 feet TDH in the 72- by 228-inch fiberglass wet-well duplex station with all stainless steel piping and lift chains. The Monovane impellers provide clog resistance on applications with lower discharge heads where the concentration of velocity in the single passage effectively passes solids.
Result: The pumps have not clogged since their August 2010 installation. Cole reports no odor, much less grease and no clogs. 937/778-8947; www.cranepumps.com.
Valveless piston pump cures priming issues for methanol metering
Problem: A suburban college wastewater treatment plant in New York was looking for a cost-effective method to remove nitrate from wastewater effluent. The denitrification process required the addition of methanol. Diaphragm pumps were originally installed, but at the low flow rates required for methanol addition, check valves became air-bound, causing the pumps to lose prime. The challenge was to find a metering pump to accurately add low volumes of methanol.
Solution: The QDX Valveless Ceramic Piston Pump from Fluid Metering was installed. The CeramPump technology relies on only one moving part, a rotating and reciprocation ceramic piston, to accomplish pumping and valving functions, eliminating check valves. For metering methanol, the pump head is close-coupled to a QDX hazardous-duty drive.
Result: The pump eliminated low-flow priming issues and self-primes even between long periods of downtime. Sapphire-hard ceramic internals are chemically inert and wear resistant for long-term drift-free accuracy, eliminating downtime and recalibration. 800/223-3388; www.fmipump.com.
Mortar pump assists in quick resurface of lift station
Problem: Commonwealth Epoxy Coatings of Newport News, Va., received the contract to resurface a wastewater transfer station for a regional water and sewer authority in North Carolina. The specifications called for two cementitous materials of different viscosities. Commonwealth had never before sprayed the heavier of the two materials and recognized that its existing equipment could not handle it. Hand-troweling the materials would double the timeline.
Solution: The company chose the M680 Mortar Pump from Graco. It handles materials of varying viscosities at low pressures (typically 200 to 500 psi). It is easy to use, enabling Commonwealth to begin spraying quickly. The spray provided thickness control, producing a consistent layer of material.
Result: According to Commonwealth Vice President Jeff White, the Graco M680 cut project time in half and reduced costs by one-third. 877/844-7226; www.graco.com.
Pump system used to move effluent with high solids content
Problem: The 420 mgd (design) Village Creek Wastewater Treatment Plant in Fort Worth, Texas faced the challenge of moving biosolids at 27 to 29 percent solids through a pipe that went up 30 feet, making a 90-degree turn and traveling 150 feet.
Solution: Operators installed a KSP50V(HD)L pump from Schwing Bioset. A 10-foot-tall, 940-cubic-foot sliding frame silo was used for storage, and live-bottom hoppers were used to load trucks for the land application program.
Result: The plant beneficially reuses 500,000 pounds of biosolids per week. Rather than going to a landfill, the Class A material is hauled to a strip mine for site reclamation. 715/247-3433; www.schwingbioset.com.
SRD valve helps eliminate cavitation
Problem: Pittsfield Township, Mich., was experiencing pressure drops from 70 to 7 psi due to 16-foot fluctuations in tank elevation caused by varied water levels. Consequently there was cavitation in the valve that had already destroyed two reducers, and the plug valve was not able to modulate the rate of flow into the tank.
Solution: Operators chose the Single Rolling Diaphragm (SRD) with anti-cav trim from Singer Valve to eliminate cavitation damage without sacrificing other valves and changing processes or system dynamics. It allows the valve to operate steadily at high and low flows due to its vertical diaphragm, which rolls while opening and closing, enabling it to lock the valve in place without any friction. The dual-cage anti-cav was custom engineered to match the drop ratio and manage maximum flow, while creating enough backpressure in the cage to prevent the microscopic vapor bubbles from escaping and causing the damage.
Result: The control valve with anti-cavitation trim operates quietly and smoothly without cavitation and with minimal maintenance. 704/391-5785; www.singervalve.com.
Resort town wipes out pump clog problems
Problem: Consumer flushables were causing regular pump clogs in the year-round resort community of Big Bear City, Calif. “Nine times out of 10, when we pulled a pump it would be clogged with rags,” says Andy Keller, sewer department foreman. The most problematic of the seven underground pump stations he operates was clogging as often as three to four times a week. Pump clogs often came one right after another, and because many were on weekends crowded with tourists, service workers were paid overtime.
Solution: After consulting with a representative from Smith & Loveless, the city purchased X-PELLER impellers for three problematic stations. The mono-port design helps counterbalance hydraulic forces and create a balanced, single flow path that passes 3-inch solids and problem flushables.
Result: Pump clogs have been nearly eliminated, according to Keller. Operation costs are down overall. Maintenance workers are freed up to work on other equipment, and they are safer with no more trips to the confined spaces of underground stations. 800/898-9122; www.smithandloveless.com.
Treatment plant upgrades require 100 mgd bypass
Problem: The Blue River Waste Water Treatment Plant in Kansas City, Mo., faced an upgrade that required old piping to be tied into new piping. The pipes ranged from 60 to 96 inches.
Solution: Thompson Pump and Manufacturing Co. bypassed up to 100 mgd, the dry weather peak flow of the plant, using twelve 18-inch primary jet pumps, including two 18JSCK pumps and 10 18JSCJ pumps. Also used were one 18-inch standby pump, one 18-inch wet-weather storm ditch pump, and four 8-inch pumps for pumping down the water remaining in the 96-inch line. All of the 18-inch pumps used 18-inch suction pipe. The project used a total of about 5,000 feet of 18-inch discharge pipe.
Result: The project went as expected, and the pipework was completed as scheduled. 386/767-7310; www.thompsonpump.com.
Prerotation pumping system attacks lift station clogs
Problem: The Allen Road Lift Station in Bakersfield, Calif., faced two problems — pumps that clogged and dirty wet wells full of floating and settled solids that caused an unpleasant odor. Maintenance personnel had to travel to the lift station to manually clean out the pumps, and a vacuum truck had to be hired regularly to remove the solids.
Solution: The city selected a WEMCO-Hidrostal Prerotation pumping system, manufactured by Weir Specialty Pumps. It incorporates a prerotation basin designed to skim floatables from the top of the wet well and scour settled solids each time the pump runs through a pumping cycle. Simultaneously, it reduces clogging with a single-vane impeller.
Result: The systems were installed in 2007 and have experienced no clogged pumps to date. Floating and settled solids have been reduced, and vacuum truck visits have been reduced by more than 75 percent. 801/359-8731; www.weirsp.com.