RAD-AX /SKG Series BJM Pumps, LLC 2016 Case Study

Transcription

1 Wastewater Treatment Plant Eliminates Clogs with SKG Submersible Shredder Pump Authors: Kelly McCollum, Regional Manager, BJM Pumps; Chris Morrow, President, Morrow Water Technologies, Inc.; Trent Turner, Consulting Engineer, Municipal Consultants Inc. Clogs can be a major headache for wastewater treatment plants. One city in Minnesota has even gone as far as filing a lawsuit against makers of "flushable" wipes. While the battle rages across the nation to make people aware of the trouble caused by hygienic wipes in sewage systems, wastewater treatment plants still have to operate efficiently. A wastewater treatment plant in Alabama contacted one of their consultants to help them find a solution to a pressing maintenance issue. Municipal Consultants Inc., a Birmingham-based engineering group, has worked with several of the utility s water and wastewater pumping stations for many years. When Trent Turner, one of the Consulting Engineers, learned about the excessive clogging issues that had been occurring at one of the wastewater treatment plant s pump stations, his search for a solution led him to work with Morrow Water Technologies, Inc., a company that provides fluid handling equipment and support services to the municipal water and wastewater markets. The small pump station inside the wastewater treatment plant contained two grinder pumps in a duplex arrangement. Having two pumps in a duplex arrangement is common for most wastewater pumping stations. While only one pump is needed to pump sewage out of the station, the second pump is available as a back-up. Running the back-up pump allows the primary pump to be pulled for service so the wastewater treatment plant can continue to operate. The grinder pumps had been clogging as a result of the scum which flowed into the station from the clarifier. This scum contained an immense amount of fibrous material, such as hair, wipes, and other consumer products that entered the waste stream. In an effort to reduce the amount of debris from the

2 incoming flow, the wastewater treatment plant s in-house maintenance team installed a basket strainer to catch the solids entering the station. Unfortunately, even after the catch basket had been installed, both grinder pumps continued to clog and cause headaches for the maintenance team. The plant manager contacted Turner to discuss their clogging problems and asked if there might be a better solution for handling the solids. Turner began to investigate available chopper and shredder pumps, knowing that effective solids handling would enable the maintenance team to: Stop pulling the pumps out each week. The maintenance team had to alternately pull up each grinder pump once a week to clean the pumps out and remove the clogs. Remove the catch basket. The maintenance team had to clean out the catch basket every single day. The sludge had to be removed so the catch basket could continue to collect solids before they could enter the pump. Spend their time on other maintenance tasks. These clogging problems had continued for about a year, forcing the maintenance team to spend their valuable time working on these grinder pumps. If the maintenance team could install a pump that could handle the solids and could pump the sludge without clogging, then maintenance personnel would be free to focus on other tasks to support the wastewater treatment plant. The plant manager asked Turner to speak with Stan Dailey, a Service Technician from Morrow Water Technologies, Inc. Morrow Water Technologies had provided quality support services in the past and is knowledgeable about pumping equipment used in wastewater applications. Turner, who had been investigating a line of chopper pumps, spoke with Stan Dailey and Chris Morrow, President of Morrow Water Technologies, Inc. Dailey, who was familiar with the wastewater treatment plant s scum application, recommended a line of BJM Submersible Shredder pumps. An SKG Series Submersible Shredder Pump was recommended for the following reasons: The SKG Series Submersible Shredder Pump is designed with RAD-AX Dual Shredding

3 Technology. This patent-pending design employs both radial and axial shredding components and has been proven to obliterate solids in wastewater (watch the video). A rotating cutter bar with serrated edges traps and shreds solids against the sharp grooves of a radial cutting ring while multiple axial cutting bars shred any leftover material exiting the radial cutters. All the shredding components of the SKG Submersible Shredding Pump are manufactured in hardened 440C Stainless Steel (Rockwell hardness of 55C plus), which means this durable pump is constructed to resist wear and operate longer than most submersible shredder pumps currently available on the market. Utilizing a 2-vane chrome-iron impeller, the SKG Submersible Shredder Pump works extremely well for wastewater applications that see larger solids. The 2-vane design is engineered with pump out vanes on its rear shroud to help protect the mechanical seal area from a build-up of solids, and the hardened impeller is wear-resistant to further lengthen service life. The SKG Submersible Shredder Pump relies on a high-torque, 4-pole motor to ensure solids-laden wastewater can be moved efficiently. The motor is protected by an oil-lubricated double seal design, which utilizes an upper seal made of silicon carbide / carbon and a lower seal comprised of silicon carbide / silicon carbide. An additional lip seal is installed above the impeller to help prevent sludge from entering the seal chamber. Manufactured with a corrosion-resistant stainless steel motor housing, the SKG Submersible Shredder Pump has winding protection that includes (NEMA) Class F motor insulation and a built-in motor thermal switch that turns the pump motor off in the case that amp draw and/or temperature gets too high. The switch automatically resets when the motor cools, allowing the pump to resume safe and reliable operation. Turner, Dailey, and Morrow all agreed the SKG Submersible Shredder Pump would be the right pump to recommend to the plant manager. The plant manager decided to install one SKG15C-460 Submersible Shredder Pump for a 90-day trial period to see how it would operate in the wastewater treatment plant s duplex scum pump station. Morrow shipped the BJM Submersible Shredder Pump to the wastewater treatment plant in July 2015, and the maintenance team promptly placed the pump in the wastewater pump station. The basket strainer installed to catch much of the incoming debris was removed so that the pump could be fully tested.

4 Because the SKG Submersible Shredder Pump was being evaluated, the wastewater treatment plant did not order guide rails to fully install the pump. The pump was suspended on a chain down into the station, with the pump resting on its cage only a few inches from the bottom of the 20-foot deep pit. Turner supported the maintenance team through the process of modifying their 2- inch discharge piping to accommodate the BJM Pumps 3-inch discharge connection. When the SKG pump did not perform as intended, Kelly McCollum, a BJM Pumps Regional Manager, scheduled a site visit to the wastewater treatment plant. Stan Dailey joined McCollum to promptly resolve the issue with the SKG pump. While the cause of the performance issues were not confirmed, McCollum and Dailey believe the problem was related to the pump being installed only a few inches off the bottom of the station; as the shredding elements of the pump had appeared to be damaged. Dailey and McCollum were able to resolve the problem by ordering a new set of shredding elements: the cutter bar, radial and axial cutter rings. After the new cutter bar was installed and all the clearances of the pump had been adjusted, the pump worked perfectly. The wastewater treatment plant evaluated the SKG15C for another 45 days after the site visit and shared their overwhelming approval with Turner. In December of 2015, the wastewater treatment plant ordered the guide rails so their maintenance team could fully install the SKG Submersible Shredder Pump. They also purchased a second SKG pump and have removed the existing back-up grinder pump, since the SKG is working so well. Once all the equipment had been received, the wastewater treatment plant fully installed both SKG Submersible Shredder Pumps along with guide rails and new 3 discharge piping in its permanent arrangement. Since getting everything installed, both pumps have worked very well. The wastewater plant maintenance team no longer has to perform daily maintenance activities on the pump station and is able to better serve the other wastewater plant activities. About Municipal Consultants, Inc. Municipal Consultants Inc. is a Civil Engineering company located at 327 S. Walnut St. in Florence, Alabama, USA.

5 About Morrow Water Technologies, Inc. Based in Birmingham, AL, Morrow Water Technologies, Inc. is the municipal sales and services division of Brownlee-Morrow Enterprises, a multi-industry supplier and producer of liquid and air handling equipment. They provide a wide range of equipment, services, and support for the municipal water and waste water markets. About BJM Pumps BJM Pumps, headquartered in Old Saybrook, Connecticut, has been providing fluid handling solutions for industrial and municipal services since Over its thirty year history, BJM Pumps has grown quickly by supplying world class pumps and accessories, priced competitively, through its global network of stocking distributors. Visit