Ford-Gelatt, a SunSource company based in Baton Rouge, Louisiana, has provided industrial process equipment and repair services since 1989. For many years, this industrial equipment distribution and service center has supported a Mississippi-based plant that manufactures acoustical ceiling tiles and suspension systems sold in many major retail stores. Since the manufacturing facility produces a large quantity of ceiling tiles each day, it needs reliable pumps that can operate 24 hours per day without clogging. When plant operators experienced frequent flooding of their washdown sump pits, they turned to their support representatives at Ford-Gelatt to find a solution.
The manufacturing plant produced wet felt and glass fiber acoustical ceiling tiles, which are essentially made of recycled paper and mineral fiber slurry. When equipment in the manufacturing plant was washed down, the system washdown water, which contained debris and particulate, drained into a washdown sump pit. In each of the two washdown sump pits, one vertical cantilever pump moved the washdown slurry to the on-site wastewater treatment plant. The manufacturing company had a water reclamation building on-site for cost-effectiveness and environmental reasons. All the water used at the facility was sent to the reclamation building to be recycled and sent back through the manufacturing plant.
With washdown water continuously flowing into the washdown sump pits, the vertical cantilever pumps repeatedly became clogged. The excessive clogging caused frequent flooding of the washdown sump pits. After having the vertical cantilever pumps rebuilt twice, the maintenance team decided to contact its representative to learn if a different type of pump was better suited for the washdown sump pits. The support representative considered two major issues surrounding the washdown sump application:
- Clogging and flooding — The washdown water contained broken tiles, paint, paper stock and other debris. The pumps operating in these washdown sump pits would need the ability to handle solids up to 1.5 inches in size to avoid clogging problems and prevent flooding.
- 24/7 continuous duty — Each sump pit relied on only one pump to perform in 24/7 continuous duty, so the plant needed durable pumps that could pump the slurry without failing. Installing reliable pumps would help the plant avoid costly downtime. Whenever one of the vertical cantilever pumps failed, it took a whole day to install a backup pump, which the maintenance team kept in inventory.
Slurry pump solutions
The support technician helped the maintenance team at the manufacturing facility select a submersible slurry pump with the following features to address issues from flooding and clogging to erosion and reliability:
- Chrome iron agitator to address flooding problems — Made from abrasive-resistant 28 percent chrome iron (600 Brinell, 57 Rockwell C), the submersible slurry pumps utilize an agitator. For this specific application, the high-chrome agitator was well-suited for keeping solids suspended in the washdown water, enabling the pump to move the slurry without clogging and flooding the washdown sump pits.
- Chrome iron semiopen impeller to avoid clogging — Engineered with a semiopen impeller, the pump was determined to be ideal for handling washdown sump liquid since it can pump slurries with concentrations of solids as high as 70 percent by weight.
- Chrome iron wear plate to counter erosion — The pump has a replaceable 28 percent chrome iron wear plate to counter the effects of erosion. On the suction side, erosion typically causes pump performance loss, so the replaceable wear plate helps improve overall pump life.
- Durable construction for continuous duty — Each submersible slurry pump has a stainless steel shaft and shaft sleeve to reduce shaft wear from abrasive slurries. The pump volutes are cast from hardened ductile iron, which at 300 Brinnell hardness, are twice as resistant to abrasives as standard ductile iron. The hardened ductile iron volutes are cast with extra-thick walls at the point at which the pumped slurry enters the discharge.
- Motor protection for reliable operation — The pumps are protected by double silicon carbide mechanical seals housed in a separate oil-filled seal chamber, and the heavy-duty lip seal offers additional protection for the mechanical seals. The motor is further protected with Class H motor insulation, built-in full-load amperage and temperature overload protection.
- Top discharge design — The two washdown sump pits had a submergence depth of about 15 feet. The submersible slurry pumps, which have a top discharge design and are cooled by the pumped liquid, can pump a sump pit down to within inches of the bottom. A side discharge pump without a cooling jacket must stay submerged to avoid overheating, leaving as much as 3 feet of unpumped slurry.
- Moisture detection system — It was important to the facility’s maintenance team that it be alerted in case the washdown sump pits were at risk of flooding. The moisture detection system was an option to help avoid flooding emergencies.
After reviewing all of the submersible slurry pumps’ features, the maintenance team decided to purchase two pumps for the washdown sump pits. Both pumps have operated reliably for the past four years.
Mike Bjorkman is vice president of BJM Corp. and has more than 30 years of experience in the pump industry. He serves as marketing and IT director for BJM Pumps LLC and All Test Pro LLC, subsidiaries of BJM Corp. Established in 1983, BJM Pumps supplies electrical submersible pumps to industrial and municipal markets throughout the United States, Canada and South America. All Test Pro LLC provides electrical testing equipment to markets throughout the world. For more information, call 860-399-5937 or visit bjmpumps.com.