Chemical Manufacturer Stops Clogs & Flooding with SKX Submersible Shredder Pumps
Authors: Kelly McCollum, Regional Manager, BJM Pumps
Based in Baton Rouge, Louisiana, Ford-Gelatt (a SunSource company) provides industrial pumping equipment and repair services to the oil and gas, power generation, and chemical process industries. Over the past 25 years, service representatives from Ford-Gelatt have supported the maintenance team working in-house at a local chemical manufacturing facility. This chemical manufacturer is the second largest producer of chemicals in the United States, and they have worked with Ford-Gelatt for over two decades to source and select pumps for a variety of applications.
When the chemical manufacturer experienced frequent clogging of their horizontal self-priming pumps, they contacted Scott Swilley, Industrial Equipment Specialist at Ford-Gelatt, to find a solution that would enable them to avoid flooding and eliminate the related clean-up costs.
Two horizontal self-priming pumps had been pumping from two separate 9-foot deep sewage sumps. These pumps were supposed to send raw sewage collected from the chemical manufacturing facility to the nearby wastewater treatment facility, but they clogged excessively and led to inconvenient flooding on two separate occasions. Each time the flooding occurred, employees had to be moved out of the manufacturing facility into rented trailers placed off-site and a third-party company had to come clean and sanitize the flooded area. The clean-up was a lengthy process, and costly!
Not wanting to risk a flood of raw sewage a third time, the chemical manufacturer’s maintenance manager contacted Swilley to discuss replacing the self-priming pumps. In discussing the problem with Swilley, it was clear that the new pumps to be selected for this sewage lift application needed to meet the following requirements:
The chemical manufacturer had previously installed BJM Pumps in several drainage sumps throughout their facility. Having 6 corrosion-resistant stainless steel submersible shredder pumps (model SKX15CSS) already operating reliably in their chemical manufacturing facility, the maintenance manager was confident in the SKX Series pumps.
For these specific sewage lift sumps, Swilley recommended an SKX model, the SKX110CSS, for the following reasons:
The SKX110CSS has “Three Seal Motor Protection”. The motor is protected with an oil-lubricated double seal design whereby the double mechanical seals are comprised of a lower seal made of silicon carbide/silicon carbide and upper seal faces made of carbon/ceramic. An additional lip seal is installed above the impeller to help prevent abrasives from entering into the seal chamber. Utilizing winding protection and (NEMA) Class F motor insulation, the SKX is superior to pumps with Class A and B insulation because the (NEMA) Class F motor insulation allows the motor temperature to raise up to 230°F. An automatic switch turns the pump motor off if the temperature and/or amp draw raises too high. When the motor cools, the switch is designed to automatically reset and the pump will once again begin operating.
After thorough deliberation, the chemical manufacturer purchased (2) SKX110CSS corrosion-resistant stainless steel submersible shredder pumps and installed them in the fall of 2016. BJM Pumps provided the guide rails to make installation and future inspection and maintenance easier for the in-house maintenance team. The pumps have worked well in the sewage application, and the chemical manufacturer has not experienced clogging and flooding since the SKX pumps were installed. The chemical manufacturer plans to purchase 2 additional SKX pumps for their other two sewage lift sumps to pre-empt any potential clogging and flooding – thereby avoiding headaches and unnecessary clean-up costs.
UNDERSTANDING THE APPLICATIONS This new recycling facility is designed to receive large bales of compressed PET bottles—bales approximately 6 cubic feet in size. These bales are dismantled, and the bottles are sorted and shredded into much smaller plastic pieces prior to being sent through a series of processes. Because PET (polyethylene terephthalate) is semi-porous and typically absorbs food and beverage molecules, the shredded plastic must be finely chopped into “flakes” and thoroughly washed and dried. The cleaned, processed plastic is then bagged and distributed to other companies who use recycled plastics to manufacture consumer packaging, plastic banding, and a range of other goods.
The design engineers specifying the pumping systems worked with Derrick Heard at Tencarva, explaining that there would essentially be two sumps—a primary and a secondary pit—used for the rigorous cleaning process. During the initial grinding and cleaning, wash down water, plastic pieces, dirt, soap, scum, and residue would all be collected in the primary wash down sump. This material would then be pumped through clarifiers and screens to separate the plastic from the wash down wastewater. While the plastic would be sent through for drying, the wash down wastewater would be sent to the secondary pit. The pumps in the secondary sump would be responsible for reliably transporting the wash down wastewater to the on-site wastewater treatment plant. The wastewater would be treated on-site, with the facility technicians making sure all plastic and sludge had been removed prior to sending the wastewater downstream to the municipal sewer system.
PICKING OUT THE RIGHT PUMPSAfter speaking with the design engineers, it was clear to Heard that there were some key requirements that needed to be considered in order to select the right pumps for these specific sump applications:
The pumps needed to withstand high temperatures. The temperature of the wash down water was estimated to reach temperatures between 131 and 140 degrees Fahrenheit (55 and 60 degrees Celsius), which is too hot for standard submersible pump motors. Submersible pumps typically rely on the fluid being pumped to cool the motor; which is why most submersible pumps cannot withstand pumping liquids at temperatures higher than 104 degrees Fahrenheit. Temperatures higher than 104 degrees Fahrenheit (40 degrees Celsius) typically cause standard submersible motors to fail.
The pumps had to be corrosion-resistant. The wash down water would include cleaning chemicals that would cause the oatmeal-like slurry to be 2 percent caustic. For this reason, it was important to select a durable pump with the right metallurgy to minimize abrasion / corrosion.
The pumps must shred the plastic pieces. The plastic solids entering the primary sump needed to be shredded into even smaller pieces so they could be transported to the next stage of the process. This severe application required a shredder pump.
Heard immediately thought of BJM Pumps, explaining, “I knew BJM had a Fahrenheit Series—not just a submersible that could handle high temperatures, but one that could shred too. The combination is unique in the industry—and prior to BJM Pumps—there really wasn’t a high temperature option that could do all these things.”
Heard recommended the BJM Pumps’ SKG Fahrenheit Series Submersible Shredder Pumps to the design engineers. In his recommendation, he shared the key features of the SKG-F Submersible Shredder Pumps:
The SKG Fahrenheit® Series Submersible Shredder Pump is proven to reliably handle very hot liquids—up to 200 degrees Fahrenheit (93 degrees Celsius).
The SKG Fahrenheit® Series Submersible Shredder Pump is designed with patented RAD-AX® Dual Shredding Technology, which employs both radial and axial shredding. 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 SKGF 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 to the market.
Two impeller trims are available for each SKGF model to expand hydraulic coverage, with large solids easily passing through impeller and volute. Controlled Shredding System Efficiency alleviates potentially high surge load to the motor.
The SKGF Submersible Shredder Pump relies on a high-torque, four-pole motor to ensure solidsladen wastewater can be moved efficiently. The motor is protected by an oil-lubricated double mechanical seal design, with separate lip seal.
Manufactured with a corrosion-resistant stainless-steel motor housing, the SKGF Submersible Shredder Pump has motor winding protection that includes NEMA Class R motor insulation – allowing motor temperatures to rise up to 428 degrees Fahrenheit (220 degrees Celsius) without damage. Automatic thermal switches embedded in the motor windings protect the motor if the temperature or amperage rise too high. When the motor cools, the automatic switches will reset and allow the pump to restart.
The design engineers reviewed Heard’s recommendation to put two SKG37CF Submersible Shredder Pumps into the primary wash down sump and two SKG15CF Submersible Shredder Pumps into the secondary wastewater sump. They also watched the video to see how the RAD-AX® Dual Shredding Technology is proven to obliterate solids. After a thorough review of the entire pumping system specs, the decision was made to purchase and install the BJM Pumps.
In February 2016, two 5-horsepower SKG37CF Submersible Shredder Pumps were installed in the primary sump, and two 2-horsepower SKG15CF Submersible Shredder Pumps were installed in the secondary sump. Heard was on-site in August 2016 when the pumps were started up, with the SKG37CF’s pumping 275 gallons per minute at 35 feet of head and the SKG15CF’s pumping 115 gallons per minute at 35 feet of head.
Since start-up, Heard has repeatedly visited the bottle recycling facility to check on these pumps. “Other than the one time we had to check the controls operation of the two sumps and clear the nasty slurry build-up off the floats, the BJM Pumps have been working great in the sumps,” states Heard. “They’re really reliable pumps.”
ABOUT THE AUTHORSteve Mosley is regional manager for BJM Pumps. BJM Pumps, headquartered in Old Saybrook, Connecticut, has been providing fluid handling solutions for industrial and municipal services since 1983. 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.
Designing explosion-proof equipment for wastewater treatment. by Jonathan Herlong and Steve Mosley
November 21, 2018
Federal standards protect groundwater by requiring some landfills to use plastic liners to collect and treat leachate. Leachate, which is the resulting liquid that drains or “leaches” through a landfill after it rains, varies widely in composition, depending on the age of the landfill and the type of waste there. When a new wastewater treatment facility was being built next to an existing landfill, the specifying engineers had to consider how leachate entering their pumping processes might affect the safety of plant personnel and pumping equipment.
While the specifying engineers at the consulting design firm were reviewing the requirements of one 15-foot deep sump inside the wastewater treatment plant, they determined that the process required:
Image 1. Leachate from a landfill near a new wastewater facility may have affected the safety of the personnel and pumping equipment. (Images courtesy of BJM Pumps)
In April 2017, two explosion-proof submersible shredder pumps were installed in the indoor sump. The pump company provided the guide rail system that enabled the installation team to easily install both pumps, which are run off level control.
The submersible shredder pumps are set up to run in an alternating lead-lag configuration, to prolong pump life and to accommodate possible higher inflows into the sump.
Managing safety is a necessity for many industries. The implementation of explosion-proof zones on the job site has created a need for explosion-proof pumping equipment and consulting engineers who must know what proven technology is available to the market.
ABOUT THE AUTHOR Jonathan Herlong is a sales engineer at Tencarva Machinery. For more information, visit tencarva.com. Steve Mosley is a regional manager at BJM Pumps.
How one submersible pump helps provide clean energy. by Keith Grgurich October 8, 2018
Infrastructure has been a hot topic for years now, particularly in utility circles. In the wider public, Americans are aware of infrastructure because so many of us depend on having navigable roads and bridges to get from one place to another, and these days they are overcrowded and often in need of repair.
Other people may have an appreciation of the importance of infrastructure if they work in an area where a broken water main has flooded homes and businesses or disrupted service. Typically, we think about infrastructure only when it is not working properly, and usually that is because it has caused an unexpected inconvenience.
Utilities, whether public or private, and the infrastructure networks they maintain serve as the (often unseen) bones and skeleton of our cities and towns. Not only do utilities provide necessary services to residential areas, but they also service retail centers, manufacturing facilities, other utilities (water treatment facilities are some of the largest users of electricity) and business districts.
Image 1. The convention center in a Midwest city underwent a renovation after a sump used to collect condensate from steam heating caused issues. (Images courtesy of BJM Pumps)That final category often includes facilities such as convention centers, ballparks and theaters.
Many large facilities and high-rise buildings found in a typical downtown make use of a utility that is not often thought of—steam. Most people at some time have walked through a stadium, for example, and looked up to see the word “STEAM” stenciled on a pipe overhead. Steam is an efficient source of heat and energy that is commonly used in manufacturing as well as business districts with concentrations of high-rise buildings and other facilities that accommodate large numbers of people.
Steam is considered “clean” energy since it is nonflammable, nontoxic and chemically inactive with several process fluids.
But there is still waste—more or less of it depending on how the steam is generated and used.
Without the proper equipment to address it, this waste can cause significant challenges for facilities that have to deal with it.
The FacilityIn the past decade, a city in the American Midwest initiated a project to upgrade and expand its convention center. Today, that facility is one of the largest convention centers in the country.
The distinction comes with significant demands on the various utilities that service the facility. Convention centers and other venues that host tens of thousands of people typically go from being virtually empty to the size of a small city in a matter of hours. One of the consequences of this quick transition is that the demands put on the infrastructure supporting the facility are nearly instantaneous and great.
In the winter, it is cold in the Midwest, and if the convention center is in use, its vast halls and meeting rooms need to be heated. In this particular facility, heat generation is accomplished with steam.
The ChallengeDepending on steam’s source and unique characteristics, the resulting condensate can be corrosive and hot. Accordingly, this expanded convention center has a number of sumps to collect condensate from the steam heating.
One sump in particular was creating constant problems for maintenance crews because the vertical-style sump pumps were being damaged due to the hot, corrosive condensate.
Image 2. A high temperature submersible pump in 316 stainless steel was chosen for this application since it can handle liquids up to 200 F continuously.“The pumps had to be replaced every year,” said Jeff Cook of Cook Fluid Products. “The hot, corrosive condensate would prematurely wear the vertical-style sump pumps. In this application, the combination of the heat and corrosive fluid damaged the pump’s bushings and shafts.”
The steam in this location is generated by the local gas utility at a central plant and then is piped out to customers. In this application, the steam is untreated and as a result contains high levels of carbonic acid. The resulting condensate is highly aggressive and “would corrode parts on the vertical sump-style pumps,” Cook said. “A lot of other places in the city that use this steam use stainless steel equipment in order to get any longevity out of it.”
Although the convention center sends condensate to waste rather than returning it, the condensate still has to be collected. Just maintaining that location was a challenge.
“The pit that the pumps are in has a Rhino liner in it because the pit itself was being destroyed by the condensate,” explained one employee.
The SolutionThe apparent answer to this ongoing problem was to find and install a stainless steel pump that would handle the highly corrosive environment and extremely high temperatures. Having reliable equipment saves time and money because production time is not wasted identifying a problem and bringing in new equipment to solve it.
“It’s a very tough application,” Cook said. Cook recommended a manufacturer that has a line of high temperature stainless steel submersible pumps for this site.
The appropriate pump line is designed to handle liquids up to 200 F continuously. Standard sump pumps are normally rated to handle 104 F continuously. The high temperature submersible pump is available in all 316 stainless steel constructions for hot corrosive applications. The higher temperature rating and stainless steel construction made this pump the correct choice for this application.
The pump manufacturer also provides standard peripheral equipment to support its pumps.
All pumps from this line come with a National Electrical Manufacturers Association (NEMA) 4X control box including start components. The control box contains some additional features for high temperature pumps that ensure the equipment maintains its reliability even in challenging environments.
“They make heavy-duty control panels,” Cook said.
Especially useful for this application is a device located in the control panel that initiates an alarm in the event there is a breach in the double-mechanical seal chamber.
“I always suggest using the seal minders,” Cook said. A moisture sensor probe is installed in the oil-filled seal chamber between the inboard and outboard mechanical seals. If the outboard seal is breached and a conductive fluid enters the seal chamber, the moisture sensing probe completes an electrical circuit that illuminates an alarm light on the control panel. This feature potentially saves time and money by alerting the user that a seal needs to be changed before moisture gets into the pump motor.
“If the inboard seal is breached and water gets in the motor, the pump will normally have to be replaced,” Cook said. “So it makes sense to use the control panel with the extra security to make sure the pumps can be serviced if necessary before water gets in the motor. Replacing a seal is inexpensive.”
The OutcomeIt has been more than a year since the pumps were installed at the convention center and none of the previous problems have resurfaced.
Ultimately, finding a solution that prevents pumps from having to be repaired or replaced on a regular basis has a positive effect on the facility’s bottom line. In addition, maintenance crews do not have to spend unscheduled time and effort repairing or replacing equipment at the expense of their regular duties.
Brian Hoskins - Owner Operator - Baller Shot Caller of BPH Pumps