Water often plays a starring role in production processes. This is especially true of paper manufacturing, a process totally dependent on the uninhibited flow of filtered water. But maintaining a water delivery system can prove costly when the system is outdated or simply not up to the task for which it was deployed. This was the challenge faced by Kimberly-Clark Corp., headquartered in Dallas and a maker of a range of paper-based industrial and consumer products.
One of the company’s New England manufacturing centers produces industrial wipes, a highly specialized operation involving the use of a bag-and-cartridge water filtration system. A well, located approximately two miles from the plant, provides water for the process, an arrangement that comes with a problem unique to its source. Due to high iron, calcium and manganese content, well water is harder. In addition, when it is used in a manufacturing scenario, solids can be an issue.
These conditions put the plant’s filtering system under a great deal of performance pressure - to which it did not respond very well. Bag and cartridge replacement was an all too frequent necessity, and in terms of dollars, cents and downtime, an extraordinarily expensive one.
“The application called for a water delivery system capable of dispensing 1,000 gallons per minute,” says Mike Assimus, president of MSC, a provider of industrial filtration equipment based in Enfield, Conn. “The delivery system in place couldn’t cope with the workload. Downtime and high maintenance costs were big issues due to the need for regular filter changes, problems resulting from wear on the high-pressure pumps and frequent water feed manifold failure. Kimberly-Clark had to send the manifolds out for remanufacturing every three months, and that alone was costing the company thousands of dollars.”
With tens of thousands of dollars already spent on system maintenance and many more at stake, Kimberly-Clark called in MSC. Assimus and his team checked out the existing system and concluded that the papermaker needed a filtering solution with sufficient muscle to handle variable flow rates.
Because the plant runs different types of products for which 400 to 1,000 gal/min of water may be required, Assimus recommended the Vortisand system from Sonitec Inc., Holyoke, Mass., because the automatic backwashable sand filter does not need adjustments to compensate for changes in water flow. The filter provides 0.45 µm nominal filtration, which provides clean water and reduces the need to replace disposable filters downstream. The system also requires little, if any, operator involvement due to its automatic backwash system.
“Traditional sand-based filtering systems are static in nature, which makes them susceptible to solids saturation and clogging,” says Keith Karl, the East Coast regional sales manager for Sonitec. “Vortisand combines centrifugal force with sand filtration. It also offers an automatic backwash feature that works in concert with the centrifugal force to capture and rinse away trapped particles and purge the system with no human intervention.”
A Good FitBecause of the production stresses involved, Kimberly-Clark opted for a Vortisand rated at 1,000 gal/min. Positioning the filtration system initially presented a space issue because the plant, built in the 1940s, was not designed to contain such a large and complex system. An appropriate area was finally selected near the piping for the water source, but its size and peculiar dimensions made it necessary to custom-design a filtering apparatus. It consists of stainless steel vessel, a network of stainless steel pneumatic valves and a control panel equipped with an Allen-Bradley programmable logic controller, which acts as the system’s brain.
Vortisand went online at the plant more than two years ago, and the results thus far have exceeded the company’s expectations, says Karl. Kimberly-Clark originally intended for the system to augment its existing bag-and-filter setup, not realizing that the automatic backwashable sand filter would work efficiently as a stand-alone device. Payback also was achieved in the form of maintenance advantages, including the elimination of changing system bags and filters. Pump wear has been reduced, and the ritual of sending the manifolds out for rework was eliminated.
Prior to installing the system, it was standard practice to shut down the papermaking operation in order to perform routine maintenance, which resulted in downtime and production loss. However, following the installation, Kimberly-Clark has been able to perform these tasks without having to shut down. According to Karl, the automatic backwashable sand filter saved the company approximately $8,000 in its first two weeks of operation.
For more information from Sonitec Inc., Holyoke, Mass., call (413) 532-6089 or visit www.sonitec.com.