Making wood and water come together to create high quality production-graded paper is the business of Blandin Paper, a subsidiary of UPM-Kymmene located in Grand Rapids, Minnesota. The water used in Blandin's paper mills comes directly from the Mississippi River. It flows through a 24-inch pipe at a rate of 4,200 gallons per minute (with a maximum capacity of 10,000 gallons per minute) via two online pumps of 400 hp and 350 hp, respectively. But Blandin Paper does not have to worry about sludge and other impurities from the Mississippi River contaminating its processing equipment and compromising the quality of its paper. The plant has installed four new, state-of-the-art, automatic Tekleen® water filters with 150-micron stainless steel screens to trap any debris that may be dredged up from the river.
After researching various types of filters, the company chose the Tekleen filter for its low maintenance requirements and reasonable cost. Blandin purchased four X 14" model ABW14-P all 316L SST filters with 11.8 Sq .Ft. 150 micron sintered mesh screens.
The Tekleen filter is a self-cleaning filter that operates on water pressure alone. As dirt particles collect on the screen, the line pressure at the filter outlet drops. When the pressure reaches a preset differential - Blandin Paper's is set at seven pounds -- the backwash cycle begins. Within 10 seconds and without interrupting the main flow, vacuum nozzles aggressively suction the dirt from the inside of the screen. Because of the automatic flushing, there is no plant downtime for routine filter cleaning, which translates to greater productivity for the plant.
The new water filter not only saves labor costs. It also saves energy and chemical costs due to the lower volume of water used in the back flushing process. "This is very important," says Stanley Roeber, production specialist at Blandin Paper. "The old system was pumping several million gallons a day. That's a lot of pumping energy," he says. Plus, all this water that could have been used for other industrial processes was going back out to the river. "We wanted to be able to put microbicides in the water before it goes to the filter, backwash with small quantities and have it go into our industrial effluent," says Roeber. Now they are able to treat the water from the river at a single point with sodium hypochloride and sodium bromide, send it through the filters, and distribute it throughout the plant. According to Roeber the new system has saved on chemical costs and been much easier to use.
When asked to sum up the benefits of the new automatic filter, Roeber responded: "Reduction in water usage, ease of maintenance, simple design, cost was reasonable, and improved efficiency on cleaning."
Tekleen filters are produced by Automatic Filters, Inc., a Los Angeles-based company that specializes in industrial and irrigation filtration systems. Tekleen filters have been recognized as the industry's highest quality self-cleaning water filters.