Wells Concrete recently reached a crossroads for managing equipment wash down slurry water at its Albany, Minn., headquarters and flagship precast/prestressed operation. An existing filter press was no longer keeping up with demand, and operated in a separate building a few hundred yards from the main washout location.
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| Full Circle Water staff assesses a twin filter press installation engineered to meet peak slurry water loads at the Wells Concrete headquarters plant. Production staff finds the equipment and companion weir system upgrades performing to specification and yielding water whose clarity speaks for itself. |
Maintenance lead David Brannen presented Full Circle Water average usage metrics: Maximum flows of 120 to 150 gallons/minute during each 10-hour production cycle, coupled with reclaiming of up to one yard of aggregates. The objective for any replacement equipment was minimizing maintenance down time and utilizing as much existing infrastructure as possible.
Full Circle Water proposed two 20-cu.-ft. semi-automatic filter presses on mezzanines, with a mixer and a pH balancing skid. The combination provided redundancy to eliminate down time, and easily accommodated projected water flow rates. With a little teamwork and ingenuity, a plan was also drawn to retrofit existing weir system pits to accommodate the two filter presses.
“We ultimately chose to go with Full Circle for two reasons,” says Brannen. “They were willing to fit their solution into our existing infrastructure, [and] we liked the idea of them being a local business.” He likewise credits the manufacturer with meeting a projected equipment manufacturing and installation timeline, and working with plant staff on site or area preparation.
During the course of the installation, crews discovered that a screen used to separate aggregates from the water was not adequately sized, prompting the addition of a small screw press to the equipment package. The upgrade enables Wells Concrete to recover up to 3 yards of aggregate per day versus the initially projected 1-yd. volume.
Custom work using multiple colors challenges Wells Concrete to reuse settled, filter press-processed water. Consequently, the producer recycles most water for equipment wash down or treats its for pH balance to enable municipal system discharge. Regular maintenance includes daily retrieval of pressed slurry fines cakes and thorough press wash down every other day.
The dual-press assembly, Brannen concludes, “is the right size solution for the space and our workload, and the quality of the water is unbelievable.” — Full Circle Water/Pristine Environmental LLC, St. Joseph, Minn., 320/529-4035; www.fullcirclewater.com