The Model 2800 NSF-certified, fixed-plate, wafer-style static injection mixer for water treatment plants from Westfall Manufacturing Co. uses a combination of alternate vortex shedding and intense shear zone turbulence to achieve 98 percent injected fluid dispersion 10 diameters downstream. Features include a short laying length of 1 to 2 inches and integral injection assemblies. The mixer is 60 inches in diameter by 1 inch thick and is available up to 10 feet in diameter.

“The real advantage of the mixer is the short line length — 1 inch to 1 1/4 inches. It just sandwiches between the pipeline flanges,” says Robert Glanville, marketing director for Westfall Manufacturing. The mixer has a flat surface, rather than fins that extend into the pipe on the downstream side, for easy removal. “You just loosen up the bolts on the flanges and slide it right out if you need to clean it,” he says. There’s no need to remove sections of pipe. “It’s a real problem-solver. We’ve built them from 1/2 inch through 72 inches. They can be installed in locations where there just isn’t room to install a conventional mixer.”

Predrilled to fit into the mating flange bolt circle of any piping system, the model 2800 mixer is made from 316 stainless steel and comes in three orifice ratios (0.7, 0.8 and 0.9 beta openings) for mixing at 1-3 FPS, 3-8 FPS or 8-11 FPS.

Mixers also can be made from other metals and plastics — PVC, CPVC, fiberglass, Teflon. “In metals, we’ve done 304 through 316 stainless, hastelloy, titanium and Alloy 20,” Glanville says. “In some cases we’ve made mixers out of carbon steel with Teflon coating.”

The mounting ring can be drilled and tapped to accommodate quills for chemical injection, including chlorine, alum, mixed oxidants, lime, activated carbon, caustic soda, hydroflustic acid, sodium hypochlorite and aqua ammonia. Mixers can be installed in approximately a half hour on a small pipeline and require no maintenance. “We’ve been building them since ’95 and we’ve never had any reports of noticeable wear,” Glanville says. “You pretty much install it and forget it.” 888/928-3747; www.westfallmfg.com.