Central States Apparatus Adds AccuMax To Industrial Truck
Vol. 20 No. 6
National Fire Protection Association Standard 1901 allows proportioning systems designed to supply 1 percent or greater solutions of Class B foam to be inaccurate up to +30 percent. FoamPro recognized the waste of resources this standard allows and decided to develop an automatic proportioning system to control such waste.
What happens when you pump $30 per gallon foam at 2,000 gpm using a 3 percent proportioning rate through a low-tech proportioner with a 30 percent inaccuracy rate?
"Not only are you wasting thousands of dollars of foam, you're consuming foam at such high rates that you have a huge logistics issue in keeping the system fed," said Bill Ballantyne, sales director for FoamPro Foam Proportioning Systems. "If you're 30 percent inaccurate that's 30 percent more foam that you and your manpower need to bring just to keep the system going."
FoamPro has introduced AccuMax, the first high-volume, multi-port foam injection system for Class B industrial applications. It provides fully automatic foam proportioning, regardless of changes in flow or pressure. In addition, greater nozzle performance is realized as AccuMax does not restrict water flow. Instead of turning knobs or activating levers, AccuMax's electronics deliver precise foam every time.
Central States Fire Apparatus, affiliated with Rosenbauer International, recently built and delivered its first industrial fire truck using AccuMax for the Shell refinery in Mobile, AL. It came complete with a Waterous S100 2,000 gpm fire pump and a FoamPro AccuMax 150 gpm foam proportioner capable of supplying 2,500 gpm at 6 percent and 5,000 gpm at 3 percent.
"The truck was originally speced for a balanced pressure eductor style proportioner," said Central States CEO Harold Boer.
By its very nature, balanced pressure proportioners utilizing a venturi device were inaccurate, Boer said.
"The biggest problem with the venturi type was the flow range," Boer said. "A specified flow range could be fairly accurate. However, if your flow goes above or below that range the proportioner can't compensate the way our computer-based system can."
Also, the venturi proportioners were limited in the amount of water that could be pushed through.
"The bottom line was that you needed more discharges on a truck so you could flow foam out of each discharge, combining them into a manifold to go into a large monitor or portable deck gun," Boer said. "With computer-based proportioners we can monitor flow within larger outlets for larger flows, reducing the number of outlets required on a truck."
AccuMax does not place flow restrictions on the plumbing, Ballantyne said.
"You get full flow capacity out of whatever size plumbing and diameter pipe you're using," he said. "We can plumb 4-inch discharges with full 4-inch piping. With the venturi type you were limited to 2? -inch to 3-inch piping."
The AccuMax operator has maximum flexibility. Each of eight discharges may flow plain water or 6-, 3- and 1 percent solution. A main waterway flowmeter located in each foam outlet provides flow data. The individual line controller receives this information and continually compares it to the chosen injection percentage, automatically opening or closing the concentrate supply valve. The flowmeter confirms the amount of foam being injected.
Meanwhile, the master control totals all individual line requirements and signals the Edwards pump to supply foam. All lines incorporate check valves to prevent water or solution backflow. Each line controller may be programmed for three default injection percentages. Each controller also displays current water flow, injection rate, total water and concentrate used.
The master control module displays current water, foam flow, total water and foam usage from all active discharges. Additionally, it warns the operator of a low concentrate level and offers an optional discharge pressure reading.
Master and individual microprocessor control modules include advanced diagnostic capabilities and system self-checks when AccuMax is powered up.
Venturi designed ratio controllers utilized in nozzle eductors. Balanced pressure and around-the-pump proportioning systems severely restrict water flow. Because of this, departments are required to run multiple discharge hoses to supply the high flow monitors or appliances. By comparison, AccuMax flowmeters do not restrict water flow, allowing greater pump performance at each outlet. This reduces the number of hose lays required, making the complete operation more efficient.
To assure quality and compliance, FoamPro requires system designs be subjected to intense third-party testing. Stringent electronic emission control is verified according to MIL-STD 461E. Designs are then tested to SAE and U.S. military specifications for heavy-use, off-road mobile apparatus by independent evaluators.
AccuMax is built around rugged Edwards all-bronze rotary gear pumps. The pumps use bearings, not bushings, to extend pump life. Timing gears, not contacting rotors, mean less rotor wear and maintained performance. Dry runs will not damage the equipment. Solid stainless steel shafts reduce corrosion. Self-priming features mean that AccuMax will handle any viscosity of foam allowed by suction piping.
Precise metering of foam concentrate will become even more important in the future as today's 3 percent concentrates are replaced by 1 percent versions. AccuMax offers the advantages of lower cost per gallon of solution, reduced freight and logistics and the ability to treat more water with a given size foam truck. The system precisely injects at any proportioning rate down to 0.1 percent. o