After the Minnesota Pollution Control Agency mandated that chute wash water could not touch the ground in any quantity, time rapidly was running out for
After the Minnesota Pollution Control Agency mandated that chute wash water could not touch the ground in any quantity, time rapidly was running out for Apple Valley Ready-Mix (AVR), a leading Twin Cities producer operating a 150-truck mixer fleet. Options available in early 2008 to meet a November 1 deadline were limited: Temporary washout sites would have to be installed at each job site, or drivers would have to bring their wash water back to the plant. Investigation of several air-operated and mechanical pump systems to collect and return wash water to the drum proved futile, since we wanted to stay away from air systems that freeze easily in the below-zero temperatures here, explains AVR owner Pete Fischer. And, another pressurized tank would just add a yearly inspection we don’t need.
AVR Batch Plant Maintenance Manager Jeff Miller hatched the winning idea in early May when he watched booster axles on the company’s trucks rotate from just below the chute to a position close to the charging hopper. His innovation was to consider using that movement to carry waste water from the chute up to the hopper. After tossing that idea around the shop, Miller reports, a prototype was cobbled together with materials laying in the weeds around here.
Refinement of the concept over three months working with several of the drivers produced a system now installed on 140 trucks Û not exclusively belonging to AVR, since other area ready mixed producers have recognized its effectiveness. A patent is pending; and, the company intends to market the system nationwide, as wash water regulations spread throughout the U.S. and Canada.
Also pending is a name for the innovation. An employee contest yielded Fischer Flush and Pete’s Pot, tags rejected in favor of Washout Tank or Booster Tank.
The comparatively simple system adds about 10 minutes to the washout. Every producer can calculate its costs, and 10 extra minutes for a washout is expensive, considering the number of trucks in a fleet operated over the course of a year, notes Fischer. But, this system takes a lot less time than others on the market.
To implement the new washout solution, a capped end chute with a vertical drain pipe is positioned over a 13- to 14-gal. tank (depending on the truck mixer model) mounted between the arms of the booster axle. As the driver washes out the chutes, a perforated plastic bucket catches and cleans any aggregate, while gray water is collected in the washout tank. If all five chutes need to be rinsed, the last two will extend beyond the washout tank, so the driver simply washes out into a 5-gal. bucket and dumps it into the tank. When the booster is activated, the tank is carried up to the charging hopper. A simple hand cable releases a hose, allowing gravity to drain the tank into the drum. Greasing two bearings that are part of the tank cradle is all the maintenance required.
Affirms Pat Jay, a 19-year veteran driver for AVR who helped refine the original system, [The washout system] makes you less wasteful of water. The chutes can be done easily in one pass. If you have contractors washing a lot of tools, you might have to run it up twice to dump the wash water. It’s simple, which is probably why it works.
According to AVR Transportation Manager Paul Chaves, who knows how drivers can be reluctant to try new products, that’s high praise for an unfamiliar system. You hold your breath with any new procedure you are introducing to the mixer fleet, he says. But, the drivers have adjusted to the new wash out system, maybe because it was designed right here, and it is easy to operate.
Pete Fischer says his employees are the best judge of the invention. When an interested party comes in and wants to hear about the system, I send them to the yard, he asserts. Producers know they are not going to get a sales pitch from the drivers. That 75 systems have been sold for retrofitting trucks attests to the drivers’ positive feedback.
Moreover, the product won an award at the annual Aggregate & Ready Mix Association of Minnesota Convention in December. A final version launched after winter testing will entail about a four-hour retrofit install on McNeilus Bridgemaster 3 and later models. Major mixer manufacturers also have shown interest, and the system may be offered as a factory-installed option in the future.
World of Concrete 2009 attendees can see the new system installed on units in the major truck mixer manufacturer displays. Now in the works is a promotional video, which will be streamed at www.AVRconcrete.com.