When Ford Motor Co. (Wixom, MI) wanted to expand its current manufacturing plant, they needed to add an addition to the existing structure and switch their water supply from well water to city water. A fresh-water booster system was needed to supply the city water to the new facility at a constant pressure.
The problem facing engineers was a lack of usable indoor space due to huge manufacturing machines inside the Ford plant. After long deliberations, the only practical option available was to house the pumps and controls, together into a massive house-like facility and ultimately mount the housed system outside the production area of the plant. A concern was that the facility be able to handle the region”s rough and tumble winter environment.
Moreover, the pump system had to ship completely assembled and ready to install. To build the enclosure, they selected Metropolitan Industries of Romeoville, IL. Installation concerns included avoiding shutdowns and resulting lost production revenue. Ford’s goal was to abandon the existing well fields, leaving the booster station the sole source of water for the entire plant.
It was neither beneficial nor economical to ship the system in pieces and assemble it at the job site. Prefabricating the system in-house provided the added benefit of having a controlled environment during manufacture and allowing delivery on time and on budget. “Prefabricating a system such as this benefits the customer by eliminating the headaches involving scheduling, logistics and varying site conditions,” says Metropolitan representative Mike Tierney.
At the factory, work was started by designing the pump system and mounting it directly onto a 3/8-inch epoxy-coated steel plate that served as the base of the entire system. Three 50-horsepower horizontally mounted, flex coupled, end suction pumps were used in this case. This combined system can deliver from zero to 2,000 GPM at a constant discharge pressure of 84 PSIG when the minimum suction pressure is 30 PSIG. Each pump is designed to match flow requirement with a variable-frequency drive control. The system is capable of meeting all conditions from zero to maximum flow without exceeding the temperature design of the motor windings. The pump speed is variable to exactly match the flow requirements at a constant pressure level.
During the installation of the pump and piping to the base, controls were designed and manufactured in-house so they were ready to mount once the housing was assembled and completed. A microprocessor-based computer controlled the entire pumping system. It coordinated operational input signals, including the system pressure set point, flow set points, operator selector switch positions, indicator lights and alarms. Also, pump operation, pump speed, alternation and system alarms are controlled by the system computer.
An interesting aspect of the controls was the use of a ruggedized programmable logic controller (PLC) that is specific for water and wastewater applications. According to Tierney, the ruggedized PLC is easily programmed in ladder logic in addition to higher level C-language for ease in handling complicated control routines. Also, it is suitable for use in extreme temperatures and is resistant to noise on power lines.
Once on site, the modular enclosure was picked up by a crane, set over the pump system and onto the base with channel supports. Fabrication materials were chosen to accommodate the location”s unpredictable weather which included high winds and heavy snows.
The material chosen for the house was molded of fiberglass reinforced polyester (FRP) and constructed with a minimum wall, door, roof thickness of 2 ½ inches and an insulation rating of R14. All materials used were ultraviolet resistant. The finished product could withstand winds up to 150 MPH and handle a 30-lb. snow load.
Because of the inclement weather, the system provides a dual, 120-volt, thermostatically controlled, resistance space heater with a quiet air circulation fan rated at 1,300-1,500 watts. During a power failure, a Sumpro back-up power supply operates the heater, so pumps and pipes do not freeze.
Other features include a low-temperature alarm with contacts for remote monitoring. Pumps and motors can be easily removed without having to disassemble other components because of the building design. Double doors provide easy access to the system so that any part of the system can be easily removed or serviced inside the heated area.
Due to its airtight seal and the need for fresh air while workers perform maintenance, the pump station is equipped with a forced draft ventilation system capable of at least 40 air changes per hour. A direct-drive, squirrel cage type blower discharges air through a rain-hooded screened outlet. A thermostat controls the blower operation.
Neil Daavettila, Ford facility engineer, who oversees the operation of the pump station, notes that the controller’s ability to rotate pumps during operation is among his favorite features. “It takes the combined stress of operation and equally distributes it to all three pumps. This will save the life of each pump over the long run,” Daavettila said.
Shipping the pump station was a task within itself. A police escort was needed to ship the billboard sized pump station from Illinois to Michigan. “Shipment was a concern due to its size, but the team effort between our inside sales staff, Kennedy Industries, the installing contractor and state agencies made the shipment go as smooth as possible,” adds Tierney.
Metropolitan Industries produces complete package fluid handling systems for water boosting services, sewage pump stations, storm water, chilled water, hydronic systems and other processes systems.
Walt Boyes is a is a principal in Spitzer and Boyes LLC, offering engineering, expert witness, development, marketing, and distribution consulting for manufacturing and automation companies.
