When Wolverine Corporation, a world leader in the manufacturing of cereal processing equipment, began searching for ways to make their drying and dust collection processes more efficient and cost effective, it needed to look no further than the next booth at a trade show.

Wolverine's neighbor at the Powder & Solids show in May, 1995 was EPR Inc., a product recovery and air pollution control company based in West Springfield, MA. Wolverine wanted a more compact and efficient solution to collecting particulate emitted during the cereal drying process than was being provided by its existing cyclones. At the same time, the company needed to cut overall costs and reduce the size of its equipment. Wolverine executives had considered several options, including installing screens, a bag house, scrubbers downstream of the existing cyclones and a cyclone like device. None of these really fit the bill.

Then, as neighbors at the trade show, Wolverine heard about EPR Inc.'s patented technology utilizing aerodynamics to collect, separate and reprocess particulate. Discussions finally turned to agreement that incorporating EPR Inc.'s technology, the Aerodynamic Module (ADM), into Wolverine's fluidized bed dryers was the best solution to its needs. The ADM satisfied Wolverine's collection requirements, used less energy, took up less space and could be easily installed, requiring minimal staff time or disruption. It offered the flexibility and efficiency Wolverine needed.
 

Initial Testing Results

EPR Inc. and Wolverine agreed to a trial at EPR Inc.'s site. EPR Inc. maintains a test facility in West Springfield. Here the ADM is constantly evaluated in single units, multiple units, in series and in various configurations using "standard" dust or dust samples provided by interested companies.

One hundred and twenty tests were conducted with materials supplied by Wolverine, including 250 pounds of cereal flakes and rice fines. The ADM proved to be 98 to 99 percent efficient on cereal flakes and 92 to 96 percent efficient on rice fines in these initial tests.

Based on these successful results, EPR Inc. and Wolverine launched a pilot program, installing two ADM-200 units at Wolverine's manufacturing facility in Merrimac, MA. Wolverine's test facility consists of three independent dryers/coolers in series. Each dryer has its own combustion chamber, fan, existing cyclone and controls for independent operation. The two ADM-200 units are installed upstream of the cyclone, in parallel to handle an airflow of 4,000 to 5,000 ACFM (2,000 to 2,500 ACFM per module) at 300 to 400 degrees Fahrenheit.

The first tests were performed at upset conditions (too much air was blown on the product during the drying process) in an attempt to plug or jam the ADM. Cereal flakes and rice fines tested at several times the normal concentration (2.6 to 3.3 grs/cf for cereal flakes and 44.2 to 54.8 grs/cf for rice fines) didn't plug the ADM. Normal concentrations for both cereal flakes and rice fines is approximately 1 grs/cf.

Then, again under upset conditions, the ADM and cyclone systems were tested side by side in separate dryer/coolers with cereal flakes for one hour. Dust from each was collected and weighed. The ADM caught 53 percent more dust than the cyclone. The ADM and cyclone were again compared, this time under normal conditions. Cereal flakes were tested on the same dryer/cooler first using the ADM, then the cyclone. Again the ADM outperformed the cyclone, collecting 20 percent more dust and using 40 percent less energy. In addition, the two ADM-200 units installed on the dryer/cooler occupied less than one third of the floor space required by the cyclones.

Based on these findings, EPR Inc. and Wolverine have formed a strategic alliance to incorporate the ADM into Wolverine's Jetzone bed dryer design.