With Coldwell Banker, Century 21, ReMax, and many other real estate companies as clients, Dee Sign Co has its signs in front of thousands of homes around the world, including all 50 states, Canada, Mexico, the Caribbean, and Singapore.

The signs are made from hardboard, steel, aluminum, corrugated plastic and polyethylene, depending on the real estate agents' needs. Some materials weather better than others; some are easier and lighter to handle; some are more expensive than others.

New Look Brings New Challenges

Over the course of the last two years, executives at Cincinnati-based Dee Sign have been working with a large real estate company to develop a new look for its signs, a look that requires a medium density fiberboard in a 5/16 in. thickness. After determining that they couldn't find a satisfactory source to produce precut boards for these new signs, Dee Sign execs decided to cut the signs themselves. They would need a CNC beam saw to cut the fiberboard, and the process would create immense amounts of sawdust. An effective industrial dust collection system would be a necessity.

"This was new to us," Dixon said. "We had to research dust collection from the ground up. We Googled; we went online. We researched it up and down and talked to a variety of sales reps. All things being equal, we like working with local companies -- that is Indiana, Kentucky, Ohio, and Pennsylvania. This is helpful from a service standpoint.

"We narrowed it down to five companies. They visited us; we visited them. We even went on-site with some of their installations. We were most impressed with United Air Specialists (UAS) because they could customize to our specific needs, one of which was the huge volume of dust."

Customizing the System

Dee Sign selected UAS to supply a dust collection system, and began discussing the specifications in January 2004. By July 2004, UAS' innovative BDC dust collector was installed outside the Dee Sign facility in Cincinnati. Actual installation took about three weeks.

"Dee Sign had some specific requirements," according to Dick Schmidt, of Airvec Systems, the authorized UAS sales representative who worked with UAS to design a system that could handle the sign maker's unique needs. "First, there were the needs of the beam saw itself, which generates a large amount of dust in surges. The medium density fiberboard has a resin binder, which when sawed creates dust with a very fine submicronic particulate.

"Two, the saw is located next to a paint finishing area. We had to capture the dust at the source. If left unattended, the airborne dust would damage the paint finishes. Third, there's a materials handling issue. What are you going to do with all this dust? Typically, most dust collectors come with 30- or 50-gal collection drums that need to be emptied. But that obviously wasn't going to do the trick here."

How did UAS and AirVec Systems solve the materials handling issue? The BDC collector was situated outside on a structural steel support over the top of a 30 yd roll-off box. The dust collector empties continuously into the roll-off box, which has a custom-made sheet metal weather cover so collected dust isn't affected by wind, rain, or snow. Dee Sign purchased two roll-off boxes, so it could maintain its waste disposal schedule.

Because sawdust is a potentially explosive material, AirVec Systems and UAS recommended the optional Pressure Relief Panel for the BDC system. The dust-conveying ductwork included a Flamex spark detection system.

The BDC, Schmidt explains, is an upward flow vertical media collector. It was selected to handle bulky "fuzz" in the dust stream. Combined with the ability of the cartridge media to handle the submicronic particles, it made the whole dust stream controllable. The upward flow system is capable of handling an increased dust volume because it has a larger open space entering the filters than does the typical downflow unit.

All Cartridges Are Not the Same

As Airvec's Schmidt says, "All cartridges are not the same." This is especially true for the BDC dust collector, which offers choices of filter media -- cartridges, pleated bags, and felted bags. No other unit on today's market offers this type of variety in filtration media.

United Air Specialists' BDC dust collector is a compact, self-cleaning, continuous-duty system that uses a pulse-jet cleaning system that effectively "pulses off" the captured dust from its filters and cleans the unit while the system stays online. That's an important consideration for an intensive constant-use operation like that at Dee Sign.

The unit is designed for easy maintenance. The BDC collector is engineered for fast, tool-free safe maintenance and filter changeout. Instead of systems that require workers to crawl inside the unit (a practice that is slow, dirty, and dangerous), the BDC's filters can be removed quickly by unlocking the cam bar and simply sliding the filter trays out. This ensures worker safety and greatly reduces necessary service time.

Learning From Experience

Dee Sign's initial experience with the BDC has lived up to expectations. Despite the intense research before choosing a United Air Specialists' air pollution control system, Dee Sign's executives still weren't sure exactly how much wood dust would be generated. It wasn't until they had the first two weeks of work under their belt that it became clear how much they needed a second roll-off box.

Just in case, the Dee Sign BDC unit was furnished with extra housing length so that when additional filtering capacity is needed, longer cartridges can be installed. The additional capacity can be up to 50% plus.

"It does three things for us," said Dee Sign's Dixon. "First, there's a human cost. You don't want your employees living in a dust cloud all day. It's a huge nuisance; it ends up in your clothes and hair. Second, you don't want to be paying your employees to sweep up dust all day. You want them to operate the equipment. And without the dust collector, we'd spend a lot of time sweeping and cleaning equipment. Finally, all that dust would just create havoc for our product. We want our boards to stay clean so that paint adheres properly. It just makes our signs better."