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Dust Collector Keeps Product Shrinkage Below Industry Average

July 31, 2009

A certain level of lost product, or shrinkage, is an unavoidable part of doing business for companies in the powdered food processing industry. When ingredients are measured out and mixed together, small amounts of dust escape into the air instead of staying within the process at hand. This may seem like no big deal, but consider a company that handles 80 million pounds of ingredients a year, and loses 1% of product; that’s 800,000 pounds of waste and lost profits!

United Air Specialists’ SFC 32-4 dust collector located on a mezzanine at Allied Blending in Bell, CA

Many powdered food processing companies use dust collection systems to keep a clean workplace and help reduce product shrinkage. These systems consist of source capture containment hoods, ducting, ventilation fans, and the actual dust collector itself. When containment hoods are properly sized and positioned for a specific process, product shrinkage is kept to a minimum. However, if a containment hood is positioned too close to a bag drop station, mixer or blender, or if the ventilation fan is sized incorrectly and causes too much suction, manufacturers will actually experience increased product shrinkage and incur higher expenses.

Allied Blending Inc. (Keokuk, IA) supplies powdered ingredients such as cheese, baking mixes, and tortillas to the food industry. Additionally, the company offers toll blending, or contract manufacturing, mixing another company’s recipe of ingredients together for them. The company has three manufacturing operations located in California, Texas, and at its Iowa headquarters. In 2007, management at Allied Blending realized its California facility was too small and underequipped to meet current demand, so the company moved out of its small facility in Bell Gardens to its newer and larger plant in Bell, both suburbs of Los Angeles.

More Production = More Dust

Since production would be nearly tripling from 10 million to 25 million pounds of ingredients a year, Allied Blending management knew that the potential for lost product due to dust would also most likely increase. “At our previous facility, we operated two dust collectors that didn’t do the job,” said Matt Stelzer, VP of operations for Allied Blending. “There was so much residual dust on the floor, on the equipment, and in the air, and our shrink levels were around 1.25%, which is above the 1% industry average. For our new facility, we knew that we couldn’t afford to skimp on a good quality dust collection system.”

Before Stelzer could get production up and running in the new facility, he needed to make arrangements for a new air pollution control system specifically designed to handle the increases in production levels. Stelzer called on three companies to help engineer and design a new system. Ultimately, he chose to work with Dave Stroze, of Clean Air Specialists, who is a manufacturer’s representative for United Air Specialists (UAS). “I liked Dave’s product, service, and price,” says Stelzer. “He provided us with answers quickly and confidently. Also, I had heard good things about the UAS dust collector installed at our Keokuk plant several years ago.”

Stelzer, Stroze, and plant manager Juan Mora evaluated the blueprints for the Bell plant and discussed the type of dust collection system required, where to install it, and the timetable in which it was needed. Based on Stroze’s recommendation, Stelzer and Mora chose UAS’s SFC 32-4 downward-flow cartridge dust collector. But, there were still four main challenges:

-Special consideration would be needed if local authorities deemed the powdered ingredient dust that was being collected explosive.
-FDA regulations would have to be met in the dairy and batch pack processing rooms to meet food safety requirements.
-Clean air would have to be recirculated back into the facility because the three production rooms were air conditioned.
-The dust collection system needed to be incorporated into three yet-to-be-built production lines.

The Allied Blending facility consists of three 1200-sq-ft production line rooms, each with a large blender, weighing station, and bagging area. The facility also has a control room for pumps, an air compressor, control panels to run the lines, and a warehouse for finished ingredient storage.
(click image to enlarge)

Allied Blending’s powdered ingredients could be considered combustible, due to their extremely small particle size. Under the right conditions, this dust could potentially ignite and cause an explosion. So Stroze had to consider several safety measures when designing the dust collector, such as location and pressure-relief panel installation options. An expert on air pollution control regulations in southern California, he came up with the idea to use the ceiling at Allied Blending as an exterior wall in case local regulations required explosion venting. He installed the SFC in the center of the plant, on top of the already-planned control room, making it into a mezzanine; the three processing rooms that required dust control were located in the center of the plant.

Stelzer liked the idea of locating the collector above the warehouse and off the production floor, leaving space for product manufacturing. In addition, the SFC would be located close enough to be easily ducted to the three production rooms, with clean air recirculating into the warehouse.

Because consumable ingredients were being processed in the Dairy 3A blending room and the batch pack room, Stroze had to use customized stainless-steel ducting and CIP (clean in place) washdown capabilities. “We use one of the rooms to process whey, nonfat dry milk, and yeast, and another for mixing tortilla premixes (batch packs) with salt, sugar, and microingredients,” said Stelzer. “So it’s critical that we comply with FDA regulations and use Types 304 and 316 stainless steel as necessary. We cannot have particles harboring anywhere on-line.”

Allied Blending’s dust collector is located on a mezzanine, above the warehouse floor. Cleaned, air-conditioned air is recirculated back into the factory through safety filters (top right).

Stainless-steel ducting and CIP customization is a requirement for food-processing companies, such as Allied Blending, because they reduce the likelihood of ingredient cross-contamination. This is especially important when blending an allergen ingredient, like powdered milk, and then switching to another batch that cannot contain even a trace of an allergen ingredient. As part of FDA regulations, containment hoods and portions of the ducting must be completely washed down between batches to avoid accidentally mixing ingredients. This is accomplished by removing sections of the ducting and cleaning it in a separate washroom using high-pressure steam cleaning with soap, water, and sanitizing chemicals. Portions not removed are cleaned in place with high-pressure air, wipe downs, and sanitizing chemicals.

For the next three months, Stroze’s team at Clean Air Specialists worked closely with a permitting engineer to install the SFC dust collection system in phases. They worked “on call” with Allied Blending to install portions of the air pollution control system at the same time that parts of the production line in each blending room were being set up. “It was like the, ‘what-comes-first scenario’ of the chicken and the egg,” said Stroze. “You can’t run the production lines without the dust collector, but you can’t set up the dust collector without the production lines.” Used as a central system, the SFC was ducted to three precisely calculated collection points in each of the processing rooms. This ensured that the correct amount of airflow would be pulled from the hooding in each production room and carried into the collector.

Good to Be Below Average

The SFC dust collector is ducted at multiple points within three blending rooms.

Stelzer says that he is pleased with the new dust collector because it is meeting the demands of increased production. “When people who are familiar with how a powdered food-processing facility typically looks visit our plant, they are surprised to learn that we do blending here because it’s so clean.” Additionally, he reports that the Bell facility’s 1.25% product shrinkage was reduced to 0.25%, putting it well below the aforementioned 1% industry average.

Maintenance Time Reduced

Plant manager Juan Mora inspects one of the dust collector’s 32 cartridge filters. When he changes out the filters, he places a bag on the bag-in/bag-out collar to avoid touching the actual cartridge.

The SFC also included a silencer to minimize noise levels from the dust collector’s self-cleaning system compressed-air pulses, a 55-gal disposal drum, and a safety after filter as an extra filtration measure. In addition, Stroze recommended bag-in/bag-out collars and two sets of cleanable cartridge filters. With three shifts running five days a week, this eliminated downtime and made for a quick and less-messy filter changeout. “We change the filters out monthly, and clean a set while the others are in use. It takes less than 30 minutes to change them out,” says Mora. This also falls in line with the company’s incorporation of the SMED (single minute exchange of die) method of lean manufacturing, which is a tool used to create quick changeovers that reduce machine downtime and increase throughput.

Complete elimination of product shrinkage is an unlikely scenario for powdered-ingredient processing companies. However, taking the time to work with an experienced professional who knows how to properly size and install complete air pollution control systems—regardless of challenges with facility layout or type of dust—will most likely decrease product shrinkage. And, other benefits typically come along when the right dust collector is used on the right application, such as reduced maintenance time and peace of mind that safety standards are being met.

An industry leader in air cleaning and pollution control, United Air Specialists (Cincinnati, OH) provides solutions to air quality problems ranging from welding smoke, oil mist, and process dusts in factories to indoor air quality concerns. For more information, visit www.uasinc.com.