What Works: Dry ice blast ups cleaning productivity by 80%
Food manufacturer finds fast ROI by shooting carbon dioxide.
For food manufacturers, removing leftover food, grease, oil, dust, flour and other residue from production equipment is critical to prevent bacteria growth, protect equipment and ensure a safe and quality product. But traditional cleaning methods such as hand-scrubbing with solvents, steam or water spray often have proven time-consuming, inefficient and ineffective against built-up, hard-to-remove residues. Driven by government regulations and costs, companies are trying to reduce dependence on chemical cleaners and water, and are being much more cognizant of costs, including labor.
At a food manufacturer in Chanhassen, Minn., a three-person maintenance crew cleaned the company’s 30 ft. by 50 ft. cooling tunnels by hand using solvents and steam. Before they could start, production was stopped so the machines could cool. The cleaning took nearly nine hours, and at best, would remove 80% of the particles baked onto the tunnels, conveyors, motors and panels. After cleaning, the crew collected and removed the wastewater, then invested time and energy to reheat the equipment and restart production.
On recommendation of a sister facility, Chanhassen plant personnel experimented with dry ice blast cleaning. “Many manufacturing leaders are finding that there are many cost and labor saving benefits that can be found in the type of cleaning solutions they use,” says Gene Cooke, CEO of Cold Jet, LLC (www.coldjet.com), a manufacturer of dry ice blast cleaning systems. “In this case, our dry ice blast cleaning solutions provide these benefits on top of being an environmentally responsible solution.”
A pre-purchase cost analysis estimated that dry ice blast cleaning would save the company roughly $15,000 per year on cooling tunnel cleaning alone. The company soon discovered that dry ice blast cleaning could do much more, delivering a payback of less than one year.
Cleaning productivity increased 80% as a result of more efficient labor allocation and reduced cleaning time. One person can do as much as the three-person cleaning crew in one-third of the time, and equipment downtime was cut by half because the maintenance crew can clean the equipment while it is still hot.
Regular and effective cleaning also extends equipment life. Build-up can reduce efficiency, increase equipment failures and cause production delays. Water in the conveyor chains can reduce their life expectancy from 10 years to two years, a significant increase in the plant’s replacement expenses as the average cost of a chain replacement is $100,000.
Standing water on equipment also can affect product quality, as well as trigger rusting. Cooke notes, “Whenever something breaks down or stops working in a bakery plant, the first question asked is, ‘Did you use water?’”
The Chanhassen plant cut cleaning preparation time in half simply by eliminating the need to cover and uncover adjacent, water-sensitive machinery, such as electric motors. The dry process also eliminates wastewater treatment and recycling issues.
A major consideration for the Chanhassen plant was finding a process that was safe to use on food production equipment and would not affect product quality. Dry ice is colorless, tasteless and odorless, and the quality of the ice is equal to the grade used in the food industry. Dry ice cleaning has been approved by the U.S. Department of Agriculture, the Food and Drug Administration and the Environmental Protection Agency.
Dry ice blast cleaning systems use recycled CO2 in the form of dry ice particles that are blasted at supersonic speed through customized nozzles. When the dry ice particles hit a dirty surface, the combination of the kinetic and thermal shock causes mini-explosions that break the residue from the equipment surfaces. The residue falls to the floor and can be easily vacuumed or swept up.
Because dry ice particles sublimate upon impact, dry ice blast cleaning eliminates the added cost and inconvenience of secondary waste treatment and disposal, as well as the worry of downstream contamination. In addition, with dry ice blasting, crews can clean hard to reach places without having to disassemble or move equipment.
Before and after
After dry ice blasting (right), the Chanhassen, Minn., food plant had removed 100% of the built-up debris in its cooling tunnels.
The Chanhassen plant managers were impressed by the results and began to use the process in other areas of the plant, including power cabinet internals, proof boxes, dough dividers, baggers, slicers and ovens.
Cooke adds, “The process is helping a variety of food manufacturing companies clean more effectively and efficiently, reduce costs and improve productivity and worker safety, while also supporting organization’s lean and green initiates.”