Food Engineering

Steam filters relieve pressure cooker QA issues

April 5, 2004
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At Weetabix Canada, Balston steam filters permit direct steam contact with food and can handle flow rates of up to 3,000 lbs/hr. Source: Parker Hannifin.

At Weetabix Canada steam filters on the feed line for a pressure cooker provide an extra level of quality assurance in producing over 90 brands of breakfast cereal. The filter removes 98+% of 0.01 micron particles and 100% of all visible particles, helping the company comply with current good manufacturing practices by virtually eliminating contamination in process steam. A critical factor in selecting the filters was the desire to reduce maintenance while assuring the highest possible level of filtration.

According to Al Cane, engineering project coordinator for Weetabix Canada, located in Cobourg, Ontario, the consideration of various what-if scenarios led the cereal maker to the idea of filtering the steam feed to the pressure cooker.

“The quality of the water that we use to make the steam is carefully controlled and we also take great care to ensure the cleanliness of the steam making equipment and associated lines,” Cane says. “But we spend a lot of time considering worst-case situations, such as what if there was a failure in the water treatment plant,” he adds. Cane and his co-workers decided that filtering the steam just before it entered each of the pressure cookers would provide an added safety measure to ensure that they are providing food grade steam to the cooking process.

Weetabix operates two lines with two pressure cookers each. One set of cookers rated at 50 pounds is used to cook short cycle products such as Weetabix biscuits. The other cookers run at 25 pounds and cook long cycle products such as cereals.

Cane and other engineers researched various steam filters. “We started thinking about Balston right in the beginning because we have had such good success with their liquid filters,” Cain states. “We ordered a bank of six filters for one processing line and four filters for the other. The filters can be rotated into and out of operation on the fly, making it possible to change media or perform other maintenance while continuing to operate the line.”

Balston steam filters that permit direct steam contact with food can handle flow rates of up to 3,000 lbs/hr. These filters reduce steam condensate mixing with the food products when steam is used for agitating, mixing or cooking. They reduce carryover of boiler feedwater chemicals into the food product, eliminating any impact on taste or order. They also can reduce maintenance requirements for valves, cookers, heat exchangers, and other equipment.

The steam filters can be rotated so that only half are working at any given time. According to Cane, the filters are included in the company’s regular preventive maintenance program. “Every month we inspect the filters and measure the pressure drop by examining gauges upstream and downstream of the filters. In the vast majority of cases, nothing needs to be done. If the filters are starting to plug up, then we change the media. We also change the media on all of the filters during our annual plant shutdown. Beyond that, these filters have not required any attention or effort on our part.”

For more information:
Parker Hannifin Corporation, 800-343-4048
www.balstonfilters.com