Based on the harmless appearance of a bagel, it’s hard to imagine that making these popular treats may, in fact, pose an occasional hazard. But it’s true, according to officials at a Canadian bread manufacturing company based in Toronto, Ontario.
Highly pressurised hot water is used extensively in the bagel making process to offset potential quality problems. The process also requires a filtration system to clean raisins, sesame seeds, bits of dough, corn meal and other materials out of the hot water. And that’s where dangers may arise.
For several years, the company had been using duplex bag filters, which led to concerns about employee safety because of the hazards of manually changing the filter bags whilst working with high water temperatures.
The bread company planned to install a new bagel boiler in its Alberta, Canada plant and required a filtering system to clean the recycled boiler water of raisins, sesame seeds, bits of dough and corn meal. Corn meal can create water quality problems if the temperature falls, requiring an expensive and time-consuming water change. It is critical that the water in a bagel boiler remain at a high temperature, even as it is filtered and recycled.
With employee safety in mind, the maintenance supervisor at the company’s Alberta plant wanted a filtering system that required less operator intervention than a bag system. The high water temperatures used in the process can be a serious hazard for operators changing the filter bags, especially if they are pressed for time during the shutdown process and open the filter housing while it is still pressurised.
Decision makers at the Alberta plant wanted a filter they could count on, without the hazards occasionally associated with bag filter maintenance. Working with Eaton, the plant manager and maintenance supervisor determined that the Eaton DCF mechanically cleaned filter offered a permanent solution for meeting their business objectives.
The plant installed two Eaton DCF-800 filters on the boiler water recycle line at the Alberta facility. The DCF filters successfully removed the raisins, sesame seeds, bits of dough and corn meal that would adversely affect the final product. Uninterrupted filtering by the DCF also ensured the consistently high water temperatures required to maintain boiler water quality.
The DCF performs a self-cleaning action by mechanically scraping collected debris from the filter screen with a disc that travels up and down the screen, parallel to the liquid flow. The collection chamber at the bottom of the filter automatically purges collected debris without halting production, in a process that takes less than seven-tenths of a second. Because the DCF continuously cleans the screen without interrupting production, it maintains a consistently high flow rate and provides the highest quality filtering.
The Alberta facility has eliminated the risk of operator injury related to changing the filter bags, as there are no bags to remove and media cleaning is automatic.
The facility’s supervisors were also impressed with the unsurpassed filtering of its bagel boiler water, as well as the ability to maintain high water temperature and avoid water quality problems.
Meanwhile, the plant is realising financial and environmental gains by eliminating media, reducing worker exposure and reducing labour and disposal costs.
In fact, the company was so happy with the performance of the DCF filters at its Alberta plant that the facility in Langley, British Columbia also installed DCF filters on its bagel boiler systems, instead of the previously planned bags.