The Food Manufacturing Brainstorm features industry experts sharing their perspectives on issues critical to the overall food industry marketplace.
In this four-part series, we ask: Which innovations in sanitation should food manufacturers be aware of and how do they aid in regulatory compliance, as well as boosting consumer confidence?
For any company processing food with linear tunnels or spiral freezers, coolers, dryers, proofers or steamers, one of the most radical innovations in sanitary design has been the “High Hygiene” coil (or heat exchanger). The High Hygiene (HH) coil eliminates all overlapping surfaces (joints/collars) and crevices in the coil/heat exchanger portion of freezers, coolers, dryers, proofers and steamers.
With respect to tunnels and spirals, the HH coil is perhaps the single-largest leap a food processor can make in moving equipment toward compliance with the most recent FSMA, AMI, USDA and 3A standards. Standard evaporator coils are generally the dirtiest component in any freezer, cooler, dryer, proofer or steamer system (meaning it accounts for the most bacterial harborage points). Unlike the HH coil, most evaporator coils (or heat exchangers) are manufactured by expanding a tube into a fin, which creates an overlapping surface (a collar) and a circular crevice (nook) around this interface (regardless of the coil material) – an inaccessible safe haven for microbes.
With regard to spiral freezers and coolers, a typical single-spiral cooler or freezer uses a heat exchanger that has 4,100-71,000 sq. ft. of total cooling surface area. Standard coils/heat exchangers this large have about 410-7,100 sq. ft. (roughly 10 percent of the total cooling surface area) of overlapping collars, which are impossible to clean and inspect. For an average coil, that is more than 3,700 sq. ft. of overlapping joints, which is more overlapping surface area than a tennis court. Even more alarming is that these same coils and heat exchangers generate 29,520-511,200 linear feet of crevice length (or harborage channels). What makes this so dangerous in terms of food safety is that coils are constructed in a dense “bundle” so they are generally manufactured 6-24 rows deep, which makes swabbing, inspecting and cleaning them incredibly difficult.
The design intent for any proofer, cooler, freezer, steamer or dryer using a finned heat exchanger is to move (force) all of the air through the heat exchanger. Therefore, it’s crucial to ensure that the object the air contacts (prior to contacting the naked food product) is the cleanest component in the system, not the dirtiest. In contrast, a food processor using a tunnel or spiral with a High Hygiene coil bodes well for boosting consumer confidence.
Andrew Knowles, Sales Support/Applications Manager, JBT FoodTech
