Desiccant system improves production of pizza-topped bagels
As part of this system, food manufacturers are looking for permanent solutions to contamination hazards such as overhead condensation resulting from daily wash downs. This condensation has a potential to contaminate the product if allowed to drip from the ceiling.
The USDA’s Code of Federal Regulation ensures that meat and poultry for use as human food are safe and wholesome when handled at processing facilities. These regulations require a thorough wash down, using steam-injected water, during each production day.
Afterward, all overhead condensation must be removed from the working area before production resumes.
Role of bagelsThe Bagel Bites Division of Ore-Ida Foods, following its own internal sanitation standards as well as USDA guidelines, performs a daily wash down process at its Fort Myers, Fla. facility.
However, this wash down was taking up to 4 hrs per day due to excessive fog and condensation. In addition, the reduced visibility created a significant safety hazard for the 17 employees who conducted the wash down.
Operations teams set out to find a process that would reduce the fog and condensation while increasing operating efficiencies. It was through this search that they first considered desiccant dehumidification.
The Bagel Bites Division manufactures pizza-topped mini-bagels in a choice of numerous topping combinations. Each 7-oz package contains nine frozen mini-bagels, which are ready to be heated in the oven or microwave.
Bagel Bites are primarily produced at Ore-Ida’s plant for distribution to markets in the United States, Mexico, and Canada. Sales are ranked second in the frozen appetizer and snack category, with an annual dollar volume of over $60 million.
Because many of its products are topped with meat, the factory strictly complies with wash down regulations, which are subject to verification by their on-site USDA inspector. The wash down is also carried out as part of the company’s Sanitation Standard Operating Procedures adopted under the government mandated food safety system.
Wash down procedureEach night, during the third shift, production is shut down to perform this wash down. At the onset, the normal temperature in the processing room is at 45Â°F.
This cold air is so close to saturation that it cannot absorb the large amounts of water vapor being sprayed into the room from the wash down hoses.
As a result, water being sprayed precipitates out, immediately forming fog and condensation throughout the room. Once the wash down is completed, all equipment, walls, and floors must be dry and free of any water or condensation.
In particular, any overhead condensation that could drip from the ceiling onto the product must be removed. This drying is done due to the threat of contamination posed by moist, wet conditions, which can potentially promote pathogen growth.
Bagel Bites and its USDA inspector ensure these dry conditions are met before allowing production to resume.
With humidity close to 100% rh during and after the wash down, the total time needed to dry the process area exceeded 4 hrs. Bagel Bites employees attempted to minimize drying time, with little improvement, by using cooling from the air conditioning system, circulation fans, and squeegees and mops on any standing water.
In order to find a solution to the hazardous and time-consuming wash down process, Ore-Ida began to explore the benefits of desiccant dehumidification.
Role of desiccantsCompared to the typical refrigeration system, desiccants are effective in removing moisture from the air at a condition far from saturation or at extremely low temperatures.
While cooling-based dehumidifiers cool the air to condense moisture and then draw it away, desiccants attract moisture molecules directly from the air in a vapor phase using a “Honeycombe” wheel. The moisture is released by the desiccant when nested in an exhaust airstream, avoiding the hazards of condensation all together.
David Simkins, business development manager for the Cargocaire Division of Munters Corp., a manufacturer of desiccant dehumidification equipment, says integrating desiccants into the hvac systems of institutional, commercial, and industrial facilities has become popular.
Demand for desiccant“In addition to more engineers familiarizing themselves with desiccant technology, stringent indoor air quality standards requiring more fresh air with less humidity have created a demand for desiccant dehumidification,” Simkins said.
This solution is growing in popularity in the food services industry, due to the unique sanitation concerns relating to moisture.
“Ore-Ida was enthusiastic about the desiccant dehumidification concept for addressing their fogging and condensation issues, but was reluctant to make the capital investment in a technology they had not previously used,” said Gary Evans, sales engineer for Munters Cargocaire.
Munters convinced Bagel Bites to try desiccant dehumidification by renting a 9,000-cfm unit for a one-month evaluation. The equipment rental was handled by Munters’ equipment rental division, Moisture Control Services.
“On the first day of operation with the rental unit, the wash down was started and fog was allowed to fill the area,” said Andrew Galloway, production support leader for the Bagel Bites Division. “The dehumidifier was then started. Within 15 minutes, all the fog was cleared from the room.”
The fog that had previously obscured the cleaning process and presented a hazard to workers was eliminated, and the wash down could continue at a safe and efficient pace.
In addition to clearing the fog, the unit continued to run after the wash down to allow drying of the equipment, walls, floors, and ceilings in the area. The drying time was reduced significantly. With the dehumidifier in operation, the wash down took little more than 2 hrs.
Following the first night of evaluation, Bagel Bites was ready to purchase its own equipment. Processing of the capital appropriation, order entry, delivery of the permanent dehumidifier and equipment, along with ductwork installation, would take 11 weeks, during which time Bagel Bites decided to retain the rental unit.
“We weren’t willing to give up the rental equipment until the permanent unit was installed and running,” said Sam Casey, manufacturing manager for Bagel Bites. “The overall benefits of improved sanitation and safety far outweighed the rental costs.”
Installation set-upInstallation in the processing area was straightforward. Conventional, ceiling-mounted evaporator coils provide cooling to the area at 45Â°. Dehumidification is handled independently by the dehumidifier mounted outside the building adjacent to the processing area.
The dehumidifier processes 9,000 cfm, delivering dry air conditions of 77Â° at 4% rh. The cooling units operate in response to a thermostatic control. A humidistat holds the room to 65% rh, an appropriate level to prevent condensation and fog while meeting food production specifications.
Along with eliminating the fog and condensation, Bagel Bites has found that its dehumidifier purchase has benefits that reach beyond the processing area. Several process freezers located inside the dehumidified area have realized a significant reduction in both frost accumulation and defrost cycles.
“Because the moisture is removed from the air, it does not accumulate as quickly on the evaporator coils and inside the freezer,” said Victor Herbert, maintenance supervisor for Bagel Bites.
“That means the energy-consuming defrost cycles have been shortened, and the interval between them stretched out.”