PROCESS EXPO: 'Cleanable design'
Sept. 17, 2015
by Lawrence Aylward
Prof. Mark Morgan, head of food science at technology at the Univ. of Tennessee, speaks about hygienic equipment design at PROCESS EXPO.
CHICAGO – Empty seats were hard to come by at Mark Morgan’s presentation during PROCESS EXPO on Wednesday afternoon at the McCormick Place. Morgan, professor and head of food science and technology at the Univ. of Tennessee, was presenting on a popular topic, “Hygienic Design of Food Processing Equipment/Opportunities for Improving Food Safety.”
As Morgan said at the outset of his presentation: It is an important topic because there continues to be meat and poultry recalls that are linked to contaminated equipment. Morgan also emphasized that “hygienic design” equates to “cleanable design.”
Morgan, Ph.D., talked about two types of equipment: open equipment, where product contact surface is exposed to the environment; and closed equipment, such as pumps and valves. With both equipment types, Morgan stressed the importance of establishing a risk assessment.
“What is the risk that product is going to get contaminated from something on that piece of equipment?” Morgan asked. He noted that the risk of product contamination is low if a pathogen harbors on the bottom piece of equipment, but is higher at the top of the equipment.
“For certification aspects, we really look at everything as being a food contact surface, especially for open equipment,” he added.
Morgan offered general recommendations for improved equipment design, such as drainability, which he called a key component of hygienic design.
“You want to make sure that all the water can drain out or off of your equipment,” he said. “If there is no water present, microorganisms won’t be able to grow and multiply. And it really takes that growth and multiplication to cause a food-borne outbreak.”
Sharp corners on equipment are easier to clean, Morgan said. He also stressed the need to rid equipment design of overlapping joints. “Metal to metal joints is a problem because they will suck water in, which can create a harboring site that could contaminate product,” he added.
Morgan also noted the importance of continuous welding on equipment. He advised not to spot weld equipment.
“Make sure any equipment welds are free of edges, cracks and porosity,” he added.
Morgan advised against using socket head screws on equipment because they are difficult to clean. He said dome head bolts are a better option.
Morgan also stressed the need for no horizontal surfaces in equipment design if possible.
“Surfaces should always slope away,” he said.