Bruce Nelson’s design addresses common deficiencies that lead to ammonia leaks.
Bruce Nelson, Colmac Coil
Colmac Coil, Colville, Wash., announced earlier this month that Bruce Nelson, its president, has been awarded a new patent for his plate-freezer innovations, which enhance the safety of the technology.
Traditional direct contact plate-freezer designs, used for direct contact cooling of processed food products, have had common reoccurring deficiencies which result in potential health hazards, Colmac said in a statement.
Often, to counteract the non-uniform distribution of liquid refrigerant, such as ammonia, in traditional plate freezers, increased levels of refrigerant are used. This creates a health hazard if the refrigerant is leaked.
The most common instance of refrigerant leakage occurs at the connection of the refrigerant conduit to the common intake and suction manifolds. Because the threaded connections are stainless steel and the plates of the freezer are aluminum, there is a difference in the linear coefficient of thermal expansion, resulting in leaks over repeated freezing cycles.
Nelson’s design resolves each of the previously mentioned deficiencies and helps ensure a safe environment for workers near the freezers, Colmac said.
By using a wicking structure and internal passageways the uniformity of the refrigerant flow can be greatly increased, thus reducing health hazards should a leak occur. A bimetallic coupling used at the connection of the conduit to the freezing plates eliminates the risk of refrigerant leaks over multiple freezing cycles, the company added.
Colmac Coil has attracted recent attention for its development of a low-charge ammonia DX system, which is installed in several cold-storage facilities.