August 22, 2011
Downloads: Technical Bulletin, Product Flyer
COLVILLE, Wash. – Colmac Coil Manufacturing's new self-positioning system eliminates damage that can occur to refrigeration evaporators during defrost cycles.
During a defrost cycle, the amount of expansion and contraction of heating elements can be relatively large. Repeated defrost cycles, along with the associated re-freezing of melted frost, can result in the heating element 'creeping' or 'walking' out of the heat exchanger.
"Understanding the mechanics of the heating element 'creeping' issue was one the most challenging aspects of solving this issue," says Roger Williams, Engineering Manager, "once we understood what was happening, the design team was able to brainstorm several new prototypes."
The design team, Bruce Nelson, Roger Williams, Jeremy Olberding, and John Wold, invented a self-positioning system for electric resistance heating elements. Colmac Coil was awarded a patent for the self-positioning system on May 11, 2010.
"The new self-positioning system works well for electric defrost coils at any temperature and in applications where electric re-heat is required," said Jeremy Olberding, Sales Manager.
The self-positioning system simplifies installation by minimizing the number of parts and eliminating the need for separate ground straps to electrically ground the element. Furthermore, the self-positioning system forces the heating element to return to their correct position at the beginning of each defrost cycle.
"Reliable operation of evaporators, especially in unattended cold stores, is extremely important," says Williams, "the development of the heating element self-positioning system has virtually eliminated heating element failures in the field."
The patent is available for viewing at Google Patents. The patent number is US 7,712,327 B2.