According to Emerson, Digital Scrolls “offer cooling equipment manufacturers an innovative new way to modulate, or automatically adjust, the capacity of the compressor from 10 percent to 100 percent, so it precisely matches the refrigeration load.
“This approach has shown to increase energy efficiency by as much as 30% in transport applications, and is capable of holding a precise temperature to plus or minus half a degree.”
“Over the years, we have carefully modified our Scroll Design to meet the specific needs of commercial refrigeration equipment, which experiences greater demands and harsher operating conditions than the traditional air conditioning applications,” said Thomas E. Bettcher, CEO of Emerson’s Copeland Corporation division and business leader for Emerson Climate Technologies.
“Now with Digital Scroll technology, we are working with companies like Thermo King to solve critical problems in a variety of applications, such as sea containers, which transport perishable food around the world.”
In order for Copeland Scroll technology to efficiently operate within the higher compression ratios experienced by commercial refrigeration applications, Emerson designed a Scroll that could guard against the heat buildup and gas re-expansion associated with these conditions. By incorporating additional new design features, such as vapor injection, the compressors can run more efficiently at continuous operation, according to Emerson.
Thermo King worked with Emerson to custom-design the Digital Scroll technology to power Thermo’s Magnum“ heating and cooling unit. The result is the first container refrigeration unit with the ability to precisely maintain -35 degrees C (-31 degrees F) in any ambient temperature condition, it was reported.
“Our sea containers face the worst operating conditions imaginable. They travel to every corner of the world, through extreme temperatures, sometimes running for hours on end in a high ambient environment,” said Bob Johnson, vice president and general manager of Thermo King’s Container Division. “Compressor reliability is crucial, and we have chosen Copeland Digital Scroll technology because we are confident it will easily meet our requirements.”
The technology also extends the usable life of containers, according to the report, which said that currently deep frozen shipments (-29 degrees C/-20.2 degrees F) are limited to containers that are less than five years old. Thermo King’s Magnum is said to offer cooling capacity to maintain -29 degrees C throughout the 15-year life of the container.
Publication date: 01/27/2003