Hot Spot Management

Need

Reduce appliance surface temperatures near the handle of a slow cooker.

Technical Assessment

High surface temperature from radiative heat transfer.

Solution Engineering

Radiant heat shield.

Validation

Reduced surface temperatures with added benefit of energy efficiency.

Lydall's diagnostic tools and understanding of thermal transfer allow us to go beyond the stated need to address the underlying thermal issue and deliver additional value.

In this case, a manufacturer found high temperatures near the handles of their slow cookers, but lacked the resources to evaluate the issue and design a solution before mass production of the unit could take place.

Lydall's engineers used infrared thermography to provide a surface temperature profile that identified the extent of the surface temperature problem. They then evaluated the manufacturer's design parameters -- including the heating element temperatures, insulation space available materials of construction and surface emissivities.

Lydall's analysis revealed high temperatures over much of the slow cooker surface due to strong radiative heat transfer between the inner and outer walls of the appliance.

A small amount of insulation near the handles would not resolve the issues in this appliance. Lydall proposed a thermal shield of foil covered glass paper -- in this instance, Manniglas® - to reflect the radiant energy back into the appliance.

Since the slow cooker was quite small, the solution could easily be tested directly. After installing the insulation solution, the appliance was heated, and a second infrared image confirmed the reduction of surface temperatures.

The high surface temperatures were symptomatic of high energy losses. During validation, energy consumption and time required to reach full operating temperature were measured. Both tests revealed an increase in appliance efficiency, and therefore cost efficiency.