Case Studies

Food Processing

Radiant-Heat Killing of Insect Infestation in Dog Food

Radiant-Heat Killing of Insect Infestation in Dog Food

The Challenge
In this dog food manufacturing operation, insect infestation was a recurring problem. The infestations caused product damage and contamination and decreased production yield.  To kill the insect eggs, larvae and adults, the dog food product needed to be heated to 140-150°F for one minute and to maintain a recommended 130-140°F in the food for 20 minutes.

The Solution
*Ten Chromalox RADD-7604 Electric Radiant Panels were suspended on a movable frame above a vibrating conveyor 10 feet long and 48 inches wide, down which the dog food would flow under intense radiation. In the event of a conveyor stoppage the Radiant Panels are lifted vertically a distance of 18 inches to prevent burning of the product.  Installed wattage is 108 kW and the capacity of the operation is 10,000 lbs. per hour.

When the food spills off the bottom end of the vibrating conveyor after an exposure time of 50 seconds, it has reached a temperature of approximately 160°F, and at this temperature falls into a holding bin where, because of lack of air circulation, the temperature remains at 140°F for 20 minutes before the food enters the packaging conveyor system.

The operation shows an overall economy of .0135 kW hour per pound of food, or a radiant energy power cost of $.27 per ton with electric power at $.1 per kW hour.

*Process has been patented by Best Feeds & Farm Supplies, Inc. 


  • Its operation is entirely automatic-requires only one attendant who has nothing to do but observe and raise the panels in the event that the conveyor stops.
  • Its radiation is uniform - all food particles are subjected to the same radiation.
  • In addition to killing parasites found in grain products, it toasts the food lightly - a feature that dogs seem to like.
  • It's a flexible heat source - panels are raised from their normal position of 2" above the conveyor so that free access can be had to the conveyor for thorough cleaning.
  • The long, maintenance-free life of the metal-sheath heater elements with which the Radiant Panels are powered.
  • The electric oven represents a much lower investment than any other. Each heating panel, in fact, is an oven section in itself with built-in elements, reflector, insulation and mounting frame, as well as bus duct for easy connecting of adjacent panels - all of which allow economical oven assembly.