Case History 3- Project: Convection Oven

Objective : Our client needed to obtain a more even temperature distribution on the face of their 12" x 30" panel. The temperature distribution on the air diffuser was uneven in ten bands which varied by up to 45°. This client was also interested in reducing cost for the heater panel assembly.

Challenges : The heater is part of a system which has to deliver even air flow and velocity along with even temperatures at 300 points on the diffuser surface. We felt that the best way to assure total performance and comprehensively address costs would be to design a complete heated air module rather than only the heater.

Solutions and their impact : Farnam designed a pressurized box which incorporates dual diffusers. The air pressure is profiled by the first diffuser so that an even flow will be directed through all the heating circuits before passing through the final diffuser on the face of the panel. Having the air forced right through all the heating circuits creates a very efficient heat exchange and even heating. This design generated the following improvements:

• Product performance is greatly enhanced. We reduced temperature variation by 70%. The pattern was reduced from 10 bands representing 45°F to 3 bands representing 13°F. Air velocity is even at all 300 points.
  
• The completed heater / diffuser module we designed is easy for our customer to drop into their oven and eliminates assembly time for them.
  
• Cost savings of over 45% are generated by this new modular panel over the previous arrangement.