A method for balancing heat fluxes validated for a newly designed pilot plant oven

Heating heterogeneity is often observed in laboratory/kitchen ovens, medium size equipments such as rotary ovens, and industrial tunnel-type ovens. Losses of bakery products are mainly due to the effect of not a uniform heat flux delivered to the product. Discarding products of not desired shape and color, from non uniform heat fluxes, is a common practice in the bakery industry resulting in waste of energy and food ingredients. A static pilot plant oven was designed and constructed to simulate industrial continuous ovens. The oven is equipped with computerized on line control system to simulate baking parameters such as wall and air temperature, velocity and humidity of air inside the baking chamber corresponding to the real baking profile of a given commercial product. A mathematical method was developed to establish appropriate coefficients and correlations for oven performance providing a uniform baking zone. Heat fluxes in the baking zones of the oven both for top and bottom chambers at various positions were experimentally measured using a specially designed total heat flux meter, the h-monitor. Results showed an acceptable uniform heat flux of less than 5% variation within the baking zone except at the corners of the oven. Several baking trials of various industrial cake products confirmed that the desired heat flux uniformity was achieved.