LYDON OVEN UNIVERSITY
Freshman Curriculum

Here is how Lydon describes the major sub-systems of an oven:

SHELL: This is the insulated envelope of the oven. It is what is most obvious to the viewer as the metallic box of the oven. Front and rear, left and right are described when the viewer faces the loading side of the shell. Inside the shell are the workspace, heater, air impeller, duct and other systems. The workspace of the oven is designed to contain the work to be heated. It is integrated with the materials handling to ease the loading and unloading of the oven.

DUCT: This is the metal system which, in concert with the shell and other components, constitutes the conduit through which the air is delivered to and removed from the work space of the oven.

CIRCULATION: This is the mechanical system which moves air through the heater, duct system and the workspace. It may consist of one or more fans, fan shafts and fan"containers" inside the shell; and shafts, shaft seals and flanges, bearings, sheaves, belts, motors, motor mounts and belt guards outside the shell. In ovens which circulate the air over and over, this system is often referred to as RECIRCULATION.

VENTILATION: This is the general term for mechanical systems which add air to, and subtract air from, the oven chamber. In a convection oven, ventilation adds to or subtracts from the air in the internal circulation system. Ventilation components which add air to the system are referred to as "injector", "supply" or "fresh air". Components which remove air from the system are commonly referred to as "exhaust" or “air discharge”. Components may include ventilation ducts and dampers, fans and drives, filters, and affiliated controls. Passive ventilation systems rely on the differential pressures of the circulation system for the induction and discharge; Powered systems have dedicated air handling fans to force ventilation.

HEATING: This system converts energy to heat the circulating air which warms the contents of the workspace. Its design must be integrated with the designs of the other major systems of the oven, as well as the mass and nature of the intended contents of the oven, for safe and efficient conversion and exchange of energy. Most of the control and safety system components are dedicated to this system.

CONTROLS: This is the system which ties together all the others and allows the user to direct the conduct of the oven process. It consists of distinct integrated components to control heating, air moving, safety and other operational aspects.

Next Class:  What does the term “oven” actually mean?