Turntable convection oven

Apparatus for heat treatment of a product comprising:

• heat control means;
• means to circulate air in heat exchange relation with said heat control means;
• product support means;
• means to rotate said product support means about an axis;
• and
• means associated with said means to circulate air adapted to form a plurality of spaced air streams and to direct said spaced air streams toward said product support means, said means to form a plurality of spaced air streams being adapted to form a plurality of substantially circular arrays of air streams spaced radially about said axis such that the ratio of the sum of the cross-sectional areas of the air streams of each substantially circular array to the total area of a food product on said support means inpinged by the array of air streams is substantially equal to the ratio of the sum of the cross-sectional areas of air streams in an adjacent substantially circular array to the total area of a food product on said support means impinged by said adjacent array of air streams, said means to rotate said product support means being adapted to repeatedly move portions of product on said support means into and out of heat exchange relation with said spaces streams of air.

A method of transferring heat between gas and a product supported by a turntable in an impingement over comprising the steps of:

• forming a plurality of arrays of distinct streams of temperature controlled gas;
• directing streams of a first array to impinge against spaced discrete areas on the surface of the product as the product is moved on the turntable in the oven;
• forming an array of inclined air streams in the vicinity of the center of the turntable to form a baking zone on one side of said array of inclined streams and a loading zone on the other side of said array of inclined streams;
• and
• drawing spent gas which has impinged the product between the distinct streams of temperature controlled gas through a return passage spaced from the array of streams.

An impingement oven comprising:

• a cabinet;
• turntable means in said cabinet adapted to support a product;
• and
• air ducts above and below said turntable means, each of said air ducts having orifices formed therein adapted to project spaced streams of air to impinge against the surface of a product on the turntable, said orifices in said ducts being formed in an array of concentric rings, each of said concentric rings having orifices formed therein such that the sum of the cross-sectional areas of orifices in each of said concentric rings has substantially the same ratio to the area of the concentric ring in which the orifices are located, such that the area of the surface of a food product rotating under each concentric ring of orifices is substantially uniformly heated.

Apparatus for heat treatment of a product comprising:

• a cabinet having an entrance opening;
• closure means movably secured to said cabinet to open and closure said entrance opening;
• product support means;
• means associated with said means to circulate air adapted to form a plurality of spaced streams of temperature controlled air and to direct said spaced streams toward said product support means;
• means to rotate said product support means about an axis to repeatedly move portions of product on said support means into and out of heat exchange relation with said spaced streams of air;
• and
• means in said cabinet to retain temperature controlled air in said cabinet when said closure means i moved to open said entrance opening into said cabinet.