Patent ID: 8322162

Claim:
A method of heating glass panels for tempering, said method comprising: heating horizontal glass panels in a lehr by upper and lower convection blast and by upper and lower radiation heating, reading information that represents a load of the glass panels and that is used for the control and/or regulation of heating, controlling and/or regulating the upper radiation heating, controlling and/or regulating at least the upper convection blast in various sections of the lehr in the way of a matrix by a profiling both in a conveying direction and in a direction lateral thereto, dividing the upper convection blast elements in the conveying direction and in the direction lateral thereto into a plurality of segments or blocks, individually controlling and/or regulating the blast effects of the upper convection blast elements in various sections of the lehr by providing a regulator for each said segment or block, wherein the relative blast effects of convection blast elements successive in both the conveying direction and in the direction lateral thereto are regulated to provide a profiling both in the conveying direction and in the direction lateral thereto; wherein profiling and individually controlling the blast effects of the upper convection blast elements minimizes glass distortion due to unified heating throughout the glass panel which thereby substantially prevents overheating of the leading and trailing edges; and wherein individually controlling and/or regulating the blast effects of the upper convection blast elements in various sections of the lehr comprises controlling the amount and pressure of the convection air.