1. Field of the Invention
The present invention relates to ignition carry-over in multiple burner heating apparatus and, more particularly, to a simple and efficient method and means for effecting ignition, with a single pilot, or spark source, of all burners in a multiple burner heating apparatus.
2. Description of the Prior Art
A continuous oven typically consists of a conveyor belt which conducts a food product to be cooked through the oven. This conveyor belt is typically heated through the use of a multiplicity of spaced, independent burners situated in a single plane directly beneath the conveyor belt.
In heating apparatus of this type, the cost and complexity inherent in providing an individual firing mechanism for each of the several burners soon becomes prohibitive as the number of individual burners increases. Thus, it has become the common practice to provide a single pilot or spark source and means for firing all of the burners from such single source.
The most common technique utilized for igniting multiple burners from a single pilot or spark source is to position the burners in closely spaced, parallel relationship so that the flame will readily jump from one burner to the next. By spacing multiple, parallel burners no more than five inches apart, a flame will generally jump from one burner to the next without requiring separate ignition carry-over means. Unfortunately, this is not a very satisfactory solution to the problem because it means that a large number of parallel burners are necessary. Since the ends of the burners are typically connected to a manifold which conducts an air-gas mixture to the burners from a blower assembly, the large number of burners requires a blower having significant capacity and an excessive use of gas.
On the other hand, if the burners are spaced apart by more than five inches so as to minimize the number of burners and to minimize the blower capacity, the flame simply will not jump from one burner to the other. It therefore becomes necessary to put in a pilot runner or multiple ignition points, both of which cause extra maintenance problems. Alternatively, it becomes necessary to provide some kind of additional ignition carry-over means and many such ignition carry-over devices have been disclosed in the prior art. However, many of these known multiple burner firing arrangements are not totally reliable, are overly complex and interfere with the normal combustion process.