This invention relates to a gas burner having one chamber yet two or more independent gas and air feeds and burner surfaces the primary being an inward firing burner and the secondary being a flat, domed, cylindrical, conical, round or inward firing.

To increase efficiency and reduce emissions on gas fired appliances it is becoming common practice to use a system where the gas and air is premixed before being ignited and burned on a burner media of differing materials. However, the use of these systems can lead to a number of difficulties as these systems use a modulating fan or damper system to increase or decrease the capacity of the burner, the air is then passed over or through a venturi or form of orifice which then by means of positive or negative pressure controls the amount of gas that is then mixed with the air. This then gives a relatively stable gas air mix and ratio. The problem arises that the air fan has a maximum and minimum speed and performance even if used with a fixed fan speed and modulating damper, also the gas valve has a minimum positive or negative pressure required to operate which is normally well above the minimum speed or performance of the air fan. Along with this the burner media material will only be stable up the a certain maximum capacity before the flame lifts from the surface and becomes unstable and a minimum capacity before the material becomes hot and the flame speed so low that the flame leaves the surface of the burner media and ignites inside the burner causing an explosion.

To overcome these problems the present invention has two or more independent burners firing inside the same burner chamber, the primary burner has an inward firing flame that fires a full 360 degree's if a cylinder design or all four internal walls if of this design. Due to the burner flame firing in on itself there is a vast increase in burner retention as the opposing flames retain each other thus the maximum capacity of the burner surface media can be increased dramatically and as such reduces the need to have a very low capacity loading of the burner media at low fire thus reducing the temperature of the burner surface. The invention also has a secondary burner that is mounted in the same chamber as the primary yet has its own independent air and gas supply by means of ducting, dampers or separate air fans. This has a result of reducing the minimum firing rate of the burner head chamber as just the secondary burner (if only one secondary) could be firing at minimum rates, all zoned burners will be interlocked by means of electronic or mechanical control systems.

The invention will now be described solely by the way of example and the accompanying drawings in which

Figure 1. Shows a cross sectional view of the primary inward firing burner

Figure 2. Shows a top view of the primary inward firing burner

Figure 3. Shows a secondary burner in a flat version

Figure 4. shows a cross sectional view of both burners Primary and secondary in the main burner chamber.

Figure 5. Shows a top view of both burners primary and secondary. In figure 1. This shows a cross sectional view of the primary inward firing burner 1. showing the outer walls of the burner chamber 2. the outlet flange 3. gas air duct 4 distribution plate 5 and burner media 6. The gas air duct can be of various shapes and the distribution plate 5 can also be of several shapes and sizes. This also shows the air duct 4. that supplies the combustion air that passes over the orifice or venturi 7. where gas is then injected 8. and feeds into the primary part of the mixing chamber 9. after which passing over the distribution plate 5. into the secondary mixing chamber 10,

In figure 2. This shows a top view of the inward firing primary burner 1. showing the outer walls of the burner chamber 2, the outlet flange 3. gas air duct 4. and burner media 6. with the mounting area for the secondary zone burner 11.

In figure 3 this shows a cross sectional view of the secondary burner 12. with the burner media 13 gas air duct 14

In figure 4. this shows a cross sectional view of both the primary burner 1. and secondary burner 12 and the burner chamber outer walls 2.

In figure 5. This shows a cross sectional view of multiple burners primary media 6.. and secondary 11.