Old gas fired water heaters generated high levels of NOx before special infrared radiant plaques were introduced to solve the problem. That’s because, to produce scalding water instantaneously, a large volume of gas had to be burnt rapidly with a high flame temperature in a small space: ideal conditions for creating large quantities of oxygenated nitrogen compounds.
Today, these infrared plaques, produced by Morgan Matroc, a specialist in technical ceramics based in Barcelona in Spain, are proving one way to convert natural and bottled gas into radiant energy with substantially lower NOx levels than other mass-produced gas burning systems.
Typical ceramic plaques have a thousand or more closely packed vents where combustion takes place. A gas or gas/air mixture is fed into a burner box, sealed to the rear of the plaque, where baffles evenly distribute the gas or mixture to all the vents at the same speed and volume.
Combustion occurs as the gas passes through a vent, where the resulting small flame heats the ceramic directly around it. Flame temperature drops as the energy is absorbed by the ceramic, and a balance is created between the flame temperature, ceramic temperature and heat emission.
As ceramic has a very low thermal conductivity, the heat is concentrated in a small volume of the material. Very swiftly the system temperature stabilises to between 700 C and 850 C depending on design where it efficiently radiates infrared energy.
With this happening at every vent on the plaque, the result is an homogeneous emission of radiation travelling perpendicular to the plaque surface.
In addition to their use in water heaters, industrial processes, such as product drying and heating, may also benefit from gas-fired infrared radiant systems when direct heat is needed. In these cases, a custom burner and plaque can be developed specifically for each application.
Morgan Matroc Tel: 01299 827000