Abstract:
A burner tube (1) for use in an oven such as a tunnel oven. The burner tube includes a tubular body (2) having an axially extending slot (3) therein and an inlet (6) for combustible gas, the burner tube further including a metal mesh (4) which covers the slot. In use, the burner tube defines a flow path for combustible gas so that combustible gas entering the burner tube at the inlet passes through the slot and exits the burner tube through a flow area of the metal mesh. The flow area of the metal mesh is greater than the area of the slot at the outer surface of the tubular body. In use, a visible flame is anchored to the flow area of the metal mesh and the metal mesh incandesces to produce radiant heat.
Abstract:
This document discusses, among other things, systems, devices, and methods that increase radiant energy output, such as by using the waste airflow of combusted gas and/or ambient airflow resulting from convection, or by reducing or avoiding cooling effects of such airflows. In one example, the collected energy can be used to drive other secondary radiant sources or to preheat combustion air or ambient air. In another example, segmented secondary radiant sources are thermally isolated from each other to operate as a cross flow exchanger that exchanges thermal energy from a heated gas to a heated surface that provides radiant energy output. In a further example, a re-radiant membrane can separate the radiant source from the environment and/or reconfigure the effective shape of the primary radiant energy source.
Abstract:
A radiant burner includes a housing for receiving a combustible air and fuel mixture and a combustor unit formed to include an open-space combustion chamber having a top opening and passageways for communicating the combustible air and fuel mixture from the housing to the open-space combustion chamber. The combustor unit is a block of insulation material formed to include a cavity defining the open-space combustion chamber and a plurality of apertures defining the passageways. The combustible air and fuel mixture extant in the open-space combustion chamber is ignited to produce a flame. The top opening of the open-space combustion chamber is covered to define a flame retention region therein so that the flame is stabilized in and contained wholly within the open-space combustion chamber. The cover is provided by a radiant member having a heat-receiving surface communicating with the underlying flame produced in the open-space combustion chamber and blocking passage of the flame through the radiant member and a heat-radiating surface emitting flameless thermal radiation to heat a product positioned above the radiant member.
Abstract:
The subject burner assembly disposes an air inlet along a base surface of a housing opposite from a radiant, multi-ply screen surface. Air enters the inlet for mixture with an associated supply of gas in a mixing chamber. An air/gas mixture exits the mixing chamber and enters a plenum chamber for distribution and combustion on the entire radiant surface. The multi-ply, radiant surface is defined by three separate screens having a predetermined weave pattern. A reverberator is spaced from the radiant surface and reflects heat from the exhaust gas toward the radiant surface.
Abstract:
A radiant burner that has a hollow body with a closed rear and a peripheral wall extending forwardly from the rear to define an open ended chamber. There is an outwardly extending, planar spacing flange on the front end of the peripheral wall. A perforated diffuser plate extends across the chamber in a plane located rearwardly from the end of the wall. The plate has a forwardly directed flange around its perimeter and an outwardly extending marginal edge which lies against the spacing flange. A primary screen consisting of a plurality of layers of fine bias cut mesh extends across the open end of the chamber with its edges overlying and adjacent to the front surface of the edge of the plate. A reverberator grid which has a planar body and a backwardly extending border flange is located in front of the primary screen with an outwardly extending edge of its flange adjacent the surface of the edge of the primary screen and its main body spaced forwardly from the primary screen by its flange. The layers of the primary screen and the reverberator grid are spot welded together at certain points. The central portion of the primary screen is dished forwardly toward the reverberator grid. Retaining lips on the spacing flange of the body are folded over inwardly against the front surface of the edge of the reverberator grid flange for retaining the diffuser plate and the primary screen and reverberator grid in place in the burner. There is an inlet for combustible gases into the chamber behind the diffuser plate.
Abstract:
An infra-red heat generator having a generally cup-shaped body which has an open front end. A perforated diffuser extends across the body lying in a plane parallel to and spaced from the open front end. The diffuser defines a mixing plenum in the rear of the body behind the diffuser. There is an inlet into the plenum for a combustible gas mixture. The percentage of open area of the diffuser is such that during operation a positive pressure is maintained in the plenum. The diffuser is held in place by a spacer which fits into the open end of the body. A multi-layer primary screen lies across the open end of the body. The layers of the primary screen are welded to each other in an orientation with the elements of each layer overlying, in part, the openings of the adjacent layer and the layers are contiguous throughout. The edges of the primary screen lie against the front edges of the generator body which define its open end and the center of the primary screen is convex relative to its edges. The elements of the screen layers are deformed against each other at their crossing points to provide substantial areas of surface contact therebetween. A centrally convex reverberator grid is positioned in front of the primary screen by a spacer that extends between the edges of the screen and the grid. The diffuser, primary screen, grid and spacer are all held in position by a cap which has an inwardly directed lip overlying the edges of the grid and a main flange which telescopes over the front of the generator body and extends around the edges of the primary screen. A retainer is wedged between the outer surface of the body and the main flange of the cap to hold the parts in assembled position.
Abstract:
A device for use in a burner, including a honeycomb body formed from a metal band. The metal band is laminated or coiled to yield a plurality of holes or apertures. The honeycomb body has first and second surfaces which are opposite to each other. The holes or apertures penetrate through the first surface and the second surface, and an outer boundary of the first surface and an outer boundary of the second surface are connected whereby yielding a lateral surface. A through hole is disposed on the lateral surface of the honeycomb body and penetrates inward through multiple layers of adjacent laminated or coiled metal bands, and a metal wire is disposed in the through hole; and/or, a part of the laminated or coiled metal bands on the first surface and/or the second surface are embedded, overlapped and engaged with adjacent metal bands to form an embedded member.
Abstract:
A radiant element which is heated on its rear side by a burning fluid-air mixture and whose front side emits the infrared radiation. The radiant element is produced from a highly heat resistant material which contains more than 50% by weight of a metal silicide, preferably molybdenum disilicide (MoSi2) or tungsten disilicide (WSi2).
Abstract:
A low NOx combustion process and burner apparatus in which a mixture of a primary fuel and air, with the air in excess of the stoichiometric requirement, is passed to a surface burner element. The mixture is distributed over the downstream side of the element where it is combusted in a primary combustion zone. Secondary fuel is mixed with surface combustion products from the primary zone and then combusted in a secondary combustion zone with a portion of excess oxygen from the surface combustion products. In certain embodiments the temperature of surface combustion products is reduced by heat transfer to the surface burner element, and in another embodiment by heat transfer to a screen or other element placed within the primary combustion zone, from which the heat is then extracted to a load, and in another embodiment by mixing the additional fuel or combustion products with cooled furnace gases. In other embodiments the placement of the secondary fuel jets is varied to achieve different combustion results.