Patent ID: 7549858
Filing Date: 2009-06-23
Classification: F23C,F23D,F23M,F23N

Abstract:
1. A burner system comprising a burner body and a burner block, wherein (A) the burner body comprises a plenum body which has back and side surfaces that enclose a plenum space which is open at its front in a uniplanar plenum opening that is defined by the front edges of said side surface, a first feed inlet in a back or side surface of said plenum body, through which gas can be fed into said plenum space, a first hollow body that is situated completely within said plenum space and that is closed against passage of gas between said plenum space and the interior of said hollow body, wherein the hollow body does not extend through said plenum opening, a second feed inlet through a surface of said hollow body, through which gas can be fed into the interior of said hollow body, 2 to 16 outlet ports through a surface of said hollow body, through which gas can pass out of said hollow body, each oriented to point outwardly of said plenum space toward the plenum opening, wherein the outer ends of said outlet ports do not extend beyond the plane of said plenum opening, a first tube extending from outside the back surface of said plenum body through the plenum space to a first tube end that is located a first distance outside the plane of the plenum opening, wherein the first tube is closed against passage of gas into said first tube from the plenum space and from the interior of the hollow body, a second tube, located inside the first tube, extending from outside the back surface of said plenum body through the plenum space to a second tube end that is located a second distance outside the plane of the plenum opening, wherein said second distance is greater than first distance, wherein said second tube is closed against passage of gas into said second tube from the plenum space, from the interior of the hollow body, and from the first tube, and wherein the axes of the first and second tubes are coaxial or parallel, a third tube, located inside the second tube, extending from outside the back surface of said plenum body through the plenum space to a third tube end that is located said second distance outside the plane of the plenum opening, wherein said third tube is closed against passage of gas into said third tube from the plenum space, from the interior of the hollow body, and from the second tube, and wherein the axes of the first, second and third tubes are coaxial or parallel, a third feed inlet for receiving gas into the space between the first and second tubes, a fourth feed inlet for receiving gas into the space between the second and third tubes, and a fifth feed inlet for receiving fuel into said third tube; and (B) the burner block comprises a front surface and a rear surface, a first passageway extending through the block, composed of a barrel segment that extends into the block from said rear surface to the inner end of said barrel segment for a length at least equal to said first distance, the diameter of said barrel segment permitting said first tube to fit snugly into said barrel segment to minimize passage of gas in said barrel segment outside said first tube, a throat segment having upstream and downstream ends and whose diameter is constant along its axis and is less than the diameter of said barrel segment and is greater than the outer diameter of said second tube, wherein the distance from the rear surface of the block to said upstream end is greater than said first distance and less than said second distance, and wherein the distance from the rear surface of said block to said downstream end is greater than said second distance, a first tapered segment that extends axially from the inner end of said barrel segment to said upstream end of said throat segment, a port segment that extends into the block from the front surface of the block to the inner end of the port segment, wherein the diameter of the port segment is constant and is greater than the diameter of said throat segment a second tapered segment that extends from the downstream end of said throat segment to the inner end of said port segment, wherein said segments are coaxial, and the sum of the axial lengths of the port segment and the second tapered segment is up to 50 times the diameter of the largest diameter of the second tapered segment; the axial length of the throat segment is up to 50 times the diameter of the largest diameter of the second tapered segment; the ratio of the largest diameter of the second tapered segment to the diameter of the throat segment is 1 to 50; and the distance from the discharge openings of the secondary passageways to the axis of the first passageway is 1-10 times the diameter of the throat segment, a plurality of secondary passageways, greater in number than the number of said outlet ports, extending through said block from inlet openings in the rear surface of said block to discharge openings in the front surface of said block, wherein said inlet openings are close enough to said first passageway that when the front edges of said plenum body are in contact with the rear surface of said block, said inlet openings are in gas contact with said plenum space, and wherein each secondary passageway has an axis at its discharge opening that converges toward the axis of the first passageway at an angle of up to 60°, diverges from the axis of the first passageway at an angle of up to 85°, or is parallel to the axis of the first passageway; and wherein said burner body is positioned with respect to said burner block so that the front edges of said plenum body are in contact with the rear surface of said block to prevent passage of gas out of said plenum space except into said secondary passageways and the first and second tubes extend into said first passageway, and outlet ports are aligned with secondary passageways so that gas passing from an outlet port passes through a secondary passageway with which it is aligned.