JP2012037110A - Tubular burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tubular burner having a flame hole member 3 fitted to the front end of a mixing tube 2 having an inlet 21 at the rear end where fuel gas and primary air flow in, in which the flame hole member is made by sheet metal working with a low material cost, so as to reduce the cost of the burner and to secure flame stability property.SOLUTION: The flame hole member 3 made of sheet metal is composed of a disk 31 with a plurality of flame holes 4 opening to the front formed therein, and a fitting cylinder 32 backwardly extended from the outer circumference of the disk 31 and fitted to an inner peripheral face at the front end of a mixing tube 2. A plurality of flame-stability holes 6 injecting mixed air to the inner circumference face at the front end of the mixing tube 2 is formed at an interval in the circumference direction in a corner curved portion 32a in the front of the fitting cylinder 32. A cylinder having a small diameter of a tapered cylinder with the diameter reducing toward the front side may be formed in the front of the fitting cylinder, and flame stability port may be formed in the cylinder with a small diameter or in the tapered cylinder.

Description

  The present invention includes a mixing tube having a rear end inlet into which fuel gas and primary air flow, and a flame port member having a plurality of flame ports opening forward is fitted to the front end of the mixing tube. It relates to a tubular burner.

  Conventionally, a burner described in Patent Document 1 is known as this type of burner. In this case, the flame opening member is made of a sintered metal thick wall. A plurality of flame ports opening forward are formed in the flame port member, and a mixed gas of fuel gas and primary air is ejected from these flame ports and burned.

  In this case, a plurality of flame holding ports are formed on the outer periphery of the flame port member at intervals in the circumferential direction. Each flame holding port is constituted by a groove formed on the outer peripheral surface of the flame port member, and the depth of the rear part of the groove is made shallow to reduce the jet speed of the mixed gas from the flame holding port. Therefore, the flame formed by the combustion of the mixed gas ejected from the flame holding port is difficult to lift, and the flame holding property is ensured.

  However, in the above-described conventional example, the flame opening member is made of sintered metal having a high material cost.

US Pat. No. 5,186,620

  In view of the above points, the present invention provides a tubular burner that can reduce the cost and secure flame-holding properties by using a flamelet member made of sheet metal with a low material cost. That is the issue.

  In order to solve the above-described problems, the present invention includes a mixing tube having a rear end inlet into which fuel gas and primary air flow, and has a plurality of flame openings opening forward at a front end portion of the mixing tube. A flame burner member is fitted into the tubular burner in which a mixed gas of fuel gas and primary air is ejected from the flame mouth and burned. The flame burner member is made of sheet metal and opens forward. A disc portion formed with a plurality of flame openings, and a fitting cylinder portion extending rearward from the outer circumference of the disc portion and fitting to the inner peripheral surface of the front end portion of the mixing tube. The front part is formed with a portion that creates an annular gap between the front end portion inner peripheral surface of the mixing tube, and a flame holding port that jets the air-fuel mixture toward the front end inner peripheral surface of the mixing tube in the circumferential direction It is characterized in that a plurality are formed with an interval of.

  According to the present invention, since the flame opening member is made of sheet metal, the cost can be reduced as compared with the above-described conventional example using a flame metal member made of sintered metal. Furthermore, in the present invention, even if the flame opening member is made of sheet metal, flame holding properties can be secured. That is, in the present invention, the mixed gas ejected from each flame holding port collides with the inner peripheral surface of the front end portion of the mixing tube, and between the portion at the front portion of the fitting tube portion and the inner peripheral surface of the front end portion of the mixing tube. After diffusing in the circumferential direction in the generated annular gap, it is ejected forward from this gap. And since the ejection speed of the mixed gas from this clearance falls by the collision diffusion of the mixed gas to the inner peripheral surface of the front end of the mixing tube, a flame that is difficult to lift is formed, and flame holding properties are ensured.

  In the present invention, a corner radius portion that is curved at a predetermined curvature toward the disc portion and is separated from the inner peripheral surface of the front end portion of the mixing tube is formed at the front portion of the fitting cylinder portion. What is necessary is just to comprise the said part of the front part of a fitting cylinder part by a part. Moreover, the small diameter cylinder part spaced apart from the front end part internal peripheral surface of a mixing pipe may be formed in the front part of a fitting cylinder part, and the said part of the front part of a fitting cylinder part may be comprised with this small diameter cylinder part. Further, a tapered cylindrical portion that is gradually reduced in diameter toward the front and separated from the inner peripheral surface of the front end portion of the mixing tube is formed at the front portion of the fitting cylindrical portion, and the front portion of the fitting cylindrical portion is formed by this tapered cylindrical portion. You may comprise the said part.

The cut | disconnection side view of the burner of 1st Embodiment of this invention. The perspective view of the burner of 1st Embodiment. The expansion cut perspective view of the important section of the burner of a 1st embodiment. The cut perspective view of the principal part of the burner of 2nd Embodiment of this invention. The cut perspective view of the principal part of the burner of 3rd Embodiment of this invention.

  Referring to FIG. 1, reference numeral 1 denotes a tubular burner according to an embodiment of the present invention. This burner 1 is used as a heat source of a heater, and is disposed to face an inflow end of a heat exchange pipe P that performs heat exchange with room air.

  The burner 1 includes a mixing tube 2 and a flame opening member 3 fitted to the front end portion of the mixing tube 2. Referring also to FIG. 2, the mixing tube 2 includes an inflow port 21 at the rear end, a venturi portion 22 that has a diameter reduced with respect to the inflow port 21, and a tapered tube portion 23 that gradually increases in diameter from the venturi portion 22 toward the front. have. Then, fuel gas and primary air injected from a gas nozzle (not shown) arranged facing the inflow port 21 flow into the mixing tube 2 from the inflow port 21, and in the mixing tube 2, the fuel gas and primary air The mixed gas is generated. The mixing tube 2 is made of sheet metal, and is formed by superposing two sheet metals 2a, 2a such as press-formed stainless steel plates.

  Although not shown, a plurality of tubular burners 1 are arranged side by side. And the hollow part 2b of the direction away from the other sheet metal 2a is formed in the front-end part of the two sheet metal 2a, 2a which comprises the mixing pipe 2, The gap which arises between both sheet metal 2a, 2a by this hollow part 2b The slit-shaped flame transfer flame port 2c is formed to transfer to the adjacent burner.

  The front end portion of the mixing tube 2 is formed in a cylindrical shape extending forward from the round-shaped enlarged diameter portion 23a at the front end of the tapered tube portion 23, and the flame port member 3 is fitted therein. The flame port member 3 is formed of a sheet metal such as a stainless steel plate. Thus, by making the flame opening member 3 made of sheet metal, it is possible to reduce the cost as compared with the above-described conventional example using the flame metal opening made of sintered metal.

  The flame opening member 3 includes a disk portion 31 having a plurality of flame openings that open forward, and a fitting cylinder that extends rearward from the outer periphery of the disk portion 31 and is fitted to the inner peripheral surface of the front end portion of the mixing tube 2. Part 32. In the disc part 31, as a flame opening opened ahead, the 1st flame mouth 4 of a center part and the several 2nd flame nozzle smaller in diameter than the 1st flame nozzle 4 located in the circumference | surroundings of the 1st flame nozzle 4 5 are formed. The first flame port 4 is formed in a cylindrical shape that protrudes from the front surface of the disc portion 31.

  By the way, when the flame opening member 3 is made of sheet metal, the mixed gas of the fuel gas and the primary air is ejected with a directional component directed radially outward due to the influence of the tapered tube portion 23 of the mixing tube 2, and the flame is generated. It becomes easy to spread radially outward. On the other hand, if the first flame port 4 is formed in a cylindrical shape as described above, the flow of the mixed gas ejected from the first flame port 4 is rectified so as to be directed forward, and the combustion of the mixed gas greatly increases the forward direction. An elongating central flame is formed. Accordingly, the flow velocity of the central flame becomes faster than the flow velocity of the surrounding flame formed by the combustion of the mixed gas ejected from the second flame port 5 smaller than the first flame port 4, and the surrounding flame is It is drawn to the center flame side. As a result, as shown in FIG. 1, surrounding flames are united with the central flame to form a collective flame Fa that elongates forward and the flame can be suppressed from spreading radially outward.

  Further, as clearly shown in FIG. 3, the front portion of the fitting tube portion 32 of the flame port member 3 is curved with a predetermined curvature toward the disc portion 31 and is separated from the inner peripheral surface of the front end portion of the mixing tube 2. A corner radius portion 32a is formed. A plurality of slit-shaped flame holding ports 6 are formed in the corner radius portion 32a with a circumferential interval.

  Here, the mixed gas ejected from each flame-holding port 6 collides with the inner peripheral surface of the front end of the mixing tube 2 as indicated by an arrow in FIG. 3, and the corner radius portion 32 a and the inner peripheral surface of the front end portion of the mixing tube 2 After diffusing in the circumferential direction within the annular gap generated between the two, the liquid is ejected forward from this gap. And since the ejection speed of the mixed gas from this clearance gap falls by collision diffusion of the mixed gas to the front-end inner peripheral surface of the mixing pipe 2, the flame Fb which is hard to lift is formed, and flame holding property is ensured.

  If the total area of the flame-holding port 6 becomes too large, red heat is generated at the front end portion of the mixing tube 2 and the durability is deteriorated. Therefore, the total area of the flame holding port 6 needs to be set to a certain level or less. For example, if the burner 1 has a rated combustion amount of 3500 kcal / h, the diameter of the inner periphery of the front end of the mixing tube 2 is 32 mm, and the radius of curvature of the corner radius portion 32a is 1 to 1.5 mm, about 16 parts are maintained. It is desirable to form the flame ports 6 at equal intervals in the circumferential direction so that the total area of the flame holders 6 is about 0.3% (about 10 kcal / h) of the total flame port area.

  Next, a second embodiment shown in FIG. 4 will be described. The basic structure of 2nd Embodiment is the same as that of the said 1st Embodiment, and the same code | symbol as the above is attached | subjected to the member and site | part similar to 1st Embodiment.

  The difference between the second embodiment and the first embodiment is that the front end of the mixing tube 2 is replaced by a front portion of the fitting tube portion 32 of the flame port member 3 instead of the corner round portion 32a of the first embodiment. That is, a small diameter cylindrical portion 32b that is separated from the surface is formed, and a plurality of flame holding ports 6 are formed in the small diameter cylindrical portion 32b at intervals in the circumferential direction.

  Also in the second embodiment, the mixed gas ejected from each flame holding port 6 collides with the inner peripheral surface of the front end of the mixing tube 2, and the annular shape generated between the small-diameter cylindrical portion 32 b and the inner peripheral surface of the front end portion of the mixing tube 2. It diffuses in the circumferential direction within the gap. Therefore, the jet speed of the mixed gas jetted forward from this gap is suppressed low, a flame that is difficult to lift is formed, and flame holding properties are ensured.

  Moreover, in 2nd Embodiment, although the small diameter cylinder part 32b is formed in the front part of the fitting cylinder part 32, like 3rd Embodiment shown in FIG. You may form the taper cylinder part 32c which diameter-reduces gradually toward the front and separates from the front-end part internal peripheral surface of the mixing pipe 2. As shown in FIG. In the third embodiment, the plurality of flame holding ports 6 are formed at intervals in the circumferential direction in the tapered cylindrical portion 32c.

  Also in the third embodiment, the mixed gas ejected from each flame holding port 6 collides with the inner peripheral surface of the front end of the mixing tube 2, and the annular shape generated between the tapered cylindrical portion 32 c and the inner peripheral surface of the front end portion of the mixing tube 2. It diffuses in the circumferential direction within the gap. Therefore, the jet speed of the mixed gas jetted forward from this gap is suppressed low, a flame that is difficult to lift is formed, and flame holding properties are ensured.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above embodiment, the mixing tube 2 made of sheet metal is used, but a mixing tube made of a cast product can also be used. Moreover, although the said embodiment applies this invention to the tubular burner for heaters, this invention is applicable similarly to the tubular burner used with combustion apparatuses other than a heater.

  DESCRIPTION OF SYMBOLS 1 ... Tubular burner, 2 ... Mixing tube, 21 ... Inlet, 3 ... Flame port member, 31 ... Disc part, 32 ... Fitting cylinder part, 32a ... Corner radius part, 32b ... Small diameter cylinder part, 32c ... Tapered cylinder Parts, 4... 1st flame mouth (flame opening that opens forward), 5... 2nd flame mouth (flame mouth that opens forward), 6.

Claims (4)

A mixing pipe having a rear-end inlet through which fuel gas and primary air flow is provided, and a front-end portion of the mixing pipe is fitted with a flame-port member having a plurality of flame openings opening forward, so that the fuel gas and the primary air are fitted. A tubular burner in which a mixed gas with air is ejected from these flame openings and burned,
The flame port member is made of sheet metal, and has a disk portion formed with a plurality of flame ports opening forward, and a fitting that extends backward from the outer periphery of the disk portion and fits to the inner peripheral surface of the front end portion of the mixing tube And a portion that forms an annular gap between the front end portion of the mixing tube and the inner peripheral surface of the front end portion of the mixing tube. A tubular burner characterized in that a plurality of flame-holding ports for injecting air-fuel mixture toward the center are formed at intervals in the circumferential direction.   A corner radius portion is formed at the front portion of the fitting tube portion, which is curved with a predetermined curvature toward the disc portion, and is separated from the inner peripheral surface of the front end portion of the mixing tube. The tubular burner according to claim 1, wherein the portion of the front portion of the tubular portion is configured.   A small-diameter cylindrical portion that is separated from the inner peripheral surface of the front end portion of the mixing tube is formed in the front portion of the fitting cylindrical portion, and the small-diameter cylindrical portion constitutes the portion of the front portion of the fitting cylindrical portion. The tubular burner according to claim 1.   A tapered tube portion is formed at the front portion of the fitting tube portion so as to be gradually reduced in diameter toward the front and separated from the inner peripheral surface of the front end portion of the mixing tube. The tubular burner according to claim 1, wherein the portion is constructed.