Low-nitrogen combustion head with orifice plate and low-nitrogen combustor

Abstract

The application discloses a low-nitrogen combustion head of a hole plate type, which comprises a premixed gas flow cavity and a plurality of inserts. A plurality of first long holes are formed in the surface of the premixed gas flow cavity. The insert comprises a body, and a plurality of tongue portions extending laterally along the body are arranged at intervals on the body. The body of the insert is located inside the premixed gas flow cavity, the tongue portions are inserted into the first long holes and extend out of the surface of the premixed gas flow cavity, a gap is left between the tongue portions and the inner wall of the first long holes, a plurality of second long holes are arranged on the tongue portions, and the second long holes extend from the inside of the premixed gas flow cavity to the outside. The cold and hot deformation of the insert is utilized to generate friction with the premixed gas flow cavity, so that the accumulation of combustion products such as carbon deposition at the flame passage is eliminated, the service life is improved, and the cost is low.

Description

TECHNICAL FIELD

[0001] The present application relates to a burner structure, in particular to a perforated plate type low-nitrogen combustion head and a low-nitrogen burner. BACKGROUND

[0002] The existing low-nitrogen burner mainly has a metal mesh arranged at the head position of the flame to form a fine combustion flame through the segmentation of the dense mesh holes on the metal mesh. For example, the burners disclosed in Chinese patents CN213453618U and CN205332211U.

[0003] The disadvantage of this structure is that the dense metal mesh is prone to be partially blocked by the accumulated carbon after combustion, and after being blocked, the flame distribution on the surface of the metal mesh is uneven and the temperature difference is large, which can cause local high temperature in other areas and damage the metal mesh, affecting the service life of the burner. Moreover, the metal mesh is a special component, and the cost of replacing the metal mesh is high. SUMMARY

[0004] In view of the above-mentioned defects of the prior art, the task of the present application is to provide a perforated plate type low-nitrogen combustion head to solve the problem of blockage of the combustion head and improve the service life of the burner. The task of the present application is to provide a low-nitrogen burner which is not easy to block and has a long service life.

[0005] The technical scheme of the present application is as follows: a perforated plate type low-nitrogen combustion head, comprising a premixed gas flow passage and a plurality of inserts, a plurality of first long holes are formed on the surface of the premixed gas flow passage, the insert comprises a body, a plurality of tongue portions are arranged on the body at intervals, the body of the insert is located inside the premixed gas flow passage, the tongue portions are inserted into the first long holes and protrude from the surface of the premixed gas flow passage, a gap is left between the tongue portions and the inner wall of the first long holes, a plurality of second long holes are arranged on the tongue portions and extend from the inside to the outside of the premixed gas flow passage.

[0006] Further, the thickness of the tongue portion of the insert is 0.2-1mm.

[0007] Further, the insert is a long strip-shaped flat plate structure, and the length-width ratio of the body of the insert is greater than 10:1.

[0008] Further, the premixed gas flow passage is a cylindrical barrel, and the length direction of the first long hole is the generatrix direction of the cylindrical barrel.

[0009] Further, the connecting point of the insert and the premixed gas flow passage is located at the two end portions of the body of the insert.

[0010] Another technical solution of the present application is as follows: a low-nitrogen burner comprising the aforementioned orifice-plate low-nitrogen combustion head.

[0011] The present application has the following advantages compared with the prior art:

[0012] The tongue of the insert piece and the inner wall of the first long hole form a gap, and the second long hole forms a vertical surface to the premixed gas flow passage and a longitudinal and horizontal gas flow passage along the surface of the premixed gas flow passage, achieving uniform combustion on the surface of the combustion head and meeting the low-nitrogen requirement. Meanwhile, during the change of each working condition of the combustion head, the tongue of the insert piece deforms and rubs against the inner wall of the first long hole, thereby eliminating the carbon deposition and other easily clogging substances in the gap between the tongue and the inner wall of the first long hole, and improving the service life of the burner. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 Structure diagram of the low-nitrogen burner of Example 1.

[0014] Figure 2 Structure diagram of the orifice-plate low-nitrogen combustion head of Example 1.

[0015] Figure 3 Structure diagram of the premixed gas flow passage of Example 1.

[0016] Figure 4 Structure diagram of the insert piece.

[0017] Figure 5 Sectional structure diagram of the cooperation between the insert piece and the premixed gas flow passage of Example 1.

[0018] Figure 6 Local structure diagram of the cooperation between the insert piece and the premixed gas flow passage of Example 1.

[0019] Figure 7 Structure diagram of the low-nitrogen burner of Example 2.

[0020] Figure 8 Structure diagram of the low-nitrogen burner of Example 2 from the bottom view. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with the examples, but not as a limitation to the present application.

[0022] Example 1, please combine Figure 1As shown, the low-NOx burner involved in this embodiment includes a connecting flange 100 and an orifice plate type low-NOx burner head 200 connected to the connecting flange 100. The connecting flange 100 is used to install the entire low-NOx burner inside the combustion chamber of the boiler. The orifice plate type low-NOx burner head 200 is fixed to the connecting flange 100. In this embodiment, a swirl vane 300 is fixedly arranged in the middle of the connecting flange 100. The mixed gas flow of fuel gas and air (oxygen) passes through the swirl vane 300 and then enters the orifice plate type low-NOx burner head 200. Through the guidance of the swirl vane 300, the mixing and homogenization of fuel gas and air (oxygen) are enhanced, and the mixed gas flows out of the surface of the orifice plate type low-NOx burner head 200 for combustion more quickly. Figure 1 As shown, the connecting flange 100 and the swirl blade 300 can be made by punching a metal plate. The root of the swirl blade 300 is connected to the intermediate ring 400, and the tip of the swirl blade 300 is connected to the connecting flange 100 through the connecting strip 500. During installation, the swirl blade 300 is twisted to a certain angle.

[0023] Please combine Figure 2 As shown, the orifice plate type low-NOx burner head 200 of this embodiment is cylindrical and includes a premixed gas flow chamber 201. The premixed gas flow chamber 201 is a cylindrical tube with a closed head and an open tail. The tail end of the premixed gas flow chamber 201 is welded and fixed to the connecting flange 100. Figure 3 As shown, multiple first elongated holes 202 are opened on the surface of the premixed gas flow cavity 201. The first elongated holes 202 are arranged at intervals along their length axis and arranged in multiple rows with the generatrix direction of the cylinder as the row. This facilitates the arrangement of inserts to form vent holes for the premixed gas.

[0024] Insert structure as Figure 4 As shown, it has a long, flat plate structure. The insert includes a long body 203 with an aspect ratio greater than 10:1. Multiple tongues 204 extend upwards from the upper edge of the body 203, spaced apart from each other. The spacing between these tongues 204 is the same as the spacing between the first elongated holes 202, allowing the insert to be inserted into the premixed gas flow chamber 201.

[0025] like Figure 5 , Figure 6As shown, when the insert is inserted into the premixed gas flow cavity 201, the body 203 of the insert is located inside the premixed gas flow cavity 201, and the tongues 204 are inserted into the first long holes 202 and extend out of the surface of the premixed gas flow cavity 201. The thickness of the insert is slightly smaller than the width of the first long holes 202, and the length of each tongue 204 is slightly smaller than the length of the first long holes 202. When the tongues 204 are inserted into the first long holes 202, a gap 206 of 0.2-1 mm is left between the tongues 204 and the inner wall of the first long holes 202, which is used for the flow of premixed gas.

[0026] The tongues 204 are provided with a plurality of second long holes 205 arranged in parallel, and the length direction of the second long holes 205 extends from the body 203 to the tongues 204, i.e. the up-down direction. Figure 4 When the tongues 204 are inserted into the first long holes 202, the second long holes 205 are along the normal direction of the surface of the premixed gas flow cavity 201, and a part of the second long holes 205 is inside the premixed gas flow cavity 201, and another part of the second long holes 205 is exposed outside the premixed gas flow cavity 201. Thus, the second long holes 205 also form a flow channel for premixed gas, and due to the length limitation of the second long holes 205, the premixed gas flows to both sides when flowing to the head end of the second long holes 205, and also collides and mixes with the premixed gas left in the gap 206 between the tongues 204 and the first long holes 202, thereby forming longitudinal and transverse intersecting gas flows on the surface of the premixed gas flow cavity 201, and meeting the requirements of combustion.

[0027] In order to enable the insert to be connected with the premixed gas flow cavity 201 and also enable the insert itself to have a certain deformation space, the two ends of the body 203 of the insert can be fixed with the premixed gas flow cavity 201 by spot welding, or the two tongues 204 can be fixed with the premixed gas flow cavity 201 by welding, or the tongues 204 can be twisted and deformed after being inserted into the first long holes 202 to be clamped with the premixed gas flow cavity 201 for facilitating replacement of the insert, or a pin can be inserted into the second long holes 205 of the tongues 204 to prevent the insert from falling out.

[0028] In the combustion and cooling processes of the burner, the long strip-shaped insert will deform in various ways, so that the tongues 204 rub against the first long holes 202, and the accumulated carbon and the like at the gap 206 can fall off to reduce the blocking phenomenon.

[0029] Embodiment 2, please refer to Figure 7 and Figure 8As shown, in order to adapt to the combustion requirements of different combustion devices, the shape of the low-nitrogen burner can not be cylindrical, such as the square ring-shaped connecting flange 100' on which the perforated plate low-nitrogen combustion head 200' is fixed. The perforated plate low-nitrogen combustion head 200' includes a rectangular box-shaped premixed gas flow passage 201' and an insert, wherein the premixed gas flow passage 201' is open at the bottom and is fixed with the connecting flange 100', and the top surface of the premixed gas flow passage 201' is used to cooperate with the insert to form a flow passage for the premixed gas. The top surface of the premixed gas flow passage 201' is a plane, which can be compared to the cylindrical surface of the premixed gas flow passage in Embodiment 1, which has an infinite radius. The specific connection form of the insert is the same as that of Embodiment 1, which will not be described here again, thereby forming a square low-nitrogen burner.

Claims

1. A perforated plate type low-NOx combustion head, characterized in that, The device includes a premixed gas flow chamber and several inserts. The surface of the premixed gas flow chamber has several first elongated holes. Each insert includes a body with several tongues extending laterally along the body at intervals. The body of the insert is located inside the premixed gas flow chamber. The tongues are inserted into the first elongated holes and extend out from the surface of the premixed gas flow chamber. A gap is left between the tongues and the inner wall of the first elongated holes. The tongues have several second elongated holes extending from the inside of the premixed gas flow chamber to the outside.

2. The orifice plate type low-NOx combustion head according to claim 1, characterized in that, The thickness of the tongue of the insert is 0.2 to 1 mm.

3. The orifice plate type low-NOx combustion head according to claim 1, characterized in that, The insert is a long strip-shaped flat plate structure.

4. The orifice plate type low-NOx combustion head according to claim 1, characterized in that, The premixed gas flow chamber is a cylindrical tube, and the length direction of the first elongated hole is the generatrix direction of the cylindrical tube.

5. The orifice plate type low-NOx combustion head according to claim 1, characterized in that, The connection point between the insert and the premixed gas flow cavity is located at both ends of the insert body.

6. A low-NOx burner, characterized in that, Includes the orifice plate type low-NOx burner head as described in any one of claims 1 to 5.

Images