JPH0364768B2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention is a method of premixing a gaseous fuel such as gasified petroleum or gas with combustion air, and ejecting the mixture from a burner head to combust it. The present invention relates to a combustion device configured to

(b) Prior art In this type of combustion device, the premixture in the premixing chamber is once squeezed into the center by a throttle plate and sent out, and then the premixture is passed through the through holes in the rectifying plate. Japanese Patent Publication No. 58-24685 has a burner head configured to evenly distribute the pressure of the premixture in the circumferential direction and then blow it out from the flame port through a wire mesh to cause combustion. It is becoming. By the way, in this conventional configuration, when the engine is started, the premixed air with a high flow rate passes through the through holes in the baffle plate and is ejected from the flame port, so it is difficult to ignite the engine. In addition, because multiple burner ports are closely arranged in the circumferential direction of the small disc-shaped burner head, thermal stress is concentrated particularly in the center of the burner head, and there is a risk that the burner head may deform during long-term use. It was hot.

(c) Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned facts, and aims to improve ignition performance at startup and prevent thermal deformation of a flat burner head. .

(d) Means for Solving the Problems The present invention includes a burner body having a premixing chamber therein for premixing gaseous fuel and combustion air, and a burner head provided inside the burner head on the downstream side of the premixing chamber. A flat burner head is provided inside the burner body between the burner head and the premixing chamber, and has a plurality of burner ports lined up in the circumferential direction to eject the premixed mixture sent from the chamber. A current plate with a plurality of small through holes arranged in the circumferential direction is provided between the current plate and the burner head, and one end is in surface contact with the inside of each flame port of the burner head, and the other end is in the center of the current plate. It has a cylindrical holder that makes surface contact with each other, and the burner head and current plate are connected by a plurality of screws passing through the holder.

(e) Effect The premixed mixture sent from the premixing chamber 25 through the aperture 28 of the aperture plate 27 passes through the through hole 3 of the rectifying plate 29.
0, it is ejected from the flame ports 33, 33, . . . of the burner head 32 through the annular buffer space X, and combustion begins.
At the start of this combustion, the premixture having a high velocity passing through the through holes 30, 30... is reduced in velocity in the annular slow space X, and then ejected from the flame ports 33, 33... It can improve ignition performance by alleviating lifting combustion. In addition, since the burner head 32, the current plate 29, and the holder 41 are connected by a plurality of screws 42, 42 passing through them, the surface contact portions at both ends of the holder 41 are connected to the inside of each flame port 33, 33 of the burner head 32. and the center of the current plate 29, and the heat that collects in the center of the burner head 32 from each burner port 33, 33 can be transferred well to the center of the current plate 41 via the holder 41, and the burner head 32 thermal deformation can be prevented.

(f) Example An example of the present invention will be described below based on the drawings. 1 is a cylindrical burner case secured to a supporting plate 2 with screws 4, 4 through a seal packing 3; 5 is an air supply pipe connected to the end face of the burner case 1;
An air supply duct (not shown) that communicates with an air supply blower (not shown) is connected to. Reference numeral 6 denotes a shallow dish-shaped bar support plate provided inside the burner case 1, into which combustion air supplied from the air supply pipe 5 flows. 7, 7... are secondary air circulation holes drilled on the outer periphery of the burner support plate 6, and 8 is the burner support plate 6.
This is the primary air supply port drilled approximately in the center of the main body.

Reference numeral 9 denotes a burner body fixed to the burner support plate 6 with screws 11 via an annular heat insulating material 10.The burner body 9 has a bottomed cylinder shape and is made of aluminum or cast iron. An electric heater 12 for preheating is embedded. Further, the burner body 9 has an annular protrusion 13 formed approximately in the center thereof, and a stepped portion 14 is formed at a portion spaced apart from the protrusion 13 by about 5 to 10 mm toward the opening of the tip. 15 is a burner thermistor that detects the temperature of the burner body 9.

16 is a support plate 2 on the opposite side of the burner case 1
screws 18, 1 through the annular heat insulating sealing material 17.
The combustion tube support tube 19 fixed at 8 is a hollow cylindrical combustion tube whose one end is fitted onto the outer periphery of the combustion tube support tube 16 and fixed by spot welding. Reference numeral 20 denotes a secondary air supply chamber formed around the outer periphery of the burner body 9, in which a part of the air supplied to the burner support plate 6 flows into the burner body 9 through the primary air supply port 8 as combustion primary air, and The remaining part flows into the secondary air supply chamber 20 through the secondary air circulation holes 7, 7, . . . as combustion secondary air.

Reference numeral 21 denotes a motor fixed to the outside of the end face of the burner case 1 via a packing 22;
The first motor shaft 23 protrudes into the burner body 9. 24 is a rotating atomizer attached to the motor shaft 23 that can be inserted into the burner body 9, and includes a cone 24A with a tapered shape that widens at the end, and a disc-shaped scattering plate 24.
B and a stirring blade 24C. The interior of the burner body 9 facing this rotary atomizer 24 serves as a vaporization premixing chamber 25.
Reference numeral 26 denotes a fuel supply pipe opened on the cone 24A, through which fuel such as petroleum is supplied by a fuel supply means (not shown) such as an electromagnetic pump.

Reference numeral 27 denotes an annular aperture plate formed into a shallow drawing having an aperture opening 28 in the center, and 29 a rectifier plate having a plurality of small diameter through holes 30, 30, etc. arranged in an annular manner on the outer periphery. The plate 27 and the rectifying plate 29 are connected to the plate 27 at the diaphragm.
are positioned on the rising side of the premixed airflow, their peripheral edges overlap, and are fixed to the outer surface of the protrusion 13 of the burner body 9 with a plurality of screws 31, 31.

Reference numeral 32 denotes a burner head attached to the front part of the burner body 9, and the burner head 32 is located at the front and has a plurality of flame ports 3 divided on its outer periphery.
A head main plate 34 with openings 3, 33, etc., and a head blessing plate 3 located on the rear surface with a plurality of openings 35, 35,... on its outer periphery through which the premixture passes.
6, at least two small wire meshes 37, 38, and a space plate 39 interposed between these wire meshes 37, 38.
It is made up of. Then, with the space plate 39 interposed between the wire meshes 37 and 38, as shown in FIG. By bending the outer peripheral edge of the head main plate 34 inward, the burner head 32 is integrated by caulking.

Further, the space plate 39 is formed of a thin plate of about 0.5 mm, and has a plurality of communication holes 40, 40... bored in the outer circumferential portion that substantially coincides with the flame ports 33, 33... The distance between 37 and 38 is kept substantially constant. That is, wire mesh 37, 38
An interval corresponding to the thickness of the space plate 39 is maintained between the two.

Reference numeral 41 denotes a cylindrical holder having a thickness of about 7 to 9 mm, and the holder 41 has an outer diameter located inside the small diameter through holes 30, 30, . . . of the rectifier plate 29. Then, the burner head 32 is attached to the rectifying plate 29 via this holder 40 with a plurality of screws 4.
2, 42, . Also, 43, 43... are the screws 4
2, 42, . . . are through holes. X is the outer periphery of the holder 41 and the burner head 32
This is an annular buffer space formed within the burner body 9 between the current plate 29 and the current plate 29.

Reference numeral 45 denotes a secondary air supply ring having a substantially L-shaped cross section that fits on the outer circumferential surface of the front end of the burner body 9, and its flange 46 is connected to the inner surface of the front end of the combustion tube support tube 16 via a packing 47. On the other hand, a peripheral wall that is substantially parallel to the combustion flame 48 formed at the flame ports 33, 33... blows out combustion secondary air toward the combustion flame 48 so as to be perpendicular to the combustion flame 48. A large number of secondary air supply holes 49, 49, . . . are bored therein. 50 is a spark plug, and 51 is a flame rod.

Next, the operation will be explained. First, when the electric heater 12 is energized, the burner body 9 is heated. When the burner body 9 reaches the vaporization temperature of oil, the burner thermistor 15 detects the temperature, and the air supply blower supplies combustion air from the air supply pipe 5. Next, the motor 21 is driven to rotate the rotary atomizer 24 at high speed, and at the same time, the fuel supply means is operated to supply petroleum fuel from the fuel supply pipe 26 onto the cone 24A. The fuel supplied onto the cone 24A is guided to the scattering plate 24B and is dispersed into fine particles by the centrifugal force. Then, the scattered fuel is instantaneously vaporized on the inner surface of the heated burner body 9 and becomes gaseous fuel in the vaporization premixing chamber 25.

On the other hand, combustion primary air is fed into the vaporization premixing chamber 25 from the primary air supply port 8, and the gaseous fuel is premixed with the primary air in the vaporization premixing chamber 25. This premixture is then passed through the throttle plate 27.
When passing through the throttle port 28 of
The pressure is evenly distributed in the circumferential direction through the burner head 32, and the combustion flame 48 is ejected from the burner head 32.
forms and burns.

In addition, a part of the air in the burner support plate 6 flows into the secondary air supply chamber 20 through the secondary air distribution holes 7, 7..., and flows into the secondary air supply chamber 20 as secondary air.
... is ejected toward the combustion flame 48 to promote secondary combustion. After the start of combustion, the tip of the burner body 9 is heated by the combustion flame 48, so the power supply to the electric heater 12 is stopped.

By the way, at the start of combustion, such as when starting up,
Although the flow rate of the premixture passing through the small-diameter through holes 30, 30, . , 33 is slowed down to soften lifting combustion during ignition, improving ignition performance. Also, burner head 3
2 and the rectifier plate 29 are connected by a plurality of screws 42, 42 passing through the holder 41, so that both end surfaces of the holder 41 are connected to the inside of each flame port 33, 33 of the burner head 32 and the rectifier plate 29. They are in close contact with the central part. During combustion, the heat that gathers in the center of the burner head 32 from the flame ports 33, 33 is well transferred to the center of the baffle plate 41 via the holder 41, so that the burner head 32 is heated during long-term use. It can be prevented from deforming.

Note that the combustion apparatus of the present invention is applicable not only to oil vaporization burners but also to gas burners such as propane and city gas.

(g) Effects of the Invention As explained above, this invention includes a burner body having a premixing chamber therein for premixing gaseous fuel and combustion air, and a burner body provided inside the burner body on the downstream side of the premixing chamber, A flat burner head is provided inside the burner body between the burner head and the premixing chamber, and has a plurality of burner ports lined up in the circumferential direction to eject the premixed mixture sent from the chamber. A current plate with a plurality of small through holes arranged in the circumferential direction is provided between the current plate and the burner head, and one end is in surface contact with the inside of each flame port of the burner head, and the other end is in the center of the current plate. The present invention includes a cylindrical holder that makes surface contact with each other, and the burner head and current plate are connected by a plurality of screws passing through the holder, so that the following effects are achieved.

(1) An annular buffer space is formed by the holder between the burner head and the rectifying plate, which reduces the speed of the premixed mixture ejected from the flame nozzle, softens lifting combustion during ignition, and improves ignition performance. This greatly improves reliable ignition and reduces ignition noise.

(2) The burner head and the current plate are integrally connected, and the holder can prevent the central part of the flat burner head from bending, so the outer periphery of the burner head can be brought into close contact with the inner wall of the burner body, allowing gas to flow from the outer periphery of the burner head. Can prevent leakage.

(3) Even during combustion, the annular buffer space regulates the flow of the premixture, allowing stable combustion to continue.

(4) Since the burner head and the current plate are integrally connected by multiple screws that pass through the holder, the surface contact portions at both ends of the holder can be connected to the inside of each flame port of the burner head and the center of the current plate. The heat that collects in the center of the burner head from each flame port can be transferred to the center of the rectifying plate through the holder, and thermal stress is not concentrated in the center of the flat burner head. This prevents the burner head from deforming due to heat during long-term use.

[Brief explanation of drawings]

The drawings all show embodiments of the present invention; FIG. 1 is a cross-sectional view of the combustion device, FIG. 2 is an exploded perspective view of the burner head, holder rectifier plate, and throttle plate;
FIG. 3 is a front view of the burner head, FIG. 4 is a sectional view taken along line A-A' in FIG. 3, and FIG. 5 is an exploded perspective view of the burner head. 9...burner body, 25...premixing chamber, 29
... rectifier plate, 30 ... through hole, 32 ... burner head, 41 ... holder, X ... annular buffer space.

Claims (1)

[Claims] 1. A burner body that has a premixing chamber inside that premixes gaseous fuel and combustion air, and a burner body that is provided inside the burner body on the downstream side of the premixing chamber and blows out the premixed gas sent from the premixing chamber. A flat burner head in which a plurality of flame ports are arranged in the circumferential direction, and a current plate that is provided inside the burner body between the burner head and the premixing chamber, and in which a plurality of through holes smaller than the flame ports in the burner head are arranged in the circumferential direction. and a cylindrical holder provided between the current plate and the burner head, one end of which is in surface contact with the inside of each flame port of the burner head, and the other end of which is in surface contact with the center of the current plate. A combustion device characterized in that a current plate and a holder are connected by a plurality of screws passing through the holder.