JP2529638Y2 - Gas burner - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner for supplying and burning gaseous fuel.

[0002]

2. Description of the Related Art Generally, in a gas burner of this kind, as shown in FIG.
A gas nozzle pipe 32 provided with a plurality of nozzles from which gas is jetted into an air flow path 31 inside the cylinder, and a cylindrical combustion cylinder 33 extending from the peripheral edge of the gas nozzle pipe to the inner peripheral surface of the draft tube 30 are provided. It is known that a plurality of air holes 34 are formed on the peripheral surface of the combustion cylinder 33. Then, the gas nozzle pipe 3 is set in the combustion cylinder 33.
2 and the air in the draft tube 30 ejected from the air holes 34 are mixed and burned, whereby a combustion flame is formed.

[0003]

However, in the above-described gas burner, since the combustion flame 35 is formed concentrated in the combustion tube 33, when the burner is attached to a boiler or a heat exchanger or the like. Due to the synergistic effect of these structures, the combustion temperature rises to a high temperature, and nitrogen and oxygen in the air combine to generate thermal NOx.

An object of the present invention is to provide a gas burner capable of lowering the temperature of the combustion flame of the burner itself and reducing thermal NOx.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention is to dispose a closed tubular combustion head on the opening side of a draft tube, and to provide an outer peripheral surface of the combustion head and the draft tube. An air flow path is formed between the inner gasket and the inner peripheral surface, a plurality of main gas outlets are formed on the outer surface of the combustion head, and a main gas inlet pipe is connected to the outer surface of the combustion head. Is provided in front of the front end face of the combustion head, and the auxiliary gas introduction pipe is connected to the mixing cylinder and an air inflow portion is provided. A plurality of pilot flame outlets capable of generating a pilot flame in a direction intersecting a combustion flame generated by extending to the opening side of the draft tube via a main gas outlet of the combustion head. It is.

[0006]

According to the present invention constructed as described above, the auxiliary gas supplied from the auxiliary gas introduction pipe is mixed with the air flowing from the air inflow section in the mixing cylinder, and the pilot flame is generated from the pilot flame outlet. You. The main gas supplied from the main gas inlet pipe is ejected from the main gas outlet of the combustion head, is mixed with the air of the air passage, combustion flame extending on the opening side of the draft tube is produced by the pilot flame.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a gas burner for burning low-pressure gas will be described below with reference to FIGS.

As shown in FIG. 3, the base end (left side in FIG. 3) of the cylindrical draft tube 1 is sealed with a lid member 1a, and the front end (right side in FIG. 3) is formed with an opening 1b. Have been. A blower 2 is provided on the outer peripheral surface on the base end side of the draft tube 1, and the air supplied by the blower 2 forms an air flow path A in the draft tube 1 and flows to the opening 1 b side. It has become.
Sub and main gas introduction pipes 3 and 4 are inserted and fixed to the lid member 1a of the draft tube 1 to the vicinity of the opening 1b.

As shown in FIGS. 1 and 2, at the distal end of the main gas introducing pipe 4, a closed cylindrical combustion head 5 is provided at a position deviated from the center of the base end face (left side in FIG. 1). The connection is made through the connection port 5a. A slant wall 6 is formed between the outer peripheral end of the front end surface (the right side in FIG. 1) and the end of the outer peripheral surface of the combustion head 5, and a plurality of slant walls 6 are arranged concentrically on the slant wall 6. In this case, 12) main gas outlets 7 are formed. The main gas S introduced from the main gas introduction pipe 4 is ejected from the main gas outlet 7 toward the inner peripheral surface of the draft tube 1 via the combustion head 5, and the outer peripheral surface of the combustion head 5 and the draft tube The air flowing between the inner peripheral surface 1 and the inner peripheral surface 1 is discharged from the opening 1b as a laminar mixed gas.

At the center of the combustion head 5 from the base end face to the tip end face, a covered cylindrical air inflow cylinder 8 as an air inflow section having a diameter larger than that of the auxiliary gas introduction pipe 3 is fixed through. One end is opened and is flush with the tip end surface of the combustion head 5. The base end face of this air inflow cylinder 8 (FIG. 1)
The auxiliary gas introduction pipe 3 is inserted and fixed to the left side of the draft tube 1, and the distal end thereof extends to the opening 1 b of the draft tube 1 and is sealed. A plurality of air inlets 9 are provided in the outer peripheral surface on the base end side of the air inflow cylinder 8.
A sub gas outlet 10 is provided on the outer peripheral surface of the sub gas introduction pipe 3 corresponding to the air inlet 9. further,
One of the air inlets 9 has a spark plug 1
A 1-shaped front end portion 11 a is inserted and arranged, and faces the auxiliary gas outlet 10.

At the center of the tip surface of the combustion head 5,
A mixing cylinder 12 having a diameter larger than that of the air inflow cylinder 8 and having a tubular shape is fixed at a base end side where the mixing cylinder 12 is opened, and a distal end portion is sealed so as to be outward from the opening 1 b of the draft tube 1. positioned. A plurality of pilot flame outlets 13 are provided through the outer peripheral surface of the mixing cylinder 12.

An insertion hole 14 is formed in the base end surface and the end surface of the combustion head 5 in the vicinity of the auxiliary gas outlet. The insertion hole 14 detects a pilot flame C generated from the pilot flame outlet 13. A frame rod 15 is inserted and disposed, and its tip end projects beyond the tip end surface of the mixing cylinder 12. In addition, a cylindrical insertion wall 16 is fixed between the two insertion holes 14 to block outflow of the main gas S in the combustion head 5. The sub-gas F introduced from the sub-gas introduction pipe 3 is ejected from the sub-gas outlet 10 of the air inflow cylinder 8, mixed with the air flowing from the air inflow 9, and ignited by the spark plug 11. Then, the pilot flame C is formed so as to be divided vertically from the pilot flame outlet 13 of the mixing cylinder 12 with respect to the air flow path. Further, the combustion flame D ignited by the main gas S and extending toward the opening 1b of the draft tube 1 in the same direction as the air flow path is divided and generated by the pilot flame C.

Next, the operation of the gas burner thus configured will be described. When the gas burner is used, first, the power switch is turned on to drive the blower 2 to form the air flow path A in the draft tube 1. Next, the control circuit opens a solenoid valve (not shown) and
The auxiliary gas F brought into a low pressure state of about 00 mmH ₂ O is introduced into the auxiliary gas introduction pipe 3. Then, the auxiliary gas F is ejected from the auxiliary gas outlet 10, and the air flows from the air inlet 9 into the air inlet tube 8 and is mixed. And
When the spark plug 11 is sparked, the sub-mixed gas is ignited and the pilot flame C is divided and generated from each pilot flame outlet 13 of the mixing cylinder 12 in a direction perpendicular to the air flow path. Then, the current value in the frame rod 15 changes due to the heat of the pilot flame C, and when this is detected by the control circuit, a solenoid valve (not shown) is opened and a maximum of 500 mm
The main gas S brought into a low pressure state of about H ₂ O is introduced into the main gas introduction pipe 4. Then, the main gas S is ejected from each main gas outlet 7 through the combustion head 5, and the main mixed gas is laminar-flowed by the air flowing between the outer peripheral surface of the combustion head 5 and the inner peripheral surface of the draft tube 1. The air is discharged in the same direction as the air flow path A. In this state, the main mixed gas is ignited by the pilot flame C, and the combustion flame D is divided and generated.

As described above, in the gas burner of this embodiment, the pilot gas C is ignited by premixing to divide the pilot flame C in a direction perpendicular to the air flow path A, and the pilot flame C is formed. Because the main gas S is ignited in a laminar flow state together with air to form the combustion flame D by dividing it into two-stage combustion, a stable combustion flame is formed, and the flame is not a concentrated flame but a divided flame. As a result, the surface area of the combustion flame is increased, the heat radiation is improved, the combustion flame temperature of the gas burner itself can be lowered, and the thermal NOx can be reduced.

Further, the combustion speed of the combustion flame D can be increased by increasing the reaction speed of the auxiliary gas F with the air by the combustion of lean oxygen and increasing the reaction speed of the main gas S with low oxygen combustion. Since it can be formed, the heat dissipation is improved, the combustion flame temperature of the gas burner itself can be reduced, and the thermal NOx can be reduced.

Further, since the pilot flame C is located downstream of the combustion head 5, the pilot flame C is hardly affected by the air flow path A, and a stable pilot flame C can be formed.

In the pilot flame C, since the air and the auxiliary gas F are premixed in the air inlet tube 8 and the mixing tube 12, a stable mixed gas can be supplied. It should be noted that the present invention is not limited to the above embodiment, and can be modified as follows without departing from the spirit of the present invention. In the above embodiment, the air inflow tube 8 was fixed through the center of the combustion head 5, and the auxiliary gas introduction pipe 3 was inserted and fixed from the base end surface of the air inflow tube 8, as shown in FIG. The arrangement of the auxiliary gas introduction pipe 3 is changed, and the flame rod 1
An insertion hole 17 is separately provided from the insertion hole 14 for 5, and a cylindrical insertion wall 18 is fixed between the two insertion holes 17, and the auxiliary gas introduction pipe 3 is inserted through the insertion hole 17. Further, the opened distal end of the auxiliary gas introduction pipe 3 is connected to the outer peripheral surface of the mixing cylinder 12, and a plurality of auxiliary gas outlets 19 are passed through the mixing cylinder 12 to eject the auxiliary gas F into the mixing cylinder 12. You may do so. In this case, the air inflow cylinder 8 is sealed by the rear end wall 5b of the combustion head 5, a plurality of air inlets 20 are provided in the rear end wall 5b, and the plug insertion holes 21 are formed.
The auxiliary gas F and the air may be mixed and ignited by inserting the tip 11a of the spark plug 11 through the spark plug 11.

[0018]

As described above in detail, the gas burner of the present invention has an excellent effect that the temperature of the combustion flame of the burner itself can be reduced to reduce thermal NOx.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing the inside of a gas burner according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing the appearance of the gas burner.

FIG. 3 is a longitudinal sectional view schematically showing a configuration of a gas burner.

FIG. 4 is a partial sectional view showing the inside of a gas burner according to another embodiment.

FIG. 5 is a partial sectional view showing the inside of a conventional gas burner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Draft tube, 3 auxiliary gas introduction pipe, 4 main gas introduction pipe, 5 combustion head, 7 main gas outlet, 8 air inflow cylinder, 9 air inlet, 10 auxiliary gas outlet, 12
Mixing cylinder, 13 pilot flame outlet, A air flow path, F
Secondary gas, S main gas, C pilot flame, D combustion flame

Claims (1)

(57) [Scope of request for utility model registration] A combustion head (5) having a cylindrical shape with a cover is disposed at an opening side of a draft tube (1), and an outer peripheral surface of the combustion head (5) and an inner peripheral surface of the draft tube (1) are arranged. Are used as air passages, a plurality of main gas outlets (7) are formed on the outer surface of the combustion head (5), and a main gas inlet pipe (4) is formed on the outer surface of the combustion head (5). A closed cylindrical mixing tube (12) for communicating and mixing the auxiliary gas and air is provided forward of the front end face of the combustion head (5), and the auxiliary gas introduction pipe ( 3)
And an air inflow section is provided so that the mixing cylinder (1
On the peripheral surface of 2), a pilot flame is generated in a direction intersecting the combustion flame generated by extending to the opening side of the draft tube (1) through the main gas outlet (7) of the combustion head (5). A gas burner comprising a plurality of possible pilot flame outlets (13).