JP3227461B2 - 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 gas burner suitable for heating a casting ladle and metal.

[0002]

2. Description of the Related Art In recent years, natural gas having good flammability and low air pollution has been used for heating a ladle for casting.
The forced-air premix gas burner with the highest output requires a thick air pipe and a large blower, and it is necessary to heat multiple ladle sequentially while moving the burner. There is a problem that a large gantry for attaching a burner is required, and it is not easy to attach / detach or move the burner to / from the gantry. On the other hand, a gas jet suction type premix burner that sucks outside air with a high pressure gas jet does not require air piping, so it is small and lightweight, but has the drawback that the required amount of air cannot be suctioned due to the small gas flow rate. there were.

[0003]

Accordingly, the present applicant has previously developed an improved gas jet suction type burner as shown in FIG. This is because a gas is supplied to the base end of the substantially cylindrical burner main body 1 and an air suction port 18 is provided in a gas jet suction type burner in which an air suction port 18 is provided around a gas jet port 17.
Compressed air jets 19 directed obliquely forward are arranged in a ring on the cylindrical wall of the main body, and the compressed air enhances the air suction force by the gas jet. However, this method also has the drawbacks that the amount of air suction does not increase as expected and that a high-pressure gas is required. SUMMARY OF THE INVENTION An object of the present invention is to provide a premixed burner which solves these problems, is compact, lightweight, does not require a large gantry, can be easily mounted, removed and moved, and has a high output. .

[0004]

As shown in FIG. 1, a gas burner according to the present invention supplies compressed air to a base end of a substantially cylindrical burner main body 1 and supplies the compressed air from a cylindrical throat section 2 to the burner main body. A plurality of air suction ports 3 are arranged in a ring on the peripheral wall of the main body around the throat portion 2, and the throat portions 2, 5 and the air suction ports 3,
6 are formed in two stages along the axial direction of the main body, the outside air is sucked from these air suction ports 3 and 6 by the jet of compressed air, and a gas suction port provided on the peripheral wall near the front end of the main body 1 is formed. In this embodiment, the fuel gas is sucked from No. 4. Note that the second stage throat unit 5 is the first stage throat unit 2
The second air suction port 6 is arranged in the peripheral wall of the main body.

[0005]

According to the above construction, the compressed air is supplied to the burner main body.
3 and the entire peripheral surface of the compressed air jet contributes to the suction of the outside air. Therefore, the suction amount of the outside air is much larger than the conventional example of FIG. Therefore, there is no need to suction air with a high-pressure gas as in the prior art, so that a sufficiently high output can be obtained even if a low-pressure gas is used. For example, in the present invention, combustion air that was conventionally supplied by a 2-inch pipe can be obtained only by supplying compressed air through a 1 / 8-inch pipe, and the fuel gas blower can be downsized. Throat parts 2, 5
The reason why the air suction ports 3 and 6 are formed in two stages is that the opening area of the air suction ports 3 and 6 is appropriately narrowed so that a suitable amount of outside air is suctioned at a time, so that the venturi effect functions efficiently. is there.

[0006]

FIG. 1 shows an embodiment of the present invention, in which a hose for supplying compressed air is connected to the base end of a substantially cylindrical burner main body 1. In order to maintain the pressure on the supply side, the jet is ejected from an ejection hole 7 formed in the distal end surface of the cylindrical throat portion 2 to form a jet flow toward the distal end of the main body 1. A plurality of air suction ports 3 are annularly arranged in a row on the peripheral wall of the main body around the throat section 2, and a further set of a throat section 5 and an air suction port 6 having the same structure are further provided on the distal end side. Outside air is sucked from the air suction port 3 by a Venturi effect by a jet of compressed air. The air suction ports 3 and 6 are formed obliquely in the peripheral wall of the main body 1 so as to minimize the suction resistance.

At a sufficient distance from the throat portion 5 of the second stage, a throat portion 8 for gas suction is provided near the tip of the main body 1.
Is formed, and a gas suction port 4 is provided in a ring shape around the gas suction port, so that the fuel gas is sucked by the jet of the primary air by the compressed air and the sucked outside air. Further, the inner cylinder 9 having the gas suction throat portion 8 formed at the tip is formed to have a length sufficient to rectify the mixed air flow of the compressed air and the outside air.
The gas can be efficiently sucked by passing through the portion at a constant flow rate instead of a turbulent flow. 1 in the figure
Reference numeral 0 denotes a hose connection for supplying low-pressure gas, and fuel gas is supplied to a space between the peripheral wall of the main body 1 and the inner cylinder 9. The premixed fuel gas and primary air are
In front of the flame stabilizing plate 11 provided at the tip of the main body 1, the fuel burns while being mixed with the secondary air. 12 is a secondary air hole,
13 is a combustion cylinder.

FIG. 2 shows a state in which the gas burner A according to the present invention is used for heating the casting ladle B. Even if the low pressure gas hose 14 and the compressed air hose 15 are connected to the gas burner A, the gas burner A becomes too bulky. The simple stand 1 does not require a large base like the conventional
6 and can be used, and the movement between the ladles B is very easy.

[0009]

According to the present invention, as described above, since the entire peripheral surface of the compressed air flow contributes to the suction of the outside air, the suction amount of the outside air is extremely large, and the fuel gas is also suctioned by this jet flow. There is an advantage that it is not necessary to suction air by a high-pressure gas as in the related art, and a sufficiently high output can be obtained even when a low-pressure gas is used. Further, since the throat portion and the air suction port are formed in two stages, there is an advantage that an appropriate amount of outside air can be sucked at a time, and the venturi effect can be efficiently functioned. Further, since a large combustion air supply pipe and a large-capacity blower are not required and the size and weight are reduced, there is an advantage that a gas burner suitable for heating a ladle or metal which requires installation / removal and moving work can be provided.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 2 is a sectional view showing a use state of the above.

FIG. 3 is a longitudinal sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner main body 2 Throat part 3 Air suction port 4 Gas suction port 5 Second-stage throat part 6 Second-stage air suction port 7 Jet hole 8 Throat part for gas suction 9 Inner cylinder 10 Hose connection part 11 Flame holding plate 12 Secondary air hole 13 Combustion cylinder 14 Low pressure gas hose 15 Compressed air hose 16 Stand

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-55512 (JP, A) JP-A-5-280714 (JP, A) JP-A-53-72712 (JP, A) 156831 (JP, U) Fully open 1956-80433 (JP, U) Fully open 4-82508 (JP, U) Fully open 47-2247 (JP, U) Fully open 49-56536 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) F23D 14/04 F23D 14/64 F23D 14/22

Claims (2)

(57) [Claims] 1. A compressed air supplied to a base end of a substantially cylindrical burner main body is blown out from a throat portion toward a main body front end, and a plurality of air suctions are formed annularly on a main body peripheral wall around the throat portion. A gas burner in which ports are arranged in line, external air is sucked from these air suction ports by the jet of the compressed air, and fuel gas is suctioned from a gas suction port provided on a peripheral wall near the front end of the main body 1. 2. The gas burner according to claim 1, wherein the throat portion and the air suction port are formed in a plurality of stages along the axial direction of the main body.