JP2002139212A - Powder melting burner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a flame having the shape that becomes bold from the neighbourhood of a tip end of a burner. SOLUTION: A powder melting burner 10 comprises a gas fuel nozzle 12 for injecting a gas fuel such as town gas from its center toward an outer periphery, a primary combustion assist gas nozzle 14 for injecting primary combustion assist gas employing oxygen as a chief ingredient, and a powder nozzle 16 for injecting powder together with carrying gas and a secondary combustion assist gas nozzle 18 for injecting secondary combustion assist gas employing oxygen as a chief ingredient, all being arranged in this order concentrically. A spacer 26 is concentrically disposed inside the gas fuel nozzle 12, and a nozzle hole 12a opened at a tip end of the gas fuel nozzle 12 is set to be annular. More specifically, a gas fuel is injected from the nozzle hole 12a of the gas fuel nozzle 12 annularly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for melting powders such as fine and fine particulate incineration residues, sewage sludge and its incineration residues, and ceramic powder in a flame, and converts oxygen into a combustion supporting gas. The present invention relates to a powder melting burner containing as a main component.

[0002]

2. Description of the Related Art As the powder melting burner, there is one disclosed in, for example, JP-A-10-244187.
The powder melting burner disclosed in this publication has a fuel nozzle, a primary combustion supporting gas nozzle containing oxygen as a main component, and a solid-gas mixture of powder and a carrier gas. The nozzle and the nozzle for the secondary combustion supporting gas containing oxygen as a main component are arranged concentrically in this order.

[0003]

In the above-described conventional structure of the powder melting nozzle, the powder is supplied from the outer periphery of the fuel nozzle or the primary combustion supporting gas nozzle, so that the powder can be reliably melted. In order to carry out the process promptly, it is strongly desired to increase the diameter of the flame near the tip of the burner so as to form a flame having a straight traveling property that can increase the contact time without the powder coming off the flame.
However, although the nozzle hole of the fuel nozzle is a circular single hole and can form a straight flame, it cannot form a thick flame near the tip of the burner.

[0004]

Accordingly, the inventor of the present invention has sought various solutions for the above-mentioned problems, and found that the reason why the flame diameter is not increased is that fuel is ejected from a single hole in a cylindrical shape.
The fuel at the center and the primary supporting gas supplied from the outer periphery are separated from each other, and the primary supporting gas and the entire fuel near the tip of the burner are not mixed promptly, and expansion due to oxidation reaction occurs. It was confirmed that the strength was weak. In other words, the entire amount of fuel ejected from the tip of the fuel burner is 1
It can be seen that, by bringing the fuel closer to the secondary combustion supporting gas, the fuel and the primary combustion supporting gas are mixed quickly, the expansion force due to the oxidation reaction is increased, and the flame diameter near the burner tip can be increased. Was.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned drawbacks of the prior art, and has been proposed in order to solve the problem in a favorable manner. An object of the present invention is to provide a powder melting burner that can surely and quickly melt powder.

[0006]

[MEANS FOR SOLVING THE PROBLEMS]
In order to suitably achieve the intended purpose, the powder melting burner according to the present invention is provided with a gas fuel nozzle, a primary combustion supporting gas nozzle mainly containing oxygen, And a nozzle for a secondary combustion supporting gas containing oxygen as a main component are arranged concentrically in this order, and the gaseous fuel is supplied from the gaseous fuel nozzle in a substantially annular shape. It is characterized in that it is configured to squirt.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a powder melting burner according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments.

[0008]

First Embodiment FIG. 1 shows a powder melting burner 10 according to a first embodiment, and a gas fuel nozzle for ejecting a gas fuel such as a city gas from a central portion to an outer peripheral portion thereof. 12. Inject primary combustion supporting gas mainly composed of oxygen 1
The nozzle 14 for the next combustion support gas, the nozzle 16 for the powder that ejects the powder together with the carrier gas, and the nozzle 18 for the secondary combustion gas that ejects the secondary combustion gas containing oxygen as a main component are respectively in this order. They are arranged concentrically in independent flow paths. Also,
The nozzle tip of the primary support gas nozzle 14, the nozzle tip of the powder nozzle 16, and the nozzle tip of the secondary support gas nozzle 18 are set to face the same plane.
The nozzle tip of the gas fuel nozzle 12 is positioned so as to be retracted by a predetermined length from the nozzle tip of the primary combustion supporting gas nozzle 14 located outside. A cooling cylinder 20 to which cooling water is circulated and supplied is provided at the outermost part of the powder melting burner 10.

The primary combustion supporting gas nozzle 14 comprises a distal nozzle 22 and a proximal nozzle 24 (which also forms a powder nozzle) disposed on the outer periphery thereof. The gas flow path of the side nozzle 22 and the gas flow path of the base side nozzle 24 are formed by a plurality of combustion supporting gases that are formed in the front end side nozzle 22 at the joint of the two nozzles 22 and 24 and extend substantially in a tangential direction. (See FIG. 3). That is, the primary combustion supporting gas is supplied to the base side nozzle 24.
From the gas flow path through the plurality of holes 22a.
A swirling flow is given when flowing to the second gas flow path, and the primary combustion supporting gas is ejected from the nozzle tip while swirling. By swirling the primary combustion supporting gas in this way, mixing with the gaseous fuel ejected from the gaseous fuel nozzle 12 is promoted, and the powder and the flame ejected from the powdery nozzle 16 are mixed. It also encourages contact. The gas flow path at the nozzle tip of the tip side nozzle 22 is narrowed in the direction of the central axis, and the nozzle hole 14a opened at the nozzle tip is set as a single circular hole.

The nozzle hole 16a opening at the nozzle tip of the powder nozzle 16 is formed in an annular shape surrounding the nozzle hole 14a of the primary combustion supporting gas nozzle 14, as shown in FIG. The powder flow path at the nozzle tip of the powder nozzle 16 is narrowed in the central axis direction, and the powder is obliquely ejected from the nozzle hole 16a toward the axial center.

At the nozzle tip of the secondary combustion supporting gas nozzle 18, on a circumference of a required diameter surrounding the nozzle hole 16 a of the powder nozzle 16, as shown in FIG. Thus, a plurality of nozzle holes 18a are opened. The gas flow passage communicating with each nozzle hole 18a extends along the axial direction (see FIG. 1), and the secondary combustion supporting gas is ejected from each nozzle hole 18a so as to go straight along the axial direction.

As shown in FIG. 1, a spacer 26 having a circular cross section is concentrically arranged inside the nozzle tip of the gas fuel nozzle 12, and a nozzle hole 12a opening at the nozzle tip of the gas fuel nozzle 12. Is the spacer 26
It is comprised so that it may become annular. That is, the gaseous fuel is ejected from the nozzle hole 12a of the gaseous fuel nozzle 12 in an annular shape. A plurality of holding members 28 are arranged on the outer circumference of the spacer 26 at predetermined intervals in the circumferential direction, and the distance between the outer circumference of the spacer 26 and the inner circumference of the gas fuel nozzle 12 is maintained by these holding members 28. It is configured to be kept at equal intervals to secure a fuel flow path. The base end of the spacer 26 (the side opposite to the nozzle tip)
The adjusting shaft 30 connected to adjusting means (not shown)
The shaft 30 is moved back and forth in the axial direction, so that the spacer 2
6 can be adjusted in position.

[0013]

Next, the operation of the powder melting burner according to the first embodiment will be described. The gas fuel nozzle 12, the primary combustion supporting nozzle 14, the powder nozzle 16 and the secondary combustion supporting nozzle 18 correspond to the gas fuel, the primary combustion supporting gas, the powder and the carrier gas, respectively. The gas fuel and the powder are burned by each supporting gas by supplying the secondary supporting gas. At this time, the gaseous fuel ejected from the nozzle hole 12a of the gaseous fuel nozzle 12 becomes annular, and is ejected from the nozzle hole 14a of the primary combustion supporting gas nozzle 14 located outside the gaseous fuel nozzle 12.
The whole gaseous fuel is physically close to the next supporting gas. As a result, the mixing of the gaseous fuel and the primary combustion supporting gas is promoted near the burner tip, the expansion force due to the oxidation reaction is increased, and the flame diameter is increased near the burner tip. Further, since the gaseous fuel is ejected so as to travel straight along the axis, the powder ejected from the nozzle hole 16a of the powder nozzle 16 comes into contact with the flame for a long time without coming off the flame, and The body melts reliably and quickly.

In the illustrated example, the tip of the spacer 26 and the nozzle tip of the gaseous fuel nozzle 12 are positioned so as to face the same plane, but the adjusting shaft 30 moves the spacer 26 back and forth in the axial direction. This causes the tip to protrude forward or recede with respect to the nozzle tip of the gaseous fuel nozzle 12. Thereby, the state of the gaseous fuel ejected from the nozzle hole 12a of the gaseous fuel nozzle 12 can be changed in accordance with the combustion conditions, and optimal combustion can be performed.

[0015]

Second Embodiment FIG. 4 shows a main part of a powder melting burner 32 according to a second embodiment.
Since this embodiment is the same as the embodiment, only different parts will be described. Note that the same members are given the same reference numerals.

In the powder melting burner 32 of the second embodiment, swirl vanes 34 as swirl means for gaseous fuel are provided on the outer periphery of the spacer 26 arranged at the center of the gaseous fuel nozzle 12 in the circumferential direction. A plurality of spirals are provided at a distance from each other. That is, the gas fuel nozzle 12 and the spacer 2
When the gaseous fuel passes through the fuel flow path between the gaseous fuel nozzle 6 and the gaseous fuel nozzle 6, a swirling flow is given to the fuel by the swirling blades 34, and the gaseous fuel is swirled from the annular nozzle hole 12a of the gaseous fuel nozzle 12. It is configured to be squirted. The turning direction of the gaseous fuel is set to be the same as the turning direction of the primary supporting gas. The swirl vanes 34
And the function of maintaining the inner periphery of the gas fuel nozzle 12 at equal intervals.

That is, the powder melting burner 3 of the second embodiment
2, the nozzle hole 12a of the gas fuel nozzle 12
The gaseous fuel ejected from
Because it becomes an annular shape physically close to the next supporting gas,
As in the embodiment, the flame diameter can be increased from near the tip of the burner, and the powder can be reliably and quickly melted. In the second embodiment, since the gaseous fuel is jetted while being swirled in the same direction as the primary supporting gas, the mixing of the gaseous fuel and the primary supporting gas is further promoted, and a larger flame diameter is obtained. Immediate melting of the powder can be improved.

[0018]

Third Embodiment FIG. 5 shows a main part of a powder melting burner 36 according to a third embodiment. In the third embodiment,
The gas fuel nozzle 38 is connected to the outer tube 4 opening at the tip.
0, and an inner tube 42 concentrically disposed inside the outer tube 40 and having a closed end, and the two tubes 40, 42 form an annular nozzle hole 38a at the nozzle tip. Is formed. In the vicinity of the distal end of the inner pipe 42, a plurality of holes 42a as gaseous fuel swirl means extending in a substantially tangential direction are formed, and both pipes 40, 42 are formed through the holes 42a. It is configured to communicate. That is, the gaseous fuel supplied to the inner tube 42 is given a swirling flow when flowing from the inner tube 42 to the outer tube 40 via the plurality of holes 42a, and the gaseous fuel is swirled while the nozzle tip It is constituted so that it may be spouted in a ring from. Therefore, the powder melting burner 3 of the third embodiment
6 also has the same operation and effect as the above-described second embodiment. Reference numeral 44 denotes a backflow prevention plate disposed so as to close the space between the two pipes 40 and 42 on the rear end side of the burner from the position where the hole 42a is formed, and the backflow prevention plate 44 squirts from the hole 42a. It is configured to stop the backflow of gaseous fuel.

[0019]

EXPERIMENTAL EXAMPLE A powder melting burner according to a conventional example in which the nozzle hole of a gas fuel nozzle is a single hole, a powder melting burner 10 of the first embodiment, and a powder melting burner 32 of the second embodiment are used.
Table 1 shows the results of measurement or observation of the burner tip flame diameter, combustion state, flame straightness, and the like. Each condition at this time is as follows: combustion amount: 175 kW, fuel: 13 A of city gas, supporting gas: about 93% of oxygen obtained by separating oxygen from air by the PAS method.
And the oxygen ratio m = 1.0. Note that the powder nozzle was in a state where air was ejected without ejecting the powder. The flame diameter is 100mm from the burner tip.
And the flame diameter in the conventional example was set to 10
Others are shown as 0.

[0020]

According to the results shown in Table 1, as in the first embodiment and the second embodiment, the gaseous fuel is ejected in an annular shape, so that the flame diameter at the burner tip is larger than that of the conventional example. became. FIG. 6A shows an experimental state using a powder melting burner according to a conventional example, in which the flame diameter near the burner tip is small, and there is an unburned portion of gaseous fuel in the center. It was confirmed that. On the other hand, FIG. 6B shows an experimental state using the powder melting burner according to the first embodiment, in which the flame diameter near the tip of the burner is large, and the gaseous fuel is in the center. It can be seen that there is no unburned portion.

In each of the embodiments, the nozzle hole of the gas fuel nozzle is formed in an annular shape. However, a plurality of arcuate nozzle holes constituting a part of the annular shape are opened at predetermined intervals in the circumferential direction. The gas fuel ejected from the nozzle hole may be configured to be substantially annular. The means for providing the swirling flow to the gaseous fuel is not limited to the configuration of each of the above-described embodiments, and other means such as providing a spiral groove on the inner peripheral surface of the gaseous fuel nozzle may be used as appropriate. Can be adopted. Further, as for the means for giving the swirling flow to the primary combustion supporting gas, the same means as the means for giving the swirling flow to the gaseous fuel can be adopted.

[0023]

As described above, in the powder melting burner according to the present invention, since the gaseous fuel is ejected from the gaseous fuel burner in a substantially annular shape, the flame diameter near the burner tip is increased. And a reliable and rapid melting of the powder can be achieved. In addition, by providing the gaseous fuel with a swirling flow in the same direction as the primary combustion supporting gas, the mixing of the two is further promoted, the flame diameter is further increased, and the reliable and prompt melting of the powder can be further improved. .

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a powder melting burner according to a preferred first embodiment of the present invention.

FIG. 2 is a front view of the powder melting burner according to the first embodiment.

FIG. 3 is a sectional view of a nozzle for a primary combustion supporting gas of the powder melting burner according to the first embodiment.

FIG. 4 is a sectional view of a main part of a powder melting burner according to a second preferred embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a powder melting burner according to a third preferred embodiment of the present invention.

FIG. 6 is an explanatory diagram showing a flame state of an experimental example using the powder melting burner according to the conventional example and the first example.

[Explanation of symbols]

 12 Gas Fuel Nozzle 14 Primary Combustion Gas Nozzle 16 Powder Nozzle 18 Secondary Combustion Gas Nozzle 22a Holes (Combustion Gas Swirl Means) 34 Swirl Blades (Gas Fuel Swirl Means) 38 Gas Fuel Use Nozzle 42a hole (swirl means for gaseous fuel)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kanto ▲ Hiro ▼ Ichiro 1-2-5 Rokuno, Atsuta-ku, Nagoya City, Aichi Prefecture Daido Steel Co., Ltd. Takakura Works (72) Inventor Hideshi Hirose Nagoya City, Aichi Prefecture 1-2-5, Rokuno, Atsuta-ku Daiko Specialty Steel Co., Ltd. Takakura Works (72) Inventor Shinichi Miyake 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo Nippon Oxide Corporation (72) Inventor Yamada Susumu Aichi Pref. 19-18 Sakurada-cho, Atsuta-ku, Nagoya-shi F-term in Higashi Kokugas Co., Ltd. (Reference) 3K061 NB03 NB08 3K065 QB10 QC03 4D004 AA36 CA29 CB02 CB34

Claims (2)

[Claims] 1. A gas fuel nozzle, a primary combustion supporting gas nozzle containing oxygen as a main component, a powder nozzle for ejecting powder together with a carrier gas, and a gas containing oxygen as a main component. A powder melting burner, wherein the nozzles for the secondary combustion supporting gas are arranged concentrically in this order, and the gas fuel nozzle is configured to eject gas fuel from the gas fuel nozzle in a substantially annular shape. 2. The primary combustion supporting gas is given a swirling flow by a combustion supporting gas swirling means provided on the primary combustion supporting gas nozzle, and swirls from a nozzle tip narrowed in a central axis direction. The gaseous fuel is ejected, and the gaseous fuel swirling means provided in the gaseous fuel nozzle is provided with a swirling flow in the same direction as the primary supporting gas, so that the gaseous fuel is ejected while swirling from the gaseous fuel nozzle tip. The powder melting burner according to claim 1, wherein the burner is constituted.