JPH06172828A - Coupling for discharging powdery material - Google Patents

Abstract

PURPOSE:To prolong the service life of a powdery material discharging coupling, to improve the reliability of pulverized coal blowing equipment and also, to reduce the maintenance cost. CONSTITUTION:In the inside of a tee 15 in the powdery material discharging coupling 10 mixing the pulverized coal and dilute gas blown through a powdery material nozzle 11 from a powdery coal supplying tube 4 and through a dilute gas nozzle 13 from a dilute gas supplying tube 5, respectively, a wear resistant sleeve 16 having a passing-through hole 16a passing through the pulverized coal blown from the powdery material nozzle 11 is fitted. The inside of the tee 15 is protected and the service life of the tee 15 is prolonged, therefore the reliability of the pulverized coal blowing equipment is improved. As the changing interval and the repairing interval of the powdery material discharging coupling 10 are prolonged, maintenance cost is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder cutting joint for use in a pulverized coal blowing facility for blowing powdered pulverized coal into a blast furnace or the like, and more particularly to mixing pulverized coal with a diluent gas. The present invention relates to a powder cutout joint having improved mixing zone durability.

[0002]

2. Description of the Related Art As an example of the above powder cutting joint, for example, US PAT. 323016 (Jan.
18, 1966) are known.
Hereinafter, this will be described with reference to FIG. 6 which is a sectional view thereof. A mixing unit (hereinafter referred to as a powder cutting joint) 24 is provided below the pressure feed tank 12. The pulverized coal which is powder is passed through the pipe 20 and the powder nozzle 24a, and the diluent gas is used as the diluent gas nozzle 26 and the pipe 2.
7 and the mixing zone 5 inside the Qi 24b.
It is about to be supplied to 8. Then, the solid-gas mixture composed of the pulverized coal and the diluent gas mixed in the mixing zone 58 as described above is pressure-transmitted to the Qi 24b via the transportation pipe 28 connected to the opposite side of the pipe 27. In this case, it is pumped to the blast furnace). In addition, the pipe 27
It is needless to say that the supply amount of the diluent gas is adjusted to the solid-gas ratio required for transportation by a control valve (not shown) or the like.

The cheek 24b in which the mixing zone 58 is formed and the powder nozzle 24a are integrated by welding or screw joining. The chee 24b is generally made of a weldable steel material, and is manufactured by any of forging, casting, or shaving a rolled steel material, or a combination thereof. By the way, the valve body 52 may be incorporated in the powder nozzle 24a as shown in the same drawing, but it is replaced by a valve provided on the upstream side of the powder cutting joint 24, and the powder nozzle 24a is replaced with the valve. There is also a structure in which the valve body is not built in.

[0004]

In the above powder cutout joint, the powder sent from the pressure feed tank via the powder nozzle 24a is mixed with the diluent gas sent from the pipe 27 in the mixing zone 58. As a result, erosion occurs in the mixing zone 58 when pressure is fed from the transport pipe 28 to the pressure destination side. As the erosion progresses, a hole finally opens in the chee 24b, and the powder is ejected from this hole. Thus, Qi 24b
If a hole is made in the hole, the amount of injection will be reduced and the injection will be unbalanced.Therefore, whenever a problem occurs, the operation of the pulverized coal injection device is stopped and the powder cutting joint is replaced. Or it is repaired by overlaying with welding or patching.

However, in the case where a pulverized coal blowing facility for a blast furnace requires, for example, as many as 40 powder cutting joints, the loss due to such trouble cannot be ignored, and the facility It has been desired to realize a powder cutout joint having a longer life in order to achieve stable operation and reduce maintenance cost of equipment.

Therefore, it is an object of the present invention to provide a powder cutting joint having a mixing zone with excellent durability.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. Therefore, in the structure of the powder cutting joint according to claim 1, the powder nozzle and the dilution gas nozzle communicate with each other. , A mixing zone for mixing a powder supplied from a powder nozzle and a diluent gas blown from a diluent gas nozzle into a solid-gas mixture is provided inside, and the solid-gas mixture is provided on the downstream side from the mixing zone. In a powder cutting joint provided with a transport pipe for transporting to a pressure destination, an abrasion resistant sleeve made of a hard material is fitted in the mixing zone.

Further, in the structure of the powder cut-out joint according to claim 2, the powder nozzle and the diluent gas nozzle communicate with each other, and the powder supplied from the powder nozzle and the diluent gas blown from the diluent gas nozzle are provided. In the powder cutting joint, which comprises a mixing zone for mixing to form a solid-gas mixture inside, and a transportation pipe for transporting the solid-gas mixture from the mixing zone to a pressure destination on the downstream side, the mixing zone The wear resistant sleeve made of a hard material is fitted to the front side of a position away from the tip of the dilution gas nozzle by C, where C is the inner diameter of the wear resistant sleeve.

[0009]

According to the powder cutout joint according to the first aspect of the present invention, since the wear resistant sleeve made of a hard material is fitted in the mixing zone, the mixing zone is formed inside the wear resistant sleeve. The wear resistant sleeve protects the inner wall of the powder cutting joint.

In such a powder cutting joint, when the inner diameter of the mixing zone is C, erosion occurs in the range of 1.5C to 4C in front of the dilution gas outlet of the dilution gas nozzle. Therefore, according to the powder cutout joint according to claim 2 of the present invention, the wear-resistant sleeve is separated from the tip of the dilution gas nozzle of the powder cutout joint by C when the inner diameter of the wear-resistant sleeve is C. Since it is fitted in front of the position, the wear resistant sleeve protects the inner wall of the powder cutout joint where severe erosion occurs.

[0011]

EXAMPLES Examples of the powder cutting joint used in the pulverized coal blowing line of the pulverized coal blowing equipment according to the examples of the present invention will be described below with reference to FIG. It will be described with reference to FIG. 2 which is a sectional view of the body cutout joint.

First, the outline of the pulverized coal blowing equipment will be described. Reference numeral 1 shown in FIG. 1 is a pulverized coal blowing equipment, and reference numeral 10 in the pulverized coal blowing equipment is an inverted T shape. It is a powder cutting joint having a configuration described later that is arranged. At one end of the powder cutting joint 10 corresponding to the two T-shaped strokes,
The pulverized coal supply pipe 4 for supplying pulverized coal which is powder from the intermediate tank 2 through the distribution pressure feeding tank 3 communicates with each other, and a T-shaped 1
A dilution gas supply pipe 5 is connected to one end corresponding to the drawing, and a transport pipe 6 is connected to the other end, and the tip end side thereof is connected to a blower branch pipe 9 communicating with a tuyere 8 of a blast furnace 7 for blowing hot air. is doing. Therefore, when pulverized coal is supplied to the powder cutting joint 10 from the pulverized coal supply pipe 4 and compressed air is supplied from the dilution gas supply pipe 5, the pulverized coal and compressed air are inside the powder cutting joint 10. Are mixed into a blast furnace 7 from the tuyere 8 through the transport pipe 6 and the blower branch pipe 9 into a solid-gas mixture.

Next, the powder cutting joint 10 is provided with the transport pipe 6.
Has a long “T” shape, and the other end of the powder nozzle 11 to which the pulverized coal supply pipe 4 is connected at one end is screwed to one end corresponding to the two strokes of the T shape. At the same time, a fixed metal object having a dilution gas supply pipe 5 connected to one end on the opposite side of the transport pipe corresponding to one T-shaped stroke through a union nut 12 and a dilution gas nozzle 13 inside The other end of 14 is provided with a special asymmetric chee 15 which is screwed, and the inside of this special chee 15 is provided with a passage hole 16a through which the pulverized coal supplied from the pulverized coal supply pipe 4 passes. A wear sleeve 16 is fitted. Further, the distance Ld between the tip of the dilution gas nozzle 13 and the axis passing through the radial center of the pulverized coal supply pipe 4 is configured to be adjustable by the set bolt 17, and the distance Ld is usually the wear-resistant sleeve. It is set to 0.3 to 2 times the inner diameter of 16. The tip of the nozzle for the dilution gas 5 may or may not be projected from the end surface of the fixed hardware 14.

The wear-resistant sleeve 16 is formed, for example, by mixing SKH7 tool steel powder, which is a base material, with 6.5% by weight of TiC as hard substance powder and 10% by weight of VC. After the main sintering at 1250 ° C. after the sintering, in this embodiment, the wear-resistant sleeve 16 is fitted so as to protect the entire inner wall of the chee 15. It is preferable to set the fitting position of the toe and the chi 15 as described later. In addition to the above, the wear-resistant sleeve 16 may be made of a cemented carbide alloy such as WC or a ceramics material.

That is, the wear-resistant sleeve 16 sets the wear-resistant target area to 4C when the inner diameter is C, and the position of the wear-resistant sleeve 16 to the chee 15 is set to a position farther than the position distant from the pulverized coal supply pipe 4 by C. It is preferable to set it so that it is on the threaded side of the tube 6. That is, the length of the wear resistant sleeve 16 is fitted in the range of 5.3C to 7C in front of the tip of the dilution gas nozzle 13. The wear resistant sleeve 16 was fitted in such a position as a result of cutting and investigating a used powder cutting joint having an inner diameter of C and the dilution gas nozzle 1
This is because it has been found that the erosion occurs violently in the range of 1.5C to 4C from the tip of 3.

Therefore, a mixing zone 16b is formed inside the wear resistant sleeve 16 and the pulverized coal supply pipe 4 is provided therein.
Pulverized coal and compressed air are supplied from the dilution gas supply pipe 5, respectively, and pulverized coal and compressed air are mixed in the mixing zone 16 b inside the wear resistant sleeve 16.
Then, although erosion occurs in the mixing zone 16b, as described above, the wear resistant sleeve 16 is formed by mixing the hard steel powder with the tool steel powder and then performing the main sintering. As described above, since the holes are not drilled early, the life of the powder cutting joint is greatly improved. Moreover, since such a wear-resistant sleeve 16 is used, it is not necessary to secure the durability by the material of the Qie unlike the conventional case, and the low grade steel can be used, which is advantageous in reducing the cost of the main body. There is also an effect.

Next, another embodiment according to the present invention will be described below with reference to FIG. 3 which is a sectional view of the wear-resistant sleeve. The wear-resistant sleeve 16 has a mixing zone 16b.
Is eccentric, and the wall thickness on the side facing the passage hole 16a through which the pulverized coal passes is increased. Therefore, since the wall thickness on the side where erosion due to collision of pulverized coal is more severe is thicker, the durability of the powder cutting joint is more advantageous than that of the above-described embodiment in which the wear-resistant sleeve has a uniform wall thickness.

Another embodiment according to the present invention will be described below with reference to FIG. 4 which is a sectional view of a powder cutout joint. The wear resistant sleeve 16 is formed in the radial direction of the pulverized coal supply pipe 4. The length is symmetrical with respect to the axis passing through the center of. Therefore, when erosion occurs in the range of 1.5C to 4C from the tip of the dilution gas nozzle 13 of the wear resistant sleeve 16 and progresses, it is extracted from the chee 15 and the direction thereof is reversed to fit the chee 15. The wear resistance sleeve 16 can be doubled in durability just by making it slightly longer, which is economically advantageous.

In the above, the example of the powder cutout joint in which the powder nozzle 13, the fixed metal piece 14, and the transport pipe 6 are directly screwed to the qi 15 has been described, but they are connected by using a union nut or by welding. Alternatively, when the powder cutting joint is particularly large, the connecting portion may be of a flange type, and the flanges may be connected by bolts or bolt nuts. Further, although the case where the wear-resistant sleeve 16 is integrated has been described as an example, as shown in FIGS. 5a, 5b, and 5c of the connection state explanatory diagram of the wear-resistant sleeve, a split type is used, for example, in FIGS. As shown in the drawing, a spigot part may be provided and the spigot part may be engaged with each other, and as shown in FIG. 5c, the end faces may be butted against each other. Design changes and the like can be freely made within the range not departing from.

[0020]

As described above in detail, according to the powder cutting joint of the present invention, the mixing zone is formed inside the wear resistant sleeve, and the erosion occurs on the inner wall of the wear resistant sleeve. Erosion does not occur inside the powder cutting joint. In addition, as a result of improving the durability of the powder cutting joint, the replacement interval of the powder cutting joint is extended, and the work of overlaying by welding and repair work by patching is also eliminated, so stable operation of the equipment and equipment It has a great effect on reduction of maintenance cost.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a pulverized coal blowing facility in which a powder cutting joint according to an embodiment of the present invention is interposed.

FIG. 2 is a sectional view of a powder cutting joint according to an embodiment of the present invention.

FIG. 3 is a sectional view of an abrasion resistant sleeve according to another embodiment of the present invention.

FIG. 4 is a sectional view of a powder cutting joint according to another embodiment of the present invention.

5A, 5B and 5C are explanatory views of the connection state of the wear resistant sleeve.

FIG. 6 is a cross-sectional view of a powder cutting joint according to a conventional example.

[Explanation of symbols]

1 ... Pulverized coal injection equipment, 2 ... Intermediate tank, 3 ... Distribution pressure feed tank, 4 ... Pulverized coal supply pipe, 5 ... Diluting gas supply pipe, 6 ...
Transport pipe, 7 ... Blast furnace, 8 ... Tuyere, 9 ... Blower branch pipe, 10 ... Powder cutting joint, 11 ... Powder nozzle, 12 ... Union nut, 13 ... Diluting gas nozzle, 14 ... Fixed metal object, 15 ... Chi, 16 ... wear resistant sleeve, 16a ... through hole, 16b ...
Mixing zone, 17 ... Set bolt.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Funabiki 1 Kanazawa-machi, Kakogawa-shi, Hyogo Prefecture Kado Steel Works Kakogawa Steel Works (72) Inventor Isao Mano 1-3-3 Wakihama-cho, Chuo-ku, Kobe-shi, Hyogo No. 18 Kobe Steel, Ltd. Kobe Head Office (72) Inventor Yoshihiro Yamamoto 1-3-18 Wakihama-cho, Chuo-ku, Kobe City, Hyogo Prefecture Kobe Steel Co., Ltd. Kobe Head Office

Claims (2)

[Claims] 1. A mixing zone in which a powder nozzle and a diluent gas nozzle communicate with each other and a powder supplied from the powder nozzle and a diluent gas blown from the diluent gas nozzle are mixed to form a solid-gas mixture. In a powder cutting joint comprising a transport pipe for transporting the solid-gas mixture from the mixing zone to a pressure destination on the downstream side, a wear resistant sleeve made of a hard material is fitted in the mixing zone. Characteristic powder cutting joint. 2. A mixing zone in which the powder nozzle and the diluent gas nozzle communicate with each other, and the powder supplied from the powder nozzle and the diluent gas blown from the diluent gas nozzle are mixed to form a solid-gas mixture. In a powder cutting joint comprising a transport pipe for transporting the solid-gas mixture from the mixing zone to a pressure destination on the downstream side, a wear resistant sleeve made of a hard material is provided in the mixing zone. When the inner diameter of C is C, from the tip of the dilution gas nozzle C
A powder cutting joint characterized in that it is fitted forward from a remote position.