JP2001272000A - Supply medium supply piping structure and supply method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent damage in a feed path due to a flow velocity of a supply medium. SOLUTION: This is a feed medium feed pipe structure having a feed medium supply path connected to a T-shaped header via a flow control valve, and a branch path branched from the T-shaped header into two. The distance from the flow control valve to the center of the branch path in the T-shaped header is at least 2.9 times the inner diameter of the pipe between the flow control valve and the center of the branch path.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed pipe structure and a feed method for a feed medium, and more particularly to a feed medium for feeding the medium at an appropriate speed to effectively prevent damage to a feed path caused by the feed. In the following, an example will be described in which combustion air and fuel gas used in a heating furnace for uniformly heating a steel material such as a billet to a predetermined temperature are supplied as a supply medium. .

[0002]

2. Description of the Related Art As a furnace for heating a steel material such as a billet, for example, a walking beam type heating furnace 30 as shown in FIG. 5 is used. The steel material 21 is placed on the fixed beam 22 or the walking beam 23 in the heating furnace 30, and the walking beam 23 repeats the operation of ascending → forward → down → retreat, whereby the steel 21 is conveyed in the furnace length direction. You. The air for burning is preheated to about 650 ° C. by an air recuperator (not shown) as a heat exchanger, and then provided on the left and right side walls of the heating furnace 30 through a hot air pipe 8 as a hot air supply path. Multiple burners 10
Sent to Similarly, the fuel gas is also preheated to about 270 ° C. by a gas recuperator (not shown), and then sent to a plurality of burners 10 through a gas pipe 9 which is a fuel gas supply path. Burner 10
The burner 10a for heating the upper part of the heating furnace and the burner 10b for heating the lower part of the heating furnace are arranged on the side surface of the heating furnace along the furnace length direction.

[0003] A hot air supply piping system will be described from the upstream side. The hot air pipe 8 includes a main pipe 8a having one end connected to the above-described air recuperator, and a plurality of branch pipes 8b (only two pipes are shown in the drawing) branched from the main pipe 8a. The opposite side of the branch pipe 8b from the main pipe is a T-shaped header 1.
1, the T-shaped header is provided with a branch path 13 branched to the left and right side walls. In the example shown in the figure, three burners 10 are provided for one branch path 13.
(10a in the figure) is connected. As shown in detail in FIG. 6, the branch pipe 8b is provided with a flow control valve 15 at the entry side of the T-shaped header 11.

The fuel gas supply piping system has the same configuration as the hot air supply piping system, and has a main pipe 9a having one end connected to the air recuperator and a plurality of branch pipes branched from the main pipe 9a. 9b (only two pipes are shown in the figure), a T-shaped header 11 connected to the side of the branch pipe b opposite to the main pipe, and a T-shaped header 12
There is provided a branch path 14 branching from the side to the left and right side walls. In the example shown in the figure, three burners 10 are connected to one branch path 14. As shown in detail in FIG. 6, the branch pipe 9b is provided with a flow control valve 16 at the entry side of the T-shaped header 12.

As described above, one branch pipe 8b for hot air and three branch pipes 9b for fuel gas are provided on the left and right furnace side walls, respectively.
A total of six burners 10 are connected, and branch pipes 8b, 9
By adjusting the flow rates of the hot air and the fuel gas in b by the flow control valves 15 and 16, respectively, the fuel of the six burners can be controlled collectively. The group of six burners that collectively control combustion is defined as one section, the sections are arranged in the furnace length direction, and the temperature in the heating furnace can be controlled by the position in the furnace length direction.

Incidentally, two rows of burners, a heating furnace upper heating burner 10a and a heating furnace lower heating burner 10b, are arranged on the furnace side wall. In FIG. 5, a burner for the heating furnace upper heating is used. Only the fuel / air pipe and gas pipe connected to the heating furnace 10a will be described, and the description of the fuel / air pipe and gas pipe connected to the burner 10b for the lower part of the heating furnace will be omitted because they are the same as those for the upper part of the heating furnace.

[0007]

The branch path 13,
14 or an upstream supply route, that is, a hot air pipe 8,
The gas pipe 9 is usually made of a SS400 pipe, and is lined inside as shown in FIG. 6 from the viewpoint of preventing corrosion at high temperatures and reducing heat loss by heat insulation. As the lining material, a ceramic fiber having excellent heat insulating properties and workability is used, and a ceramic fiber block 17, a ceramic fiber sleeve 18, a ceramic fiber castable (a part where the work is difficult to perform) 19 and the like are provided according to the size of the pipe. Generally, the ceramic fiber has a wind resistance specification of 30 m / cm for a ceramic fiber block from the viewpoint of strength.
s or less, 35 m / s for ceramic fiber sleeve
It is defined below.

In the lining material having the above-mentioned wind resistance specification, the flow velocity of the medium passing through the pipe depends on the piping distance on the inlet side and the outlet side of the flow control valve and the installation angle with respect to the branch path due to facility restrictions. It is inevitable that the lining material will be worn out or fall off due to local rise or drift.
The repairs required enormous costs, and the repairs had to be temporarily stopped, which meant that the productivity was inevitably reduced.

An object of the present invention is to propose a novel method capable of stably feeding a medium such as air or fuel gas while satisfying the wind resistance specification of the above-described path provided with an internal lining. Where you do it.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a feed medium having a supply path connected to a T-shaped header via a flow control valve, and a branch path branched from the T-shaped header into two. 1. a piping structure, wherein a distance from the flow control valve to the center of the branch path in the T-shaped header is an inner diameter of a pipe between the flow control valve and the center of the branch path;
A feed medium supply pipe structure characterized in that the number is nine times or more. Further, according to the present invention, when feeding the supply medium in the pipeline to each of the paths of the T-shaped header that branches right and left through the flow control valve, the distance from the center of the branch path to the flow control valve is determined by the pipe. A method for feeding a supply medium, wherein the supply medium is supplied while maintaining the diameter of the supply medium at 2.9 times or more, and the supply medium is a combustion medium used in a heating furnace such as a billet. The air and fuel gas are advantageously adapted.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the distance from the center of a branch path branched by a T-shaped header to a flow control valve is maintained at an appropriate value to locally increase the flow velocity of a supply medium or to cause a drift. The present invention is more specifically described below with reference to the drawings.

FIGS. 1 (a) and 1 (b) show the construction of a feed pipe structure of the present invention. In the figure, reference numeral 1 denotes a supply path leading to a recuperator, 2 denotes a T-shaped header,
Reference numeral 3 denotes a flow control valve interposed between the supply path 1 and the T-shaped header 2, and reference numeral 4 denotes a branch path shown in an example where the T-shaped header 2 branches right and left.

In the present invention, the distance L from the center P of the branch path 4 of the T-shaped header 2 to the flow control valve 3 is determined as 2.9 of the inner diameter D of the pipe between the flow control valve 3 and the center P. (L ≧ 2.9D), and according to this,
The medium that has passed through the flow control valve 3 smoothly flows through the branch path 4 while drawing a spiral in a state where the anti-wind pressure specification is satisfied.

In the piping structure shown in FIG. 1, the present inventors change the linear distance from the outlet side of the flow control valve 3 to the center P of the branch path 4 while keeping the flow rate of the medium constant. About, the flow velocity at each position in the pipe was analyzed. FIG. 2 shows the ratio (L / L) of the straight line distance L from the outlet side of the flow control valve 3 to the center P of the branch path 4 and the inner diameter D of the pipeline.
It is a figure which shows the relationship between D) and the maximum flow velocity (m / s), ie, the flow velocity value in the position where the flow velocity is the largest. FIG. 2 shows a case where the inner diameter D of the pipeline is large and a case where it is small. Increasing the inner diameter makes it possible to reduce the maximum flow velocity, which is advantageous for reducing the flow velocity to the wind speed V or less. However, increasing the inner diameter D of the pipeline is
Equipment costs increase, which is not preferable. Further, according to FIG. 2, in a region where the value of L / D is less than 2.9, L
It can be seen that the flow rate increases as the value of / D decreases. On the other hand, if the value of L / D is 2.9 or more, the flow rate is L / D.
It does not depend on the value of D. Therefore, it is understood that setting the value of L / D to 2.9 or more, preferably 3.0 or more, is most advantageous in reducing the flow velocity to the wind speed or less. The flow control valve may be provided at a distance of 2.9 × D or more from the center of the branch path 4. However, considering the application of the present invention to the heating furnace illustrated in FIG. It is necessary to install the branch pipes 13 and 14. Here, as shown in FIG. 5, a supply pipe for hot air or fuel gas is usually installed above the heating furnace. Considering that the recuperator is arranged above the heating furnace in the case of utilizing the above, it is difficult to install the flow control valve at a position far from the T-shaped header. Therefore, it is preferable to directly interpose a flow control valve between the T-shaped header and the supply path within a range satisfying the above L ≧ 2.9D.

[0015]

EXAMPLE When the inner diameter D of the path is 850 mm and the distance L from the flow control valve to the center of the branch path is 1390 mm (comparative example) and 2500 mm (adaptive example), the flow velocity at the flow control valve inlet side Was analyzed at each position in the branch path when the air was supplied at 28 m / s.

As a result, when air was supplied according to the present invention, as shown in FIG. 3, although a local rise in the fluidized bed was slightly observed, it was confirmed that the wind pressure resistance was 30 m / s or less. On the other hand, in the comparative example, as shown in FIG. 4, in the branch path where the ceramic fiber freeb is arranged, 50 m, which far exceeds the wind resistance specification of 35 m / s.
/ S local flow rate increase was observed.

[0017]

According to the present invention, it is possible to feed the supply medium in a state where the wind resistance specification of a path having a lining inside is satisfied, so that damage to the path is suppressed,
It is possible to avoid the operation stoppage accompanying this, and it is possible to significantly improve productivity. In particular, when applied to a steel heating furnace, it is possible to design a heating furnace excellent in energy saving.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of an embodiment of the present invention, in which (a) shows a cross section of a feeding path, and (b) shows a plane thereof.

FIG. 2 is a graph showing the relationship between L / D and flow velocity.

FIG. 3 is a diagram showing a state of a flow in a branch path when air is supplied according to the present invention.

FIG. 4 is a diagram showing a state of a flow in a branch path when air is supplied according to a conventional procedure.

FIG. 5 is a perspective view of a walking beam type heating furnace.

FIG. 6 is a diagram illustrating a main part of the feed path taken out.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Supply path 2 T type header 3 Flow control valve 4 Branch path 8 Hot air pipe (supply path) 9 Gas pipe (supply path) 10 Burner 11 T type header 12 T type header 13 Branch path 14 Branch path 15 Flow control valve 16 Flow rate Control valve 17 Ceramic fiber block 18 Ceramic fiber sleeve 19 Ceramic fiber castable

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F27D 7/02 F27D 7/02 A (72) Inventor Takaaki Ishikawa 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki (72) Inventor Koichi Uemura 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba F-term (reference) 3J071 AA02 BB14 BB16 CC03 DD14 FF16 3K023 BA01 BA15 3K068 AA01 CA04 EA03 4K050 AA01 BA02 CD02 4K063 AA08 BA02 CA05 CA06 DA08 DA13

Claims (3)

[Claims] 1. A feed pipe structure for a feed medium having a feed path for a feed medium connected to a T-shaped header via a flow control valve and a branch path branched from the T-shaped header into two. The distance from the flow control valve to the center of the branch path in the T-shaped header is at least 2.9 times the inner diameter of the pipe between the flow control valve and the center of the branch path. Characteristic supply medium feed pipe structure. 2. When feeding a supply medium in a pipe to each branch path of a T-shaped header that branches right and left through a flow control valve, the distance from the center of the branch path to the flow control valve is determined by a pipe line. Feeding the supply medium while maintaining the supply medium at 2.9 times or more the inner diameter. 3. The method for feeding a supply medium according to claim 2, wherein the supply medium is air or a fuel gas as a combustion aid used in a heating furnace such as a billet.