JP2634881B2 - Vertical preheating furnace for direct-fired strip heating furnace - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a preheating furnace for a direct-fired strip heating furnace for thin sheet annealing equipment, including a continuous galvanizing furnace.

[Related Art] The flue gas of a direct-fired strip heating furnace of a thin-plate annealing facility including a continuous galvanizing furnace has a high temperature, and is guided to a preheating furnace and used for preheating the strip. In the conventional vertical preheating furnace, one furnace body is provided for each pass. However, in recent years, as the heating capacity of the furnace has been increased, it has been often adopted to provide a plurality of furnace bodies for a plurality of passes corresponding thereto. .

FIG. 2 shows a side view of the preheating furnace. In FIG. 2, two furnace bodies of the preheating furnace 1 are provided, one for each of the descending path and the ascending path.

The strip 3 enters the preheating furnace 1 via an upper deflector roll 6 provided in a roll chamber 8 above the preheating furnace 1. Next, the strip 3 descends in the preheating furnace 1 and enters the lower roll chamber 8, and then reenters the preheating furnace 1 via the lower deflector roll 7. Next, the strip 3 rises in the preheating furnace 1 and again enters the upper roll chamber 8, exits the preheating furnace 1 via the upper deflector roll 6, and enters the direct-fired strip heating furnace (not shown). .

Here, the flue gas is fed by a flue gas pipe 14, flows between the furnace bodies of the two preheating furnaces 1 through a flue gas duct 13, and is discharged from the flue gas discharge pipe 5 while preheating the strip 3. Is done.

[Problems to be Solved by the Invention] However, since the direct-fired strip heating furnace as described above has a plurality of furnaces corresponding to a plurality of passes, a space for installing the preheating furnace becomes large, and the preheating is performed. The heat capacity of the furnace has increased. As a result, when the heating load changes, such as when the size of the strip is changed, the response is slow due to the large heat capacity of the furnace body of the preheating furnace, and the strip at the outlet of the preheating furnace is overheated to a high temperature. However, this causes oxidation of the surface of the strip, which is a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and provides a quick response when a heating load changes, such as when a strip size is changed, and also reduces a space for installation. An object of the present invention is to provide a preheating furnace that can reduce construction costs.

Means for Solving the Problems The present invention has been made to solve the above problems, and its gist is that a plurality of vertical paths are accommodated in a single furnace body, On one of the upper and lower sides of the path, a deflector roll that changes the running direction of the strip and transfers the strip to the preheating furnace is placed, and the first is separated by a reflector that opens the passageway to the preheating furnace. A roll chamber was provided, and the other of the upper and lower sides of the path was provided with a deflector roll for folding back the strip in the preheating furnace, and a second partition partitioned by a reflection plate having an open passageway to the preheating furnace. Providing a roll chamber, providing a radiation wall between the plurality of vertical paths, and burning between each vertical path on both sides of the radiation wall between the first roll chamber and an end of the radiation wall. Exhaust gas inlet for split gas supply And an exhaust gas discharge port for discharging the combustion exhaust gas is provided between the second roll chamber and the end of the radiant wall.

[Operation] In the vertical preheating furnace of the direct-fired strip heating furnace according to the present invention, the heat capacity of the furnace body can be reduced by accommodating a plurality of vertical paths in a single furnace body. Response control when the load changes can be speeded up. Also, the installation space of the preheating furnace is small, and the construction cost can be reduced.

Since the roll chamber is arranged in the furnace, surface oxidation of the strip by the atmosphere can be prevented.

By providing an exhaust gas inlet for splitting and supplying combustion exhaust gas to each vertical path on both sides of the radiation wall between the first roll chamber and the end of the radiation wall, a direct radiation type strip heating furnace with a high radiation effect is provided. The flue gas is evenly distributed to each pass, and the radiation wall is provided between the passes, so that the strip can be efficiently and uniformly preheated.

By providing an exhaust gas discharge port for discharging the combustion exhaust gas between the second roll chamber and the end of the radiant wall, the uniform flow of the gas supplied from the combustion exhaust gas inlet is maintained, and the second roll is provided. It also has the effect of preventing exhaust gas from entering the chamber.

By providing a reflector that is open in the passage of the strip to the preheating furnace in the roll chamber, radiant heat can be used effectively for preheating the strip, and at the same time, radiant heat transfer to the deflector roll in the roll chamber can be reduced. Has the effect of.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a side view of a preheating furnace 1 according to the present invention.

In the preheating furnace shown in FIG. 1, a lowering path and an ascending path are accommodated in one furnace body. A first roll chamber for transferring strips 3 to the preheating furnace 1 above the preheating furnace 1
8a, there is a second roll chamber 8b below the preheating furnace 1 where the strip 3 in the preheating furnace 1 is folded. The radiation wall 2 is provided between the descending path and the ascending path. Between the first roll chamber 8a and the preheating furnace 1 and between the second roll chamber 8b and the preheating furnace 1, there are provided an upper reflector 11 and a lower reflector 10, each of which opens a passage for a strip. Between the first roll chamber 8a and the end of the radiant wall 2, there is provided a flue gas inlet 4 for dividing and supplying the flue gas to each vertical path on both sides of the radiant wall. A flue gas discharge port 9 for discharging flue gas is provided between the second roll chamber 8b and the end of the radiation wall 2.

In this preheating furnace, the strip 3 enters the preheating furnace 1 via an upper deflector roll 6 provided in a first roll chamber 8a above the preheating furnace 1. The strip 3 descends in the preheating furnace 1 and the second roll chamber 8b at the lower part of the preheating furnace 1
And after turning it down with the lower deflector roll 7,
It enters the preheating furnace 1 again. The strip 3 rises in the preheating furnace 1 and reenters the first roll chamber 8a, exits the preheating furnace 1 via the upper deflector roll 6, and enters a direct-fired strip heating furnace (not shown). .

The flue gas from the direct-fired strip heating furnace having a high radiation effect at high temperature is fed from a flue gas inlet 4 for dividing and supplying the flue gas to each vertical path on both sides of the radiation wall, and the radiation wall 2 and the preheating furnace The inner wall 12 and the strip 3 are heated and discharged outside through the flue gas discharge pipe 5 through the flue gas discharge port 9.

From the flue gas inlet 4, the flue gas of the direct fire type strip heating furnace having a high radiation effect is evenly distributed to each pass,
In addition, the radiation wall is provided between the passes, so that the strip is preheated efficiently and uniformly. The flue gas discharge port 9 provided between the second roll chamber 8b and the end of the radiant wall 2 maintains an even flow of the gas fed into the preheating furnace, and discharges exhaust gas to the second roll chamber 8b. Prevent intrusion. Since the reflectors 11 and 10 are provided in the passage of the strip to the preheating furnace in each roll chamber, radiant heat can be effectively used for preheating the strip, and at the same time, radiation to the deflector roll in the roll chamber can be performed. Heat transfer can be reduced.

In the present embodiment, the radiation wall 2 is heated to a high temperature by the combustion exhaust gas of the direct-fired strip heating furnace having a high temperature,
The amount of radiant heat transfer to the strip 3 is about double.

In the present embodiment, the first roll chamber is provided in the upper part of the preheating furnace, and the second roll chamber is provided in the lower part. However, the first roll chamber may be provided in the lower part of the preheating furnace, and the second roll chamber may be provided in the upper part. And similar results can be obtained.

[Effects of the Invention] As described above, according to the present invention, the heat capacity can be designed to be smaller than that of the conventional preheating furnace. No non-defective products are generated. In addition, the present invention has a large effect such as requiring a small installation space for the preheating furnace and further causing a significant reduction in the heat intensity.

[Brief description of the drawings]

FIG. 1 is a side view of a preheating furnace according to an embodiment of the present invention,
FIG. 2 is a side view of a conventional preheating furnace. 1 ... preheating furnace, 2 ... radiation wall, 3 ... strip, 4 ...
... Flue exhaust gas inlet / outlet, 5 ... Flue exhaust gas discharge pipe, 6 ...
Upper deflector roll, 7 ... Lower deflector roll,
8 roll chamber 8a first roll chamber 8b second roll chamber 9 flue gas outlet 10 lower reflector
11 Upper reflector plate 12 Inner wall of preheating furnace 13 Exhaust gas duct 14 Exhaust gas pipe

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shuji Kanto 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Naoki Matsui 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan In-house council of Japan Co., Ltd. Judge Hidenobu Yoshida Judge Hiroaki Watanabe Judge Shigehiro Toyonaga (56) References JP-B 61-10019 (JP, B2) JP-B 54-41009 (JP, B2) JP-B 62-62 29490 (JP, B2) JP-B 53-2712 (JP, B2)

Claims (1)

(57) [Claims] 1. A deflector for accommodating a plurality of vertical paths in a single furnace body, and for transferring a strip to a preheating furnace by changing a running direction of a strip on one of upper and lower sides of the path. A first roll chamber partitioned by a reflector having an opening for a plate passing through the preheating furnace is provided together with the roll, and a deflector for folding the strip in the preheating furnace on the other side of the upper and lower sides of the path. Along with storing the rolls, providing a second roll chamber partitioned by a reflector that opens a plate passage to a preheating furnace; providing a radiation wall between the plurality of vertical paths; Between the roll chamber and the end of the radiant wall, provided with an exhaust gas inlet for dividing and supplying the flue gas to each vertical path on both sides of the radiant wall; and the second roll chamber and the radiant wall Exhaust gas for discharging the combustion exhaust gas between the end portions Vertical preheating furnace flame-type strip heating path, characterized in that a discharge port.