JPH0364568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating a walking beam in a metal heating furnace.

In a metal heating furnace, materials to be heated, such as steel or other metals, are transferred while being heated over a water-cooled skid pipe using a walking beam.

In the conventional walking beam, as shown in FIG.
A heat shielding plate e having a size substantially the same as or smaller than the opening d is provided on the lower surface side. In the figure, f
is the skid rail, g is the material to be heated, h is the seal water, and i is the gas seal.

As shown in FIG. 2, the walking beam a rises from the stop position j to the upper limit within the opening b, then moves forward (or backward), and then descends to the lower limit and then moves backward (or forward). This cycle of movement, which stops at the backward end (or forward end), is repeated at regular intervals. Here, the size of the opening d is 200 to 400 mm in width and 800 to 1200 mm in length, so the stroke of the walking beam a is less than the length L of the opening d, and the vertical movement is about 150 to 300 mm. .

The size of the heat shield plate e is the walking beam a
It is sufficient to have a length sufficient to block the opening d at any position during the stroke of the heat shield plate e, but as the heat shield plate e becomes longer, the distance between the gas seals i also increases. It has to be widened.

However, if the interval between the gas seals i is widened, it becomes impossible to attach a beam to the hearth c, so the length of the heat shield plate e is limited, and must be at most the same as or shorter than L above. .

Therefore, when the stopping position of the walking beam a is at the front or rear end of the forward stroke, the range shown by l in Figure 1 of the opening d (usually 200 to 500 mm) can be blocked by the heat shield plate e. First, since the stopped state of walking beam a occupies 70 to 95% of the total operating time, heat loss was extremely large.

In addition, as shown in Fig. 3, a heat shield plate is installed to avoid restrictions due to the mounting position of the gas seal i.
e' is provided on the upper surface side of the hearth c in the penetrating part of the walking beam a, and the length of the heat shielding plate e' is lengthened by a length l' on the opposite side of the stop position j, so that when the walking beam a is stopped, There are things that prevent the reduction of heat loss.

However, in this case, the shielding plate e' is exposed to the high temperature gas in the heating furnace, while there is a limit to the cooling effect of the cooling water passing through the walking beam a. Length of heat shield plate e′
Since the portion l' was not sufficiently cooled, even the heat shield plate e' made of heat-resistant steel had an extremely short lifespan. Furthermore, when the portion l' returns to the stop position after being exposed to high temperature, the area from which heat is radiated toward the sealing water h increases, resulting in large heat loss.

The present invention was made for the purpose of eliminating the above-mentioned drawbacks of the conventional walking beam, and by setting the stopping position of the walking beam approximately at the center of the forward stroke, the heat shield plate can be made smaller, and the heat shielding plate can be reduced. This invention relates to a method of operating a walking beam that can minimize loss.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a diagram showing an example of a walking beam for carrying out the method of the present invention, in which 1 is a walking beam, 2 is a hearth, 3 is an opening, 4 is seal water, 5 is a gas seal, 6 indicates the material to be heated. A heat shielding plate 7 is provided on the lower surface side of the opening 3 of the penetrating portion of the walking beam 1, and the length of the heat shielding plate 7 is made longer than the length L of the opening 3. For example, when the walking beam 1 is located at the center of its forward and backward stroke, the overlapping margin s between the hearth 2 and the heat shield plate 7 is set to 30 to 50 mm.

Although the means for stopping the walking beam 1 at the center of the forward and backward stroke is not shown in the above description, it can be done by adjusting the walking beam stop position of the walking beam drive system.

The walking beam 1 is as shown in FIG.
For example, by performing a vertical movement of about 150 to 300 mm and a horizontal movement of about 100 to 800 mm,
The material to be heated 6 is moved. As a result, the heated material 6
is heated to 1100-1200℃ in a heating furnace. That is, as shown in FIG. 5, the stopping position 8 of the walking beam 1 is the lowering limit of the walking beam 1 and the center of the forward and backward stroke, and the walking beam 1 is moved backward from the stopping position 8 and then raised to the upper limit. , after moving forward, it is lowered to the lowering limit, and then moved backward to stop position 8 and stopped. This one cycle of movement takes about 40 to 60 seconds, and one cycle is repeated at fixed time intervals. The above operation may be started by setting the stop position as the center of the forward stroke at the upper limit and moving the robot forward from the stop position.

Therefore, while the walking beam 1 is stopped, the walking beam 1 is located at the center of its forward stroke at either the lower limit or the upper limit, so that the heat shield plate 7 provided on the walking beam 1 overlaps with the hearth 2, the opening 3 is blocked by the heat shielding plate 7, preventing high-temperature radiant heat inside the heating furnace from escaping into the sealing water 4 through the opening 3, and preventing high-temperature gas from leaking out of the furnace. Can be blocked.

Further, the length of the heat shield plate 1 may be the length L of the opening 3 plus the overlap margin s×2, so it can be made smaller than the conventional example shown in FIG. 3.
Therefore, the cooling effect of the cooling water flowing in the walking beam 1 reaches every corner of the heat shield plate 1, and the life of the heat shield plate 7 is extended without overheating. Therefore, instead of attaching the heat shield plate to the lower side of the hearth, it can also be attached to the upper side of the hearth.

Note that the walking beam operating method of the present invention is not limited to the above-mentioned embodiments.
Of course, various changes can be made without departing from the spirit of the invention.

As described above, the walking beam operating method of the present invention exhibits various excellent effects as described below.

() Since the walking beam has the longest (70 to 95% of the total) stopping position at the approximate center of the forward (horizontal) stroke, the size of the heat shield plate can be minimized.

() Due to the above (), the heat affected zone of the heat shield plate becomes smaller and its life becomes longer.

() A small heat shield plate blocks the hearth opening during stoppage, minimizing heat loss and being extremely effective in terms of energy conservation.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of an example of a conventional walking beam, Fig. 2 is an explanatory diagram of the operating method of the walking beam shown in Fig. 1, and Fig. 3 is an explanatory diagram of another example of the conventional walking beam. FIG. 4 is an explanatory diagram of a walking beam used to implement the method of the present invention, and FIG. 5 is an explanatory diagram of the method of the present invention. 1 is a walking beam, 2 is a hearth, 3 is an opening, 7 is a heat shield plate, and 8 is a stop position.

Claims (1)

[Claims] 1. A method of operating a walking beam, characterized in that the stopping position of a walking beam provided with a heat shield plate for blocking the hearth opening of a metal heating furnace is set at approximately the center position of the forward and backward stroke of the walking beam.