JPS5881931A - Convector plate - Google Patents

Abstract

PURPOSE:To heat the entire of a coil at a uniform temperature, when band steel coils are piled up one over another and annealed in a batch-type annealing furnace, by providing holes having a specified configuration and dimensions for circulating atmospheric gas at convector plates to be located between the coils. CONSTITUTION:When a plurality of band steel coils 5 (A-D) are annealed in a batch-type annealing furnace, convector plates to be located between adjacent coils for improving the circulation of heating atmospheric gas are formed into the shape and dimensions as follows: An inner diameter part 21 for circulating the atmospheric gas is provided at the center of the convector plate 20, a circulating part 22 radially leading from the outer surface to the inner diameter part 21 is provided, and large opened parts 23 and small opened parts 24 are provided on upper and lower surfaces, respectively. In addition, the center of both of the opened parts 23, 24 is kept apart by 1/3 of the thickness of the coils from the inner surface parts of the coils, and the surface area ratio of the large opened part 23 to the small opened part 24 is held at 1.5-4.0. The distribution of the heating atmosphere is generally performed, and each part of the coils and each of the coils are heated and annealed at a uniform temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a convector plate suitable for being interposed between coils stacked in an annealing furnace.

FIG. 1 is a sectional view showing the annealing state of a coil in a general batch-type tight annealing furnace. A sealed inner cover 2 is disposed inside the outermost furnace body 1 made of a refractory material, and high-temperature gas from the burner 3 flows between the furnace body 1 and the inner cover 2. 2 is being heated.

Inside the inner cover 2, coils 5 (A, B, C, D) are stacked with a convector plate 4 interposed therebetween.

A pace fan 6 and a diffuser 7 are provided at the bottom of the inner cover 2 to circulate atmospheric gas inside the inner cover 2 and to heat the coil 5.

Here, the conventional convector plate 4 has a substantially disk shape as shown in FIG.
There is a flow section 9 that allows atmospheric gas to be introduced from the outer surface toward the inner diameter portion 8 in the radial direction, and a flow section 9 with the same opening area on the upper and lower surfaces so that the atmospheric gas introduced into the flow section 9 flows out toward the upper and lower coil edges. The openings 10 are arranged symmetrically. That is, the atmospheric gas inside the inner cover 2 circulates as shown by the notches in FIG.
It is possible to heat from the outer periphery, inner periphery, and both edges.

As shown in FIG. 3(5), the solid line in FIG. 3(5) indicates 1/! of the coil 5 in which the conventional convector plate 4 is interposed. Ignition 10°20.30 at each measurement position P1 to P5 in the radial direction at the height H)
It shows the temperature state after some time. A coil 5 annealed using such a conventional convector plate 4
, a large temperature difference occurs in the direction of the winding thickness, and the temperature difference slightly inward from the inner periphery of the coil occurs during the -1 heating period as shown in Fig. 3 (above).
As shown in 2), there are abnormal temperature regions such as low temperature points and high temperature points during the cooling period.

FIG. 4 shows that a conventional convector plate 4 is installed in an annealing furnace as shown in FIG. Normal size coils A and B are stacked in 4 layers with an average coil weight of 38t each, a coil height of 1100Os, and a coil plate thickness of 1cm.

It is an explanatory view showing the transition of temperature at the coldest point in the coils C and D. According to this figure 4, the coil temperature is 550℃
It took 42 hours to reach this temperature, creating a temperature difference of 50°C between the coils, and it was shown that the temperature rise was more difficult in the order of coil A, coil B, coil D, and coil C, depending on the stacked position of the coils.・I get caught. That is, when three or four stacked coils are annealed under the conditions in which the conventional convector plate 4 is used, the heating temperature difference between the coils, depending on the coil stacking position, coil size, etc. There is a problem in that a cooling temperature difference occurs and it is difficult to uniformly heat and cool all the coils.

The present invention has been made in view of the above conventional problems, and provides a convector plate that can suppress the occurrence of abnormal temperature regions within the coils and equalize the temperature difference between each coil. The purpose is to

In order to achieve the above-mentioned object, the present invention is arranged between the coils stacked in an annealing furnace, and introduces the atmosphere gas in the furnace between the upper and lower surfaces of the coils with a radial force. In the convector plate, which flows out toward the coil edge from openings provided on the upper and lower surfaces, both openings on the upper and lower surfaces are arranged from the inner periphery of the coil to the outer periphery of the coil by about 1/3 × coil winding thickness, and , the area ratio of both openings is 1
．． It is set within the range of 5 to 4.0.

Hereinafter, embodiments of the present invention will be explained with reference to the drawings. Fig. 5 is a sectional view showing an embodiment of the convector plate according to the present invention, and Fig. 86 is a cross-sectional view taken along the line MM in Fig. 5. View, 7th
The figure is a view taken along the line ■-■ in FIG. 5.

The convector plate 20 has an inner diameter part 21 through which the atmospheric gas can flow through the center, a flow part 22 which allows the atmospheric gas to flow from the outer surface to the inner diameter part 21 in the radial direction, and one of the upper and lower surfaces thereof. a large opening 23 with a relatively large opening area that allows the atmospheric gas guided to the flow section 22 to flow out toward the coil edge; A small opening 24 with a relatively small opening area is provided to allow internal gas to flow out toward the coil edge.

Here, the large opening 23 and the small opening 24 are approximately 1/3X from the inner circumference of the coil on the upper and lower surfaces of the convector plate 20.
It is arranged on the outer peripheral side of the coil by the coil winding thickness (R). That is, according to the inventors' experiments as shown in FIG. 3 (5), the coldest point position in the coil is located toward the outer circumference of the coil by about 1/A3 × coil winding thickness from the inner circumference of the coil. Based on this recognition, by arranging the large opening 23 and the small opening 24 at the above positions, the amount of atmospheric gas supplied to the coldest point position is increased, and the heat rise in the radial direction inside the fill is increased. , uniform cooling is achieved.

Further, the area ratio between the large opening 23 and the small opening 24 is set within a range of 1.5 to 4.0. That is, according to experiments conducted by the present inventors, when the above-mentioned area ratio is set to less than 1.5, between each normal-sized coil in a stacked state,
It is impossible to secure a heat transfer difference that eliminates the temperature difference based on the stacking position, and if the above area ratio exceeds 4.0, heat transfer is inhibited on the small opening side, and the large opening side The dark pressure of the coil ETSU becomes excessive on the side, causing the coil to bend at the waist and edges, which is not appropriate. Therefore, the area ratio of the large opening 23 and the small opening 24 is set within the range of 1.5 to 4.0, and the amount of atmospheric gas supplied to each coil on the upper surface side and lower surface side of the convector plate 20 is controlled. , it is possible to control the state to suit the stacking situation of each coil.

Therefore, when the above-mentioned funnel vector plate 20 is used in a general annealing furnace as shown in FIG. 1, as shown in the operation results shown in FIG. If the heating state of the By arranging the large openings 23 of both convector plates 20A and 20B on the coil C side, the amount of atmospheric gas supplied to the upper and lower coil edges of the coil C is increased.
It becomes possible to improve the heating state of the coils and to equalize the heating and cooling states among the coils.

That is, FIG. 8 shows that the average coil weight t38t1 coil height 100 is inside the annealing furnace of FIG.
Coils A, B, C, and D with a haze of 0 and a thickness of 1- are stacked in four layers, and a conventional convector plate 4 is placed on the bottom surface of the coil A and between the coil A and the coil B. , between coil B and coil C, a convector plate 20A according to the present invention is arranged such that its large opening 23 is located on the coil C side, and between coil C and coil D, FIG. 6 is an explanatory diagram showing the change in temperature at the coldest point in each coil when the convector plate 20B according to the present invention is arranged so that its large opening 23 is located on the coil C side. According to FIG. 8, the amount of atmospheric gas supplied to the coil C is increased by the large openings 23 of the convector plates 20A and 20B, and the time required to reach the coil temperature of 550°C is 38 hours, which is 44 hours longer than before. It is recognized that the time is shortened, and the temperature difference between each coil is reduced to 10° C. to 30° C., and the temperature difference between the coils due to the stacking position, coil size, etc. is made more uniform.

Further, the broken lines in FIG. 3 indicate the ignition 10 at each measurement position P1 to P5 in the radial direction at a height position of 1/2 of the coil in which the convector plate 20 according to the present invention is interposed.
, 20. It is an explanatory diagram showing the temperature state after 30 hours. According to this FIG. 3, in the convector plate 20, the large opening 23 and the small opening 24 are arranged so as to be arranged toward the outer periphery of the coil by about 1/3 × coil winding thickness from the inner periphery of the coil. Therefore, it is recognized that the temperature distribution within the coil can be made more uniform, and the occurrence of abnormal temperature regions within the coil can be suppressed.

As described above, the present invention provides an annealing furnace which is interposed between coils stacked in an annealing furnace, introduces in-furnace atmosphere gas from the radial direction between the upper and lower surfaces, and provides the introduced atmospheric gas on the upper and lower surfaces. In the convector plate that flows out from the opening toward the coil edge, both the openings on the upper and lower surfaces are arranged on the outer periphery side of the coil by approximately 1/3X the coil winding thickness from the inner periphery of the coil, and the area ratio of both openings is 1.5 to 4.0
By arranging the large opening side on the side of the coil where heating and cooling conditions are not good, abnormal temperature areas within the coil are suppressed, and the temperature between each coil is This has the effect of equalizing differences.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a general annealing furnace, Figure 2 is a perspective view showing a conventional convector plate, and Figure 3 (5).
4 is a diagram showing the temperature difference between the coils in the conventional example, and FIG. 5 is a sectional view showing an embodiment of the convector plate according to the present invention. Figure 6 is a view along the line ■-■ in Figure 5, Figure 7 is a view along the line ■-■ in Figure 5, and Figure 8 shows the temperature difference between the coils in the present invention. It is a line diagram. 5...(A, B, C, D) Coil. 20... Convector plate, 21 - Inner diameter part. 22... Distribution section, 23... Large opening, 24... Small opening 0 Agent Patent attorney Osamu Shiokawa Figure 1 Figure 2 Figure 3 Figure 4 Time (Hr) Figure 5 0 Figure 6 Figure 7

Claims (1)

[Claims] (1) It is installed between the coils stacked in the annealing furnace, and introduces the furnace atmosphere gas from the radial direction between the upper and lower surfaces, and directs the introduced atmospheric gas toward the coil edge from the openings provided on the upper and lower surfaces. In the convector plate that flows out, both openings on the upper and lower surfaces are approximately 1/3 from the inner circumference of the coil.
×The coil winding thickness is placed on the outer circumferential side of the coil, and
A convector plate characterized in that the area ratio of both openings is set within a range of 1.5 to 4.0.