JPS6156248A - Method for cooling coil in box annealing furnace - Google Patents

Abstract

PURPOSE:To enhance the cooling effect by blowing atmospheric gas circulating in a furnace on the tops and bottoms of coils. CONSTITUTION:Coils A are placed on a plenum chamber 2 under a cooling chamber 1. Atmospheric gas is cooled with heat exchangers 4 by driving the exchangers 4 and fans 7 for circulation, and the cooled gas is distributed to upper and lower directions with the fans 7 and sent to the ceiling and floor sides of the cooling chamber 1 through upper and lower ducts 5, 5'. The atmospheric gas sent to the ceiling side is blown on the tops of the coils A from blowing parts 6, and the atmospheric gas sent to the floor side is blown into the plenum chamber 2 from blowing parts 6'. The coils A are efficiently cooled.

Description

[Detailed description of the invention] (Industrial application field) The invention relates to a coil cooling method for a box-type annealing furnace.

(Prior Art) When cooling a coil in a continuous batch annealing furnace such as a box-type annealing furnace, especially a UAS method, conventionally, as shown in FIG. 2, the coil At? Circulation fan 10.1 installed on the side of the ceiling of the cooling room in the mounted state
A down-flow system was used in which atmospheric gas was blown into the ceiling zone of the cooling chamber and flowed through the blow-off nozzle 9 so as to hit the upper edge of the coil.

(Problems to be Solved by the Present Invention) However, in the above method, the atmospheric gas that hits the edge of the top surface of the coil takes away pA from the coil, and then descends through the side of the coil, placing it on the coil Ai. After passing through the plenum chamber 2, it is sent to the circulation fan 10.10 via the cooler 12.

Therefore, although the atmospheric gas hits the lower edge of the coil when passing through the plenum chamber 2, the temperature of the atmospheric gas increases due to heat exchange between the upper edge of the coil and the side part, which causes cooling of the lower edge of the coil. The effect becomes very small.

Furthermore, in the above method, when the coil width changes, the distance t between the atmospheric gas blowing nozzle 9° 9 in the ceiling zone and the top edge of the coil changes.

Therefore, in the case of a narrow coil, the distance t becomes large, and the cooling efficiency and efficiency tend to deteriorate due to a decrease in wind speed on the upper surface of the coil and a decrease in convective heat transfer coefficient.

Therefore, in the conventional coil cooling method, the cooling time in the cooling chamber is long, and the production capacity of the annealing furnace cannot be increased.

(Means for Solving the Problems) The present invention was developed through research to solve the problems of the conventional coil cooling method as described above. It is an object of the present invention to provide a method for cooling a coil in a box-type annealing furnace, which can improve the cooling efficiency of a cooling chamber and obtain good cooling efficiency even when the coil width varies.

In order to achieve the above object, the present invention is configured such that the atmospheric gas is not caused to flow only over the coil top m1, but is made to flow in a countercurrent manner from the top surface of the coil and from the top surface of the coil. This is a circulation method in which the spray is simultaneously sprayed on the lower surface of the coil, then led out through the outer circumferential side of the coil, and sprayed again on the upper and lower surfaces of the coil.

(Function) According to the above method, the atmospheric gas hits the upper edge of the coil and removes heat, and at the same time, the lower edge of the coil remains sufficiently cooled.

Therefore, there is a difference in the cooling effect between the top and bottom surfaces of the coil.
However, since the atmospheric gas is blown directly onto the edge of the bottom surface of the coil, even if the coil width is narrow and there is a distance between the ceiling zone and the top surface of the coil, the cooling efficiency from the bottom surface of the coil is good, resulting in high cooling efficiency. Obtainable.

(Example) Embodiments of the invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a coil cooling method according to the invention and a means for implementing the same, in which numeral 1 denotes a cooling chamber and a blemish chamber 2 is disposed at the bottom thereof. Reference numeral 3 denotes a suction port installed in the center of the side height direction of the cooling chamber 1, and a heat exchanger 4 for cooling atmospheric gas is installed in the suction port 3.

The suction port 3 is provided with upper and lower ducts 5, whose blow-out portions 6, 6 reach the ceiling zone and lower zone of the cooling chamber 1, respectively. A circulation fan 7 is installed at the boundary between the duct 5 and the heat exchanger 4 to distribute and pressure-feed the atmospheric gas from the heat exchanger 4. 8 is a driving source for the circulation fan 7, and 9 is a ceiling nozzle.

In order to cool the coil without invention, the coil A is placed in the Blenheim chamber 2, and the heat exchanger 4 and the circulation fan 7 are driven.After the atmospheric gas is cooled by the heat exchanger 4, , is distributed vertically by a circulation fan 7, and is divided into upper and lower ducts 5. It is sent to the ceiling side and the lower side of the cooling chamber 1 by A.

The atmospheric gas sent to the ceiling of the cooling chamber is blown into the ceiling zone of the cooling chamber from the blow-out section 6, and is blown onto the upper edge of the coil from the ceiling nozzle 9 as in the conventional case. At the same time, the atmospheric gas that has descended to the lower side of the cooling chamber is blown into the blennium chamber 2 from the blow-off section d, and is blown from the blennium chamber 2 onto the lower edge of the coil.

The atmospheric gas that hit the top and bottom surfaces of the coil A passes through the outer peripheral side of the coil, is sucked in through the suction port 3 that is open at the center of the side height direction of the cooling chamber 1, and is cooled by the heat exchanger 4. , the upper and lower ducts 5 through the circulation fan 7. It is sent to the coil and sprayed on the top and bottom surfaces of the coil.

This circulation is repeated for a predetermined period of time.

Heat transfer from the coil edge direction is several times greater than from the coil radial direction, and the coil is cooled not only from the upper edge but also from the lower edge at the same time, so the coil cooling efficiency is greatly improved according to the present invention. In particular, even when the coil width is narrow, the cooling effect from the lower edge of the coil is high, making it possible to ensure excellent cooling efficiency.

The results of actually cooling a coil using the jDUAs method according to the present invention are shown in Table 1 below in comparison with the conventional down-flow one-way method. Note that in the table, the cooling efficiency refers to the efficiency of cooling only, not including purging, extraction, and transfer into the furnace.

Note: Heating is equivalent to 5 pcc.

As is clear from Table 1 above, according to the present invention, it is possible to shorten the coil cooling time in the cooling chamber to about 3/4 of the conventional time, and in particular, good cooling efficiency is achieved even for narrow coils. You can see what you can get.

(Effects) According to the present invention as described above, when cooling the coil of a box-type annealing furnace, circulating atmospheric gas is sprayed onto the upper surface and the lower surface of the coil. Cooling efficiency can be improved even in the case of narrow coils, and the excellent effect of increasing cooling capacity and production capacity can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a coil cooling method using phase annealing according to the present invention, and FIG. 2 is a cross-sectional view showing a conventional coil cooling method. l...Cooling chamber, 2...Blenheim chamber, 3...
Suction port provided in the center of the side of the cooling chamber, 4... Heat exchanger, 5, 5'... Duct, 7... Circulation fan, A.
··coil.

Claims (1)

[Claims] When cooling the coil of a box-type annealing furnace, Sprays circulating atmospheric gas onto the top and bottom of the coil. A box-type annealing furnace coil characterized by Cooling method.