JPS60178286A - Negative load heat-insulating hearth for industrial furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention is directed to the treatment of heavy hI substances (λ) μl! This is related to the load-heavy insulated hearth of industrial furnaces suitable for tl.

]Prior art" Box-type annealing furnace When annealing a coil-shaped thin steel plate, the coil of the thin steel plate should be wound tightly with no gaps, and with a gap. There are two types of j 71-bun coils.

Tie 1 - A coil-shaped steel plate can be handled as a single steel ingot, but an oven-coiled steel plate has a small rigidity, so care should be taken to prevent deformation during heating. In order to
r 5F-use required.

In addition, since the hearth is required to withstand the coil load under high temperatures, conventionally hearths have been used that are made of heat-resistant steel, mainly made of stainless steel, and have heat insulating material filled between the ribs. There is. Conventional hearths like this are made by filling the spaces between the ribs with insulating material to reduce heat dissipation from the hearth, and by reducing the cross-sectional area of the ribs (
) to reduce heat transfer to the hearth.

Stainless steel is often used as the rib material, and the temperature is 800℃.
However, creep deformation of the rib material is unavoidable.In order to reduce creep deformation, the shape of the rib should be made larger to reduce the load on the rib material. However, increasing the shape of the ribs increases heat conduction to the hearth, which goes against energy conservation.

In addition, bricks were laid as a hearth, which was traditionally used.
Fire-resistant and insulating and able to withstand heavy loads.
There is. However, the bricks are small pieces relative to the total area of the hearth, and generally there are strict tolerances in shape and size. Therefore, it takes a great deal of effort to create a hearth that satisfies the required degree of flatness by spreading the heat.When heat treatment is performed in a box-type annealing furnace, heating and cooling are performed in the same furnace. Nl is repeated!
Therefore, it is desirable that the amount of heat stored in the hearth constituting the furnace is small.

The bricks laid on the hearth have a heat-resistant strength limit /) + f
Relatively dense (b) Heat conductive refractory bricks are used.For this reason, the heat stored in the hearth and extracted is i;
The heat 1r1 that is lost is harmful to people and becomes a prisoner of decreased thermal efficiency.

[Objectives stated in Section 15] The present invention has excellent insulation properties at a low cost and installation cost, and can easily maintain the flatness of the top surface by 1ft.]
The purpose is to provide a heavy-duty insulated hearth for industrial furnaces.

[Bright Structure] The present invention provides a heavy-load insulating hearth for an industrial furnace by forming a packed bed of refractory and insulating powder grains in the hearth.

Implementation example 1 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a box-type furnace 1 as an example of an industrial furnace, and the box-type furnace 1 has a rectangular shell made of steel plates and reinforcing steel materials. The floor surface is a hearth 2 which is rectangular, and a door 3 is attached to the front, which can be opened and closed to take in and out thin copper plate coils to be heat treated.

The hearth 2 is not shown in the enlarged vertical cross-sectional view of Fig. 2.The lowest part of the hearth steel plate 4 is a hearth steel plate 4, and the upper surface of the hearth steel plate 4 is made of steel plates in the form of a grid approximately 1 m square. A partition 5 is arranged. The height of the partition 5 is determined by the XJ method to be smaller than the depth of the filled layer, which will be explained next, and is set to a height that does not protrude to the surface of the filled layer.

On the −1 side of the hearth steel plate 4, a plate-shaped heat insulating plate 6 with high heat insulation properties is laid. The heat insulating board 6 is used to improve the heat insulating performance of the entire hearth 2. Since the heat insulating board 6 receives the weight from the upper surface, it needs to be strong.
Heat resistance is not required.

On the upper surface of the heat insulating board 6, a layer filled with relatively large coarse particles 1 having fireproof and heat insulating properties is formed. As the coarse particles 7, it is possible to use bricks made by crushing bricks into a granule shape close to a spherical shape without acute angles. In order to reduce the change, it is preferable to use a brick with an almost spherical shape without any acute angles, as there is a risk that if the bricks are still crushed and have acute angles, they will break and the C layer will shrink.

On the soil surface of the layer of coarse particles 1, a fire-resistant and heat-insulating material 8 such as asbeth is spread, and on top of that, 90 layers of small particles of fire-resistant material are filled. As mentioned above, the l1Ml9 of the small grain 9 is determined on the upper surface of the small grain 9 so that the partition 5 that partitions the two parts of the hearth does not protrude. When a ruler-shaped object is passed over the upper surface of the small particle 9, the upper surface of the small particle 9 becomes a highly accurate horizontal surface, which is suitable for placing the coil holder 10.

The fire-resistant heat insulating cloth body 8 is used to prevent the small particles 9 in the upper layer from entering the gaps between the coarse particles 7, and the upper layer of the packed layer is made up of coarse particles and the lower layer is made up of small particles. in case of,
The fireproof heat insulating fabric 8 is undefeated. However, by using small grains 9 in the high-temperature part on the inner surface of the furnace, it becomes easier to ensure C1 flatness and prevent deformation under load, so it is difficult to decide whether to make the upper layer small or coarse. Select according to each requirement.

If the load on the hearth 2 is locally extremely uneven, the strength burden on the lower packing layer is reduced, which generally improves the insulation properties. To facilitate the selection of item 9, a support made of fireproof material may be placed under an unbalanced load.

Since the pillars are minute compared to the area of the whole hearth, they do not impair the insulation properties as a whole.

[Effects of the invention] The insulation of industrial furnaces is improved, the flatness of the top surface of the hearth is easily ensured, and the amount of heat storage is reduced because the height of the packed layer is smaller than that of conventional brick-laid hearths. This reduces the energy consumption of the furnace, resulting in a large energy-saving effect as a furnace.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a box-type furnace which is an example of an industrial furnace, and FIG. 2 is a longitudinal cross-sectional view of one embodiment of the present invention. In the figure, 1 is a box furnace, 2 is a hearth, 7 is a coarse grain, and 9 is a small grain. Patent application Hitoshi Kawajima Harima Heavy Industries Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1) A heavy-load insulating hearth for an industrial furnace characterized by forming a layer of refractory and insulating bamboo powder granules on the hearth.