JPS62136518A - Method and apparatus for removing scale on skid - Google Patents

Abstract

PURPOSE:To efficiently blow off and remove scale without the need of an operator to enter a heating furnace having skids in the stage of removing of the scale formed and deposited in the furnace by injecting air from a nozzle provided in a moving body moving longitudinally in the furnace. CONSTITUTION:The iron oxide scale S formed by the oxidation of ingot surfaces deposits on the skids 1, 1B in the stage of moving and heating the ingot in the heating furnace of a walking beam type, pusher type, etc., having said skids. The skid 2 is wound with a heat insulating material 1C on the surface of a water cooled skid post 1A and is provided with a skid button 1B for conveying the ingot in contact with the ingot. The height of the skid button 1B is oversized to prevent the formation of skid marks on the ingot under heating. The firing in the heating furnace is once put out in order to prevent the deposition of the scale S on the skid 1 and the deterioration of the effect of the skid button 1B. While the moving body 2 having the air nozzle 3 and nozzle header 5 is longitudinally moved in the furnace, the air is injected from the nozzle 3 to easily remove the scale.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a method and apparatus for removing scale deposited on the skid in a continuous heating furnace having a skid such as a walking beam type or a bushing type. It is related to.

[Prior art and its problems]

In this type of continuous heating furnace, skid marks that occur on the bottom surface of the steel billet are a factor that deteriorates the fuel consumption and quality of the furnace.

In the walking beam type, as shown in Fig. 4, skid buttons IB are protruded at intervals on a skid post IA covered with a heat insulating material IC, and the skid post IA and skid button IB prevent heat radiation. The humidity of the steel piece decreases in the blocked area, resulting in skid marks.

In order to prevent such skid marks, modifications have been made to increase the height of the skid button IB.

However, even if you take the trouble to raise the skid button IB,
Since the oxidized wave film (scale) S that falls off from the surface of the steel piece is deposited on the upper surface of the skid, the effectiveness of raising the button height is significantly impaired.

For this reason, conventionally, during periodic repairs when the heating furnace is stopped for a long period of time, a person enters the furnace and removes the scale using a broom or air blow.

However, with this method, it is necessary to lower the furnace temperature to a temperature that a person can enter, and to assemble a work scaffold, which is a long and difficult task that requires many carpenters, and requires a considerable amount of time and money. Become.

Furthermore, in the case of a continuous heating furnace, the chance of stopping the furnace for a long period of time is only about once a year, and during this period the furnace is operated with scale deposits remaining.

This invention was proposed in view of the above circumstances, and its purpose is to provide a method and device for removing scale that can remove scale in a short time without cooling the furnace unattended. It is in.

[Means for solving problems]

In the method for removing scale according to the present invention, after extinguishing a heating furnace, a movable body equipped with an air nozzle is moved in the longitudinal direction of the furnace using a walking beam method or the like while the furnace is kept heated. A jet stream that blows off scale on the skid, making it possible to remove scale in a short time without cooling the furnace.

Next, in the scale removal device according to the present invention, a large number of air nozzles that spray high-pressure air onto the skids are arranged at the bottom of the moving body that moves in the longitudinal direction of the furnace, corresponding to the plurality of skids, Heat-resistant piping capable of supplying air from the outside to the air nozzle is connected to the moving body, the moving body is moved by a walking beam method, etc., and the jet from the air nozzle is applied to the skid to blow away scale on the skid. This is what I did.

〔Example〕

The present invention will be described below based on an illustrated embodiment.

As shown in Figure 1, this is an example of a walking beam type heating furnace, in which a movable skid 1' is moved in a rectangular manner by a drive mechanism (not shown) relative to a fixed skid 1, thereby moving the billet. be.

The removing device according to the present invention includes a moving body 2 made of a thick steel plate,
A large number of air nozzles 3 are arranged at the bottom of the moving body 2, and heat-resistant piping 4 that can supply air to the air nozzles 3 from the outside is provided.

The moving body 2 may be a machined slab, and has a width that can cover the entire skid in the width direction of the oven, and a length that is larger than the movement distance of one cycle of rectangular motion, for example, a thickness of 25 mm.
01111. Width 1,000jllK, length 10,000m
It is said to be 1N.

A large number of air nozzle headers 5 parallel to each fixed skid 1 are buried in the lower part of the moving body 2, and a large number of air nozzles 3 are tilted into such nozzle headers 5 so that the jet stream hits the upper surface of the fixed skid 1. It is installed protrudingly.

A heat-resistant pipe 4A is connected to the ladder 5 to each nozzle, and a flexible heat-resistant hose 4B is connected to the heat-resistant pipe 4A via a joint 6, and the heat-resistant hose 4B is moved by winding it around a hose drum 7. It follows the movement of the body 2 and can supply air from the outside.

Here, the temperature inside the furnace is about 300 to 500°C,
Air is constantly vented to cool the pipes and hoses internally.

The flow velocity of the jet from the air nozzle 3 is 30~5°71/
s is appropriate, and the air supply source is approximately 5 to 6 Kq/
The pressure is set to al.

In the above configuration, for cleaning, after extinguishing the heating furnace, charge and charge steel billets during normal operation while keeping the furnace heated.
After extraction, the moving body 2 is transported into the furnace in the same manner as the scale S on the fixed skid 1 by the jet from the air nozzle 3.
Blow away.

That is, the movable body 2 is charged into the furnace from the charging side with a pusher, and while it is stopped on the fixed skid 1, the scale is blown away by a jet stream, and the movable body 2 is sequentially conveyed to the extraction side by the movable skid 1'.

When the extraction date advances, the movable skid 1' is reversed and the movable body 2 is transported back to the charging side. During this time, the air is constantly
Let it spray.

By using the method and device described above, the work can be completed unattended and almost automatically in about one hour, and therefore, it has become possible to descale the maintenance mortar once a month.

Additionally, by eliminating scale build-up, skid marks were reduced by half. Here, when skid marks occur on the steel billet, in order to maintain the minimum temperature of the steel billet, it is necessary to burn extra fuel to compensate for the temperature drop, resulting in fuel loss. If the temperature drop is reduced, this loss will be reduced.

With the present invention, skid marks are reduced by half, so 30 to 5
The temperature drop from 0°C will increase to 15-25°C, making it possible to save hundreds of millions of yen in fuel per year.

By the way, is the above a walking beam type addition F? Although the A furnace has been described, the present invention can also be applied to a heating furnace with a set of pushers, but in the case of a set of pushers, a transfer mechanism for transferring the transfer body is required.

〔Effect of the invention〕

As mentioned above, according to this invention, the scale on the skid is blown off by a jet from the moving body's air nozzle after the moving body is transported, so that the scale can be removed almost automatically and unattended in a short time. .

This eliminates scale build-up, reduces skid marks by half, and enables significant fuel savings in the furnace.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the outline of a walking beam heating furnace, Figures 2 and 3 are a cross-sectional view and a vertical cross-sectional view of a moving body according to the present invention, and Figure 4 is a cross-sectional view of a skid. be. 1.1'...Skid, IA...Skid post, IB...Skid button, IC.
...Insulating material, 2...Moving object, 3...
...Air nozzle, 4,4A. 4B...Heat-resistant piping, 5...Nozzle header, 6...Joint, 7...Hose drum Figure 3 tΔ Figure 4

Claims (2)

[Claims] (1) A method for removing scale deposited on the skid provided on the hearth of a continuous heating furnace, in which after extinguishing the heating furnace, a moving body equipped with an air nozzle is A method for removing scale on a skid, which comprises moving the furnace in the longitudinal direction and blowing off the scale on the skid with a jet from the air nozzle. (2) A removal device for removing scale deposited on a skid installed on the hearth of a continuous heating furnace, which sprays high-pressure air against the skid at the bottom of a moving body that moves in the longitudinal direction of the heating furnace. A device for removing scale on skids, characterized in that a large number of air nozzles are arranged corresponding to a plurality of skids, and heat-resistant piping capable of supplying air to the air nozzles from the outside is connected to the moving body.