JPH052598Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention is a floating heat treatment furnace, more specifically, a heat treatment furnace equipped with a floating mechanism of a static pressure pad type. The present invention relates to an improvement for increasing the temperature of the floating heat treatment furnace, namely, a floating heat treatment furnace equipped with support rollers for maintaining the static pressure generated between the static pressure pad and the metal strip material.

<Prior art> Generally, when heat treatment such as annealing is performed on a metal strip, it is necessary to avoid damaging the surface of the metal strip and to obtain uniform quality. There is a method in which a metal strip is heat-treated in a furnace without support, that is, a metal strip is heated in a suspended state by blowing hot air from both the top and bottom surfaces of the strip. Proposed. The plenum chamber method and the static pressure pad method have been proposed as flotation means.

FIG. 3 is a drawing showing the specific structure of the static pressure pad method, in which a static pressure pad 4 is installed along the conveyance direction of the metal strip (strip) in the heating chamber and cooling chamber of the heat treatment furnace. strip) 3
It is arranged with a slight gap 6 between the two. A metal strip 3 is then passed through a pair of front and rear nozzles 5, 5 that open at the tip of each static pressure pad 4.
By blowing hot air at (Strip) 3 is provided to levitate it.

<Problems to be solved by the invention> However, in the above-mentioned hydrostatic pad type levitation method, the gap formed between the hydrostatic pad and the metal strip (strip) The problem is that a sufficient static pressure retention effect cannot be obtained due to the inability to reduce the space between the two.
namely, a hydrostatic pad and a metal strip.
In order to effectively maintain the static pressure generated between the static pressure pad and the metal strip, the distance between the pad and the metal strip should be made as small as possible. It is required to reduce the amount of hot air flowing out from the gap, but as shown in this example, it is necessary to reduce the size of the gap formed between the static pressure pad and the metal strip. In such cases, the amount of hot air flowing out from within the same space can be reduced, and a stable static pressure maintenance effect can be obtained. In this case, a new problem arises in that the metal strip comes into contact with the static pressure pad. Therefore, in order to maintain a constant static pressure between the static pressure pad and the metal strip (strip), an amount of hot air that exceeds the amount flowing out from the gap described above must be blown against the metal strip (strip). However, when a large amount of hot air is blown onto the metal strip, the atmospheric temperature inside the furnace decreases and the surface of the metal strip where the hot air is blown decreases. This leads to a new problem in that the temperature drops. In other words, hot air is normally blown onto the metal strip from the static pressure pad at a temperature lower (850°C) than the ambient temperature inside the furnace (1100°C) due to the temperature resistance of the blower. In this way, by blowing a large amount of hot air at a temperature lower than the ambient temperature inside the furnace, the temperature inside the furnace decreases by that amount, and the temperature of the surface of the metal strip material (strip) onto which the hot air is blown decreases. This will result in

This invention is an attempt to improve the above-mentioned problems by reducing the amount of hot air flowing out from the gap formed between the static pressure pad and the metal strip. The problem to be solved lies in making it possible to effectively generate static pressure with a small amount of hot air by reducing the amount of hot air as much as possible. That is, the present invention has a structure in which the front and rear openings of the gap formed between the static pressure pad and the metal strip are opposed to each other, and the tapered surface of the static pressure pad and the metal band material (strip) are opposite to each other. A metal band-shaped material (strip) is formed to interrupt the gap.
A supporting roller is placed horizontally, and the above static pressure pad and metal strip material (strip) are attached by the supporting roller.
The above-mentioned problem is solved by partially closing the front and rear openings between the is as follows.

<Means for solving the problem> The tapered surface of the static pressure pad and the metal strip material (strip) are arranged so as to face the front and rear openings between the pads formed between the static pressure pad and the metal strip material (strip). ) A support roller made of a metal band material (strip) is horizontally suspended so as to be freely rotatable, blocking the gap formed between the two.

The supporting roller is used between the static pressure pad and the metal strip, and between the static pressure pad and the metal strip.
By horizontally suspending the device with a space smaller than the space between the ends, it is possible to minimize the outflow of hot air blown into the space.

The support roller is installed to rotate at the same speed as the conveyance speed of the metal strip (strip), so that when the metal strip is drooped, the support roller is rotated at the same speed as the conveyance speed of the metal strip (strip). It is designed to be able to support the metal strip while rotating in synchronization with the conveyance speed.

<Function> The amount of hot air blown into the gap formed between the static pressure pad and the metal strip (strip) can be suppressed to a small amount. The amount of spray can be reduced. That is, the static pressure can be maintained at the first level by blowing a small amount of hot air, thereby preventing a drop in the temperature of the atmosphere inside the furnace and a drop in the temperature of the metal strip.

If the metal strip becomes undulating or drooping, it can be supported by support rollers. That is, the metal strip can be conveyed without coming into contact with the static pressure pad.

<Examples> Specific examples of the present invention will be described below with reference to illustrative drawings.

FIG. 1 is a cross-sectional view schematically showing a floating heat treatment furnace. In the heat treatment furnace, 1 is a heating chamber, 2 is a cooling chamber, and heating chamber 1 is equipped with a heating device such as a heater or a radiant tube burner. A source 8 is provided. The heat treatment furnace is provided with a conveyance passage for a metal strip 3 passing through the heating chamber 1 and cooling chamber 2, and in the heating chamber 1, a static pressure pad (float nozzle) is installed on the lower surface of the conveyance passage. ) 4 are arranged at regular intervals with gaps 6 between them and the metal strips 3, respectively. The static pressure pad 4 has a hollow, substantially trapezoidal vertical cross section in the longitudinal direction of the furnace, and a pair of front and rear tapered surfaces 9, 9 are formed at its tip. A pair of front and rear nozzles 5, 5 are installed in opposite directions with appropriate inclination angles, so that hot air can be blown toward the metal strip 3 from both nozzles 5, 5. established in That is, by blowing hot air toward the metal strip 3 from both nozzles 5, 5, static pressure is generated in the gap 6 formed between the metal strip 3 and the metal strip 3. It is provided so that the metal strip 3 can be levitated by static pressure.
Further, the tip of the static pressure pad 4 is arranged to face the front and rear openings of the gap 6, and is connected to tapered surfaces 9, 9 of the static pressure pad 4 and a metal strip 3.
A pair of support rollers 7, 7 are placed horizontally across the gap 10, 10 between the static pressure pad 4 and the metal strip 3. The material (strip) 3 is horizontally suspended with a dimension L' smaller than the distance L of the gap 6 formed between the material (strip) 3 and the material (strip) 3. Further, the support rollers 7, 7 are provided so as to be driven to rotate at the same speed as the conveyance speed of the metal strip 3. That is, when the metal strip 3 comes into contact with the support rollers 7, 7,
The support rollers 7, 7 are provided so as to be able to rotate in synchronization with the conveyance speed of the metal strip 3.

Next, its effect will be explained.

After a part of the atmospheric gas (hot air) inside the furnace is taken out of the furnace and cooled to a constant temperature (850°C), it is sent to each static pressure pad 4 through the rotation of the blower, and the static pressure is reduced in this way. By blowing the hot air sent into the pad 4 against the metal strip 3 from both nozzles 5, 5, a gap 6 is formed between the static pressure pad 4 and the metal strip 3. Static pressure is generated at the pad 4, and this static pressure has the effect of levitating the metal strip 3. The tip of the static pressure pad 4 is located opposite to the front and rear openings of the gap 6. Let it be and the above〓
Since the support rollers 7, 7 are horizontally suspended across the gap 10, the support rollers 7, 7 are provided with the above-mentioned gap 6 between the metal strip 3 and the metal strip 3.
By being horizontally suspended with a distance L' smaller than the distance L between the two, the hot air blown onto the metal strip 3 from the nozzles 5, 5 as described above is The amount flowing out from the front and rear openings of the gap 6 can be suppressed to a small amount. That is,
Metal strip material (strip) 3 from nozzles 5, 5
It is possible to increase the yield of hot air blown onto the surface. Since the yield of hot air can be increased in this way, the effect of maintaining static pressure can be obtained with a small amount of hot air blown.

In addition, as mentioned above, support rollers 7, 7 are horizontally suspended at the tip of the static pressure pad 4 so that they can rotate in synchronization with the conveyance speed of the metal strip. If the metal band material (strip) 3 in the middle is wavy or droops, the same metal band material (strip)
3 can be supported by the support rollers 7, 7. That is, contact with the static pressure pad 4 can be prevented.

In the above embodiment, the static pressure pads are provided only on the lower surface of the metal strip (strip), but it is also possible to arrange a pair of upper and lower static pressure pads facing each other between the metal strips. It is.

<Effects of the invention> The invention is constructed as described above.
As mentioned above, it is formed between the tapered surface of the static pressure pad and the metal strip (strip), facing the front and rear openings between the pads and the metal strip. The support roller is formed between the static pressure pad and the metal strip (strip), and the support roller is formed between the static pressure pad and the metal strip (strip). By horizontally suspending the space between each other with a space smaller than the space between each other, it is possible to suppress the amount of hot air blown into that space to a small amount. It has now become possible to enhance the effect of maintaining static pressure. In other words, it has become possible to generate static pressure with a small amount of hot air blowing. By being able to reduce the amount of hot air blown onto the metal strip, the temperature of the atmosphere inside the furnace and the surface of the metal strip where the hot air is blown can be prevented from decreasing. I was able to do something.

In addition, in the case of the present invention, as described above, the tapered surface of the static pressure pad and the metal strip material are arranged so as to face the front and rear openings of the gap formed between the static pressure pad and the metal strip material (strip). The support roller is placed horizontally so that it can rotate in synchronization with the conveyance speed of the metal strip (strip), blocking the gap formed between the metal strip and the metal strip. By making it possible to use the support rollers to support the material if it becomes undulating or sagging on the way, the metal strip can be transported without coming into contact with the static pressure pad. I was able to do it.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view in the longitudinal direction of the furnace schematically showing a floating heat treatment furnace according to the present invention, and FIG. 2 is an enlarged vertical sectional view in the longitudinal direction of the furnace of a static pressure pad portion.
Further, FIG. 3 is a diagram showing a conventional structure, and is an enlarged longitudinal cross-sectional view of the static pressure pad portion in the furnace length direction. 1... Heating chamber, 2... Cooling chamber, 3... Metal strip material (strip), 4... Static pressure pad (float nozzle), 5... Nozzle, 6, 10... Between,
7...Support roller, 8...Heat source, 9...Tapered surface, L, L'...〓dimension.

Claims (1)

[Scope of utility model registration request] There should be an appropriate distance between the metal strip material being transported inside the furnace.
In a floating heat treatment furnace in which static pressure pads are arranged at regular intervals along the conveyance direction, the front and rear openings between the pads and the metal strip material are formed between the static pressure pads and the metal strip material. The support roller is placed horizontally across the gap formed between the tapered surface of the static pressure pad and the metal strip material, and the support roller is placed between the metal strip material and the static pressure pad. and the metal strip-shaped material so that the space between them is smaller than the distance between them, and the metal strip-shaped material is horizontally hung so as to be able to rotate in synchronization with the conveyance speed of the metal strip-shaped material. A floating heat treatment furnace equipped with support rollers for maintaining static pressure.