JPH0576153B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an induction heating roller device.

(Prior art) In this type of device, even if a plurality of jacket chambers are installed independently from each other along the axial direction inside the peripheral wall of the roller in order to avoid application as a pressure vessel, the circumference of the roller It is required to prevent temperature differences from occurring along the circumferential direction.

In order to satisfy this requirement, another jacket chamber is installed inside the jacket chamber described above along the circumferential direction of the roller, and a gas-liquid two-phase heating medium is sealed inside each jacket chamber. It has already been proposed by the present inventor (Japanese Patent Application Laid-Open No. 62-4918
See publication. ).

However, in this case, if the inner jacket chamber is configured as an annular chamber along the circumferential direction of the roller, the heat medium will completely adhere to the outer wall surface of the jacket chamber during high-speed rotation. The entire inner wall surface becomes the evaporation surface for the heat transfer medium, and the entire inner wall surface becomes the condensation surface. Therefore, the conduction efficiency of latent heat released to this condensation surface is reduced.

Therefore, in the previously proposed inventions, a plurality of grooves extending in the axial direction of the roller are further provided on the outer wall surface of the inner jacket chamber, or a plurality of holes extending in the axial direction of the roller are formed in the jacket chamber. (See Figures 3 to 6 of the above publication).

This advantageously provides a condensation surface that is not covered by the heat transfer medium on the outer wall surface of the inner jacket chamber. However, the former configuration requires grooves and is therefore complicated to process, and the latter configuration requires two series of holes, one on the outside and one on the inside, and is troublesome to manufacture in either case.

(Problems to be Solved by the Invention) This invention provides a plurality of mutually independent jacket chambers extending in the axial direction on the peripheral wall of the roller,
It is an object of the present invention to simplify the structure of a jacket chamber for eliminating temperature differences along the circumferential direction of a roller in a configuration designed to eliminate temperature differences in the axial direction.

Another object of the present invention is to effectively promote uniform temperature of the roller.

(Means for Solving the Problems) This invention provides a plurality of first jacket chambers extending in the axial direction of the roller on the peripheral wall of the roller, and an annular groove communicating the first jacket chambers. Further, a hollow second jacket is provided inside each of the first jacket chambers and is independent of the other.
The present invention is characterized in that a two-phase gas-liquid heat medium is sealed inside each of the first and second jacket chambers.

(Example) An example of the present invention will be described with reference to the drawings.1
A roller is rotated by a rotational drive source (not shown), and a shaft 2 is connected to this roller, which is rotatably supported by a bearing 4 installed on a fixed platen 3. A magnetic flux generating mechanism 5 is arranged inside the roller 1. This magnetic flux generation mechanism 5 is
It mainly consists of an induction coil 6 and an iron core 7 around which it is wound, and this is supported by a fixed shaft 8.

A fixed shaft 8 is inserted into the inside of the shaft 2, and the shaft 2 is rotatably supported with respect to the fixed shaft 8 by a bearing 4A. When the induction coil 6 is excited by an AC power source, a current is induced in the peripheral wall of the roller 1,
This current causes the peripheral wall to generate heat. 9 indicates a lead wire for the induction coil. These configurations are not particularly different from ordinary devices of this type.

Reference numeral 10 denotes a first jacket chamber, which is formed by a hole extending in the axial direction of the peripheral wall 1A of the roller 1. A plurality of jacket chambers 10 are installed in parallel in the circumferential direction of the roller 1, and both ends thereof are communicated with each other by an annular groove 11 formed in the roller 1 along the circumferential direction. has been done. Reference numeral 12 denotes a gas-liquid two-phase heat medium that is vacuum-sealed within the jacket chamber 10.

Reference numeral 13 denotes a second jacket chamber, which is installed in a hollow shape inside the first jacket chamber 10. Specifically, a hollow pipe 14 with both ends closed.
is installed by inserting it into the jacket chamber 10. Each jacket chamber 13 is independent from the other, and a gas-liquid two-phase heat medium 15 is vacuum sealed therein.

The heat medium 12 sealed in the jacket chamber 10 is preferably a heat medium with a high boiling point, a relatively low vapor pressure even at high temperatures, and a small latent heat, such as an organic heat medium, and a heat medium sealed in the jacket chamber 13 is preferable. 15 is preferably one having a relatively low boiling point, high vapor pressure, and large latent heat, such as distilled water.

In the above configuration, the roller 1 is the induction heating mechanism 5
When heat is generated, the heat medium 12 in each jacket chamber 10 repeats evaporation and condensation. The jacket chamber 10 is formed into a groove 11 along the circumferential direction of the roller 1.
Based on the fact that the heat medium 12
Due to the aforementioned condensation, the temperature difference along the circumferential direction of the surface of the roller 1 is reduced.

Originally, in this type of induction heating roller device, the roller generates heat by a constant secondary short-circuit current flowing along the circumferential direction of the roller. Therefore, in the circumferential direction of the roller, uniform heat generation energy is generated at all locations, and theoretically, the temperature is also uniform.

However, in reality, even if uniform heat generation energy is generated, temperature differences may occur due to non-uniformity in the wall thickness of the roller, or thermal energy generated from paper, film, etc. from outside the roller. Due to the non-uniformity of the load, there is a tendency for temperature non-uniformity in the circumferential direction.

However, the temperature non-uniformity caused by these is not so large, and therefore the amount of thermal energy transferred to the heat medium 12 may be relatively small. It can be anything that has certain characteristics.

On the other hand, regarding the temperature distribution in the axial direction of the roller, via the shaft 2 and bearing 4 connected to the end of the roller,
A large amount of thermal energy flows through the fixed platen 3, and as a result, the temperature at the ends of the roller becomes lower than that at the center.

Conversely, if the width of the thermal load such as a film is shorter than the length of the roller in the axial direction, there will be areas on the roller surface where the thermal load is present and areas where the thermal load is not. occurs, and the temperature at the location where the thermal load is present begins to drop.

In this way, in order to equalize the temperature in the axial direction of the roller, a large amount of thermal energy is required to be transferred.
Furthermore, since the moving distance is long, the heat medium 12 with low latent heat described above is often insufficient. In order to eliminate this tendency, a jacket chamber 13 is provided in which a heat medium 15 having a high vapor pressure and a high latent heat is enclosed.

When a temperature difference occurs along the axial direction of the roller, the heat medium 12 that comes into contact with the high temperature part of the roller evaporates, and steam is generated in the axial direction and in the circumferential direction via the communication part toward the low temperature part of the roller. Of course, it creates a flow. However, at the same time, it also condenses on the outer wall surface of the hollow pipe that constitutes the jacket chamber 13, which faces the evaporated portion at a short distance, giving latent heat.

The heat medium 15 having high vapor pressure and high latent heat sealed inside the jacket chamber 13 actively evaporates in response to this latent heat of condensation, and steam is generated inside the jacket chamber 13 at high speed along the axial direction of the roller. flows. Then, it condenses on the wall surface of the jacket chamber 13 in the low temperature section, giving latent heat. Furthermore, the heat transfer medium 12 evaporates on the outer wall and condenses on the wall surface of the jacket chamber 10 facing a short distance away, imparting latent heat thereto.

The above-mentioned effect of the mutually related thermal energy transfer between the two jacket chambers 10 and 13 is expected to be effective in terms of shortening the moving distance of the heat medium 15 for temperature equalization in the circumferential direction as well. It goes without saying that it can be done.

Assume here that the roller 1 rotates at high speed and a large centrifugal force acts on the heat medium 12 in the jacket chamber 10. At this time, the heat medium 12 is in the jacket chamber 10.
Inside, it adheres along the wall surface portion on the outer peripheral side. This adhering wall surface becomes the evaporation surface of the heat medium 12.

However, each jacket chamber 10 is hole-shaped and has a closed surface with a circular cross-sectional shape. Therefore, a wall surface portion to which the heat medium 12 does not adhere exists on the inner peripheral side of the jacket chamber 10, and this wall surface portion becomes a condensation surface. Further, the heat medium 12 that has condensed into a liquid phase returns to the outer circumferential side due to centrifugal force.

Also, at this time, the heat medium 15 in the jacket chamber 13
The jacket chamber 13 exhibits a similar behavior under the action of centrifugal force, and thus the jacket chamber 13 forms a jacket chamber having both an evaporation surface and a condensation surface.

In this way, the jacket chamber 10 communicates through the groove 11 and therefore occupies a large volume, but contains a heat medium with a low vapor pressure.
On the other hand, the jacket chambers 13 are independent from each other, so although their volumes are small, they contain a high vapor pressure heat medium. Therefore, both jacket chambers come to be within the range of the regulation value as a pressure vessel based on the product of volume and vapor pressure.

Furthermore, both jacket compartments are interconnected,
Effectively works to equalize the temperature of the roller in both the axial and circumferential directions. Moreover, as previously proposed, the jacket chamber communicates along the circumferential direction of the roller, and in order to ensure a condensing surface for the heat medium, it is necessary to process the wall surface into an uneven shape or to form other holes. will disappear.

At this time, the outer circumferential surface of the jacket chamber 13 (the outer circumferential wall of the pipe 14) also acts as a condensing surface for the heat medium 12. This latent heat during condensation is transferred from the outer peripheral wall of the jacket chamber 13 to the outer periphery of the roller 1 via the end wall of the roller 1. Therefore, this also promotes the heat equalization effect along the circumferential direction of the roller 1.

Also, the distance between the jacket compartments 10 and 14 is small. Therefore, latent heat and sensible heat can be exchanged efficiently between the two chambers.

(Effects of the Invention) According to the invention described in detail above, a plurality of mutually independent jacket chambers are provided along the axial direction of the roller, and the jacket chambers are provided in order to reduce the temperature difference along the circumferential direction of the roller. Even if you set
The jacket chamber does not require any complicated processing, making it extremely easy to manufacture.
Also, since both jacket compartments are close to each other,
Heat transfer between the two chambers is now performed with extremely high efficiency, and the heat carriers in both jacket chambers interact effectively with each other, thereby effectively promoting equalization of the temperature of the rollers. When it becomes, it produces an effect.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention;
FIG. 2 is a cross-sectional view of the same. 1...Roller, 5...Induction heating mechanism, 10...
First jacket chamber, 11...groove, 12...heating medium, 13...second jacket chamber, 15...heating medium.

Claims (1)

[Claims] 1. A plurality of first jacket chambers extending in the axial direction of the roller are installed on the peripheral wall of a roller that is provided with a magnetic flux generation mechanism for induction heating inside, and an end of the first jacket chamber is connected to the They communicate through an annular groove provided along the circumferential direction of the roller,
Further, inside each of the first jacket chambers, second jacket chambers each having a sealed hollow shape and independent of each other are installed, and inside each of the first and second jacket chambers, vaporization and condensation are prevented. An induction heating roller device that encloses a repeating gas-liquid two-phase heating medium.