JPH0822416B2 - Steam far infrared heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention heats a member coated with far-infrared emitting ceramics by heat of steam to emit far-infrared rays, and the far-infrared rays are dried. The present invention relates to a steam type far-infrared heater used for irradiating and drying the steam.

[Conventional technology]

For example, when drying a coated product such as a woodwork product or a resin molded product, if the temperature of the heater is raised to increase the drying speed, the woodworked product, the resin molded product, etc. that is the coated product due to high temperature heating. May be thermally deformed or deteriorated.

For this reason, it is preferable that the above-mentioned coating material which is unfavorable to high temperature is dried at a low heating temperature. However, if the heating temperature of the heater is lowered, the drying efficiency will drop sharply.

On the other hand, it is known that when a coating material containing a resin as a main component is irradiated with far infrared rays, the coating material is efficiently absorbed, and thus the coating material dries quickly.

[Problems to be Solved by the Invention]

The present invention mainly reduces the surface temperature by increasing the radiation area of far-infrared rays in the case of drying an object to be dried that is thermally deformed or deteriorates when heated at a high temperature as described above. Then, the radiant heat amount required as a whole is secured, thereby reducing the temperature difference with the object to be dried, and it is an object to provide a steam type far infrared heater capable of performing low temperature drying. is there.

[Means for solving the problem]

The steam far-infrared heater according to the present invention for solving the above-mentioned problems is a large number of steam steel pipes for passing steam, and the surface is coated with far-infrared radiation ceramics, and has a shape of the steam steel pipe. Corresponding multiple semi-cylindrical parts are provided at predetermined intervals and consist of a set of two corrugated housing plates, and each semi-cylindrical part of one set of housing plates is used for steam steel pipes. Sandwich it,
It is characterized in that the pair of housing plates are integrally joined.

[Operation of the invention]

Heat is conducted from the steel pipe heated by the steam to the housing plate, and the housing plate is heated. Since the surface of the housing plate is coated with far-infrared radiation ceramics, the far-infrared rays are emitted by heating the housing plate, and the far-infrared rays irradiate and heat the object to be dried,
Thereby, it is dried.

On the other hand, the pair of housing plates that sandwich the steel pipe for steam function as a kind of fin for the steel pipe for steam, so that the heat transfer area becomes large and the radiant heat transfer area becomes large. The amount of heat transferred to the air in contact therewith also increases. As a result, the temperature of the air is increased, and the material to be dried is heated by the heat transfer effect of the convection of the air, and is auxiliary dried.

In this way, since the steel pipe for steam is sandwiched by each half-cylindrical portion of the housing plate of a set of two far-infrared radiating ceramics coated on the surface, the one set of housing plates is integrally joined, Since the surface area (radiation area) of the far-infrared heater is large, the required amount of radiation heat can be secured as a whole even if the surface temperature is lowered. Therefore, it is possible to perform low temperature drying with a small temperature difference from the material to be dried without lowering the drying efficiency.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to examples.

1 to 3, a steam type far-infrared heater (hereinafter simply referred to as heater) H according to the present invention
Is a large number of steam pipes for passing steam 1
And a set of two housing plates 2.

The housing plate 2 has a corrugated plate shape in which a large number of semi-cylindrical parts 3 corresponding to the shape of the steel pipe for steam 1 are provided in the length direction at predetermined intervals along the width direction by pressing a steel plate. It is molded into. Many semi-cylindrical parts 3
Are provided on the same side of the housing plate 2. The flat plate portion 4 between the adjacent semi-cylindrical portions 3 of the housing plate 2
The air circulation holes 5 are provided at predetermined intervals along the length direction. The surface 2a of the housing plate 2 is coated with far-infrared radiation ceramics such as zirconia and alumina with a thickness of 0.01 to 0.2 mm.

When two housing plates 2 are set as a set, the steel pipe 1 for steam is sandwiched between the semi-cylindrical parts 3 of each housing plate 2, and the flat plate parts 4 of each housing plate 2 are spot-welded (W) to be integrally joined. The semi-cylindrical portion 3 of the housing plate 2 is in close contact with the outer peripheral surface of the steam steel tube 1 to hold it. In this way, the positions of the multiple steam steel pipes 1 forming the tube row are determined by the semi-cylindrical portion 3 of the housing plate 2, and the multiple steam steel pipes 1 and the set of housing plates 2 are separated from each other. Assembled together. The means for integrally joining the two housing plates 2 is not limited to spot welding, and may be a Holt, for example.

As shown in FIG. 4, the heaters H having the above-described structure are arranged on both left and right sides of the stationary furnace 6, and on the upper side,
Steam is poured onto the steam steel plate 1 to dry the coated object 8 placed on the receiving shelf 7.

In the stationary furnace 6 shown in the figure, a discharge duct 11 and a suction duct 12 are attached inside the furnace wall 9, and a fan 13 circulates air in the furnace to generate convection.
This eliminates uneven temperature distribution in each part of the furnace. Close to the ducts 11 and 12 for discharge and suction, heater H
However, since the flat plate portion 4 of the housing plate 2 constituting the heater H is provided with the air circulation hole 5, the heater H does not interfere with the air circulation in the furnace. The air smoothly convects through the holes 5.

When steam is flown through the steam steel pipe 1 that constitutes the heater H to heat the steam steel pipe 1, the steam steel pipe 1 is in close contact with the outer periphery of the steam steel pipe 1. Heat is conducted to the plate 2 and it is heated. Since the surface 2a of the housing plate 2 is coated with far-infrared radiation ceramics, the far-infrared rays are radiated by heating the housing plate 2, and the far-infrared rays irradiate the coating object 8 held by the receiving shelf 7. , The paint is heated. The coated article 8 is mainly heated by the irradiation of far infrared rays and dried.

Further, the housing plate 2 sandwiching the steel pipe for steam 1 acts as a fin with respect to the steel pipe for steam 1, so that the heat transfer area becomes large and the air temperature in the furnace in contact with this is increased, and Since the convection is generated in the air in the furnace by the action of the fan 13, the coating object 8 is heated by the heat transfer due to the contact with the air whose temperature has been raised, and is auxiliary dried.

Further, since the surface 2a of the housing plate 2 that constitutes the heater H is coated with far-infrared radiation ceramics, the surface area (radiation area) as a far-infrared heater is large, and the surface temperature is lowered. Also, the amount of radiant heat required for drying can be secured. Therefore, even if the surface temperature of the heater H is lowered to reduce the temperature difference with the coated object 8, the coated object 8 can be dried without lowering the efficiency. Therefore, the coated object 8 is not overheated during the drying.

In the above embodiment, the housing plate 2 has a flat plate shape, but the housing plate 2 may be bent in accordance with the shape of the object to be heated so as to improve the drying efficiency.

Further, the heater according to the present invention is suitable for drying a coating material using a urethane coating or an alkyd coating which easily absorbs far infrared rays, and FIG. This is an example of use in which the coated article is dried by using the heater of the present invention after applying the intermediate coating and the top coating, respectively, and then polished to obtain a product.

The same (b) is the water content of each paint which is undercoated, intermediate-coated, and closed to the object to be coated by the heater according to the present invention as the preheating drying before the top coating with the ultraviolet curing type coating and the ultraviolet curing drying. It is an example of use when drying
The same (c) is an example of use when the heater according to the present invention is used to pre-dry the coated object before coating with the ultraviolet curable paint. This is an example of use in a case where after coating, the solvent in the coating material applied to the object to be coated is dried by the heater according to the present invention, and then the coating film is cured by irradiation with ultraviolet rays.

The heater according to the present invention is most suitable for low-temperature drying of coated products such as woodworking products and resin molded products.
The material to be dried is not necessarily limited to these, and is also suitable for drying inks printed on paper and dyes dyed on fibers, which are preferably dried at low temperature.

〔The invention's effect〕

(1) Even if the surface temperature (radiation area) of the far-infrared heater becomes large and the surface temperature is made low, the necessary irradiation heat quantity can be secured, so that the temperature of the material to be dried can be maintained without lowering the drying efficiency. Low temperature drying with a small difference can be performed. Therefore, high-temperature heating is suitable for drying a coated product such as a woodwork product or a resin molded product that is easily thermally deformed or deteriorated.

(2) Since the housing plate sandwiching the steel pipe for steam functions as a fin of the steel pipe for steam, the heat transfer area becomes large and the air in contact therewith is heated by heat transfer, and the action of this heat transfer Also, since the material to be dried is supplementarily dried, the drying is promoted.

(3) The heat of the steel pipe for steam heated by the steam is conducted to the housing plate coated with the far-infrared radiation ceramics by conduction heat transfer, and the far-infrared ray is thereby radiated. It is sufficient if the space between the two can be increased and the required thickness of the housing plate can be ensured. Therefore, the heater is light in weight and easy to handle.

(4) A large number of steam steel pipes and a set of two housing plates are integrally assembled into one unit, so that the heater according to the present invention is installed in the drying oven or the dryer body. Even in the case of mounting, it is not necessary to mount the steel pipes for steam one by one, and the mounting becomes easy.

[Brief description of drawings]

1 is a sectional view of a heater H according to the present invention, FIG. 2 is an enlarged sectional view of the same, and FIG. 3 is a large number of steel pipes for steam 1 constituting the heater H according to the present invention, FIG. 4 is an exploded perspective view of a pair of housing plates 2; FIG. 4 is a sectional view of a stationary furnace 6 including a heater H according to the present invention;
FIGS. 9 (a) to 9 (d) are process charts for performing various drying operations using the heater H according to the present invention. The explanation of the reference numerals of the main parts constituting the present invention is as follows. H: Heater, W: Spot welding 1: Steel pipe for steam, 2: Housing plate 3: Semi-cylindrical part (semi-cylindrical part) of housing plate 4: Flat plate part of housing plate 5: Air flow hole

Claims (2)

[Claims] 1. A large number of steam steel pipes for passing steam and a far-infrared radiation ceramics coated on the surface, and a large number of semi-cylindrical portions corresponding to the shape of the steam steel pipes are arranged at predetermined intervals. It is composed of two sets of corrugated plate-shaped housing plates, and the steel pipes for steam are sandwiched between the semi-cylindrical parts of the one set of housing plates, and the one set of housing plates are joined together. Steam type far infrared heater characterized by being. 2. The steam type far infrared heater according to claim 1, wherein an air circulation hole is provided in a flat plate portion of the pair of housing plates integrally joined together.