JPS6119430Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a drying device for veneer veneer (hereinafter referred to as veneer).

Conventionally, as disclosed in "Veneer Drying Apparatus" (Japanese Patent Publication No. 44-29027), a drying apparatus that wraps a veneer around a heating roll and dries it can, in principle, directly transfer and receive heat. It has various advantages over existing hot air circulation type drying equipment such as roll dryers and net dryers, such as high thermal efficiency and short drying time. In addition to the difficulty in stabilizing the veneer conveyance between each heating roll when multiple heating rolls are connected or close together and the drying distance is set to be long, the peripheral surface of the heating roll If the veneer is not brought into sufficient contact with the veneer, a heat insulating layer of air will be present, and the above advantages may be halved.

That is, as is well known, undried veneer has a flat shape, but as drying progresses, there is a tendency for cracks to occur due to local shrinkage errors, etc., especially when using the direct heating method as described above. In the case of drying equipment, because the heat exchange is highly efficient, shrinkage error occurs between parts with relatively good contact and parts with poor contact, and abrasion is likely to occur. When this occurs, the heat exchange becomes even more uneven, and the abrasion becomes more and more enlarged, causing the veneer to lift up in different parts.
There is a possibility that the above-mentioned advantage will be halved due to the presence of a heat insulating layer of air in the local area.

Therefore, we developed a ``veneer veneer drying device'' (1973-).
As disclosed in Japanese Patent Publication No. 23510, a so-called suction drum type device has been proposed in which the inside of a heating roll is subjected to negative pressure to adsorb the veneer to the peripheral surface. When multiple heating rolls are connected or close together and a long drying distance is set, negative pressure will be applied to both sides of the veneer when the veneer is transferred between each heating roll. Therefore, transportation becomes extremely unstable, and defects that cause inconveniences such as the edges of the veneers folding over each other, or, in the case of narrow veneers, misalignment due to their own weight, etc., are the basic defects. In the case of veneers with defects such as small width veneers, curls, and chips, it is difficult to set negative pressure caused by the suction of a large amount of air from these defects, and the difficulty of setting negative pressure. Since defects such as hole clogging are inherent, only high-quality veneers that exhibit a perfect band shape and have no defects are
It was practically unusable.

On the other hand, "thin plate drying and smoothing equipment" (registered utility model)
As disclosed in Japanese Patent Publication No. 44571, a method has been proposed in the past in which two lines of endless guiding cloth are wound around the circumferential surface of a plurality of heating rolls in a meandering manner so that the veneer can be conveyed smoothly. However, in such a method, an insulating material called induction cloth is interposed between the veneer and the heating roll, which drastically reduces the advantage of direct heating, and furthermore, Since the dissipation of steam is also hindered by the presence of the induction fabric, the thermal efficiency is extremely low and the required drying time is inevitably long, so its practical value is extremely low. At present, neither type of equipment has been put into practical use in factories.

The present invention was developed to eliminate the deficiencies of the conventional methods, and through repeated experiments and insights, it is well adapted to the characteristics of veneer, effectively demonstrating the advantages of direct heating, and It has been completed as a drying device that can dry well, and specifically,
The veneer is transported in a direction perpendicular to the fibers by placing multiple linear bodies from one side of the veneer and the other side at intervals of approximately 150 times the thickness of the veneer or less. At the same time, the linear body is configured to hold the veneer in contact with a plurality of heating rolls, and on the outer peripheral surface of the heating roll, the veneer is located on the heating roll side of the veneer. The filament is placed in a groove formed in the heating roll so that it is submerged from the circumferential surface, and the heating roll is driven. It is designed to dry.

According to the drying apparatus configured as described above, the veneer is brought into direct contact with the circumferential surfaces of a plurality of heating rolls one after another, and the advantages of direct heating are effectively exhibited, resulting in good thermal efficiency and short drying time. Not only can the veneer be shortened, but also when the veneer is transferred between the heating rolls, it is held between one side and the other side by the linear bodies, so it can be shortened. Whether it is a veneer or a veneer with defects such as curls or chips, it can be transported smoothly without any problems.
There is no risk of inconveniences such as folding or misalignment of the ends, and the presence of the linear body is extremely effective in preventing burrs caused by shrinkage errors, etc. There is no risk that the advantages of direct heating will be lost.

In other words, in order to achieve good contact with the heating rolls that overlap almost the entire surface of the veneer, promote uniform heat exchange, and prevent lifting caused by abrasion, it is not necessary to apply heat over the entire surface of the veneer. There is no need to press, and the stiffness of the veneer in the fiber direction is greater than in the direction perpendicular to the fibers, and it tends to increase or decrease approximately in proportion to the thickness of the veneer. If the fibers are conveyed in a direction perpendicular to the fibers using linear bodies arranged at intervals of approximately 150 times the plate thickness or less, good drying can be achieved while preventing abrasion to a practically acceptable level. This was revealed through experiments during the development process of the present invention, and by adopting such a configuration, not only the vapor dissipation during drying process but also the required number of linear bodies can be reduced. Since it is possible to simplify the device including reduction in the amount of noise, it is extremely useful in practice.

Hereinafter, the present invention will be described in more detail with reference to an example of implementation illustrated in the drawings.

Fig. 1 is a schematic side view of the drying device according to the present invention, Fig. 2 is a partial sectional view taken along the dotted line XX in Fig. 1, and Fig. 3 is a partial front view of Fig. 1. .

Reference numeral 2 in the figure indicates a plurality of heating rolls by which the cylindrical portion 8 is heated by introducing heating steam into the cylindrical interior 9, etc., which are arranged close to each other as shown in the figure, and are driven by a drive mechanism (not shown). Driven in the direction of the arrow, a linear body 3 (described later) is caused to travel, and the veneer 1 in contact with the cylindrical portion 8 is heated and dried.

3 is made of coil springs, heat-resistant resin, etc., which are arranged in plural numbers on one side and the other side of the veneer 1 at intervals P that are approximately 150 times or less than the thickness T of the veneer. A linear body 3 having some elasticity, and on the outer peripheral surface of each heating roll 2, a linear body 3 located on the heating roll side of the veneer 1 is formed on each heating roll 2. They are positioned in the grooves 7 and submerged from the circumferential surface, and if necessary, are wound with tension applied as shown in the figure through the turning rolls 5, and a plurality of heated A conveyance path is formed along the circumferential surface of the roll 2 to convey the veneer 1 in a direction perpendicular to the fibers.

4 is a conveyor for carrying in the veneer 1, and 6
is a conveyor for carrying out the veneer 1.

For example, when a veneer 1 is carried into the drying device constructed as described above via a carrying-in conveyor 4, the veneer 1 is dried.
The fibers are transported along the peripheral surfaces of a number of heating rolls 2 in a direction perpendicular to the fibers, successively heated and dried by each heating roll 2, and then discharged via a discharge conveyor 6. As is clear from the figure,
When the veneer 1 is transferred between each of the heating rolls 2, it is held on one side and the other side by the linear bodies 3. Therefore, even if the veneer is narrow or has defects such as warping or chipping, it can be transported smoothly without any hindrance, and there is no risk of problems such as folding over of the ends or misalignment.

Moreover, when paying attention to the outer peripheral surface of each heating roll 2, the linear body 3 located on the heating roll side of the veneer 1 is located in the groove 7 formed in each heating roll 2 and is sunk from the peripheral surface. Because of this, the veneer 1 is brought into direct contact with the circumferential surface of each heating roll 2, and the advantages of direct heating are effectively exhibited, so it goes without saying that the thermal efficiency is good and the drying time is short. The linear body 3 located on the side opposite to the heating roll of the veneer 1 has a thickness T of the veneer 1.
Since the veneer 1 is pressed against the circumferential surface of each heating roll 2 at a distance P that is approximately 150 times or less than There is no risk that the benefits of heating will be lost.

In addition, the fact that the interval P between the linear bodies can be set relatively wide in this way not only improves vapor dissipation during drying but also simplifies the equipment, including reducing the number of linear bodies required. Of course, since the reduction in the transfer area can be kept to a minimum, there is almost no decrease in thermal efficiency.
This is extremely useful in practice.

The linear body preferably has some elasticity, such as a coil spring, but other materials such as a steel belt or wire may also be used. However, if the linear body contains iron and the iron reacts with the resin of the veneer, there is a risk that dark marks may remain on the surface of the veneer. It is preferable to select a material that does not easily react with the resin component of the veneer, such as eg, or it is effective to apply a plating made of nickel, chrome, etc. to prevent reaction.

In addition, the positional relationship of each linear body between one side and the other side of the veneer can be set in a desired relationship, for example, to stabilize the veneer transport between the heating rolls. Naturally, if emphasis is placed on dryness, it is preferable to have the grooves as close as possible, but in order to proactively avoid the occurrence of uneven drying due to the presence of the grooves, it is possible to shift the grooves slightly as shown in the example above. is practical, and on the other hand,
Although not shown in the drawings, it has been confirmed from experimental results that if emphasis is placed on preventing fringing of the veneer, it is preferable to mutually shift the veneers by about half the distance P.

As is clear from the above, the drying device according to the present invention is well suited to the characteristics of the veneer, and can effectively dry the veneer while effectively demonstrating the advantages of direct heating. The practical implementation effects are extremely large.

[Brief explanation of the drawing]

The drawings are for explaining the present invention, and FIG. 1 is a schematic side view of the drying device according to the present invention;
2 is a partial sectional view taken along the dotted line XX in FIG. 1, and FIG. 3 is a partial front view of FIG. 1. 1... Single plate, 2... Heating roll, 3... Linear body, 4... Loading conveyor, 5... Turning roll, 6
... Carrying out conveyor, 7... Groove formed in the heating roll, 8... Cylindrical portion, 9... Inside the cylinder.

Claims (1)

[Scope of utility model registration request] A plurality of linear bodies are placed from one side of the veneer veneer and the other side at intervals of approximately 150 times the thickness of the veneer veneer or less, and the veneer veneer is perpendicular to the fibers. The veneer veneer is held in contact with a plurality of heating rolls by the linear body, and the veneer veneer is heated on the outer peripheral surface of the heating roll. The linear body located on the roll side is positioned in a groove formed in the heating roll so that it is submerged from the peripheral surface, and the heating roll is further driven. A drying device for veneer veneers that is characterized by drying while being transported in orthogonal directions.