JPS63210591A - Heater for tabular article - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a heating device for a plate-shaped object.

Conventionally, heating devices for heat-treating plate-like materials such as plywood and veneers have been used, for example, "continuous plywood manufacturing equipment" (Japanese Patent Publication No. 49-32051) and "continuous press drying equipment for materials such as thick veneers". ” (Utility Model Publication No. 59-34872)
As disclosed in "Drying Apparatus for Plate Materials" (Japanese Patent Publication No. 12547/1983), a pair of endless belts are arranged opposite each other so as to be able to run intermittently to form a conveyance path for plate-like materials, and each endless belt is A process in which a plate-like object is intermittently conveyed by an endless belt, in which a pair of heating plates, each consisting of an arbitrary number of plates, are arranged opposite each other, with at least one of the surfaces movable up and down. There is a known heating device that heats a plate-like object through an endless band using a heating plate, and in principle, it has better thermal efficiency than other heating devices such as hot air ventilation type heating devices. Although it was expected that it would contribute to the development of industry, in reality it had various drawbacks and very few examples were put into practical use.

Therefore, the inventor of the present invention first pointed out that one of the biggest drawbacks that hindered the generalization of the above-mentioned type of device is that conventional devices of this type cannot accurately grasp the running characteristics of the endless belt. First, we analyzed and clarified that the device itself became long because it adopts a configuration in which a pair of endless bands are placed vertically opposite each other to form one level conveyance path, and we also solved the aforementioned drawbacks. As a countermeasure to reduce this problem, we proposed a new type of device that forms a unique meandering conveyance path and has multiple pairs of heating plates, as will be detailed later. However, during the development process of the present invention, it was discovered that there was another problem common to this type of device.

That is, when, for example, an undried veneer is dried using the apparatus known in the above-mentioned publications, local drying unevenness occurs in the dried veneer. Conventionally, the cause of this is the moisture content of the undried veneer. It was recognized that the outbreak was inevitable due to the heterogeneity of the

However, as a result of detailed analysis and examination of the temperature distribution of dried veneer by the inventor of the present invention, it became clear that there are local temperature differences, and some of the factors that cause the drying unevenness are localized. It was analyzed that there is a large temperature difference.

Therefore, we further investigated the cause of the temperature difference, and found that the direct cause was that the frequency of heating differed depending on the local area of the undried veneer, and the remote cause was that the temperature difference in the known equipment It turned out that the problem lies in the irrationality of the structure.

In other words, in the known device, the length of the heating surface of the heating plate with respect to the running direction of the endless belt and the conveyance distance per endless belt did not have a specific relationship and were chaotic. Furthermore, the number of times that the heating plate heats the undried veneer varies depending on the area of the undried veneer, which is one of the causes of uneven drying.

On the other hand, this phenomenon has been overlooked in the past because it is difficult to clearly identify it from its appearance or due to a combination of other factors such as rough skin of the veneer. This also occurs when heat treatment is applied to plywood, and as a result, it becomes part of the cause of uneven adhesion, and the actual situation is much the same in other uses as well.

The present invention was developed in order to easily solve the newly identified problems mentioned above, which are common to this type of device, including fully distributed type devices, with a rational configuration. , Specifically, a pair of endless strips are arranged opposite each other so as to run intermittently to form a transport path for a plate-like object, and an appropriate number of pairs of heating plates, each consisting of an arbitrary number, are placed inside each endless strip. are arranged opposite to each other so that at least one of the surfaces can be raised and lowered, and in the process of intermittently conveying the plate-like object by the endless belt, the plate-like object is conveyed by the heating plate through the endless belt. A heating device that repeatedly heats the heating plate, in which the length of the heating surface in the running direction of the endless belt is an integral multiple of the conveyance distance of the endless belt per time. The length of the heating surface of the heating plate with respect to the running direction of the endless band is related to the conveyance distance per one time of the endless band so that the length substantially extends in the running direction of the endless band. This heating device is characterized by:

According to the above configuration, in any pair of heating plates, the length of the heating surface in the running direction of the endless belt is greater than or equal to an integral multiple of the conveyance distance of the endless belt per time. Therefore, since the endless belt is continuous in the running direction, any part of the plate-shaped object that is intermittently conveyed by the endless belt is heated the same number of times by the heating plate, so that one local area is not heated. This is effective because there is no risk of inducing large temperature differences and the heat treatment is performed evenly.

The present invention will be described in further detail below with reference to an example of implementation illustrated in one drawing.

As shown in a schematic side view in FIG. 1, the heating device according to the present invention is configured to stretch a plurality of rolls 1aalb and 2a and 2b, respectively, in order to form a conveyance path for a plate-shaped object, for example, a veneer 5. and the surface is either one of rolls la or 1b and 2a
or 2b, a pair of endless bands 1 and 2, which are made to travel intermittently in the direction of the arrow in the figure by a drive source (not shown) with a conveyance distance P per time, and the endless bands l and 2b. A fixed heat source 3 having a continuous length of heating surface in the running direction of 2 and fixedly disposed inside the endless*2, and the fixed heat source l! With approximately the same length facing the heating surface of 13,
Split movable heating elements 4a each have a heating surface that is substantially continuous in the running direction of the endless bands 1 and 2, and are arranged so as to be able to rise and fall inside the endless band 1 via an elevating mechanism (not shown). 4b・4
C.4d, fixed surface 3 and movable surface 4.
The length L of the heating surface of a・4b 4c*4d is the endless band l・
It is characterized in that they are associated so as to be an integer multiple (in the embodiment, five times) of the transport distance P per transport of 2.

According to the heating device having the above configuration, the veneer 5 carried in from the left side of the figure is intermittently conveyed by the endless belt lφ2, and is heated by the movable heat fi4a synchronized with the stop of the endless belt lφ2.
Every time s4b * 4c * 4d descends, it is repeatedly heated through compression by the fixed heating element 3 and the movable heating elements 4a, 4b, 4C, and 4d via the endless band lφ2, and is eventually carried out to the right in the figure. There will be a pair of fixed heat sinks 3 and movable heat sinks 4.
The length of the heating surface of a, 4b, 4C, and 4d is the endless band l.
Since it is an integral multiple of the conveyance pressure #P per transfer of 2,
Since any part of the veneer 5 is heated by the fixed heat 513 and the movable heat heaters 4a-4b, 4C, and 4d the same number of times, there is no possibility of local temperature differences being induced.
It is effective because it is heated evenly.

To prove this by giving an example, for example, as illustrated in FIG. 2, a veneer 5 having an arbitrary length intersection has a length fL2 inward with respect to the front end A of a fixed heat l113. Assuming that it is carried in leaving the outside of the fixed heat source 3, it reaches the rear end B of the fixed heat source 3 through the process shown in the figure, but the length L between A and 8 is
Since the setting is 5P, the lengths located outward and inward with respect to the rear end B are 11-12, respectively, so as a result, in any part, there is no fixed heat. The movable heat source is heated the same number of times (a total of 5 times in the example).

Next, the embodiment illustrated in FIG. 3 avoids the instability of veneer transport caused by the bending of the pair of endless bands, which has been considered difficult in the past, or the trajectory caused by the bending of the pair of endless bands. In order to avoid deviations from the process, reduce the length of the device itself to about 1/3 of the conventional length, and improve practicality, the applicant first developed a ``veneer veneer drying device'' ( Patent application 1986-23767
No. 9) - ``Method for adjusting the trajectory of an endless band in a drying device for veneer veneers'' (Japanese Patent Application No. 61-242276) This heating device has been further improved.

That is, the pair of endless bands 6 and 7 are each rolled by a plurality of rolls 6a.
*6b*6c*6d and 7a*7b*7c/7d are stretched in a meandering manner, and are a combination of a flat road, a curved road, and a flat road - a curved road and a flat road, in other words. , a series of flat heating paths in three upper and lower stages, and two curved relay paths from the upper heating path to the middle heating path and from the middle heating path to the lower heating path. Forming a conveyance path for the veneer 5, and through at least one roll, for example, the roll 7b, the veneer 5 is intermittently moved in the direction of the arrow shown by a drive source (not shown) at a conveyance pressure of 1llPl per - turn. In addition, inside the endless band 6, there is a movable heat l! 18a/8b+18d/8e and fixed heat IIt8C
Also, inside the endless band 7, there is a fixed heat I! ! I9a・
9d and movable heat sinks 9b and 9C are disposed facing each other, and the movable heat sinks 8a, 8b, 8dII8e and 9bφ90 are configured to be able to be raised and lowered together or separately by a lifting mechanism (not shown). 6 pairs of fixed heat sinks 9a and movable heat sinks 8
The length Ll of the heating surface of a fist 8b, the length Ll of the heating surface of movable heat 9b/9C and fixed heat 8C, and the length L/3 of the heating surface of fixed heat 9d and movable heat 118d/8e. Both of these heating devices are configured to have an integer multiple (in the embodiment, 3 times each) of the conveying pressure fill per time of the endless bands 6 and 7.

For example, even with the heating device configured as described above, each part of the veneer is heated the same number of times (9 times in total in the example), so there is no risk of local temperature differences being induced. It is effective because the heat treatment is done evenly, and the fact that the number of times (opportunities) of being heated in this way is the same is achieved by assuming that there are three separate devices separated for each pair. It is extremely easy to understand if you look at the example in Figure 1.
The length of the interval S formed between the six pairs of heating plates has no effect on the heating frequency of the plate-shaped object.

To demonstrate with another example, for example, as shown in FIG. 4, the length L4 of the heating surface in the running direction of the endless band 10 is
A relatively wide degree interval S2 is provided between a and 11b, and the veneer 5 having a length intersection of 3 is conveyed. The same heating plate 11a is used as shown in FIG.
A relatively narrow interval S1 is provided between and llb.

When comparing the case where a veneer 5 having a length of 3 is conveyed and heat-treated, as is clear from each figure, the length of the heating surface of each heating plate in any part of the veneer 5 is The sum of
Divide by the transport distance and get 11 (Illf, L4x
z÷P2=2, that is, the plate is heated twice, and the length of the interval S1 or S2 has no effect on the heating frequency of the plate-shaped object.

The above characteristics were previously proposed by the applicant on February 1, 1986, as one of the other proposals for improving the practicality of this type of device.
Utility model registration rIn (name of invention,
It is useful to utilize the technology disclosed in the invention (heating device for plate-shaped objects).

That is, as illustrated in FIG. 6, for example, an interval of arbitrary size is provided between the heating lids 13a and 13b located below the endless band 12, and a rotating body 14 that can be driven or driven is provided in the interval. is provided so that it can freely appear and retract from the heating surfaces of the heating plates 13a and 13b, and the endless band work 2 and the heating plate 13
It is useful to utilize the technology to prevent wear of both parts due to sliding contact between a-13b, and in this case as well, the point is that the endless band 12
If the length of the heating surfaces of the heating plates 13a and 13b in the running direction is an integral multiple of the conveyance distance of the endless belt 12 per time, the length of the interval will affect the heating frequency of the plate-shaped object. There is no risk of causing any harm.

In addition, in the present invention, since the heat treatment is performed through the S end, although it is passive, there is some heat exchange effect in the vicinity of each hot spot. What is the relationship between the length of the heating surface of the heating plate in the running direction and the conveyance distance of the endless belt at one time?

It does not need to be very exact, and the existence of errors can be tolerated.

However, the allowable error value depends on conditions such as the heating temperature of each heat, the heat conductivity/heat retention of the endless belt, or the properties of the plate-like material. Since the range of influence of the give-and-receive action varies, it is difficult to determine it uniformly, and it is preferable to determine it experimentally according to the above conditions.

In addition, since there is room for error as shown in 4 above, the heating plates on one side of any pair, or on both sides of any pair (although not shown), are divided into parts as in each of the above embodiments. Even if a very small gap is provided between the individual heating plates to facilitate the raising and lowering of each heating plate, this gap can be ignored in practical terms, and the point is that these divided heating plates As long as the heating surfaces of the endless strip are substantially continuous in the running direction of the endless strip, there will be no practical problem, and if necessary, as illustrated in Figure 57,
It is also possible to combine the ends of adjacent heating plates 15a and 15b in a staggered manner to achieve uniform heating.

As the heat source for each heating plate, heating steam is relatively inexpensive and simple, and the present applicant first proposed on February 9, 1988 that heating plates with surfaces located above the conveyance path were used. It is effective to smoothly remove the drain by utilizing the technology disclosed in the utility model registration order (name of the invention, heating device for plate-like objects) submitted in the attached article, that is, the technology to raise the product non-horizontally when it is raised. However, in addition to these, various conventionally known heat sources such as heating oil, electric heaters, etc. may be used.

Further, it is preferable that the endless band is made of stainless steel,
Although the surface is not shown in the drawings, it is preferable to arrange a scraping member consisting of a leaf spring, brush, etc. on the outer periphery of the surface so that the green matter can be removed. As disclosed in ``Hot Heat for Drying Veneer Plywood'' (Japanese Patent Application No. 152241/1982) submitted by the applicant earlier, the heating surface of each plate is formed to be convex in any direction. There is no problem.

Furthermore, in the case where one of the heating plates is divided into a plurality of parts, the heating temperature does not necessarily have to be uniform. Although it is fixedly arranged, if necessary, it may be configured to move up and down in synchronization with the heating plate located above the conveyance path, and the surface is also the same as in the embodiment shown in Fig. 3. It is desirable to provide a trajectory correction mechanism as disclosed in Japanese Patent Application No. 61-242276 to more accurately stabilize the running trajectory of the endless belt.

[Brief explanation of the drawing]

The drawings are for explaining the present invention, and FIG. 1 is a schematic side view of a heating device according to the present invention, and FIG. 2 is a schematic diagram showing the progress of conveying a veneer in the device illustrated in FIG. FIG. 3 is a schematic side view of another embodiment of the heating device according to the present invention, and FIGS. 4 and 5 are schematic diagrams illustrating the progress of conveying a veneer in still another embodiment. FIG. 6 is a partial side view of the heating plate, and FIG. 7 is a partial plan view of the heating plate. 1.2,6,7,10.12-...Endless band, 3.8c,
9a, 9d**e Fixed heating plate, 4a. 4b, 4c, 4d, 8a, 8b, 8d, 8e.

Claims (1)

[Claims] A pair of endless belts are arranged opposite each other so as to be able to run intermittently to form a conveyance path for plate-shaped objects, and an appropriate number of pairs of heating plates, each consisting of an arbitrary number, are placed facing each other inside each endless belt. , a heating device in which at least one of the surfaces is arranged so that it can be raised and lowered, and the heating plate repeatedly heats the plate-like object via the endless band during the process of intermittently conveying the plate-like object by the endless band. In any of the pairs of heating plates described above, the length of the heating surface in the running direction of the endless belt is a length that is an integral multiple of the conveyance distance of the endless belt per time. The length of the heating surface of the heating plate with respect to the running direction of the endless band and the conveying distance per one time of the endless band are configured so as to be substantially continuous in the running direction of the endless band. Heating device for plate-shaped objects.