JP2019168167A - Venner drying device - Google Patents

Abstract

To prevent a foreign material such as chips and wood dust adhering to a conveyance member such as a chain conveying a veneer from being ignited in a veneer drying device.SOLUTION: In a veneer drying device 10 which is configured to expose a veneer to hot wind and dry while being conveyed from an inlet 12 to an outlet 13 of a dry chamber 11 by conveyance means 14 having a chain 15 (conveyance member) circulating in the dry chamber, moisture injection means 28 (moisture applying means) for injecting steam toward the chain is provided at a place (inlet and/or outlet) where the chain comes out of the dry chamber. Even when a foreign material adheres to the chain, the moisture content thereof is increased by the moisture injection means so as to prevent the foreign material from touching air and being ignited.SELECTED DRAWING: Figure 3

Description

The present invention relates to a veneer drying apparatus used for adjusting a moisture content suitable for a subsequent bonding process and product quality from a veneer cut from a raw wood by a rotary race or the like.

As such a veneer drying apparatus, a so-called roller dryer is widely used which is dried by applying hot air while conveying the veneer while being sandwiched between rollers driven by a chain. It is known.

In a veneer dryer, foreign matter such as chip chips and wood powder falls during transportation of the veneer and is left in various places in the device, so these foreign matters are gradually carbonized by exposure to hot air. In the end, there is a risk of fire. In order to solve this problem, the following Patent Document 2 proposes that a dust removing device for removing these foreign substances and transferring them to the storage chamber in the vicinity of the single plate inlet of the single plate drying apparatus is proposed. .

Japanese Patent No. 5490499 Utility Model Registration No. 2546774

However, in Patent Document 2, it is proposed to remove foreign matters that are detached from the single plate during transfer of the single plate and fall and stay below the apparatus, but foreign matters such as chips and wood powder fall from the single plate. Not only does it adhere to the chain that drives the roller. Since machine oil is applied to the chain for lubrication and rust prevention, the chain circulates in the apparatus in a state in which foreign matter derived from a single plate adheres to the machine oil of the chain. In particular, since the softwood veneer contains more oil such as spider than the hardwood veneer, a larger amount of foreign matter derived from the veneer tends to adhere to the chain.

The inside of the veneer dryer is in a low-oxygen state, so even if foreign matter adheres to the chain, it will not ignite in the device, but hot air will flow while the foreign matter attached to the chain is transported inside the device. When exposed to air and exposed to air when exposed to high temperatures, this foreign object could ignite, resulting in a fire accident.

Therefore, the problem to be solved by the present invention is to prevent foreign matter such as chips and wood powder adhering to a conveying member such as a chain conveying a veneer in a veneer drying apparatus from igniting.

In order to solve the above-mentioned problems, the present invention according to claim 1 is characterized in that the veneer is exposed to hot air while the veneer is conveyed from the inlet to the outlet of the drying chamber by the conveying means having a conveying member circulating inside and outside the drying chamber. In the veneer drying apparatus configured to be dried, by applying moisture to the conveyance member at a position where the conveyance member comes out of the drying chamber, ignition of foreign matter derived from the single plate attached to the conveyance member is performed. It is characterized in that a moisture applying means for preventing is provided.

According to a second aspect of the present invention, in the veneer drying apparatus according to the first aspect, the moisture applying means is provided at least close to the inlet of the drying chamber.

According to a third aspect of the present invention, in the veneer drying apparatus according to the first or second aspect, the moisture applying unit jets water vapor toward the conveying member.

According to a fourth aspect of the present invention, in the veneer drying apparatus according to the third aspect, the moisture applying means further includes a pressure adjusting means for adjusting the water vapor jet pressure.

According to the first aspect of the present invention, even when foreign matter derived from a veneer such as chips or wood powder adheres to a conveying member such as a chain due to oil such as spear that is contained in a large amount in a softwood veneer, moisture imparting means To prevent its ignition. That is, when a foreign object that has been exposed to hot air in the drying chamber and has reached a high temperature comes out of the drying chamber together with the conveying member and touches the outside air, the moisture applying means imparts moisture to the conveying member, so that the foreign matter is ignited. To prevent that.

According to the second aspect of the present invention, the foreign matter removing means provided on the inlet side of the drying chamber increases the amount of water adhering to the conveying member coming out of the drying chamber on the inlet side of the drying chamber. It can prevent more effectively that the foreign material adhering to ignite.

According to the third aspect of the present invention, the moisture applying means is configured to inject water vapor having a high temperature (about 100 ° C.) close to the temperature in the drying chamber. It is possible to effectively prevent the foreign matter from firing without adversely affecting the heat drying.

According to the fourth aspect of the present invention, since the pressure of the water vapor sprayed toward the conveying member is optimally adjusted by the pressure adjusting means, it is possible to effectively prevent the foreign matter adhering to the conveying member from igniting. Can do.

It is a side view which shows roughly the whole structure of the veneer drying apparatus by one Embodiment of this invention. It is the A section enlarged view in FIG. FIG. 3 is a top view of FIG. 2. It is a side view which expands and shows the 1 step | paragraph veneer conveyance means and conveyance path | route shown by FIG. It is the C section enlarged view in FIG. It is the D section enlarged view in FIG. It is the B section enlarged view in FIG. FIG. 8 is a top view of FIG. 7.

With reference to FIG. 1 thru | or FIG. 8, the structure of the veneer drying apparatus 10 by one Embodiment of this invention is demonstrated. This veneer drying apparatus 10 feeds a veneer cut from a log with a rotary race or the like into the drying chamber 11 from the inlet 12 (part A, FIG. 2) of the drying chamber 11 and dries hot air in the drying chamber 11. Then, it is sent out from the outlet 13 (B section, FIG. 3). The veneer 1 (FIGS. 2, 4, and 7) is transported in a substantially horizontal direction by the transport device 14 from the inlet 12 to the outlet 13 of the apparatus main body 11. The humidity in the drying chamber 11 is maintained at 30 to 40%.

In particular, as shown in FIG. 4, the conveying device 14 is driven by a driving means (not shown) such as a motor and circulates inside and outside the drying chamber 11, and is arranged on the chain 15 at a predetermined interval. It has the lower roller 16 and the upper roller 17 arrange | positioned upwards facing the lower roller 16 on both sides of the single plate 1. Cams (not shown) are fixed to both ends of the lower roller 16 and the upper roller 17, and the lower roller 16 and the chain 15 are engaged with the chain 15 that comes out of the drying chamber 11 by the cam of the lower roller 16. The upper roller 17 rotates in the opposite direction at the same speed as the lower roller 16 as the cams of the lower roller 16 and the upper roller 17 mesh with each other. The veneer 1 is sandwiched between the lower roller 16 and the upper roller 17 and conveyed at a predetermined speed in the arrow X direction.

The lower roller 16 is provided over a relatively long region reaching the inlet 12 of the drying chamber 11, whereas the upper roller 17 is provided only in a region close to the inlet 12 of the drying chamber 11 (region shorter than the lower roller 16). It has been. With this configuration, the veneer 1 is placed on the lower roller 16 and conveyed, and then further conveyed in a state of being sandwiched between the front of the inlet 12 of the drying chamber 11 and the upper roller 17. It is sent into the drying chamber 11, passes through the drying chamber 11, and is sent out from the outlet 13. Since the veneer 1 is conveyed in the drying chamber 11 while being sandwiched from above and below by the rollers 16 and 17, even if it is exposed to hot air in the drying chamber 11, generation of warpage and wrinkles is prevented or suppressed.

The drying chamber 11 is provided with a multi-stage (six-stage in the illustrated embodiment) single-plate conveyance path so that a plurality of single-plates 1 can be dried at the same time. A transport device 14 as shown in FIG. 4 is provided for the transport path. 2 and 7, the chain 15 shown on the upper side of the transport device 14 of each stage moves from the outlet 13 toward the inlet 12, and the chain 15 shown on the lower side moves from the inlet 12 toward the outlet 13. . Moreover, the conveyance surface of the single plate 1 by the conveyance device 14 at each stage is indicated by a dotted line as a symbol T.

In the drying chamber 11, a heater zone 19 having a steam pipe (not shown) is provided above the multistage transport path by the transport device 14. Further, the heater zone 19 is provided with an intake duct 20, an intake fan 21, a hot air fan 22 and an exhaust duct 23. The air in the drying chamber 11 is heated by high-temperature steam generated by a boiler (not shown) passing through an erotic fin heater (not shown) in the drying chamber 11 and sent downward by a hot air fan 22. The veneer 1 conveyed by the conveying device 14 is heated and dried. A portion of the hot air dampened by drying the veneer 1 is discharged to the outside from the exhaust duct 23, and the hot air remaining in the drying chamber 11 is heated again and circulates in the heater zone 19.

In this way, the veneer 1 is dried with hot air while being transported through the drying chamber 11 from the inlet 12 to the outlet 13 by the transport device 14 and adjusted to a moisture content suitable for the subsequent bonding process and product quality. Is done. Although not shown, a cooling zone may be provided in the vicinity of the outlet 13 of the drying chamber 11.

In the veneer drying apparatus 10 having the basic configuration described above, it moves together with the chain 15 in a state where it adheres to machine oil pre-applied to the chain 15 and particularly oil such as spear contained in a large amount in the case of a softwood veneer. In order to prevent foreign matter (chips, wood powder, etc.) derived from a single plate from being heated to a high temperature and ignited, a place where the chain 15 circulating through the drying chamber 11 comes out of the drying chamber 11 (inlet 12 and / or Or, the outlet 13, the inlet 12 and the outlet 13 in this embodiment, is provided with moisture injection means 28 for injecting moisture toward the chain 15 (see FIGS. 3 and 8). Since the water injection means 28 provided on the inlet 12 side and the water injection means 28 provided on the outlet 13 side have substantially the same configuration, the water injection means 28 provided on the inlet 12 side will be described with reference to FIG. I will explain.

The water spray means 28 includes a steam pipe 29 extending in the height direction over a single plate conveyance path provided in multiple stages, and a steam ejection nozzle provided in connection with the steam pipe 29 in each stage of the single plate conveyance path. 30 and an adjustment handle 31, and the steam fed from the steam pipe 29 is ejected from the steam ejection nozzle 30 toward the side surface of the chain 15 at a desired ejection pressure (for example, 0.2 MPa) adjusted by the adjustment handle 31. It is configured as follows. As a result, even if foreign matter adheres to the chain 15, the amount of moisture can be increased, thereby preventing the risk of ignition. Although it is conceivable to spray water or mist only for the purpose of preventing ignition of the foreign matter adhering to the chain 15, heat is taken away from the drying chamber 11 and adversely affects the heat drying of the veneer 1 due to the temperature drop. Therefore, it is preferable to spray water vapor having a high temperature (about 100 ° C.) close to the temperature in the drying chamber 11.

The veneer drying apparatus 10 of the illustrated embodiment is provided with the above-described moisture ejecting means 28 that ejects moisture toward the chain 15 in order to prevent the foreign matter derived from the veneer attached to the chain 15 from igniting. In addition, foreign matter that removes foreign matter attached to the chain 15 at a location where the chain 15 circulating in the drying chamber 11 exits from the drying chamber 11 (inlet 12 and / or outlet 13, in this embodiment, inlet 12). A removing means 24 is provided. According to this foreign matter removing means 24, foreign matter is removed from the upper chain 15 (moved from the outlet 13 to the inlet 12) coming out of the drying chamber 11 at the inlet 12 of the drying chamber 11, and machine oil is applied at the inlet 12. After that, the lower chain 15 enters the drying chamber 11 again from the inlet 12 and moves toward the outlet 13. Since the foreign matter is removed before the machine oil is applied, the foreign matter can be efficiently removed without wasting the machine oil.

As shown in detail in FIGS. 4 and 5, the foreign matter removing means 24 according to this embodiment is fixed to a frame 25 having a sufficient height over a single plate conveyance path provided in multiple stages via air cylinders 26. The plurality of wire brushes 27 are configured. The wire brush 27 is provided at a height position that abuts on the side surface of the chain 15 provided in the single plate conveyance path of each stage, and a predetermined pressure (0.1 to 0.3 MPa, preferably 0.2 MPa) by the air cylinder 26. ) Makes contact with the side surface of the chain 15 so that the foreign matter adhering to the chain 15 is efficiently removed. The foreign matter removed from the chain 15 by the wire brush 27 falls, is captured and accommodated in the tray 18 disposed below the position where the wire brush 27 contacts the chain 15, and is automatically or manually discharged as appropriate. When the position where the wire brush 27 contacts the chain 15 is different in the transport direction, a plurality of trays 18 are provided according to the position.

A member that removes the adhered foreign matter in contact with the side surface of the chain 15 is not limited to the wire brush 27, but a scraper or the like can be used. However, the foreign matter attached to the uneven surface of the chain 15 can be effectively removed. In that respect, the use of a wire brush 27 is preferred.

In the illustrated embodiment, the wire brush 27 is brought into contact with the outer surface of the chain 15 to remove the adhered foreign matter, but instead of or in addition to this, the inner surface of the chain 15 is contacted. You may provide the wire brush 27 so that it may contact.

In the veneer drying apparatus 10 of the illustrated embodiment, the foreign matter removing means 24 is provided at the inlet 12 of the drying chamber 11, but similar foreign matter removing means 24 may be provided at both the inlet 12 and the outlet 13. If the chain 15 with the extraneous foreign matter attached enters the drying chamber 11 as it is, there is a high risk of igniting by touching the outside air when exiting from the outlet 13 after being exposed to hot air in the drying chamber 11, In order to prevent this effectively, the foreign matter removing means 24 is preferably provided on the inlet 12 side when provided only on one of the inlet 12 and the outlet 13.

Although the present invention has been described in detail with reference to examples, the present invention is not limited to this, and can be implemented with various modifications or changes within the scope of the invention defined by the description of the scope of claims. is there. In the illustrated embodiment, a transport device provided with a roller that moves and rotates together with a chain that circulates inside and outside the drying chamber is used. However, the present invention is not limited thereto, and a transport member that circulates inside and outside the drying chamber is used. The present invention can be applied to any conveying apparatus having the above. For example, in a single plate drying apparatus called a band dryer (or belt dryer) that transports a single plate placed on a net-like transport member that circulates between pulleys provided outside the inlet side and the outlet side of the drying chamber. Since the foreign material derived from the single plate adheres to the net-like conveying member, the present invention can be applied so as to prevent moisture from being ignited by applying moisture thereto.

DESCRIPTION OF SYMBOLS 1 Single plate 10 Single plate drying apparatus 11 Drying chamber 12 Drying chamber inlet 13 Drying chamber outlet 14 Conveying device (conveying means) 15 Chain (conveying member) 16 Lower roller 17 Upper roller 18 Tray 19 Heater zone 20 Intake duct 21 Intake Fan 22 Hot air fan 23 Exhaust duct 24 Foreign matter removing means 25 Frame 26 Air cylinder 27 Wire brush 28 Moisture ejecting means (moisture imparting means) 29 Steam pipe 30 Steam ejecting nozzle 31 Adjusting handle (pressure adjusting means)

Claims (4)

In the veneer drying apparatus configured to be dried by being exposed to hot air while the veneer is conveyed from the inlet to the outlet of the drying chamber by the conveying means having a conveying member that circulates inside and outside the drying chamber, Single plate drying characterized in that a moisture applying means is provided to prevent ignition of foreign matter derived from a single plate adhering to the conveying member by applying moisture to the conveying member at a position where the conveying member comes out of the drying chamber. apparatus. The veneer drying apparatus according to claim 1, wherein the moisture applying means is provided in the vicinity of at least the entrance of the drying chamber. The veneer drying apparatus according to claim 1 or 2, wherein the moisture applying unit sprays water vapor toward the conveying member. 4. The veneer drying apparatus according to claim 3, wherein the moisture applying means further includes a pressure adjusting means for adjusting a water vapor jet pressure.