JP2000230781A - Device for preventing hot-air leak of veneer dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately shield hot air inside a dryer and air outside the dryer by bringing a heat-resistance flexible sheet into contact with the starting- and/or ending-edge position of a carrying path for connecting to the air at the incoming and/or outgoing side of the dryer, and by circulating the hot air in a ventilation path to the carrying path. SOLUTION: In a veneer dryer 1, a required number of heating sections 2 are installed, a ventilation path where a heating body and a blower 4 are installed in each section 2 are formed, and hot air is supplied by a horizontal circulation system. A plurality of stages of carrying paths 11 are installed at the lower part of the ventilation path, and a plurality of sets of upper and lower rolls 12 are provided at arbitrary intervals. A roll 23 is subjected to bearing at appropriate intervals at the starting- and/or ending-edge positions. Between the rolls 23, a heat-resistant flexible sheet 25 being mounted onto a partition board 24 crosses the carrying path 11 from an upper to lower part or from a lower to upper part on the carrying surface of the roll 23 for contacting, and the hot air inside the dryer 1 and air are shielded. The flexible sheet 25 is bent for doubling, and the double part is set to a loop shape where both ends are opened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of circulating hot air generated in a ventilation path in a veneer dryer to a transportation path provided at a lower portion of the veneer dryer. The present invention relates to a hot air leak prevention device that shields hot air inside a veneer dryer and air outside the veneer dryer.

[0002]

2. Description of the Related Art Conventionally, when a transport path is constituted by a pair of upper and lower feed rolls which rotate and sandwich veneer veneers from both sides in the thickness direction, they are located at the start and end of the transport path. A heat-resistant packing made of asbestos or the like is pressed against a pair of upper and lower feed rolls via a supporting member as appropriate to shield the hot air inside the veneer dryer and the atmosphere outside the veneer dryer.

Further, a pair of upper and lower wire mesh conveyors in which a conveying path circulates while sandwiching a veneer veneer in the plate thickness direction, or a lower winding / conveying means for supporting and conveying veneer veneer is a wire mesh conveyor, and an upper winding When the hanging and conveying means is composed of a chain conveyor or a spring conveyor, a heat-resistant flexible sheet such as Teflon is hung from above the entrance side and the exit side of the veneer dryer toward the conveyance surface of the conveyance path. It was installed in a lowered position to shield the hot air inside the veneer dryer and the atmosphere outside the veneer dryer.

[0004]

However, in the former case, the upper feed roll of the upper and lower set of feed rolls is placed on the lower feed roll by its own weight, so that the feed path into the veneer dryer is carried out. When the veneer veneer is inserted from the start end of the veneer or the veneer veneer is taken out from the end of the transport path to the outside of the veneer dryer, the upper feed roll is lifted at least by the thickness of the veneer veneer from the lower feed roll, and the veneer veneer is removed. Each time the veneer is lifted, hot air in the veneer dryer will leak.

In the latter, in order to prevent the veneer veneer from being clogged when the veneer veneer is inserted into or taken out of the transport path, the lower end of the heat-resistant flexible sheet suspended toward the transport path is provided with a transport surface. And a slight clearance, and the hot air inside the veneer dryer leaks from the clearance, making it difficult to shield the air from the outside of the veneer dryer.

Further, the hot air circulated to the lower conveying path in the veneer dryer dries the veneer veneer having a high water content while being conveyed, so that the temperature decreases toward the downstream side in the veneer dryer. In order to prevent this, an auxiliary heat source such as a steam pipe or a hot oil pipe, or a baffle plate or the like that regulates the wind direction of circulating hot air to the transport road surface is provided at the upper and / or lower portion of the transport road surface. Installed where hot air circulates.

[0007] When the above-described installation exists in the hot air circulation path, resistance due to the installation is large, so-called Karman vortex is easily generated in the downstream area, and the pressure loss of the circulating hot air is increased. If it is desired to obtain a certain pressure in the basin, the output of the blower installed above the veneer dryer must be increased. As a result,
Since the pressure inside the veneer drier becomes large, the pressure difference between the veneer drier and the outside of the veneer drier increases, and the above-described method of shielding the hot air inside the veneer drier and the atmosphere outside the veneer drier is described above. Then, leakage of hot air was inevitable. SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and it is an object of the present invention to appropriately shield hot air inside a veneer dryer and air outside the veneer dryer.

[0008]

Accordingly, the apparatus for preventing hot air leakage of a veneer dryer according to the present invention comprises a required number of heating sections to constitute a veneer dryer, and an upper part of the veneer dryer. It has a heating element and a blower to make a hot air ventilation path,
A transport path for transporting veneer veneers is installed below the veneer dryer, and the heat-resistant flexible sheet abuts the start and end positions of the transport path that communicates with the atmosphere on the entrance and exit sides of the veneer dryer. The problem is solved by circulating the hot air generated in the ventilation path to the transport path.

[0009] A preferred example of the transport path is a heat-resistant flexible sheet in which the starting end and the end are rolls whose upper surfaces are almost the same as the transport surface of the transport path and whose transport speed is almost the same as the transport speed of the transport path. The contact state between the hot air inside the veneer dryer and the atmosphere outside the veneer dryer is enhanced.

When the heat-resistant flexible sheet is brought into contact with the start and end positions of the conveyance path, the heat-resistant flexible sheet is conveyed from above the conveyance surface of the conveyance path to below the conveyance surface or from below the conveyance surface to above. If it is provided in a plane across the road, the shielding of the hot air inside the veneer dryer and the atmosphere outside the veneer dryer can be further enhanced.

The heat-resistant flexible sheet is preferably not in a single sheet state, but is formed by folding a single sheet into a double sheet, forming the double section into a loop, and forming both ends of the loop. By setting to the open state, the hot air circulating in the veneer drier reaches the inside from the opening of the loop of the heat-resistant flexible sheet and presses the loop from outside and inside with the same pressure. Thereby, the heat-resistant flexible sheet itself can be strengthened, and the shielding of the hot air inside the veneer dryer and the atmosphere outside the veneer dryer can be enhanced.

The veneer veneer to be supplied onto the transport path is obtained by cutting a continuous sheet obtained by rotationally cutting a log into an arbitrary width in parallel with the fiber direction. The veneer veneer, the fiber direction is the same as the transport direction, in this case, the transport path is a plurality of pairs of upper and lower feed rolls that feed while rotating while sandwiching the veneer veneer from both sides in the thickness direction It becomes a direct type installed at intervals, and this transport path is installed at a lower portion of the veneer dryer at a plurality of stages at arbitrary intervals in the vertical direction.

Therefore, a required number of heating sections are installed to constitute a veneer dryer, and a heating element and a blower are provided above the veneer dryer to provide a hot air ventilation path. A transport path for transporting veneer veneers is provided at the bottom, and a single heat-resistant flexible sheet is preferably provided at the start and end positions of the transport path communicating with the atmosphere on the entry side and the exit side of the veneer dryer. By bending it to form a double, this double part is formed into a loop, and by opening both ends of the loop, the hot air circulating in the veneer drier is used to form a loop of the heat-resistant flexible sheet. The loop is extended from the opening to the inside, and the loop is brought into contact with the same pressure from the outside and the inside of the inside of the loop, so as to shield the hot air generated in the ventilation path from the outside of the veneer dryer. Things.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Veneer dryer 1 shown in FIGS. 1 and 2
Is configured by installing a required number of heating sections 2, a heating element 3 such as a steam pipe, an electric heater, or heat oil is provided on one side of the upper part of each heating section 2 orthogonal to the transport direction, and the heating section 2 is provided on the other side. A ventilation path 5 having a blower 4 for blowing air toward the heating element 3 is formed, and hot air is supplied from a hot air supply side 8 between an outer wall 6 and an inner wall 7 of the heating section 2 to a hot air take-out side 9 located on the opposite side. It is supplied by a horizontal circulation system.

A plurality of conveying paths 11 for conveying a single sheet of veneer veneer 10 are provided in the inner wall 7 below the ventilation path 5 in a vertical direction. This transport path 11
A plurality of sets of upper and lower feed rolls 12 are arranged at arbitrary intervals in a manner such that the veneer veneer 10 is sandwiched from both sides in the thickness direction and fed while being rotated in the longitudinal direction of each stage. Each feed roll 12 is rotatably supported by a bearing 14 installed between the vertical beams 13 constituting the inner wall 7, and a chain 16 is attached to a chain sprocket 15 attached to one shaft end of the lower feed roll 12. , And a gear 17 is attached to the other end of the shaft.
The veneer veneer 10 is sandwiched from both sides in the plate thickness direction by being engaged with the gear 17 attached to the shaft end of the shaft 2 and rotating the respective feed rolls 12 in opposite directions to be conveyed by frictional force. I have.

In the vertical direction of the transport path 11 of each stage and within the interval in the transport direction, an elongated ejection box 18 having substantially the same length as each of the feed rolls 12 is installed in a direction perpendicular to the transport direction. At the same time, the hot air supply side 8 of the injection box 18 is opened, and the hot air extraction side 9 located on the opposite side is closed, and the hot air generated in the ventilation path 5 and circulated from the hot air supply side 8 is injected into the injection box 18. From the formed holes or slits, the veneer veneer 10 conveyed on the conveyance path 11 is jetted onto the upper and lower surfaces of the veneer veneer 10, and the jetted hot air is ejected on the hot air outlet 9.
The air is exhausted by the blower 4.

In the veneer dryer 1 shown in FIGS. 5 and 6, a heating element 3 such as a steam pipe, an electric heater, or heat oil is provided substantially in the center of an upper ventilation path 5 where a required number of heating sections 2 are installed. A pair of blowers 4 are installed facing each other on one side in the transport direction. At this time, the suction duct 19 protrudes from both sides of the heating section 2 in the conveying direction located on the side of the blower 4 and communicates with the lower portion of the heating section 2 located immediately below. Blow duct 2 from both sides of the heating section 2 located in the conveying direction
0 overhangs and heating section 2 located immediately below
The hot air is supplied from the suction duct 19 to the blow duct 20 by a vertical circulation system.

In the vertical direction of the transport path 11 of each stage and the interval in the transport direction, the length of each of the feed rolls 12 is substantially the same as that of the feed rolls 12 in a direction orthogonal to the transport direction, and the diameter thereof is set to the large diameter. The heated heat rolls 21 are connected to a steam branch pipe 22 which is raised and supported vertically in the inner wall 7 to supply and discharge steam into each of the heat rolls 21, and is conveyed on the conveyance path 11. As an auxiliary heat source for the veneer veneer 10, the drying efficiency of the veneer veneer 10 is promoted.

Rolls 23 whose upper surfaces are substantially the same as the transport surface of the transport path 11 are supported at the start position and the end position of the transport path 11 of each stage, and are mounted on one axial end of the roll 23. The chain 16 is wound around the chain sprocket 15 and the rotational speed of the roll 23 is set to be substantially the same as the transport speed of each feed roll 12 constituting the transport path 11. In the embodiment, the transport path 11 has a three-stage configuration, and three rolls 23 are supported at an arbitrary interval in the vertical direction at the start and end positions of the transport path 11, respectively.

In the vertical interval between the rolls 23, the roll 2
The partition plate 24 attached to the lower portion of the heating section 2 over the entire length direction of the heating section 3 and the heat-resistant flexible sheet 25 attached to the partition plate 24 are provided from above the conveying surface of the roll 23 to below the conveying surface. Or across the transport path 11 so as to extend from below to above the transport surface of the roll 23 to shield the hot air inside the veneer dryer 1 from the atmosphere outside the veneer dryer 1. I have.

Therefore, when the veneer veneer 10 inserted into the veneer dryer 1 reaches the roll 23 at the start position of the transport path 11, the veneer veneer 10 moves from above the transport surface of the roll 23 to below the transport surface. The heat-resistant flexible sheet 25 abutting in a plane is lifted, and then a pair of upper and lower feed rolls 12
Is inserted into the veneer dryer 1 while rotating while sandwiching from both sides in the thickness direction, and when the rear end passes through the roll 23, the heat-resistant flexible sheet 25 is again transported from above the transport surface of the roll 23 to the transport surface. The sheet is abutted in a planar manner across the transport path 11 so as to reach the lower part of the single-pan dryer 1 to shield the hot air inside the single-pan dryer 1 from the atmosphere outside the single-pan dryer 1. At this time, roll 2
On the lower surface of 3, the heat-resistant flexible sheet 25 is abutted in a planar manner across the transport path 11 from below to above the transport surface.

When the veneer veneer 10 is inserted into the veneer dryer 1, the hot air horizontal circulation system shown in FIGS.
The veneer is sent while rotating while sandwiching the hot air circulated from the hot air supply side 8 of each heating section 2 to the hot air take-out side 9 in a direction orthogonal to the transport direction while sandwiching the hot air from both sides in the thickness direction by a pair of upper and lower feed rolls 12. The hot air, which has been supplied to the veneer 10 and has been cooled after the work, is returned to the hot air outlet 9.
The air is sucked by a blower 4 from above, heated to a desired temperature by passing through a heating element 3, and supplied from a lateral direction to a veneer veneer 10 via a hot air supply side 8.
0 is to be dried.

5 and 6, the hot air circulated in the conveying direction from the suction duct 19 to the blow duct 20 is supplied to the plate dryer 1 by a pair of upper and lower feed rolls 12. It is supplied to the veneer veneer 10 which is sent while rotating while sandwiching it from both sides in the thickness direction, and the hot air whose temperature has been reduced after work is sucked in again from the suction duct 19 by the blower 4 and passed through the heating element 3. The temperature of the veneer veneer 10 is increased by raising the temperature, and supplied to the surface of the veneer veneer 10 from the vertical direction through the blowing duct 20 to dry the veneer veneer 10.

When the veneer veneer 10 dried by the veneer dryer 1 reaches the terminal position of the transport path 11, the leading end of the veneer veneer 10 is rolled at the terminal position of the transport path 11, as described above.
3, the heat-resistant flexible sheet 25 abutting planarly from above the conveying surface of the roll 23 to below the conveying surface is lifted, and the rear end of the veneer veneer 10 passes through the position of the roll 23. At this time, the transport path 11 is moved so that the heat-resistant flexible sheet 25 again extends from above the transport surface of the roll 23 to below the transport surface.
, So that the hot air inside the veneer dryer 1 and the atmosphere outside the veneer dryer 1 are shielded.

When the veneer veneer 10 is dried,
In order to prevent the temperature of the circulating hot air from lowering,
Is used as an auxiliary heat source to maintain drying efficiency,
Since the hot roll 21 is located in the flow path of the circulating hot air, the pressure loss of the circulating hot air also increases, particularly in the single-plate dryer 1 of the hot-air vertical circulation system, and a certain pressure is generated even in the downstream region. If it tries to find, the output of the blower 4 installed in the upper part of the veneer dryer 1 has to be increased, and the pressure difference between the pressure in the veneer dryer 1 and the atmosphere increases with the increase in output. Even if the heat-resistant flexible sheet 25 is abutted in a plane across the transport path 11 of the roll 23, the heat-resistant flexible sheet 25 may be heat-resistant due to the pressure difference between the inside of the veneer dryer 1 and the outside of the veneer dryer 1. The flexible sheet 25 and the roll 23 do not come into contact with each other in a planar manner, and hot air leaks from the inside of the veneer dryer 1 to the outside of the veneer dryer 1.

In this case, if a single heat-resistant flexible sheet 25 is bent to form a double, the double portion is formed into a loop, and both ends of the loop are opened, a single-plate dryer is provided. The hot air circulating through the inside of the heat-resistant flexible sheet 25 reaches the inside from the opening of the loop of the heat-resistant flexible sheet 25, and presses the loop from outside and inside with the same pressure. 25 itself can be firmly pressed against the surface of the roll 23 in a planar manner, and the hot air in the veneer dryer 1 and the veneer dryer 1
Even if the pressure difference with the outside atmosphere increases, the shielding state can be maintained.

[0027]

As described above, according to the present invention, the functions and effects described in the claims can be obtained, and the hot air inside the veneer dryer and the atmosphere outside the veneer dryer can be shielded. Leakage can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view when an embodiment of the present invention is applied to a hot air horizontal circulation type single plate dryer.

FIG. 2 is a front sectional view of FIG.

FIG. 3 is an explanatory diagram of a transport path.

FIG. 4 is an enlarged side view of a main part of FIG. 1;

FIG. 5 is a partially cutaway side view when the embodiment of the present invention is applied to a hot air vertical circulation type single plate dryer.

FIG. 6 is a partially cutaway side view of FIG. 5;

[Explanation of symbols]

1 ... single plate dryer, 2 ... heating section, 3 ... heating body,
4 blower, 5 ventilation path, 6 outer wall, 7 inner wall, 8 hot air supply side, 9 hot air extraction side, 10 veneer veneer, 1
DESCRIPTION OF SYMBOLS 1 ... Conveyance path, 12 ... Feed roll, 13 ... Vertical beam, 14 ... Bearing, 15 ... Chain sprocket, 16 ... Chain, 17 ...
Gears, 18: injection box, 19: suction duct, 20: blowing duct, 21: heat roll, 22: steam branch pipe, 23
... Roll, 24 ... Partition plate, 25 ... Heat-resistant flexible sheet

Claims (5)

[Claims] 1. A required number of heating sections are installed to constitute a veneer dryer, and a heating element and a blower are provided above the veneer dryer to provide a hot air ventilation path. A transport path for transporting veneer veneer is provided at a lower portion, and a heat-resistant flexible sheet is brought into contact with a start end and an end position of the transport path communicating with the atmosphere on the entry side and the exit side of the veneer dryer, and the ventilation path is provided. A hot air leakage prevention device for a single plate dryer, characterized in that the hot air generated in step (1) is circulated to a conveying path. 2. The single-plate dryer according to claim 1, wherein the start and end of the transport path are rolls whose upper surfaces are substantially the same as the transport surface of the transport path and whose speed is substantially the same as the transport speed of the transport path. Hot air leak prevention device. 3. A starting point and an ending position of the transport path, wherein the heat-resistant flexible sheet is traversed across the transport path from above the transport surface of the transport path to below the transport surface, or from below to above the transport surface. 2. The hot air leakage prevention device for a veneer dryer according to claim 1, wherein the hot air leakage prevention device is abutted in a plane. 4. The hot air leakage prevention device for a veneer dryer according to claim 1, wherein the heat-resistant flexible sheet is bent into a loop, and both ends of the bent loop are open. 5. A plurality of sets of upper and lower feed rolls for feeding while rotating and sandwiching a veneer veneer from both sides in the thickness direction are installed at an arbitrary interval in the transport path. The hot air leakage prevention device for a veneer dryer according to any one of claims 1 to 3, wherein a plurality of stages are installed at an arbitrary interval in a vertical direction at a lower portion of the dryer.