JPS59164877A - Veneer drier - 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 drying device for drying 11 sheets of thin sheets turned from logs, which are used as raw materials for plywood products.

So far, 11 methods and devices have been announced and put into practical use as means for drying veneers. Many of these drying means, for example, as in Q44 Publication No. 56-18871 by the present applicant, are used as control means for the drying process of heavy plates.
1! It detects the moisture content of the board and adjusts the time it takes to pass through the drying device, and controls the transport speed of the material to be dried depending on the degree of drying.

In this drying method, it is possible to obtain a uniform 4 (finished moisture content) of the 11χ board.Naturally produced boards turned from logs come in a variety of shapes, with a uniform Depending on the actual condition of board drying, many labor keys may be
We are losing staff.

l) To explain the appearance of the board, the natural raw wood used as the raw material for veneer has unevenness on its outer circumferential surface, and at the beginning of turning, it is less than the specified width (in the length direction of the raw wood). ,
The so-called scrap board is cut, and then short pieces of a predetermined width begin to be produced intermittently, and the length gradually increases as the cutting progresses, until it reaches the horizontal 1tJi plane of the log or approximately in the shape of a deep circle. , long 1j plates connected in the shape of .11; with a predetermined width are continuously produced.

The veneers to be subjected to the drying device are the continuous veneer in the middle of cutting, which is connected in a band shape, and the short, loose veneer in the early stage of cutting.
In the case of continuous veneer, the continuous veneer wound on the reel is not rewound automatically, just like unraveling a cloth.)・2 Introduced into the drying device. .

On the other hand, the length of a short bulk medium board (width -) is generally 6.23 shaku. Sending them in must be done manually.

Naturally, the shorter the island of a short deck, the more frequently manual insertion is required, and the filling efficiency is also lower.

The general configuration of the f11 board drying apparatus will be explained with reference to FIG. The illustrated device has three stages of upper and lower veneer feeding,
As can be seen in the heated intermediate section 11S, which is shown with the exterior insulation board removed, the rolls 14 disposed in the upper and lower three legs dry the veneer from above and below. By holding and rotating the
This constitutes a conveyance device that IM-feeds the veneer in the B and C directions. On the other hand, the hot air is energized by the hot air fan 13, passes through the heat exchanger 17 through the arrows ○ and ■), is heated, and then passes through the arrows Q, R, and S in the veneer transport direction. It travels backwards, rises through arrow T, reaches the hot air fan 13, and repeats internal circulation in the direction of the arrow.

All of these devices, except for the inlet shelf 1 of the veneer feed section and the outlet shelf 22 of the veneer take-out section, are covered by a heat insulating plate loaded with a heat insulating side.

The veneer is dried as it is generally transported from left to right through the drying device shown in the figure, and once it has passed the drying route, the transport speed is controlled to achieve the desired finished moisture content.

On the other hand, as a drying heat source, 100% veneer is used in the drying equipment.
A customer heat exchanger is provided that can dry the product to a predetermined finished moisture content while being loaded and transferred, and, in the case of using steam, for example, continuously supplies a steam pressure that meets the specifications.

To explain the actual situation of short veneer drying using the above drying device, the veneer filling rate is low because of the short bulk veneers, and the hot air dries a small amount of short veneers very quickly. The temperature drop is small and the temperature is high, so don't use the inside of the aircraft.
i'! It will go around.

Il here! Analyzing the hot air consumption of these drying devices seven times, it is found that the amount of air supplied to the device is 0)
20 to 30% is consumed directly without being involved in drying the 11 board.
This loss is due to heat dissipation from the open parts of the equipment, heat insulation plates on the outside walls of the equipment, dry foundation floors, etc.

Said,! “The loss of 1 shi is due to improvement of the heat insulation board, etc.
Although there is a tendency to gradually reduce it, it is impossible to close off the entrances, exits, etc. that cause the most losses, and this can be said to be a fatal flaw of the device, and a significant reduction cannot be achieved.

Against this background, the drying of short m-plates cannot be expected to improve the filling rate, and ends up repeating the above-mentioned vicious cycle. Furthermore, even in the case of a long continuous l'' board, this same phenomenon occurs when there are frequent interruptions in the feeding of the veneer due to breakage or the like in the middle.

The present invention eliminates the above-mentioned deficiencies and achieves a remarkable effect on energy saving.The filling rate of short m plates, etc. This system indirectly detects the steam pressure of the dryer and sends an appropriate signal to minimize heat loss in the drying equipment.For example, in the case of a low filling rate, it issues an alarm as necessary, and the heat exchanger It is characterized by the fact that the rotation of the hot air fan is lowered to slow down the heat exchange of the hot air.

An embodiment will be described below based on the drawings. FIG. 1 is a side view of the entire drying device, and FIG. 2 is a front view.

The drying device 10 is roughly divided into an upper part that serves to dry and transport the veneer, and an upper part that serves as an air path for drying hot air.
The lower part is placed approximately in the middle of the drying section 113 as shown in Figure 11 with the board removed.
Rolls 14 that rotate while holding the veneer from above and below as a conveying device are arranged in three stages above and below, and constitute one 11] drying section. drying section 101
-1.

1 is arranged at the starting end of the continuous drying section) i
At the entrance shelf q, the boards to be dried (g1) are distributed and fed into three upper and lower stages as shown by arrow A.

A cooling section IOC is placed at the end of the continuous drying section 101-1. 1 is missing (=IshiJ cooling)', lO
F is cold, 14 fans.

Resistance to cold, exit shelf 2 connected to section 11 IOC
2nd stage: iq, h'-F The dried veneer coming out of the 3rd stage is taken out of the machine in the direction of arrow 0 and transferred to 11th stage 1 conveyor 2
3 is placed below.

21 is a drive IJJ device that drives each roll of the drying section and the conveyor of the entrance and exit shelves, and usually,
It is configured to be variable speed.

Reference numeral 15 denotes a ventilation duct installed near the starting end 1 of the continuous drying section, and as shown in FIG. The fan 13 sucks hot air in the downward direction as indicated by the arrow.

On the other hand, a nozzle vent 15' is provided near the terminal end 1 (11) of the drying section, and the ventilation vent 15' shown in FIG.
The structure is almost the same as that of 10, or the ventilation direction force and tact are reversed, and the hot air passes from top to bottom from the arrow RIJz to the arrow S direction in Figure 1. be.

12B +B1 to variable speed f1 which drives the hot air fan 13
This is a removed drive unit. 16 is a hot air ventilation path arranged above the drying section 10I.

17 is a heat exchanger, and in the case of Fig. 1, a fin heater etc. is used, and air is supplied from the steam pipe 17S. Alternatively, a steam heater or the like made of a steel pipe installed in parallel with the rolls 14 of the conveying device may be installed in the ventilation duct 15.
Multiple rows are arranged nearby.

Reference numeral 18 denotes a JJ 1 cylinder, which increases the power by 1 as the veneer drying progresses, and removes the moist air inside the machine to the outside of the machine via a damper or other adjustment device. 1.1 is a temperature detection device, and is one or more temperature detection devices installed on the front side of the heat exchanger for dry hot air passing through the heat exchanger.
Reference numerals 1 and 2 denote one or more temperature detection devices, which are also arranged on the rear side of the heat exchanger. In addition, as a simple force type, it is also possible to omit the temperature detectors '1 and 2 on the rear side and use ζ.

The thermometer is configured to output an electric signal corresponding to hot air i'l'li 1 degree, or to output a signal when it reaches a set temperature of 12 IL degrees.

8) when steam is used as the heat source using a pressure switch. It emits a signal corresponding to the atmospheric pressure or when a predetermined set pressure is reached, and is installed near the steam supply port 1 (11) with a heat exchange ratio of 2:4.

Reference numeral 30 denotes a control device which activates an alarm device such as flashing a signal light or sounding an alarm such as a buzzer using a temperature detection device such as the above-mentioned TI or “l゛2” or a pressure sensor P or the like. The hot air fan drive device 12 is controlled manually or automatically based on the alarm.

Reference numeral 33 denotes a control valve that controls the feed pressure, flow rate, etc. of a heat source such as steam to be fed into the heat exchanger.

The drying apparatus of the present invention having the above configuration will be explained based on embodiments. The ffl slope, which is the material to be dried, is fed in the direction of arrow A at the entrance shelf 1, and is transferred to the drying sections 101 (in the direction of arrow 13) through three upper and lower stages.

The hot air is energized by the fan 13, passes through the heat exchanger 17 from arrow O to arrow P, becomes high/2 liter hot air, and then passes through arrow R and Nosuldak I. Show S
In the direction, r! 1] Move the outer surface of the veneer backwards in the veneer transfer direction (direction of arrow B);
Arriving near the beginning of the drying section, open the ventilation duct 1-
15 arrow below jii J L rise up, fan 1
3, proceed in the direction of arrow O, and then proceed in the direction of arrows P and Q.
, R, S, and T directions.

When the high-temperature hot air rubs the surface of the veneer, it heats the veneer and the moisture in the veneer is scattered.Therefore, the hot air turns into low-temperature hot air because it has heated the veneer, and continues to be sent to the fan 13.
By passing through the heat exchanger 17, the air becomes high temperature 74!5 again and heats the veneers that are successively fed in.

On the other hand, the heat exchanger generates lU by passing the hot air that has become low temperature.
The temperature decreases and the pressure inside the vessel also decreases, but by introducing new steam at a predetermined pressure, the temperature becomes high and high IE again, and the hot air is reheated. Thereafter, the same phenomenon will be repeated, but in reality, an equilibrium state will be maintained at a pressure and temperature slightly lower than the introduced vapor pressure.

To explain the case where the veneers to be fed are short bulk lλ plates and the filling rate to the dryer is low, the veneers are transferred one after another in a sparse manner, and the hot air continues to circulate inside the machine, or the material to be dried is The amount of hot air is small, and the hot air reaches a high temperature quickly as it circulates. This kind of cabin temperature is detected by the detection device "rl".
, 1'2, but it can be seen that the lower the filling rate, the closer the detected temperatures of the detection devices TI, 1'2 become.

Furthermore, as a result of the hot air circulating at a high temperature, the heat exchanger 17
heat exchange is stagnant, the heat exchanger maintains the high pressure of the introduced steam, and the pressure switch I] is operated. Signals from the above temperature detection device and pressure switch, for example, activate warning devices such as signal lights or buzzers at multiple stages of the veneer filling rate, such as low, medium, and high, to detect abnormalities in the filling rate. It conveys. - After this, based on the alarm, the drive device 12 of the hot air fan 13
The filling rate can be increased by appropriately controlling the amount by the control device 30 or by increasing the number of veneer feeding departments.

The above control is also automated, with temperature detection devices '1'1 and '2'.
The control device 30 receives a signal from either one of the pressure detection device (pressure switch P in this example) of the q45 exchanger, and controls the drive device 12 of the hot air fan 13. Automatically control, for example, if the hot air is at an abnormal height of 611
．． In this case, it indicates that the veneer filling rate is extremely low, so the rotation of the hot air fan is slowed down.

As the rotation of the hot air fan decreases, the amount of circulating hot air passing through it decreases, and the amount of air passing through the heat exchanger 17 also decreases. At the same time, it is possible to reduce power consumption by reducing the rotation of the engine.

As a result, the loose 1.1x sheets are dried using hot air at an appropriate temperature 6 that matches the filling situation, and as time passes, the detection devices detect n, 1. When the temperature and detected pressure return to predetermined values, a signal from the control device causes the rotation of the multi-air fan to return to compaction rotation.

below,? The fan rotation is appropriately controlled every 93 times from consolidation rotation to deceleration rotation based on the signal from the detection device. In addition, the above-mentioned detection of the veneer filling rate in the machine using command signals from each detection device and the fan rotation control using control signals from the control device that receives the above-mentioned information are performed by a method of steplessly changing the speed from consolidation rotation to sequentially decelerated rotation. , there is a method of changing gears within a certain range at each predetermined stage.

Since the hot air temperature detected by the temperature detection device T2 can be assumed to be approximately constant due to the specifications of the drying device, the temperature detection device T2 is omitted, and one or more devices are installed on the front side of the heat exchanger. [Temperature detection device] 1] It may be configured such that an alarm device or the like is activated according to the set temperature sequentially, or the volume of hot air is increased or decreased based on only the signal from 1.

According to the above device, it is possible to grasp the actual state of the veneer filling rate point by point, and it is possible to increase the filling rate, or to control the hot air volume or air speed to match the filling rate. The abnormally high temperature inside the machine during drying, the associated H&E leakage of high-temperature hot air to the outside of the machine, and the high heat energy consumption from heat insulation boards and other sources are alleviated, making it possible to save significant energy and achieve efficient veneer drying. It has become.

In this example, a so-called hot air vertical circulation type drying apparatus was described in which the direction of circulation of the drying hot air was the same as the direction of transport of the veneer to be dried. It is also possible to use a cross-circulation type veneer drying device that has practical effects.

[Brief explanation of the drawing]

FIG. 1 is a side view of a drying device according to the present invention, and FIG. 2 is a front view. ■・・・・・・・・・・Entrance shelf 1 (1・・・・・・・・Drying device 10C・・・・・・・・・Cooling section ior;'・
・・・・・・・・・Cooling fan 10) ■・・・・・・・・・
・Drying section 11...Unit drying section 12...Fan drive device 13
・・・・・・・・・Hot air fan 14・・・・・・・・・Roll 15・・・・・・Ventilator tact 30・・・・・・・・・Control device

Claims (1)

[Scope of Claims] (1) In a veneer drying device that dries the intermediate board using circulating hot air while transporting the intermediate board, a conveying device that transports the fi'i board;
A heat exchanger that heats hot air, a hot air fan that circulates hot air, a variable-speed drive device that drives the hot air fan, a temperature detection device installed after the heat exchanger's niJ, and a hot air fan that circulates the hot air. The steam supply [Iβ11] is equipped with a pressure gas inlet installed near 11, the above-mentioned 4 degree detection device, and a control device that receives signals from the pressure gas inch and controls the alarm device and/or the hot air fan drive device at 4J. Characteristic veneer drying equipment. 21. Claim j characterized in that the temperature detection device is constituted by a detector disposed in front of the heat exchanger.
- The veneer drying device according to item 1 between n. (Margin below)