CN101512277A

CN101512277A - Method and apparatus for drying wood

Info

Publication number: CN101512277A
Application number: CNA2007800327914A
Authority: CN
Inventors: R·彭迪凯南
Original assignee: Wood Neste Oy
Current assignee: Wood Neste Oy
Priority date: 2006-09-04
Filing date: 2007-08-31
Publication date: 2009-08-19
Also published as: FI20060791A0

Abstract

The invention relates to a method and apparatus for drying wood by means of vapor. In the method according to the invention the vapor essentially is generated from the wood's (3) own liquid by means of electric energy (2) by conducting the electric energy (2) by means of electrodes (1) directly to the wood (3) to be dried so that the vapor generated first in the center of the wood (3) pushes out the liquids in the wood (3) via the capillaries of the wood. The apparatus according to the invention comprises a current source (2) and electrodes (1) connected thereto built to be brought into contact with the wood (3) to be dried in order to conduct electricity to the wood.

Description

The method and apparatus of desiccated wood

Technical field

The present invention relates to utilize the method and apparatus of steam drying timber.

Background technology

Count from very traditional outdoor air dry, known desiccated wood before has a lot of different modes.Industrial common use drying equipment by means of the moisture in heat and the air flow evaporator timber, and is drained humid air in drying equipment from dry place.High energy consumption is the characteristics of these drying equipments.Usually, dry result's quality may be better.Dry as a result the time when what will produce, just must carry out drying at leisure, it means very long drying time simultaneously.

It has been observed that, drying bottleneck still not in wood industry, but also be considerable cost factor.Therefore, people sketch the contours of some kinds of different drying means based on different physical phenomenons.Negative pressure in the dry place, malleation and positive negative pressure alternately obtained utilization.Microwave, ultrasonic wave and different rays also have been proposed even have been used for desiccated wood by test.Even also have more the trial, but only some method is applied in industry.

Summary of the invention

The purpose of this invention is to provide a kind of method and device, utilize this method and apparatus desiccated wood faster more cheap than former.Another object of the present invention provides a kind of device, and this device can very well be attached on the many kinds of production lines of sawmill and woodwork factory, and these factories produce sawn timber, round log and wooden finished product.

Invention according to the present invention is based on the use of contained liquid in the timber, and this liquid makes electricity pass through timber.Electric current is connected on the not homonymy of timber, thereby electric flowing through from timber to the heating of the liquid in the timber and with this liquid changes into steam, and the high pressure of this steam is ordered about the capillary outflow timber of this liquid via timber.

Finally, have only steam to discharge, along with timber resistance increases, even this also can stop during the drying of wood.What should be noted that is, a large portion of the liquid in the timber is discharged from timber with the form of liquid significantly, compares with the desired evaporation fully of many previous drying means, and the present invention has saved a considerable amount of energy thus.

Appended claim can make feature of the present invention more obvious.

Understand the present invention by means of a preferred exemplary embodiment below, but this embodiment does not limit the present invention.

Description of drawings

Fig. 1 is a schematic diagram of implementing the layout of the method according to this invention;

Among the figure, numeral 1 is represented electrode; Numeral 2 is represented power supply; The timber that numeral 3 representatives are dried; Numeral 4 is represented the groove of the liquid that woods.

The specific embodiment

In the method according to the invention, electrode 1 is located on the not homonymy of the timber 3 that is dried and forms with their and contacts, utilize the conduct electrical power 2 that directly is added on the timber that is dried, when the high-tension current from power supply 2 was conducted to timber by electrode, the moisture in the timber began along with the heating of timber to separate.The timber centre is the driest usually, so the resistance maximum in centre, and this just means that the centre of timber 3 begins to heat up at first.When the evaporation of the water at position, center, it is driven the water in the timber of its front away via the capillary of timber, and this liquid falls in the groove 4 that is placed on below the timber.Only remaining at last small amount of steam, the steam in timber centre is hotter drier than peripheral position.Therefore hotter drier steam also has higher pressure, will drive away in the more moist steam on the top layer of its front.After steam was discharged, timber obtained drying, and it has so high resistance makes the electric current of being supplied by power supply 2 reduce, and it causes the automatic minimizing of this plant energy consumption in essence.

Readily understand dry latest developments by the variation of observing the electric current on the ammeter.Can influence dry result by changing voltage, the voltage rising can provide better dry result.On the other hand, when drying begins, because quantity of fluid separates with timber greatly, for fear of producing spark even may needing to reduce voltage.Preferably, applied voltage is 200V to 10000V, preferably is in 2 kilovolts of in 7 kilovolt range several kilovolts.

Energy consumption for drying can be automatically or self-control, so this device reduces power when timber becomes dry.

In practice, can use many different alternative to implement the present invention.Fig. 1 illustrates the drying of round log spare, for example bar.Yet it should have more applications in the drying of sawmilling.So can adopt circular electrode, the sawmilling part lies in the there adjacent to each other, and the centre is separated with little the air gap, air stream can be blown over this air gap to take away moisture.Aspect another electrode, to lie more by being made into collection liquid down or very close to a groove of this electrode, liquid goes out with recirculation from this concentrated flow.This liquid is very suitable for chemical industry, is used for medicine or perfume.If the liquid in wishing to wood very up hill and dale, drying can be arranged in the hydrophobic light liquid carries out, and whole like this device all is arranged in this liquid.Then, the liquid in the timber is fallen the bottom of groove, is easy to collect it from that.Certainly, this liquid must be non-conductive and fire-retardant.

In order to strengthen the discharge of steam and liquid, electrode also can be penetrated or be changed kind of a mode for steam and/or liquid and be said so permeable.In order to ensure flowing of electricity, the contact-making surface between electrode and the timber can be arranged to have spongy surface appearance and damping device.If necessary, can use a kind of liquid to carry out humidification, this kind liquid has electric conductivity more, as salt solution.

If wish to increase the eliminating of timber liquid, electrode can be divided into several sub-electrodes (PART-ELECTRODES) in the given side of electrode, these several sub-electrodes have the power supply that is arranged to continuous impulse, " operating wave " or analog one by one and all.

Move with respect to wood surface with roller by top electrode being made the belt that for example resembles crawler by means of rotation, perhaps utilize other modes to make electrode move into the direction of hope, also can increase the fluid removal that enters desired directions along wood surface.

If there is extra or cheap thermal source to utilize, can be preheating to a certain degree by dry timber, its electric energy that has reduced actual drying equipment expends.

Because the unnecessary heating of hothouse or similar spaces does not take place, but only to wanting dry timber to apply drying, so the expection of the efficient of apparatus of the present invention is very good.In addition, whole machining area does not transmit the pipeline of heat.

It should be apparent that by foregoing description the present invention can implement by various mode.The present invention is certainly easily with being used by the known drying means of people before.Therefore, the present invention not only is not limited to example described above, and can change to some extent within the scope of the claims.

Claims

1. method of utilizing steam drying timber, it is characterized in that: utilize electric energy (2) steam to be produced substantially by the liquid of timber (3) self, thereby make the steam that at first is created in timber (3) center the liquid in the timber (3) be released via the timber capillary by this electric energy (2) directly being led by means of electrode (1).

2. the method for claim 1 is characterized in that: quite a few of the liquid in the timber (3) is to discharge with liquid form, and these liquid are collected in the groove (4).

3. the method for claim 1 is characterized in that: utilize the dry result of Control of Voltage, the power consumption self-control in the drying, this power consumption reduction when timber becomes dry.

4. Wood drying apparatus is characterized in that: this device comprises power supply (2) and is connected to electrode (1) on this power supply (2), and this electrode is made into the timber that is dried (3) and contacts to conduct electricity to timber.

5. device as claimed in claim 4 is characterized in that: electrode (1) is permeable for steam and/or liquid.

6. device as claimed in claim 4 is characterized in that: another electrode (1) is made into along the surface of timber (3) and moves at least.

7. device as claimed in claim 4 is characterized in that: the preferred liquid that utilizes groove (4) collection in the device bottom to separate from timber.

8. device as claimed in claim 7 is characterized in that: groove (4) is big must to be enough to make the quantity of its hydrophobic, non-conductive, fire-retardant liquid of packing into to make whole device be suitable for being immersed in the liquid to operate.

9. device as claimed in claim 4 is characterized in that: electrode (1) is divided into sub-electrode, and electric current is supplied on these sub-electrodes as continuous operating wave.

10. device as claimed in claim 4 is characterized in that: applied voltage be 200V to 10000V, preferred several kilovolts.