CH713511A2 - Method and device for drying logs. - Google Patents

Abstract

A method of drying a log (1), the log having first and second faces (S1, S2), outside (1f) and full length (L), creating a longitudinal bore (1b) extending along the entire length (L) from the first to the second end face (S1, S2) extends, so that at the first end face (S1) an inlet opening (1c) and at the second end face (S2) an outlet opening (1d) is generated the longitudinal bore (1b) has an inside (1e) by keeping the log (1) in a substantially vertical position and supplying a drying gas (G) from below the log (1) such that the drying gas (G) also flows through the longitudinal bore (1b), and in that both the inside (1e) and the outside (1f) are directly flowed around by the drying gas (G), so that the log (1) from the inside (1e) as well as from the outside (1f) ago dried w ill.

Description

Description: The invention relates to a method and an apparatus for drying logs.

PRIOR ART [0002] Wood drying is the process for removing moisture from wood. With regard to drying methods, a distinction is made, in particular, between chamber-dried wood, which is dried in a controlled manner in a drying chamber, and air-dried wood, which loses moisture slowly only when covered outdoors. The aim of controlled drying processes is that the moisture of the wood reaches a so-called usage humidity. This is usually in the range between 6% and 16% wood moisture based on the weight of dry wood, that is wood in virtually anhydrous condition. Forest-fresh wood contains about 40% to 60% water. In order to obtain high quality wood, controlled, artificial drying of the wood is required to prevent fungal growth, discoloration, cracking, boarding or discarding of the wood. A disadvantage of the artificial drying is in particular the energy consumption. The air drying has the advantage that no energy needs to be supplied. The disadvantage is that the drying takes a long time, and that the wood loses quality or is damaged in such a way that it becomes unusable.

From the document KR 101 359 476 B1 a method for drying pine logs is known. In this process, a continuous longitudinal bore is created along the log, the outside of the log is covered with a watertight foil, and then warm air is passed through the longitudinal bore of the lying log to dry the log from the inside out. This reduces the likelihood of cracking on the log outside.

This drying method allows the drying of pine logs in one piece. Pine wood is a softwood and therefore easy to dry. However, this known drying method is not suitable to dry completely logs consisting of wood species that are difficult to dry, especially wood species such as hardwood, and especially beech wood.

From the document CA 1 129 681 A, a further method for drying logs is known. This process also involves reducing the formation of cracks in the log caused by drying. In this method, a continuous longitudinal bore is again created along the log.

Subsequently, a plurality of such strains are stacked in the horizontal direction, wherein the mutual distance of the stacked logs can be very small, because the longitudinal bore is accessible to a drying air.

DESCRIPTION OF THE INVENTION The object of the invention is to form a more advantageous method and apparatus for drying logs. The method and the device should be particularly suitable for drying hardwood logs.

This object is achieved with a method comprising the features of claim 1. The dependent claims 2 to 12 relate to further advantageous method steps. The object is further achieved with a device having the features of claim 13. The dependent claims 14 and 15 relate to further advantageous embodiments.

The object is achieved in particular with a method for drying a log, wherein the log has a first and a second end face, an outer side and an entire length by a longitudinal bore is generated, which extends along the entire length of the first to extends to the second end face, so that at the first end side an inlet opening and at the second end side an outlet opening is generated, wherein the longitudinal bore has an inner side by the log is held in a substantially vertical position and fed a drying gas from below the log is that the drying gas also flows through the longitudinal bore, and by both the inside and the outside is flowed around in direct contact with the drying gas from the drying gas, so that the surface of the log is extracted simultaneously from the inside and from the outside water, and d the log is dried in this way.

The object is further achieved in particular with a wood drying device for logs, comprising a longitudinal bore extending along the entire length of the respective log, comprising a plurality of holding devices for logs for holding the logs in a substantially vertical position, wherein the holding devices in vertical direction are arranged spaced such that at least two logs can be arranged one above the other in the vertical direction. Preferably, the holding devices are designed such that the inlet opening and the outlet opening of the longitudinal bore of each of the logs can be kept open for the flow of the drying gas.

Particularly preferably, the vertically extending log wood is removed by this is evaporated at the surface of the longitudinal bore, thereby moisturizing the drying gas located in the longitudinal bore and thereby reducing the increase in moisture density drying gas locally reduced in the longitudinal bore is, so that the drying gas located in the longitudinal bore at least partially has a reduced density, which produces a buoyancy on the located within the longitudinal bore drying gas. The effect described, that the humidified drying gas has a lower density and thereby strives upward, can also occur to a reduced extent on the outside of the log. However, this effect occurs more pronounced within the longitudinal bore, which can not mix within the longitudinal bore, moistened drying gas within the longitudinal bore with drying gas from the ambient air, so that within the longitudinal bore a so-called chimney effect occurs by the humidified drying gas can escape only to the top and thereby causes a suction or a movement of the entire located within the longitudinal bore column of the drying gas.

In a particularly preferred embodiment, the inner diameter and the length of the longitudinal bore are configured so adapted to each other that within the longitudinal bore by the inflowing from below and rising in the longitudinal bore drying gas, a chimney effect is generated, and the drying gas thus within the longitudinal bore in the Has substantially vertically directed, preferably laminar flow. The movement of the drying gas within the longitudinal bore upwards can also be assisted by arranging the log in a flow field with drying gas preferably flowing parallel to the log, and / or by heating the drying gas supplied to the log. The flow of the drying gas can be generated for example with a fan. The flowing drying gas and / or the heated drying gas is preferably supplied from below the longitudinal bore. The natural upward movement of the preferably warm drying gas along the inner surface of the longitudinal bore allows for efficient dewatering over the inner surface, thus enabling efficient drying of the log from within. In addition, the log is also flowed around on the outside of drying gas, so that the log is dried both inside and outside. In a particularly preferred embodiment, the drying device is designed such that in addition a chimney effect arises within the entire drying device, so that the entire log, especially the outside of this chimney effect, or a stream of ascending drying gas, preferably air, is exposed. Thus, particularly preferably, both the inner surface and the substantially cylindrical outer surface of the log are exposed to this chimney effect, or this is flowed around by ascending air. This drying process is particularly advantageous for drying hardwood logs. It is much more difficult to extract water from the hardwood, which is why no attempts have been made to dry hardwood logs in one go. The drying of whole hardwood logs has so far led to the problem that these logs strangled after beating and then rotten.

With the drying method according to the invention also very humid and / or freshly felled logs, especially hardwood logs can be dried easily by the logs are arranged vertically after creating the longitudinal bore in the drying device, and by the drying process then at least two steps comprises a first process step, during which liquid water flows down from the logs, and a second process step, during which only evaporated water is removed, which is absorbed by the drying gas from the surface of the longitudinal bore and the outside of the logs.

So far, it has been common to process logs to sawn wood, for example, to boards, and then to dry this lumber. The inventive method has the advantage that logs are provided after hitting with a longitudinal bore, then dried and processed after drying to sawn wood. This approach has the advantage that larger components such as beams or beams can be produced that warping of the wood during drying does not affect the lumber, since the lumber is produced only after drying, and that the timber exploitation is preferably greater. The wood exploitation of a log may be increased, for example, by knowing the exact mass of a plurality of logs, that in a CAD model the dimensions of the desired log are known, and that the logs are cut based on that data such that desired lumber with as little waste wood from the logs is cut.

The to be dried with the inventive method logs preferably have an outer diameter in the range of 16 cm to 90 cm, and preferably have a length in the range between 100 cm to 1600 cm, wherein the continuous longitudinal bore preferably has an inner diameter in Range from 5 cm to 50 cm.

It has surprisingly been found that with the inventive drying process beech logs can be dried. Beechwood is a very widespread type of wood in Switzerland, but is mainly processed into firewood. Fresh beech wood has a water content of about 50%, the bark of the beech is impermeable to water. In addition, beech wood is a hardwood, which is why it takes a relatively long time until the water has completely escaped. With beech wood there is thus a great risk that the wood suffocates during drying, or that mold and bacteria form, which damage the wood and make it worthless for high-quality products.

It is therefore extremely difficult to produce high quality products such as support columns, beams or boards made of beech wood. Because beech wood is extremely difficult to dry, it is usually split to allow the large amount of water stored in the wood to drain off as quickly as possible, for example to prevent mold growth. In addition, the splitting creates a larger drying surface, which additionally supports drying. However, such split wood can only be used as firewood.

The drying method according to the invention makes it possible for the first time to dry whole beech logs by cutting the log after cutting the tree and removing its bark by thereafter boring a longitudinal hole along the entire length of the cut log, and then cutting the cut log into vertical direction is dried by a drying gas rising from below. The drying of beech wood has been extraordinarily difficult, since beech wood is particularly susceptible to discoloration or stifling due to storage or process. The discoloration of the beech wood may be due to different physiological, microbiological, biochemical and chemical reactions, and may be biotic, for example, by fungi or bacteria, or may be, for example, abiotic, mostly due to oxidation reactions such as asphyxiation of the wood , The decisive quality criterion for beech wood, in addition to the trunk dimension and the stem shape, is thus the avoidance of storage and process-related discolorations that can occur after the wood has been hit. Such quality-reducing discolorations may occur during storage and drying of the wood, for example by infestation with bacteria or fungi, or by suffocation of the wood. With the drying method according to the invention, these discoloration effects can be avoided. The drying process according to the invention also makes it possible to dry large beech logs safely too dry. From the dried beech logs can then produce high-quality and hochpreisi-ge products, such as support columns, beams or boards, the products, for example, a support column, can also have a large dimension, for example, 3, 5 or 8 meters in length, and the Support column thus suitable for example for the construction of multi-storey houses.

The inventive drying method for logs can be performed as a further possibility also such that the felled tree is cut to at least one log of the log is not debarked, however, that thereafter a longitudinal hole along the entire length of the cut log is drilled that the cut to length Log is then arranged in a substantially vertical direction running in a drying device, and that below the log a drying gas is supplied so that the ascending drying gas flows around the log through the longitudinal hole and from the outside, whereby the bark of the log dries during the drying process, tears open and at least partially falls, so that the at least partially bark-free log is dried from the inside and the outside.

In an advantageous method step, a relaxation section is created along the entire length of the log, which extends from the longitudinal bore to the outside of the log, and extending from the first end face to the second end face. Such a relaxation cut has the advantage that the wood during drying little more or no longer ruptures, which increases the yield of high-quality wood.

The invention will be explained with reference to exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings used to explain the embodiments show:

Fig. 1 is a perspective view of a log;

Fig. 2 is a longitudinal section of the log according to Fig. 1;

Fig. 3 is a perspective view of a log with relaxation section;

Fig. 4 wood moisture of a log after 14 weeks without longitudinal bore;

Fig. 5 wood moisture of a log after 14 weeks with longitudinal bore;

Fig. 6 wood moisture of a log with longitudinal bore at different times;

7 shows schematically a drying device;

8 shows schematically a further drying device;

9 shows by way of example an arrangement of logs in the drying device;

Fig. 10 by way of example aligned one above the other arranged logs.

Basically, the same parts are given the same reference numerals in the drawings.

1 shows a log 1 in a perspective view and FIG. 2 in a longitudinal section, wherein the log 1 has a first end face S1 and a second end face S2, an outside 1f and an entire length L. Preferably, the wood trunk 1 to be dried has been peeled, that is to say the outermost layer comprising, in particular, bark, bast and cambrium have been removed. A longitudinal bore 1b extends along the entire length Ldes log 1 from the first end face S2 to the second end face S2, so that the first end face S1 has an inlet opening 1c and the second end face S2 has an outlet opening 1d. The longitudinal bore 1b is preferably configured as a central bore to remove the medulla of the log.

Advantageously, the central bore is designed as a core hole, and the wood of the core produced thereby is supplied to a further use. However, the longitudinal bore 1b could also run eccentrically in the log 1. In addition, the log 1 could also be provided with a plurality of parallel longitudinal bores 1b. The log 1 has to the longitudinal bore 1b towards an inner le or an inner surface le, via which the log 1 water is removed during the drying process water. The log 1 is held during drying in a substantially vertically extending position, wherein a drying gas G is preferably supplied from below the log 1, that the drying gas G on the one hand flows through the longitudinal bore 1b and on the other hand flows along the outside 1f, so that both the inner side le and the outer side 1f is flowed around directly, that is to say under direct contact with the drying gas G, so that water is withdrawn from the log 1 at the same time via the inside le as well as over the outside 1f. The drying gas G could also have little or no flow outside the log 1, wherein the drying gas G located within the longitudinal bore 1b moves upward due to the absorption of water vapor and the associated reduction of the specific weight within the longitudinal bore 1b, so that over the Inlet opening 1c drying gas G is sucked into the longitudinal bore 1b into it.

Advantageously, the inner diameter 1g of the longitudinal bore 1b and the length L of the longitudinal bore 1b are adapted to each other adapted that within the longitudinal bore 1b by the incoming drying gas G, a chimney effect is generated, and the drying gas G thus within the longitudinal bore 1b a vertically directed , Preferably laminar flow has. This through-flowing drying gas G can dry out the inner surface 1e particularly well, or can divert any water or water vapor particularly well from the inner surface 1e.

Fig. 3 shows that along the entire length L of the log 1, a relaxation section 1 a was created, which extends from the longitudinal bore 1b to the outside 1f of the log, and extending from the first end face S1 to the second end face S2 extends. This relaxation section 1a is particularly advantageous for logs made of beech wood, because a trunk of beech wood during drying despite careful drying under certain circumstances can distort massively or even heavily, and by the relaxation section 1a cracking in the log can be largely avoided. After completion of drying, the beechwood trunk can be further processed, for example to support beams, beams or boards. Since the dried beechwood trunk has hardly any cracks, thus high-quality wood parts can be cut from the trunk, and this with a high yield, since there are few cracks.

Fig. 3 also shows an additional heater 2, for example, an electric heater, which is disposed in the log 1 according to FIG. 1 or FIG. 3 within the longitudinal bore 1 b, and is flowed around by the drying gas G, wherein the heating device. 2 injects additional heat energy into the longitudinal bore 1b and supplies it to the drying gas G, and thus increases or accelerates the drying process on the inside le, in particular by the fact that the heat supplied increases the upward movement of the drying gas G or its flow velocity within the longitudinal bore 1b, which increases the gas exchange in the longitudinal bore 1b increases, so that an increased amount of water vapor from the longitudinal bore 1b can be conveyed out, and thus the drying process can be accelerated. In an advantageous embodiment, the heating device 2 extends along the entire length L of the log 1 within the longitudinal bore 1b, wherein the heater 2 is dimensioned such that it fills only a portion of the cross-sectional area of the longitudinal bore 1b, so that the drying gas within the longitudinal bore 1b a free Flow cross-sectional area is available, which is preferably at least 50% of the total cross-sectional area of the longitudinal bore 1b. The heating device 2 is preferably designed hose-shaped, and in one possible embodiment comprises a water hose extending through the longitudinal bore 1b through which warm water is conveyed, or, for example, an electrical resistance heater.

Fig. 4 shows the wood moisture within a log 1, wherein starting from the outside 1f, the moisture in the direction of radial distance inwards at the distance points 1.5 cm, 3 cm, 4.5 cm, 6, 7.5 cm cm, 9 cm 10.5 cm, 12 cm and 13.5 cm was measured. Fig. 4 shows the wood moisture for a log without longitudinal bore after 14 weeks drying time.

Fig. 5 shows the wood moisture within another log 1 at the same distance points as described in Fig. 4. The log according to FIG. 5 has a longitudinal bore 1b extending in the middle of the log and shows the wood moisture after a drying time of 14 weeks. From Fig. 5, the effect of additional drying on the inner bore 1b, with vertically arranged log, clearly visible, namely the fact that the log 1 is dried from the inside and the wood moisture thus towards the center, at the values 12 and 13.5 cm decreases.

Fig. 6 shows the wood moisture of a beechwood trunk 1 at a radial distance from the outside 1f for a log with centered longitudinal bore as a function of time, the 1st removal at the beginning of drying, the 2nd removal after 2 weeks, the 3rd after 5 weeks, the 4th after 8 weeks, the 5th after 11 weeks, the 6th after 14 weeks, the 7th after 17 weeks and the 8th after 20 weeks. From Fig. 6 it can be seen that the wood moisture of the beech wood trunk at the 8th removal, that is after 20 weeks, in function of the distance from the outside 1f has a substantially constant, low value of about 9 to 11% wood moisture. It can be seen that the method according to the invention makes it possible to evenly dry a beechwood trunk into its interior. In view of the fact that it was known that it is extremely difficult to dry beech wood, it was surprising that it is possible with the method according to the invention to dry beech wood trunks so uniformly.

Fig. 7 shows an embodiment of a drying device 10 for logs 1, wherein each log I has a longitudinal bore 1b, not shown, extending along the entire length L of the log 1. The drying apparatus 10 comprises a plurality of trestles 1 for holding logs 1 in a substantially vertical position, the holders being spaced apart in the vertical direction such that at least two trunks 1 can be stacked one above the other. The holding devices 18 hold the respective inlet openings 1c and outlet openings 1d of each longitudinal bore 1b open. FIG. 7 shows by way of example only three holding devices 18, each log 1 being held by such a holding device 18. The drying apparatus 10 illustrated in FIG. 8 comprises a tower-shaped drying space II with a steam-diffusion-open outer shell 12, the drying space 11 enclosing an interior space 10a which has an inlet 10b at the bottom and an outlet 10c for the drying gas G at the top, namely air. In the interior 10a gas-permeable intermediate floors, namely a first intermediate floor 13a, a second intermediate floor 13b and a third intermediate floor 13c are arranged, which carry the vertically extending logs 1 wood. Following the drying chamber 11, outlet channels 15a and at the bottom supply air channels 14a are arranged at the top to admit ambient air Gl down through the supply air channels 14a and above the outlet channels 15a to discharge the moistened drying gas G or the humidified ambient air G2. In an advantageous embodiment, the buoyancy of the drying gas G caused by the evaporation of water in the longitudinal bore is sufficient to produce an ascending air flow in the interior 10a. However, this effect decreases in particular with increasing drying of the logs 1. It may therefore prove to be advantageous to provide devices which force a flow of the drying gas in the interior 10a, for example, in which the drying gas G is promoted, for example with a fan, or by the drying gas G is heated, for example with a heater, so that Drying gas due to the heat within the interior 10a rises upwards, or for example from a combination of fan and heater. The heating is preferably carried out ecologically in that the heat is generated by solar energy, for example, in which solar panels 20 are arranged on the roof, and the energy thus obtained is used for heating the drying gas G. Instead of a fan or in addition to the fan, a flow of the drying gas G within the interior 10a may also be generated by means of heat, for example, by heating a side wall of the drying apparatus 10 and / or the roof of the drying apparatus 10 with solar energy, and thereby Drying gas G is locally heated so that forms a flow.

Fig. 8 shows a further drying apparatus 10 for logs 1, wherein each log 1, not shown, along the entire length L of the log 1 extending longitudinal bore 1b has. The drying apparatus 10 comprises a plurality of trestles 1 for holding logs 1 in a substantially vertically extending position, wherein the holding devices 18 are arranged in the vertical direction at a distance such that at least two trunks 1 can be arranged one above the other. 8 shows by way of example only three holding devices 18, each log 1 being held by such a holding device 18. The drying device 10 shown in FIG. 8 comprises a tower-shaped drying space 11 with a steam-diffusion-open outer casing 12, wherein the drying space 11 encloses an inner space 10a. In the interior 10a gas-permeable intermediate floors, namely a first intermediate floor 13a, a second intermediate floor 13b and a third intermediate floor 13c are arranged, which carry the vertically extending logs 1 wood. Following the drying space 11, exhaust air ducts 15 and at the bottom supply air ducts 14 are arranged at the top to supply a dry drying gas Gl from below and to remove a moistened drying gas G2 from above. The moistened drying gas G2 is fed via a line 16 to an air-conditioning device 17, which at least partially extracts moisture from the moistened drying gas G2 and also heats it before the dry drying gas is returned to the drying space 11. The air-conditioning device 17 also serves as an air circulating device for sucking up the drying gas G upwardly from the inner space 10a and supplying it down to the inner space to thereby generate a vertical flow of the drying gas G in the tower-like interior. The drying gas is usually air.

In an advantageous embodiment, the drying device 10 has a height in the range of 5 m to 30 m, to produce a pronounced vertically directed air flow in the interior 10a.

In the drying apparatus 10 according to FIG. 8, a so-called convection drying is preferably carried out. In this case, a drying gas flow, übli cherweise air, within the drying chamber 11 is generated with a fresh air-exhaust air flow or a circulation flow. In this case, the temperature, the flow rate and the relative humidity of the drying gas G in the drying chamber via the air conditioning device 17 is controlled. During a warm-up phase, the relative air humidity is first kept at a high level for better heat transfer, and partly increased by spraying water into the drying chamber. During a subsequent drying phase, the drying gradient is then optimized depending on the type of wood. During a subsequent conditioning phase, at the end of the drying process, a moisture balance within the wood is sought.

In a preferred embodiment, the drying device 10 according to FIG. 7 or 8 also includes solar panels 20, wind generators 20 or solar cells 20 to operate the drying device 10 partially and preferably completely autonomous from the public power grid. A completely autonomous operation has the advantage that the drying device 10 can also be installed in areas that have no power supply, it being ensured that at the selected location enough solar and / or wind energy is available. In an advantageous embodiment, the drying device also comprises an electrical energy storage, for example a battery to store electricity produced by the solar cells and / or wind turbines, advantageously so that the drying process can be continued without interruption even at night. Advantageously, the drying device 10 is arranged and configured such that the drying process requires less energy than the existing, produced solar and / or wind energy, or if the drying process is interrupted, that for the drying process then more energy is available than the currently produced Amount of solar and / or wind energy, which is particularly advantageous if the currently produced amount of energy is too low to ensure safe and / or timely drying.

Fig. 9 shows a feeder to the drying device 10 to load efficiently with logs 1 can. The loading device comprises a multiplicity of holding devices 18, it being possible in each case for a log 1 to be fastened in a vertical direction to a holding device 18. The holding devices 18 are arranged movably, and are movably mounted along a rail 19, for example, so that the logs 1 can be moved in the direction of the rail 19, and in particular the drying device 10 can be supplied or removed therefrom. The rail 19 could also be arranged extending above the logs 1, so that the logs 1 example meadow are fastened hanging on cars, the cars are guided by the rail 19, and are arranged on these movable in the direction of the rail 19. It could also be provided a plurality of rails 19. The charging device may be configured in a variety of ways to move the logs 1 in the horizontal and / or vertical direction in the drying device 10. The feeder could also include a plurality of jigs 18 located at fixed positions and could also include a repositioning device, such as a crane or robotic arm, to position the logs 1 in the jigs 18 or a log 1 from one Reposition fixture 18 to another fixture 18. The charging device according to FIGS. 8 and 9 could also be configured such that logs 1, for example during drying, can be displaced in a horizontal position within the intermediate plane 13a, 13b, 13c in a horizontal direction, or that the logs are in a vertical position Move direction from one to the other intermediate plane 13a, 13b, 13c, or that the logs can be moved both in the horizontal direction and in the vertical direction within the drying device 10. This is particularly advantageous for individually influencing the drying process of a log, for example to dry a log more quickly by positioning it in the lowest intermediate plane 13a, in which the drying gas has a lower atmospheric humidity and / or a higher temperature, or by one Slow drying of log by positioning it on topmost intermediate plane 13c, where the drying gas has a higher humidity and / or a lower temperature. In an advantageous embodiment, at least some and preferably all logs 1 are provided with individual moisture sensors, so that the course of the drying process can be measured as a function of time for these logs, and, if necessary, the logs in the drying device 10 can be repositioned to the course the drying process with respect to a log individually.

In addition, it is possible in an advantageous embodiment, at least one of the logs 1 to supply an individually heated and / or humidified drying gas G in order to flow its longitudinal bore 1b and / or its outer side 1f with the individual drying gas G. In addition, it may be advantageous to arrange a heating device in the longitudinal bore 1b at least in sections, for example a hot water hose supplied by solar collectors, in order to supply additional heat energy to the inner side.

Shows by way of example two in the vertical direction in each case arranged one above the other wooden logs 1, which are arranged such that their longitudinal bores 1 b are arranged mutually aligned in the vertical direction, so that the emerging from the longitudinal bore 1 b of the lower log 1 drying gas G. at least partially flows into the longitudinal bore 1b of the overlying log 1. Advantageously, at least some of the logs 1 are arranged mutually aligned in the drying apparatus 10, and most advantageously most or all logs 1 arranged in groups in each group, for example, each 2, 3 or 4 groups of logs arranged one above the other, the total possible number arranged in groups one above the other Timber logs on the total height of the drying device 10 depends. The aligned arrangement has the advantage

Claims (15)

on that thereby the buoyancy of the drying gas G is increased. As shown in Fig. 10, it may prove to be advantageous in each case between two stacked logs 1 to be arranged only schematically and dashed lines guide 21 which at least partially seals the space between the two logs 1, and preferably substantially airtight seals, so the drying gas G emerging from the longitudinal bore 1b of the lower log 1 is forced to flow into the longitudinal bore 1b of the upper log 1. In an advantageous embodiment, a line, preferably a flexible hose, along the entire length through the longitudinal bore 1 b is passed. Advantageously, a warm fluid, preferably water, is passed through the conduit to heat the interior of the longitudinal bore 1b. Preferably, the conduit has a diameter of at most one third of the diameter of the longitudinal bore 1b. The drying gas G in the interior of the longitudinal bore 1b, between the inner side of the longitudinal bore 1b and the conduit surface of the conduit, is preferably heated so that the drying gas G flows upward as natural air flow, and thereby the moisture absorbed by the drying gas G in the longitudinal bore 1b the longitudinal bore 1b is conveyed out. Advantageously, the tower-like device 10 is filled such that the interior 10a is filled to a maximum of two thirds with logs 1, so that at least one third of the interior 10a is empty or filled with drying gas G. It may prove advantageous to guide the rising inside the interior 10a air by means of guide elements, for example, with horizontal, starting from the outside of the inner space 10a to a respective log 1 reaching guide elements to supply the flowing drying gas G advantageously the outer surface of the logs 1 so that the drying gas G can absorb or divert more water vapor from the outer surface of the log, and / or thereby save energy in particular. claims A method for drying a log (1), wherein the log has a first and a second end face (S1, S2), an outside (1 f) and an entire length (L), - by a longitudinal bore (1b) is generated which extends along the entire length (L) from the first to the second end side (S1, S2), so that an inlet opening (1c) on the first end face (51) and an outlet opening (1d) on the second end face (52) is produced, wherein the longitudinal bore (1b) has an inner side (1e), wherein both the inner side (1e) and the outer side (1f) is directly flowed around by a drying gas (G), so that the log (1) simultaneously from the inside (1e) as well as being dried from the outside (1f), characterized in that the log (1) is held in a substantially vertical position and a drying gas (G) is supplied from below the log (1) in that the drying gas (G) is also durc h the longitudinal bore (1b) flows. 2. The method according to claim 1, characterized in that the log (1) water is withdrawn by this is evaporated at the surface of the longitudinal bore (1b), characterized in that in the longitudinal bore (1b) located drying gas (G) is moistened and thereby its density is reduced, so that within the longitudinal bore (1b) acting on the drying gas (G) buoyancy is generated. 3. The method according to claim 1 or 2, characterized in that the inner diameter (1g) and the length (L) of the longitudinal bore (1b) are configured adapted to each other such that within the longitudinal bore (1 b) by the flowing drying gas (G) a chimney effect is generated, and the drying gas (G) thus within the longitudinal bore (1b) has a vertically directed flow. 4. The method according to any one of the preceding claims, characterized in that the log (1) and thus also the longitudinal bore (1 b) has a length (L) of at least one meter, along which the drying gas (G) within the longitudinal bore (1 ) flows upwards. 5. The method according to any one of the preceding claims, characterized in that the drying method after vertically arranging the Holstamms (1) comprises at least two steps, a first step, during which liquid water from the log (1) flows downwards, and a second Process step, during which only evaporated water is removed, which is absorbed by the drying gas (G) from the surface of the longitudinal bore (1b) and the outside (1f). 6. The method according to any one of the preceding claims, characterized in that a log (1) consisting of beech wood, dried. 7. The method according to any one of the preceding claims, characterized in that the longitudinal bore (1b) has an inner diameter in the range of 5 to 50 cm. 8. The method according to claim 6 or 7, characterized in that along the entire length (L) of the log a relaxation section (1a) is created, which extends from the longitudinal bore (1b) to the outside (1f) of the log, and the extends from the first end face (S1) to the second end face (S2). 9. The method according to any one of the preceding claims, characterized in that a plurality of logs (1) are dried in a tower-like device (10), wherein the logs (1) are arranged partly next to each other and partially in the vertical direction one above the other, wherein the tower-like Device (10) is designed in such a way and the drying gas (G) is supplied in such a way that in the tower-like device (10) a substantially vertically extending air flow is generated. 10. The method according to any one of the preceding claims, characterized in that in the vertical direction in each case stacked logs (1) are at least partially arranged such that the longitudinal bores (1b) are mutually aligned in the vertical direction, and that from the longitudinal bore (1b) of the lower log (1) emerging drying gas (G) at least partially flows into the longitudinal bore (1b) of the overlying log (1). 11. The method according to any one of the preceding claims, characterized in that at least some of the logs (1) with preheated drying gas (G), in particular with individually preheated drying gas (G) flows around and / or flowed through. 12. The method according to any one of the preceding claims, characterized in that the inner side (1e) of the longitudinal bore (1b) of the log (1) with a heater (2) additional heat is supplied. 13. Wood drying device for logs (1) each having a along the entire length (L) extending longitudinal bore (1b), comprising a plurality of holding devices (18) for logs (1) for holding the logs (1) in a substantially vertically extending Position, wherein the holding devices (18) are arranged in vertical lease spaced so that at least two logs (1) can be arranged one above the other, and wherein the holding device (18) are configured such that an inlet opening (1c) and an outlet opening (1d ) of the longitudinal bore (1b) of each of the logs (1) can be kept open. 14. The apparatus according to claim 13, characterized in that it has a tower-like interior, and that an air circulation device sucks a drying gas (G) above in the interior and below the interior feeds to produce a vertically extending air flow in the tower-like interior. 15. The device according to claim 13, characterized in that it is designed as a tower-like device (10) and has a height in the range of 5 m to 30 m in order to generate within the tower-like device (10) a pronounced vertically directed air flow, and in that the device (10) has at the bottom an inlet (10b) for ambient air and at the top an outlet (10c) for the drying gas (G) to the ambient air.