EP0766612A1

EP0766612A1 - Device for drying and protecting wood

Info

Publication number: EP0766612A1
Application number: EP95903749A
Authority: EP
Inventors: Leos Senjuk
Original assignee: ELS Ltd
Current assignee: ELS Ltd
Priority date: 1994-06-15
Filing date: 1994-12-22
Publication date: 1997-04-09
Also published as: PL174760B1; SK158996A3; PL317642A1; WO1995034414A1; CZ146894A3; CZ279668B6

Abstract

Device for drying wood and products based on wood and for protecting it against harmful diseases such as rot, mildew, mushrooms diseases etc. In the rear portion of the case (1) executed of a heat insulation material and adapted for receiving charging stock carried on the railway (2) a heat exchanger (4) provided by a spraying nozzle (7) is situated adjacent to a suction valve (5). Above the suction valve (5) an entrance emitter (9) turned to the air stream entering the case (1) is installed. On a partition separating the rear portion of the case (1) from the inner space of the case (1) a circulation fan (3) is mounted. In the internal space of the case (1) at least one internal emitter turned towards the charging stock is disposed.

Description

Device for drying and protecting wood

Background of the invention

The invention relates to a device for drying wood and products based thereon and protecting it against harmful diseases such as rot, mildew, mushrooms diseases, etc. collectively called also as fungous diseases.

Description of the prior art

The known chamber devices for drying wood use the hot air for drying out the wood. The rying chamber is executed as a masonry structure or a construction composed of heat insulation panels. The inside walls of the chamber ensure the thermal and humidity insulation of the interior of the chamber. Inside the chamber a radiator heated by hot water or steam as well as circulation fans and a ventilation fan are installed. The circulation fans cause the air to flow transversally across the block of timber placed inside the chamber. The ventilation fan draws the humid air off the chamber in order to replace it by the air of a lower moisture content. Inside the chamber temperature and humidity sensors are installed to measure the temperature and humidity for example a dry and wet thermometer, probes for measuring the wood moisture content etc.

The drying process is regulated in taking into account the difference between the temperature indicated by the dry thermometer and that of the wet thermometer, the working temperature inside the chamber, type and shape of the wood to be dried, initial wood moisture content and the required final wood moisture content.

To ensure the initial humidity level in the chamber an air stream in which the water is sprayed is introduced into the chamber.

A disadvantage of the prior art devices for drying wood is that the walls are very thick in order to ensure their insulation properties. On the side walls of the chamber circulation fans are mounted, which fans force the circulation air to flow transversally to the block or^" wood. Such deployment of the circulation fans results in a lower speed of the forced air stream over the heating radiator what causes the reduction of the heat-transfer coefficient on the part of the air to be warmed up. Thus, the necessary heating surface of the radiator is to be enhanced. The known devices for drying timber do not provide the protection of the timber against diseases such as rot, mildew, mushrooms diseases etc. from which the wood may suffer inside its structure.

Object of the invention

The above mentioned drawbacks are in greater part eliminated by a device for drying and protection of wood and products based on the wood against harmless diseases such as rot, mildew, mushrooms diseases etc. collectively known also as fungous diseases. The device is executed as a sealable case- made of heat insulation material and provided by a door for insertion of a charging stock. The essential features of the invention consist in that in the rear portion of the case a heat exchanger provided with a water nozzle for injection of warm water is located adjacent to a suction valve and above the suction valve an entrance emitter is installed. The entrance emitter is turned towards the air stream entering the case. In a partition separating the rear portion of the case from its inner space an circulation fan is mounted. In the internal space of the case at least one internal emitter facing the inserted charging stock is disposed.

Placing of the emitter at the suction side of the circulating fan results in the increased speed of the circulating air flowing across the heat exchanger and consequently in reduction of the necessary heat surface what favorably effects the construction and operational costs. The injection of warm water into the circulating air flow inside the chamber makes the operation and attendance of a boiler which is used as a source of heat for the drying device easier. The control of the entrance emitter or the inside emitter which discontinues or eliminates the detrimental activity of wood pests is performed with respect to the extent to which the charging wood stock is affected by diseases such as rot and"fungous diseases etc. Brief description of the drawing

The invention is described in more detail in connection with the accompanying drawings where Fig.l is an elevational view partly in section of the rear portion of the device for drying wood and products based on wood and for their protection against diseases, Fig.2 is a top view of the device with its rear portion partly in section, Fig.3 is a side elevational sectional view of the device where the vertical section plane is disposed before a partition on which the circulation fan is mounted.

Examples of the embodiments of the invention

The case 1 of the drying device is a compact block formed of corrosion-resistant materials. The walls are made of heat insulation material^"covered from both the outside and the inside by a surface having corrosion-resistant properties and by a layer of acrylate. The case 1 represents a self-supporting complex and is gastight sealed by silicone materials. The case 1 is secured to the mounting frame which includes also an internal railway 2 for a lorry designed to carry a charging stock, for example timber, which is however not shown in the drawing. In the front wall of the case 1 a door and in the rear wall of the case 1 a suction valve 5 are mounted. In the rear portion of the case 1 a heat exchanger is situated adjacent to the suction valve 5. Above the suction valve 5 an entrance emitter 9 turned towards the stream of air coming from the valve 5 is mounted. In the upper part of the heat exchanger 4 a water spray nozzle 7 is fixed. The suction valve 5, the heat exchanger 4, the spray nozzle 7 as well as the entrance emitter 9 are partly separated from the inner space of the case 1 by a partition 8. In the partition 8 beyond the heat exchanger 4 a circulation fan is installed. The circulation fan 3 is represented by a conventional axial-flow fan 3. On the side wall, inside the case 1 a measuring bracket with a psychrometer, probes for measuring the humidity and thermometers is secured which are however not shown in the drawing. In the ceiling 6 of the case 1 an exhausting fan 6 is built in. On the side wall of the case 1 in its upper portion at least one internal emitter 10 is mounted. The internal emitter 10 is turned towards the space in which the charging stock, for example the wood or products of wood to be dried, is placed. The internal emitters 10 may be situated on both side walls of the case 1 and turned towards the space where the dried wood is received. The embodiment where greater number of internal emitters 10 is provided is not shown in the drawing. The emitters 10 and 11 are ultraviolet discharging lamps.

The device operates as follows. Before charging the device the door of the case 1 is opened and the charging ^'stock to be dried and cured of diseases such as rot and diseases caused by mildew, mushrooms etc. is brought in. The charging stock is carried by the lorry. After closing the door the circulation fan 3 is turned on. The fresh outside air flows through the suction valve 5 into the space beyond the partition 8. Due to the suction effect of the circulation fan 3 the air passes the heat exchanger 4 and is heated up. Simultaneously the water nozzle 7 sprays into the stream of the circulating air warm water whereby the air stream is properly humidified. The air stream further passes through the circulation fan 3 into the inner space of the case 1 where during the circulation the air takes up the moisture comprised in the charging stock and get it dried. The exhausting fan 6 withdraws the^' humid air from the case 1. The internal emitter 10 generates short discharges of ultraviolet radiation in the range from 10 to 400 nm to which radiation the charging stock is exposed for the determined time subject to the specific conditions set up with respect to the specific character of the charging stock. The discharges produce changes in the living organisms causing diseases such as rot and fungous diseases which changes result in the reproduction incapacity and suppression of the viability of the living organisms. In this way the living organisms in the charging stock causing the said diseases are destroyed. If the charging stock has been already affected by the said diseases their adverse effects will be after their exposure to the radiation discontinued. The irradiation of the charging stock inside the case 1 is to be supported by the effect of the entrance emitter 9, which exposes to the radiation the outside air entering the case 1 through the suction valve 5 which air passes under the entrance emitter 9. The discharges of the entrance emitter 9 destroy the infectious germs comprised in the air which may cause diseases such as rot, fungous diseases etc.

In the course of the whole process the temperature is measured by means of the dry and wet thermometer; the changes in humidity of the air circulating in the case 1 and the moisture content of the wood subjected to the drying process are also measured. All those data are loaded into the storage block not shown in the drawing and the same applies for the initial data referring to the type of charging stock, its moisture content and to which extend it is affected by the diseases. Using those data and the values picked up in the case 1 during the whole process the storage block controls the time of drying, the operation of the exhausting fan 6, the intensity and period of radiation from the entrance emitter 9 and the internal emitter 10 and indicates the completion of the process.

After completion of the process the dried up and treated charging stock is replaced by a new charging stock. If necessary, the initial parameters in the storage block are modified and the whole of the process is repeated.

Industrial applicability

The invention may be used in drying timber and in protection of the dried timber or products made of wood, for example furniture, and other products, based on wood which has been affected by the diseases such as rot and fungous diseases.

Claims

Device for drying wood and products based on wood and protecting it against harmful diseases such as rot, mildew, mushroom diseases etc. executed as a sealable case made of heat insulation material and provided by a door for the insertion of charging stock characterized in that in the rear portion of the case /l/ a heat exchanger with a spraying nozzle /7/ is situated adjacent to a suction valve /5/ and an entrance emitter /9/ is mounted above the suction valve /5/ in the position turned to the air stream entering the case /5/ and in a partition /8/ separating partly the rear portion of the case /I/ from the inner space of the case /I/ an circulation fan /3/ is installed wherein at least one internal emitter /10/ turned towards the charging stock is disposed in the internal space of the case /!/.