RU2319088C1 - Method for wood drying and installation for its realization - Google Patents

Abstract

FIELD: drying equipment, in particular, wood drying in a chamber, applicable in wood-working, furniture, construction and other branches of industry.

SUBSTANCE: the method of wood drying consists in laying of wood on a tray placing of radiators in it. The wood is subjected to action of electromagnetic radiation in several places, unidirectional nanosecond pulses of electromagnetic waves with a power of at least 1 MW, duration of not more than 1 ns and repetition frequency of at least 1 kHz are used for electromagnetic radiation, and processed by heated flow-through air. The installation has a drying chamber with a body, pulse generator located outside the body, fan unit, air heaters, air conduit, tray for placing the material to be dried, radiators coupled to the generator. The chamber body also serves as a radiator. The tray is made with wheels. The fan unit is installed in the upper part of chamber body, installed in which are also the air heaters and the air conduct in the form of a branch pipe for air exchange.

EFFECT: provided more qualitative radiation of wood, simple construction and effective removal of water from it.

2 cl, 2 dwg

Description

The invention relates to drying equipment, namely to drying wood in a chamber, and can be used in woodworking, furniture, construction and other industries.

A known method and installation for drying wood, described in US Pat. RF №2157490 "Installation for drying wood" according to cl. F26B 9/06, 3/347, claimed 04/21/99, publ. 10/10/2000.

The known method consists in the fact that a stacked stack of timber beams is irradiated uniformly throughout the volume through a horn antenna with rotating polarization, a ventilating air stream is supplied across the working chamber having walls in the form of honeycomb screens. The known installation comprises a working chamber, a microwave generator coupled to it, the output of which is connected to a radiator made in the form of a horn antenna and equipped with a section of a square waveguide with a dielectric insert, the length of the waveguide having a length multiple of odd quarters of the wavelengths in the waveguide, installed across working chamber fans, while the walls of the emitter and the working chamber are made in the form of cell screens.

A disadvantage of the known means is the rather complicated construction of the walls of the emitters and the working chamber in the form of cellular screens.

A known method of drying wood and installation for its implementation, described in US Pat. RF №2228497 "Method for drying lumber with microwave energy" according to class. F26B 3/347 stated 07.24.02, publ. 05/10/04.

The known method consists in the fact that sources of microwave radiation are brought to the dried lumber or a stack of lumber from the side of their opposite ends and moved along the dried material from the ends to their middle part along the length at a speed depending on the speed of filtration of water vapor, given the initial and final humidity of wood, a given basic density of wood, specific volume of steam.

The known installation contains a drying chamber for placing a stack of lumber in it using dielectric spacers, microwave emitters connected to microwave generators using waveguides and matching devices to ensure the movement of microwave emitters along the guiding paths along the chamber.

A disadvantage of the known means is the difficulty of implementation, requiring the movement of emitters along the stack.

Closest to the technical nature of the claimed are the method of drying wood and installation for its implementation, described in US Pat. RF №2189549 "Installation for drying wood" according to cl. F26B 3/347 stated 08/14/2000, publ. 09/20/2000 and selected as prototypes.

The known method consists in the fact that the material to be dried is placed on a pallet, alternating it with dielectric spacers, then microwave radiation is fed to it through waveguides and antennas on the side walls of the chamber, the axes of which are mutually perpendicular and are located at an angle of 45 ° to the vertical, then blow a stack of material with moist and warm air from the material during periodic switching on and off of the air heater, maintaining a given air temperature.

The drying installation comprises a chamber equipped with a limit switch, magnetrons placed staggered on the side walls of the chamber in such a way that the axes of the radiation antennas of adjacent magnetrons are mutually perpendicular and located at an angle of 45 ° to the vertical, a processor, a sensor for measuring harmful microwave energy flux, microwave energy power meter, tray for the material to be dried, air circulation system, including a tray in the form of a box with holes on the side walls, the diameter of which does not exceed 0.1 radiation wavelength of neutrons located at a distance of 1/4 of the wavelength of magnetron radiation, the cavity of which is connected to an air duct installed in the upper part of the chamber with openings on the bottom, identical in size and arrangement to openings on the walls of the pallet, air heater and fan, and vertical between the pallet and side walls partitions of a translucent moisture-proof material, such as polyethylene.

A disadvantage of the known means is the complexity of the design and implementation of the method.

The task of the claimed means of drying wood is to simplify the drying technology and installation design.

The problem is solved in that:

- in the method of drying wood (lumber, material to be dried), which consists in placing the material to be dried on the pallet, exposing it in several places to electromagnetic radiation and treating it with running hot air, according to the invention, the emitters are placed in the material being dried, and as electromagnetic radiation using unipolar nanosecond electromagnetic pulses with a power of at least 1 MW, a duration of not more than 1 ns and a repetition rate of at least 1 kHz.

- in the installation for drying wood, containing a drying chamber for placing a stack of lumber in it using dielectric gaskets, a fan unit, heaters and duct installed in the upper part of the chamber, electromagnetic radiation emitters connected to the radiation source, according to the invention, one of the emitters is a housing cameras, and other emitters are removable for possible changes in their position relative to the stack of lumber and are equipped with means for supplying them with exercises, and as a radiation source, a generator of unipolar nanosecond pulses with a power of at least 1 MW, a duration of not more than 1 ns and a repetition frequency of at least 1 kHz, located outside the camera, was used.

It is known that wood contains two types of water: free water in the pores and capillaries and bound water in the cell walls. It is also known that water has a cluster structure, i.e. contains ordered elongated groups of molecules. In the claimed method, when wood is exposed to very powerful short unipolar pulses, the water contained in it radiolyses, hydrated electrons are formed, which are very active chemical particles, they increase the intermolecular interaction energy, which leads to the formation of shorter and spherical bulk molecules instead of elongated chains clusters with reduced intermolecular voids. The viscosity of water decreases and water quickly approaches the surface of the wood, which accelerates its drying.

In the claimed installation, the use of a camera body as one of the electrodes of the emitters and the execution of other emitters electrodes removable with means for supplying radiation energy to them in combination with the use of a high-power unipolar nanosecond pulses generator as a radiation source allows the wood to be irradiated more efficiently, providing with a simple design effective removal of water from it.

The technical result is the effective removal of water with a simple design.

The inventive method has a novelty in comparison with the prototype, differing from it by such significant features as the use of unipolar nanosecond electromagnetic pulses as a source of electromagnetic radiation with a power of at least 1 MW, a duration of not more than 1 ns and a repetition frequency of at least 1 kHz and the placement of emitters in the processed material providing in aggregate the achievement of a given result.

The inventive installation has a novelty in comparison with the prototype, differing from it by the presence of such essential features as the implementation of the radiation source in the form of a generator of unipolar nanosecond electromagnetic pulses with a power of at least 1 MW, a duration of not more than 1 ns and a repetition frequency of at least 1 kHz, the execution of one of emitter electrodes in the form of a drying chamber housing and other electrodes in the form of removable electrodes equipped with means for supplying energy to them from a radiation source and having the ability to change position electrodes relative to the dried material, ensuring the achievement of a given result.

The applicant does not know the technical solutions possessing the indicated distinguishing features, which together ensure the achievement of the desired result, therefore, he believes that the claimed method of wood drying and installation for its implementation meet the criterion of "inventive step".

The inventive method and installation can be widely used in forestry, woodworking, furniture and other industries, and therefore meet the criterion of "industrial applicability".

The invention is illustrated by drawings, where shown in:

- figure 1 is a functional diagram of the installation;

- figure 2 is a layout diagram of the installation.

The inventive method of drying wood is as follows. Lay the dried material on a pallet, placing emitters in it. They are exposed to it in several places of electromagnetic radiation, using unipolar nanosecond electromagnetic pulses with a power of at least 1 MW, a duration of no more than 1 ns and a repetition rate of at least 1 kHz as electromagnetic radiation, and process it with heated running air.

The installation comprises a drying chamber with a housing 1, a pulse generator 2 located outside of the housing 1, a fan unit 3, an air heater 4, an air duct 5, a tray 6 for laying the dried material 7, emitters 8 connected to a generator 2. The camera housing 1 also acts as a radiator . The tray 6 is made with wheels 9. The fan unit 3 is installed in the upper part of the camera body 1 and includes motors 10 and fans 11 located in the upper part of the body 1, where there are also heaters 4 and an air duct 5 in the form of a pipe for air exchange. The housing 1 of the camera is equipped with a door 12. The emitters 8 are equipped with clips 13 in the form of "crocodiles" for supplying energy from the generator 2. The implementation of the generator 2 is described in detail in US Pat. RF №2004064. Inside the chamber 1 there are temperature and humidity sensors (not shown in the drawings) for monitoring temperature and humidity during the drying process.

The inventive method of drying is carried out using the inventive installation as follows.

The material to be dried is laid on a pallet 6, laying emitters 8 between the rows of boards 7, a pallet 6 is installed in the camera body 1, the pulse generator 2 is connected through clamps 13 to the embedded emitters 8, and the chamber door 12 is closed. Then, a pulse generator 2, a ventilation unit 3, and a heater 4 are turned on. The heating of the material 7 begins. At the same time, the wood is irradiated with unipolar nanosecond pulses with a power of at least 1 MW, a duration of no more than 1 ns, and a repetition frequency of at least 1 kHz. When wood is exposed to very powerful short unipolar pulses, the water contained in it radiolyses, hydrated electrons are formed, which are very active chemical particles, they increase the energy of intermolecular interaction, which leads to the formation of shorter and spherical volume clusters with smaller molecules instead intermolecular voids. The viscosity of water decreases and water quickly approaches the surface of the wood, which accelerates its drying. Water evaporates, warm air from the stack of material rises to the upper part of the chamber 1, enters the air duct 5, from where it is removed when the chamber is ventilated using the fan unit 3 and is discharged through the nozzle 5. During the drying process, the temperature inside the chamber is controlled by temperature and humidity sensors and humidity. If necessary, heaters 4 periodically turn off.

In comparison with the prototype of the inventive drying means are simpler.

Claims (2)

1. The method of drying wood, which consists in laying the wood on a pallet, exposing it in several places to electromagnetic radiation and treating it with heated running air, characterized in that the emitters are placed in the wood, and unipolar nanosecond electromagnetic pulses are used as electromagnetic radiation, with a power of at least 1 MW, a duration of no more than 1 ns, and a repetition rate of at least 1 kHz. 2. Installation for drying wood, containing a drying chamber for placing a wood stack using dielectric gaskets, a fan unit, heaters and duct, electromagnetic radiation emitters connected to the radiation source installed in the upper part of the chamber, characterized in that one of the emitters is a camera body, and other emitters are made removable for possible changes in their position relative to the wood stack and are equipped with means for supplying radiation to them, and in As a radiation source, a generator of unipolar nanosecond pulses with a power of at least 1 MW, a duration of no more than 1 ns, and a repetition frequency of at least 1 kHz, located outside the camera, is used.

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