FR2711937A1 - Process and installation for the heat treatment of wood, in particular beams of frames against pests. - Google Patents

Abstract

a) Process and apparatus for treating wood, particularly beams of frameworks against parasites. b) Process characterised in that: - the pieces to be treated are enveloped with a heating electrical element, the external surface of which has good heat-insulating (lagging) characteristics, closely covering the piece to be treated, - a temperature profile as a function of time is controlled in order to bring the core (heart) of the piece to be treated up to a given temperature, guaranteeing the destruction of the parasites inside the wood, - the temperature profile is determined as a function of the nature and age of the wood as well as of the cross-section of the piece to be treated, - the, preferably alternating, supply to the various heating elements is controlled using a control station, and at the end of the treatment each heating element is removed.

Description

"Process and installation for heat treatment of wood, in particular

beams of frames against

parasites".

  The present invention relates to a method and an installation for the heat treatment of wood, including beams of frames against parasites. The protection of wood, and in particular of structures against pests, is a problem

more and more delicate.

  Indeed, until recently, he was

  the protection of wood, especially

  thick as the timber beams, for

  injection of an insecticide, combined with

  to a spray of the outer surface of the wood.

  However, products formerly used

  have proved to be very dangerous for the health of

  the man, so we gave up these products. It exists

  also products which do not appear to be

  no danger to the man. However, their effectiveness

  cacity is relatively low and their implementation quite complicated. In fact, these products are used in the form of fog, so it is necessary to

  you close in a way almost hermetic at the level of the frame of a house then to pump the vapor

  loaded with this product in this chamber. The installations

  tions for the application of such treatment are relatively complicated; you need a vehicle equipped with

  the equipment supplying this vapor loaded with insects

  ticide as well as ducts to connect the vehicle to the

  attic, for the supply of gases.

  As the treatment is relatively long

  (several hours), the application of this process represents

  a significant inconvenience, especially for

  in urban or suburban areas.

  Trials have also been made to

  treat the heart of the wood with microwaves. Toute-

  Once again, the equipment to be used is relatively delicate and heavy, especially since

  protect the operator against radiation leaks

  is lying. The object of the present invention is to create a simple and effective means of heat treatment of woods, in particular beams of frameworks, joistings, etc., by simple means that are easy to implement and do not create any inconvenience.

  particular inconvenience to the environment or

  tives. For this purpose, the invention relates to a method of treating wood by heat, characterized in that: - the parts to be treated are wrapped with an electric heating element whose outer surface has good thermal insulation characteristics, surrounding closely the workpiece, - we order a temperature profile as a function of time to drive the heart of the workpiece to

  a certain temperature, guaranteeing the destruction

  pests in the interior of the wood, - the temperature profile is determined according to the nature and age of the wood, the hygrometry and the section of the piece to be treated. alternate feeding alternately of the different heating elements with the aid of a

  command post and at the end of the treatment,

ve each heating element.

  The invention also relates to an installation

  for the implementation of this method, this installation being characterized in that it feeds

  in a nested way the different layers.

  The present invention will be described below in more detail with the aid of the accompanying drawings in which: - Figure 1 is a schematic drawing of

  the installation according to the invention and its implementation

on a roof form.

  - Figure 2 schematically shows a

heated.

  - Figure 3 shows a particular heating element. According to the figures, the invention relates to a method and a facility for the heat treatment of wood, in particular timber, against

parasites.

  The installation consists of heating elements

  fants in the form of flexible sheets, one of which

  dull) of the faces is heating and the other side (face

  exterior) is insulating. These elements, of

  tangular, triangular, or generally poly-

  gonale, are provided with closure means such as removable fastening strips for enveloping

  the piece to be treated with the element and to close the

  element on the piece. These attachment means allow

  try to stretch the tablecloth of the element to apply it

  tightly against the workpiece.

  In the example shown in FIG. 1, the heating elements 1, 2, 3, 4 surround parts of beams 100, 101, 102 of a framework truss.

  The number of elements to be set up de-

  hangs from the yard. The shape of the heating elements

will be discussed later.

  These elements 1-4 are connected by cables 11, 12, 13, 14 to a power supply unit

  , controlled by a control panel 16. The ele-

  1-4 are also equipped with temperature sensors.

  21-24, which provide their signals on the

  16 through the feed unit.

  15. The control panel 16 manages the power supply

  different heating elements 1-4 according to a specific program and according to the temperature

  measured in the treated room using the sensor as-

associated with each element.

  The temperature sensors 21-24 can be integrated into the sheet or constitute bodies

  separate but preferably associated with each

  as heating element (1-4). The cable for transmitting electrical signals for temperature measurement

  is preferably connected to the power supply cable

  the heating element to simplify the installation and removal of cables and heaters. In some cases, for large surface elements or lengths, it may be useful

to provide several sensors.

  The connection of the heating elements (1-4) on the power supply unit 15 is by means of receptacles 151-154 making it possible to place the elements, to connect

pending items, etc.

  In addition, to simplify the drawing, the pri-

  its connectors for sensors have not been

felt on the unit 15.

  To facilitate management and implementation

  these heating elements, these and the plugs of the power supply unit 15 are marked with references

references or codes.

  The control panel 16 also allows the sequential feeding of the various elements

  to avoid power calls, excessive

  sifs when starting the installation.

  In this way, the various elements are fed successively or nested (by a chopped current, distributed between the various elements), at least during the rise in temperature and then for maintaining it during the heating regime.

  cruise, for keeping the temperature.

  This also makes it possible to

  electrical power supply normally available in the building and which would be insufficient to provide the starting power of all the elements,

all connected at the same time.

  The power supply is provided for example from the building via

  a simple cable 17 connected directly to the unit of

food 15.

  The control panel 16 has a micro-

  processor to manage the electrical distribution

  the different temperature curves and a

  printer 161 which draws up a report of the

  treatment by recording on a medium in

  paper the evolution of temperature at the level of

that item or piece processed.

  According to the invention, the installation is preferably used in the following manner: The manipulator begins by placing some elements 1-4 around 100-102 beams to protect and then plugs their power supply which is managed automatically by the table of 16. During this treatment period, it sets up as and when the other elements around other parts to be treated; it plugs them in and their temperature rise is done while the elements already placed are at their

  temperature of regime; this also allows for

  to start on a regular basis the demand for power

  electric over the treatment period.

  The operations are repeated; at the end of the

  treatment period of the first pieces, the

  lateur disconnects these elements, removes them for

  possibly place on other pieces to be treated.

  The wood heating of the rooms is controlled so that the temperature rises in the heart of the wood and destroys the wood pests by simply raising the temperature. As the treated areas are surrounded relatively tightly with the heating element (s), the moisture that might be released from the wood remains confined in this heating chamber; when cooling the moisture gets in

  and again in the wood which avoids drying out

expensive treated woods.

  As also the temperature of treatment

  the maximum temperature is controlled according to the nature of the woods and the

  parts to be processed, it is possible to optimize the

  at the same time in temperature and duration.

  Figures 2 and 3 show two examples of

  forms of heating elements 200, 300.

  The heating element 200 is a

  flexible tangular with the characteristics already de-

  (inner heating surface and outer surface

  insulation). This element is provided with fasteners 201, 202 on one side and fasteners 203, 204 on the other

  side to wrap the piece to be treated

  two winding directions. These fasteners 200-204 are for example adjustable fasteners, claws or

adhesive fasteners.

  Figure 2 also shows two sensors

  205, 206 whose conductors are

  connected to the power supply cable 207 of the

  200. The cable 207 terminates with the power connector 208 and the driver connector 209.

sensors.

  The heating element 200 is for example used

  readable like the elements 1-4 of Figure 1.

  FIG. 3 shows a particular element 300 that can be used to wrap a T-junction of

  two beams like beams 100/102.

  For this, it has itself a T-shape with two branches 301, 302 and fasteners 303, 304, 305, 306 and temperature sensors 310, 311, 312 connected to the common cable 307. The latter is provided with previously a 308 power connector

  and a connector 309 for the temperature signals

  re. It should be noted that the heating elements

  They can also be used to treat partially inaccessible parts, such as failures, of which only three faces can be covered by the heating elements which will then be held in place if possible by straps or clips. The temperature control program will take into account this particular placement feature of

the heating element.

Claims (1)

R E V E N D I C A T I 0 N S   Process for the heat treatment of wood by heat, in particular of structural beams against pests, characterized in that: - the parts to be treated are wrapped with an electric heating element whose external surface has good thermal insulation characteristics by covering the workpiece closely, a temperature profile is controlled as a function of time to drive the core of the workpiece to be treated.   a certain temperature, guaranteeing the destruction   pests in the interior of the wood, - the temperature profile is determined according to the nature and age of the wood, the hygrometry and the section of the piece to be treated. alternate feeding alternately of the different heating elements with the aid of a   command post and at the end of the treatment, ve each heating element.   2 ') Process according to claim 1, characterized   terized by nested supplying different heating elements.   3 ') Installation for thermal treatment of wood against pests, particularly for the application of   process according to one of claims 1 and   2, characterized in that it consists of - a set of electric heating elements in   form of webs (1-4, 200, 300) whose surface area   is heated and the outer surface   insulating material, these elements being provided with means for   electrical cables (11-14, 207, 307),   - a power supply unit (15) at the   which the heating elements (1-4) are connected, this unit regulating the power supply of the heating elements according to a predetermined temperature and multiplexing the supply of the elements (1-4, 200, 300) when several elements are in service simultaneously,   - a control panel (16) equipped with a micro-   computer to handle the temperature curves of the   or heating elements according to a program   born, - temperature sensors (21-24, 205, 206, 310, 311, 312) associated with each element to detect the temperature of the workpiece, this information   of temperature being transmitted to the switchboard   mande (16) which slaved the temperature curve of the corresponding heating element according to this information and parameters related to the material of the piece and its dimensions.   Installation according to claim 3, characterized in that the heating element (200) is rectangular shape.   ) Installation according to claim 3, characterized in that the heating element (300) is T-shaped). Installation according to claim 3, characterized in that the heating element (200, 300) comprises fasteners (201, 202, 203, 204, 303, 304, 305, 306).