US2384027A

US2384027A - Process and device for full-cell treatment of timber or similar material

Info

Publication number: US2384027A
Application number: US478988A
Authority: US
Inventors: Hager Bror Olof; Kjellstrom Stig Bertilsson
Original assignee: Bolidens Gruvaktiebolag
Current assignee: Bolidens Gruvaktiebolag
Priority date: 1942-02-08
Filing date: 1943-03-12
Publication date: 1945-09-04
Anticipated expiration: 1962-09-04

Description

Sept 4, 1945' B. o. HGER ET AL Y 2,384,027

PROCESS AND DEVICE FOR FULL-CELL TREATMENT i oF TIMBER 0R SIMILAR MATERIAL Filed March 12, 1945 "III II I IIIII 1| 'I I IIIIIIIDTI A. IIIII..4| I KN RSE me/rm mz' /afger SyBerilss 012 Kjellszom E( QM A Patented Sept. 4, 1945 PROCESS AND DEVICE FOR FULL-CELL TREATMENT OF TIMBER R SIMILAR MA- TERIAL Bror Olof Hger and Stig Bertilsson Kjellstrm, assignors to Bolidens Gruvaktiebolag, Stockholm, Sweden, a jointstock company limited of Sweden Application March 12, 1943, Serial No. 478,988 In Sweden February 8, 1942 (ci. zi-ss) Stockholm,

Claims.

The impregnation of timberland similar material is effected in practice mainly in accordance with the empty-cell or the full-cell process.' The empty-cell process is adopted when the preservative is an oil, the full-cell process when the pre- 1- ervative is dissolved or emulsifled in some cheap liquid such as water.

In principle, the empty-cell process proceeds in the following manner. The material to be treated is rst exposed in an impregnating cylinder to an initial air-pressure above the atmospheric pressure after which the cylinder is filled with the preservative oil, while the same pressure is maintained. The pressure in the cylinder is then increased, whereby the preservative oil is introduced into the material. After some time the cylinder is emptied of preservative oil and the material is subjected to a vacuum, whereby part of the preservative oil is expelled from the cell-cavities of the material by the internal air pressure which prevails there. 'I'he consumption of the preservative oil is thus considerably reduced,as the cell-cavities will be only partially filled with the preservative oil, whilst a uniform distribution of the preservative oil in the material is nevertheless obtained. When treating timber with preservative oils it is for economic reasons necessary to use the empty-cell process.

By full-cell process the material to be treated is subjected in a cylinder to a vacuum, after which the cylinder, while the vacuum is maintained, is filled with a solution or emulsion of the preservative. The solution or emulsion is then Introduced into the material by pressure, so that the cell-cavities are filled with solution or emulsion. When treating with solutions or emulsions the amount of preservative absorbed by the material is controlled byregulating the concentration of the solution or emulsion, so that the comparatively4 complicated empty-cell treatment need not be resorted to.

The present invention relates to a process and device for effecting full-cell treatment of timber and similar material. An impregnating chamber or cylinder is charged with the material to be treated and is filled with a liquid. All the liquid is thereupon expelled from the cylinder with a pump or pumps, the other inlets to the cylinder being closed, for creating a vacuum in the cylinder. By relling the cylinder with liquid, letting out the air that has been sucked out from the timber during the previous vacuum-stage, and pumping the liquid out again the vacuum in the cylinder may be improved, if desired. When the vacuum has acted for some time, the

Sweden,

cylinder is lled with a preservative solution or emulsion, which is then introduced into the material by pressure.V When the material has absorbed the requisite amount of the solution or emulsion, the solution or emulsion is again pumped out of the cylinder and air admitted. The dripping from the material of the solution or emulsion after treatment can be reduced, however, by keeping out the air during the last-named expulsion state thus creating a vacuum. In this way small amounts of the solution or emulsion `are sucked out from the outer layers of the material. The material, when completely impregnated, is removed from the cylinder and is allowed to dry.

As two illustrative embodiments of the invention two devices for full-cell treatment are shown diagrammatically in Figures l and 2 of the accompanying drawing. According to the rst of these figures, the device includes an impregnating chamber A for the material to be treated, a container C Vfor the impregnating substance, and a pump D situated in a line, having a valve B, connecting chamber A and container C, in addition to another line provided with valve E and located between chamber A and container C. The second gure includes the same elements but with the container C placed at a higher level rela-r tive to the chamber A, and with a valve F for the admission of air directly to the chamber A. 'I'he manner in which the respective devices are employed in practicing the invention is described more fully hereinafter.

Referring now to Fig. 1, the device is used in the following manner: The impregnating chamber or cylinder A is charged with the material to be treated and is then closed, whereupon the valve B is opened and the cylinder A is lled with solution or emulsion from the container C by means of the pump D, while the valve E is open. When the cylinder A is completely filled with solution or emulsion the valve E is closed and, by the pump D, the solution or emulsion is pumped from the cylinder A back to the conlrainer C, whereby a vacuum is produced in the cylinder A, and then the valve B is closed. When the vacuum has acted on the material for some time, the valve B is opened and the solution or emulsion is repumped'from the container C into ,the cylinder A, whereupon the pump (with pressure) forces the solution or emulsion into the material. Any air that may have been formed in the cylinder A is discharged through the valve E. When the material has absorbed the requisite quantity of solution or emulsion, the solution or Sis used in the following manner. `nating chamber or cylinder A is charged with the material to be treated and is then closed,

emulsion is returned by the pump to the container C while the valve E is open. 1n order to valve E closed during the last step of pumping the solution or emulsion out of the cylinder A.

lThe valve B is closed and before the impregnated `material is removed from the cylinder A air is adlmitted to the cylinder A through the valve E.

Referring now toFig. 2, the device there shown The impregwhereupon the valve E is opened so as to illl the `cylinder A with solution or emulsion from the container C. The valve E is closedV and valve B opened and by the pump D the solution or emullsion is pumped from the cylinder A back to the container C, whereby a vacuum is produced in `the cylinder A, and then the valve B is closed. `When the vacuum has acted on the material ior some time the valve E is opened, whereby the cylinder A is lled with solution or emulsion from the container C, The valve E is closed and the valve B is opened, whereupon the pump D (with pressure) forces the solution or emulsion into the material. When the material has absorbed the requisite quantity of solution or emulsion, the solution or emulsion is returned by the pump D to the container C while the valve F is open. In

order to reduce the dripping of solution or emul- 1 sion from the impregnated material after treatment, however, a vacuum can be formed anew in the cylinder A and upheld for some time by keeping the valve E closed during the last step of pumping the solution or emulsion out of the cylinder A. Before the impregnated-material is removed from the cylinder A air is admitted to the cylinder A through the valve F.

lower level than the rest of the plant. Owing to the simplicity of the apparatus, the management of an impregnation plant according to the present invention will be very easy. The initial and operating costs will moreover be low.

Having thus described our invention we declare that what we claim:

1.` A process for effecting full-cell treatment of timber or similar material comprising charging an impregnating chamber with the material to be treated, lling the chamber with liquid and then pumping out the said liquid, thereby creating a vacuum in the chamber, which after some 1 time is iilled with a substance selected from the 4class consisting of preservative solutions and emulsions, the latter then being introduced into the material by pressure.

2. A process for effecting full-cell treatment as claimed in claim l, wherein the liquid with which the chamber is first lled during the treatment is a substance selected from the class consisting of preservative solutions and emulsions.

3. A process for effecting full-cell treatment of timber and similar material as claimed in claim l, wherein the preservative substance contains at least one arsenic compound.

4. A device for full-cell treatment of timber or 'similar material, comprising an impregnating chamber for holding the material to be treated, a container for a substance selected from the class consisting of preservative s'olutions and emulsions communicating with said chamber, and means for creating a vacuum in said chamber prior to introducing the preservative substance thereinto, said means including pump means for filling said chamber with a liquid and for withdrawing said liquid to thereby create the vacuum in said chamber.

5. A device for full-cell treatment of timber or similar material, comprising an impregnating chamber for holding the material to be treated, a container for a substance selected from the class consisting of preservative solutions and emulsions, a conduit communicating with said chamber and with said container, and a single pump situated in the communicating conduit be-` tween the chamber and the container for creating vacuum and pressure in the impregnating chamber and for conveying the preservative substance between the chamber and the container.

BROR oLoF HAGER. sTIG BERTILSSON KJELLSTRM.