US1586159A - Low-temperature explosion process of disintegrating wood and the like - Google Patents

Description

Patent ed May 25, 1926. v

UNITED STATES 1,586,159 PATENT OFFICE.

WILLIAM H. MASON, OF LAUREL, MISSISSIPPI.

Low-TEMPERATURE EXPLOSION raocnss or msmrnena'rme woon AND THE LIKE.

No Drawing. Original applicationfiled September 24, 1924, Serial No. 739,748. Divided'and this application filed July 6, 1925. Serial No. 41,898.

My. invention relates to a process of disintegrating ligno-cellulose material such as wood, for example by explosion at relatively low temperatures whereby charring and discoloration is avoided.

This application is adivision of my prior copending application Serial #739,748,.filed September 24, 19%.

The wood or other ligno-cellulose material,

preferably reduced to chips, is placed in a closed, high pressure chamber, having a restricted valved outlet or outlets of an area, which is relatively restricted as compared with cross section of area of chamber. To

secure best results, the section of the outlet should be less than of the section of cylinder bore.

Steam, water or other moisture supplying fluid material is introduced into the closed 0 chamber or gun, whereby the chips are penetrated, moistened and heated. For example, hot water or steam at pressures of, say, -100 lbs. per square inch, may be advantageously made use for such preliminary 5 penetration and moistening steps. The tem peratures of the moisture supplying penetrating material may be considerably higher than this, but steam pressures and corresponding temperatures having a tendency to 0 produce charring and discoloration are to be avoided, and in any event in carrying out the resent invention the steam pressure shou d not exceed 350 lbs. per square inch. When steam at 100 lbs. per square inch is 5 used for this preliminary step, exposure of the chipped wood to the steam for a part of a minute is ordinarily sufficient, but the steaming may be continued for a longer interval, if desired. D After the chips have been subjected to penetration by hot moisture supplying material, the un is charged with compressed fluid material of such a'nature that high pressures may be secured without the accompanying high temperatures necessarily present with high pressure steam. For example, fluids such as compressed air, oxygen, nitrogen, and other fixed gases, may be used. In this way, the pieces of ligno-cellulose mate- 0 rial, such as wood chips, after apreliminary heating and moistening may be surrounded and penetrated, and their interstices filled with the fluid material, as compressed air, at a pressure which is greater than 275 lbs. 5 and preferably in excess of 400 lbs. per

square inch. I have found that it is necessary to malre use of pressures of 275 pounds per s uare inch or over, in order to produce an e ective fibration of the wood. I have obtained very eflicient fibration with pros sures of 700-800 lbs. and higher pressures, such as 1000 lbs. per square inch, or even higher may be made use of.

The introduction of the low-temperature, high-pressure fluid is preferably carried out in such a manner as to avoid undue coolmg of the ligno-cellulose material. The purpose of using such fluids isto obtain high penetrating pressures, without temperatures which would char or discolor the wood, and so long as such undesirable temperatures are avoided, it is not necessary and is, in fact, undesirable to produce any considerable reduction oftemperature in the course of in-" troducing the lowtemperature, higl1-pressure fluid. In carrying out the operation in this Way, the gun chamber can be brought up to pressure with less gas than would be required were undue lowering of temperature permitted. 1

After the pressure inside and outside the pieces of wood has become substantially bal-' anced, which ordinarily does not require more than a fractionof a minute, the constricted outlet of the gun is opened, and the contents are progressively discharged into a region of lower, preferably atmospheric, pressure therefrom and are reduced to a highly divided fibrous state. The high pressure is preferably maintained in the gun so far as possible until the discharge is completed or substantially completed, and when this is done the fibration of the material last discharged is not materially reduced, as will be the case where the pressure is not'maintained during discharge. By carrying out the operation in the manner which I have described, the charring and discoloration temperatures being avoided, the fibrated product obtained is substantially completely free from discoloration, and is well adapted for theproduction of high grade pulp, as for the manufacture of good quality paper and other products.

I claim l. The process of disintegrating lignocellulose material which consists in introducing same into a high-pressure chamber, introducing moist fluid in the said chamber, introducing compressed gas into said chamber at a pressure higher'than that of the moist fluid material, and discharging the contents of the chamber through a relatively restricted outlet, whereby material is disintegrated without being'subjected to temperatures which would char or discolor.

2.-The process of disintegrating lignocellulose material which consists -in introducing" same into a high-pressure chamber, introducing moist fluid 1n the said chamber, introducing compressed air into said chamber at a pressure higher than that of the moist fluid material, and discharging the contents of the chamber through a relatively restricted outlet, whereby material is dlsintegrated without being subjected to temperatures which would char or discolor.

3. The process of disintegrating l 1gnocellulose material, which consists in introducing same into a highpressure chamber, introducing steam into said chamber, introducing compressed air into said chamber at a pressure higher than steam pressure, and ejecting the contents of the chamber through a relatively constricted outlet opening,whereby the material is disintegrated to such an extent as to be immediately available for use in apparatus such as paper mill heaters and the like, and substantial discoloration is avoided. v

4:. The process of disintegrating lignocellulose material, which consists in introducing same into a high pressure chamber, introducing steam into said chamber, introducing compressed air. into said chamber at a pressure higher than steam pressure, and ejecting the contents of the chamber through a relatively constricted outlet opening, while maintaining high pressure within said cham ber, whereby the material is disintegrated to such an extent as to be immediately available for use in apparatus such as paper mill beaters and the like, and substantial discoloration is avoided' 5. The process of disintegrating lignocellulose material into a substantially nondiscolored product, which consists in subjecting same in a closed chamber to the action of steam under pressure of 350# per sq. in., subjecting same to the action of gases at relatively low temperatures and at a pressure in excess of steam pressure, and progressively discharging same from said chamber through a relatively constricted opening.

6. The process of disintegratin ligno: cellulose material into a substantia ly nondiscolored product, which consists in sub-.

jecting same in a closed chamber to the action of steam under pressure of 350.11: per sq. in., subjecting same to the action of gases at relatively low temperatures and at a pressure in excess of steam pressure, and progressively discharging same from said chamber through a relatively constricted opening,

- while maintaining a high pressure within said chamber.

In testimony whereof, I have signed my name hereto.

WILLIAM H. MASON.