US1328505A - Process of drying lumber - Google Patents

Description

F. K. FISH, Jn. PROCESS OF DBYINGLUMBER. APPLICATION FILED sEPLzo., I9I6. RENEWED IIov. 9. 1918.v

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F. K. FISH, Jn.

PROCESS 0F DRYING LUMBEH.

APPLICATION FILED sEPLzo, I9Ie. IIEIIEwED Nov. 9, 1918.

1 ,328, 505 Patented J an. 20, 1920.

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FREDERICK K. FISH, JR., 0F NEW YORK, N. Y., ASSIGNOR T0 LUMBER TIE AND TIMBER VULCANIZING COMPANY, 0E NEW YORK, N. Y.

Pnocnss or nnYING LUMBEn.

To all whom t may concern.'

Be it known that I, FREDERICK K. FISH, Jr., a citizen of the United States, residing at 2 Stone street, New York city, in the county of New York and State of New York,

is closely allied to the cellulose of the wood,

and since it forms a part of the permanent 1ustructure of the wood, it may, for purpose of the present invention, be regarded as identical with the cellulose.

Of the other organic substances, the principal are starches, sugars, gummy substances, albuminous compounds and sap together with resin or resinous compounds mainly to be found in resin cells or ducts. The starches, sugars, stances with the sap are elements principally necessary to the life of the growing tree but their presence in felled wood, timber or lumber, if in any quantity, is largely detrimental as affording principal elements leading to the decay or destruction of the wood. .Therefore any proper treatment to preserve the wood should be directed 'to the removal of injuriousstarches, soluble gums, albuminous substances and sap with the proper preservation and distribution of the resins and resinous substances throughout the structural elements, care lbeing taken to arrest the treatment and if a liquid is einployed to remove t e same from around the wood before disintegration of the wood begins so that all` elasticity, strength and that which .is termed life are retained.

In carrying out my improved process, certain steps are provided to utilize the natural resins, acetic acid and tannic acid existing in the woodfas preservative agents; that is to say, these constituents or substances are dislodged from their cellular confinement, and separated from their original vehicle,

gums and albuminous sub-l Specification of Letters Patent. Patented Jan, 20, 1920, Application filed Septemler 20, 1916, Serial No. 121,187. Renewed November 9, 1918. Serial No. 261,938.

Athe wood, and 'dissolves and dislodges the soluble ummy sap matters and softens the resins. his step causes the soluble mmy sap matters and thesap water to ecome intermingled with the vehicle in the container. To obtain the desired results, the f period of treatment, the temperature and the pressure, must be such as not to injure the wood. This step in Ytheprocess also saturates and swells the wood, causing it to further expandupon removal of pressure, and softens the resins and puts themA in condition to permeate the wood structure in a'subsequent-step or steps in the process. This step in the process also puts the wood in good physica condition to give up its aqueons content in the subsequent steps of the process.

In the next step, as the water and pressure are removed from around the wood, the differences between the internal pressure within the wood and the external pressure surrounding it causes the wood and the liquid within the wood to further expand and considerable of the liquid with its dissolved constituents are removed from the wood in the form of vapor and otherwise. Then a partial vacuum is created, the vacuum being maintained for a suiicient time to remove a portion of the aqueous content of the wood to be evaporated without taking with it the values of the sap, such for instance as the resin or the resin-producing constituents. But' this vacuum should not be continued long enoughvto greatly cool down the wood, allow its resins to harden, or close the moisture outlets of the wood at the surface. To

assist the withdrawal of the moisture from the wood the vacuum is replaced with live steam, and a pressure created in and around the wood thereby raising the temperature of the wood, the last named vacuum materially assisting the live steam to penetrate the wood structure.

Next, the wood is again subjected to a vacuum for a suitable period, which continues the drying of the wood.

Finally, the wood is subjected to what 1 term an equalizing step, which consists in maintaining around the wood an atmosphere of proper humidity, and a temperature sufficient to cause continuous evaporation of moisture, at the same time keeping the resins in a softened state until the Wood is seasoned. 1t is in this step particularly that permeation of the Wood bers by the softened resins takes place. rlhe wood thus described will be sterilized, tanned and dried, without removing the insoluble resins, the fibrous structu`re of the wood being permeated with these resins. The wood is furthermore rendered substantially nonhygroscopic, and correspondingly immune from spores, or fermentation or the like, and undergoes the minimum amount of shrinkage. 'llo illustrate one way of carrying out the process, reference is made to the accompanying drawings wherein Figure 1 is a vertical longitudinal section of a container, in which the Wood is partially treated. v

Fig. 2 is a cross section taken through the container.

Fig. 3 is a diagrammatic illustration of an apparatus for carryingout the steps of the process in the container.-

Fig=l 4 is a vertical sectional view of an equalizing chamber.

Fig. 5 is a cross section of the same on the line 5 5 of Fig. 4.

1n the drawings, the same reference characters designate like parts in all the figures.

1 indicates a container suitable for containing water under pressureat a temperature above the boiling point. 1n the container is a presser plate 2, adjusted by screws 3, by means of which the wood, retained under mechanical pressure is pre vented from floating and warping while being subjected to treatment. The container is also provided with heating coils 4f, by

means of which the temperature of the at- Inosphere within the container and the temperature and pressure of the water in the container may be y regulated. Perforated pipes 5, are arranged in the container for supplying free steam to the latter, when des1re Suitable equipment is associated with the container for conveniently developing the war-ions conditions incident to the different steps in the process; 10 indicating a pipe shown) and connected to the top of the container by a branch pipe 9, and to the bottom of' the container by means of a branch pipe (5, provided with a valve 6a; and in the pipe 10a is a double acting pump 11. Extending from the junction of the pipes 9 and 10, is a branch pipe S, provided with a valve 8C, leading to a condenser 8, and from the condenser extends a short pipe connected to a vacuum pump 7. 1n the bottom of the container are rails to receive a truck, upon which the Wood to` be treated is loaded.

Referring to Figs. 4 and 5, 13 indicates an equalizing chamber constructed to have a high co-etlicient of heat insulation, and is preferably provided with' a presser device 2, 3 similar to that employed in the container. The equalizing chamber is further provided with heating pipes 14, and a lower air inlet controlled by a suitable damper16, and a stack or outlet, controlled by a damper 17. 1n the bottom of the equalizing chamber are tracks for convenient introduction of the truck with the charge of wood, previously treated in the container.

1n practising the process, a charge of wood is loaded on a truck, andis introduced into the container. the pressure .devices are screwed down, and the container is hermeti- `cally closed. c rlhe appropriate valves are opened, and the vacuum pump 7, is operated, and a partial vacuum created in the container 1. This partial vacuum is maintained for a suitable time to expel air from the wood, and render the fibrous structure more receptive to the penetration of the boiling water. This 'step also preliminarily prepares the wood for the future treatments.

The valves are closed, and boiling water from the elevated tank is introduced into the container through the pipes 9 and 10, the

,water being fed to the container by gravity,

or by pump 11. The vacuum in the container is broken by the introduction of the boiling Water.

Suiiicient water is introduced into the container to submerge the wood, and about twenty pounds pressure is produced and .maintained by introducing steam through the heating coils 4r, which continues the boillng of the water and produces the necessary pressure and temperature to superheat the Water.

lThis superheated Water step is maintained for a sufficient time to dissolve the water soluble constituents of the wood, the superheated water being forced throughy the entire fibrous structure of the wood. F or one inch yellow pine green from the saw about one hour is required.

By treating the wood'in superheated water the wood is rendered hot and soft vthe internal stresses are relieved, the resins are softened and the water soluble substarces are dissolved and with the sap water are mixed or intermingled with the water surrounding the wood. In addition" to these results, the superheated Water being confined causes a deposition of the colloidal substances on the fibers ofthe Wood, and tans the surface of the latter giving the Wood a distinctive appearance.

The Water introduced into the container, and in which the Wood is submerged, re` mains as a relatively fixed body during the treatment, the valves being closed to prevent circulation, and the pressure devices preventing thevwood floating or warping during this step in the process.

After the wood is subjected to the boilingstep, the valve (ia is "opened, and the pressure in the container will lforce the Water back into the elevated tank, or the pump 11, maybe operated to effect this result.- The valve 6 is closed, and the' valve 8 is opened and the vacuum pump 7 is started and a partial vacuum of about 20 inches is created in the container, the change from liquid pressure to vacuum being effected as quickly as possible, say in about fifteen minutes. The Wood now has a high internal temperature and some pressure which will readily convert Water into steam, making the Whole body of the wood favorable to giving up moisture.

The vacuum may be malntained for a suiiicient time to cause the aqueous content of the wood to largely evaporate Without taking with it the resins or resin-producing constituents. But this eva oration should not be continued long enoug togreatly cool down the Wood, or close its pores at the surface. Now to continue the evaporation of moisture from the interior of the wood and prevent external drying, or danger of checking, the vacuum is gradually replaced by an artificial atmosphere of highv tempera'- ture, say about 290 degrees F. This condition is created by introducing steam to theL container, through the perforatedv pipes 5,

the increase in temperature being 'assisted by circulating steam through the heating coils. Some pressure is maintained during this time-say about thirty pounds, and the step' is continued. for-say one-half hour, and has the effect of raising the temperature of the wood throughout Well above the boiling point and keeping the retained resins in good permeating condition.

Next the steam is cut off from the perforated pipes 5 and the wood, at high internal temperature and wlth softened fibrous structure, favorable to giving up -moisture, isl

This step is preferably continued for about two `hours, lbut the vacuum may be increased-say to abouttwenty-iveinchestoward the end of the step-say for the last half hour thereof. This step in the process has the eiiect of aiding the uniform distribution of the resins throughout the wood structure, and when completed, the Wood is in condition to be removed from the container.

The load of wood is now transferred as rapidly as possible, to the equalizing chamber 13, the load being preferably covered to minimize loss of heat during the transfer. While the Wood is being treated in the equalizing chamber, another charge can be introduced to the container.

It is important in carrying out the final step of the process that the temperature and humidity be such as to prevent premature hardening of the resins of the wood, and insure continuous evaporation of moisture,

without checking or otherwise deteriorating the value of the Wood. -It is to be borne in mind that the internal temperature of the Wood when introduced into the equalizing chamber is high, and that it contains moisture, and the resins are in. a softened state. It is here, and while'the resins are in this condition that permeation of the cellulose by resins and such of the ummy substances remaining in the Wood ta es place.

Steam is admitted to the heatin pipes 14, to maintain a temperature favora le to continuous evaporation of moisture from the wood, and the dampers 1G and 17 are opened periodically to create a current or currents of air to the chamber for periodically carryving off the moisture as it accumulates. This step evaporates moisture from the wood and equalizes its moisture content and insures the permeation of the individual fibers of the wood with its resins.

Inthe treatment and drying of wood, I have had in mind the fact that it is essential that the resins must be retained and yet the major portion of the water solublecon-v stituents and the water sap closely associated ment, should as far as possible, as a preliminary step, be removed.` Hence, when the Wood is placed in the sealed container and the first vacuum is created, alarge portion of the air throughout the body of the wood is ex lled, and while the Wood is in this condition boiling water is introduced to 'at least submerge the wood. Then p ressure is createdA in the container by operating the pump and the tempe ature of the water is raised by introducing steam through the coils Je, the added temperature and consequent pressure causing the Water to be superheated, and in this condition it is forced into the Wood. rlhe change from vacuum to pressure takes place to insure as perfect penetration of the yvood as possible, the con# dition of change from vacuum to pressure heilig controlled by the proper manipulation of the valves. The yvood is, by this means, and Without loss of time. put into good condition for the effective penetration of the water. to readily attack the yvater soluble constituentsl throughout the whole Wood structure. The vacuum having been broken or destroyed, and the Isuperheated Water having been substituted. the wood is treated until it is rendered hot and soft and will become enlarged upon release of thepressure surrounding it. The` Water soluble constituents are dislodged from their cellular conlinement. and dissolved in the Water in the wood, and because of the boiling action under pressure these dissolved ingredients are conveyed or removed from the interior of the Wood ,and become mixed or intermingled with the confined body of water in the container. The water and heat. together with the pressure which forces the Water int'o the Wood. acts to dissolve the gummy sap matters, but in so doing care must be taken to regulate the temperature and pressure and duration of treatment to prevent disintegration or destruction of the Wood.'

Stress is put on the fact-that treating the Wood for a short time under low h eat and corresponding pressure to soften the resins and expel yvater soluble constituents. 1s to be distinguished from what is known in the art as cooking the life from the wood.

T he superheated water. chai'ged with the water soluble kgums and sap water, is removed from the container by manipulation of the proper valves, and returned to the elevated tank for re-use. The wood now' is hot and soft, the internal stresses having been relieved, 'its pores are opened up, and its contained resins are in a softened state. Therefore. the succeeding steps in the process have to do largely with the evaporation of the moisture in the wood structure, the maintaining of the resins in good condition to permeate the fibers, and the thorough permeation of the fibers with the resins. without liability to produce checking of the wood.

The Water having been removed, a second vacuum is now createdto evaporate the moisture content of the wood and permit penetration of steam introduced in a further step. rlhe second mentioned vacuum 1s gradually replaced hy artificial atmosphere of high pressure and highl temperature to raise the internal heat in the wood well above, the boiling point. This step insures the retained resins in the wood remaining in a softened condition, to later enable them' to permeate the individual bers of the Wood in a subsequent step or steps in the process.

After this step of the treatment, the Wood is lsubjected to the action of the third vacuum with dry heat which acts to cause the softened resins to be uniformly1 distributed throughout the wood structure.

It is essential however that the Wood be further treated to complete its dryingwithout. hardening its resins and vchecking or otherwise degrading it. Therefore, I provide the next or equalizing step in the process. After the last mentioned, or third vacuum is broken. the load of wood is removed to the equalizing chamber Where it is permitted to remain until sufficient moisture evaporates. The yvood at this time contains high internal heat'` and the chamber is pro-- vided with means to maintain a temperature effective to sustain a moderated and continuous evaporation of the moisture in the Wood and to maintain the resins in a melted condition in the Wood until the wood is finally dried and cooled.

Upon the first introduction of the Wood in the chamber the dampers 16 and 17 are closed and the e 'aporated moisture rapidly creates a humid condition within the cha1n ber. As the humidity increases, a deposition of moisture occurs on the surface of the ivood, and as the point of saturationis appreached evaporation of the moisture ceases. At such time the dampersare operated to relieve the condition within the chamber, and this may be secured either by opening the upper damper alone, or by periodically opening` both dampers. If the upper damper-alone is opened it causes a lowering of the slightly. raised pressure within the chamber, the excess moisture around the vvoodv 1being removed from -the equalizing chamber. As the pressure Within the cham: ber is so lowered the high heatand consequent pressure within the interior of the Wood produces vaporization of the interiorly contained moisture and such pressure withinV thevwood causes a movement of the moisture surfacewise. whereby a too rapid surface drying is avoided and in` addition an increased rapidity of drying of the Wood as a Whole is secured.

If the lowerdamper is opened simultaneously or periodically with the upper damper open, a currentof air is caused to circulate throughout the chamber to accelerate the evaporation of the moisture.

As the moisture content evaporates from the wood fibers, the resins being in a softened condition spread, and replace this evaporated ,moisture the resins permeati'ng the wood structure and flowing about and into the wood fibers in such manner that upon cooling the setting resins aid to maintain the wood fibers in their expanded con-"' dition so that when finally dried the Wood shows the minimum degree of shrinkage.

wood in previous treatments forms a diluted solution, and when treating the next load of green Wood, the contained substances act to tan the Wood, theV effect and res-ult depending largely on the character of Wood and the number of times the Water is used.

What I claim is l 1. The process of treating Wood comprismg subjecting the Wood to superheated watei` until its Water soluble constituents are dissolved and with its sap Water largely removed and the Wood thoroughly sterilized throughout, and arrestin the treatment before any deterioration if the Wood occurs, to produce a Wood resistant to decay and jvith its strength and elastic'properties urnlmpaired.

2./The hereindescribed process of treating Wood comprising the subjection of the wood to heated Water under pressure to dissolve its Water soluble matter While held submerged and to prevent warping, remoring the Water and releasing the Wood, and subsequently drying the Wood.

3. The herein described process which comprises dissolving in Wood substantially all Water soluble constituents and removing the major portion of the same, then drying the wood at a temperature suicient to cause evaporation of the moisture in the wood, prevent hardening of its resins and cause permeation .of the fibers with the residue and the resins.

4. The process of treating' Wood comprising4 applying boiling water to wood, submerging the Wood therewith, and` thereafter superheating the Water to raiseits tempera- .ture and pressure to cause same to permeate the Wood throughout, and arresting the treatment before deterioration ofthe Wood occurs. v

5. The'proccss of treating Wood comprising submerging wood in a confined body of superheated Water to dissolve and extract the soluble gums and sap, and subsequently subjecting the wood to a temperature to induce evaporation of the moisture of the wood and prevent hardening of the resins, causing the resins to permeate the fibers of the wood.

, 6. A process of treatin wood comprising' treating the Wood to disso ve and remove its sap matters, subjecting the .wood to alter- A nate vacuum and pressure treatments and maintaining a temperature the Wood sufficient to cause the molsture 1n the wood to evaporate and prevent hardenmg 'of the quently permeation of the Wood throughout and to i' dissolve substantially all constituents which may be dissolved in Water and removing the major portion of these constituents with the water, and drying the wood.

8. The process of treatin Y, wood comprising submerging the wood 1n a fixed body of water under pressure and with heat to extract Water-soluble constituents and sap Water from the Wood and melt the resins therein, removing the Water, and subsequently subjecting the Wood to a temperature sufficient to induce' evaporation of the moisture in the Wood and prevent hardening of the resins and vcause the resins to permeate the individual fibers ofthe wood.

9. The process of, treating wood comprising submerging the wood in water containing the water soluble constituents of Wood under pressure to saturate the same, dissolve and extract the major portion of the Water soluble constituents and subsedrying the Wood.

l0. he process of treating Wood by subjecting it to a deposition of tanning col. lodial substances on the' surface portions of the Wood thereby tanning the same While removing the major portion of the Water soluble constituents.

lmajor portion of the water soluble constituents and sap Water therefrom, and expand the fibers thereof, then drying the wood to remove the major portion of the moisture in the Wood, the tanning colloids removed from the wood and retained in the water being deposited-on the fibers of the Wood to thereby tan the same.

12. The process of treating and drying wood, comprising subjecting the wood to steam and heat, to maintain the steam and raise the temperature throughout the wood, then to a vacuum to cause a movement of the interior moisture surface-wise to evaporate moisture therefrom, and finishing the drying at atmospheric pressure.

13. The process of treating wood comprising applying boiling Water to wood, which has been previously employed 'in a similar treatment of Wood, then submerging thel wood therewith and thereafter superheating the Water to raise its temperature and ressure to cause same to permeate the woo throughout.

14.- The process of treating wood which comprises surrounding the wood with heated water which has beenV previously similarly melted condition, comprising subjecting the Wood to a temperature to induce evaporation of the moisture in the Wood, prevent hardening of the resins and to cause the latter to permeate the fibers of the Wood.

16. The process of drying Wood having soluble gums and sap Water removed and its resins in a softened condition. consisting in subjecting the wood to heat sufficient to induce evaporation of the moisture in the \vood and prevent hardenmg of the resms, causing the resins to permeate the fibers of the wood,

and periodically subjecting the wood to a current. of air to carry off the moisture as it accumulates around the wood, at the time. the wood is subjected to the heat.

1T. The process of drying wood having a portion of its gummy sap matter and sap 4water removed and lts resin softened, consisting in subjecting the wood Ito alternate vacuum and pressure and maintaining suiieient heat to prevent hardening of the resins, and then removing the moisture surrounding the wood by periodically subjecting the wood tov acurrent of air to produce a substantially sterilized Wood, having its preservative elements retained and distributed throughout the struc-ture.

18.. The process of treating wood comprising treating the wood with water to dissolve, dilute and remove the major portion of its water soluble constituents, and cause the thorough permeation of the wood With the unremoved remaining preservative elements and drying the Wood.

19. The process of treating wood comprising subjecting the Wood to treatment to remove the major portion of the soluble gums and sap matter and thereafter treating the Wood to evapo 'ate moisture and cause the retained resins to spread throughout the wood to substantially replace the soluble gums and sap matter.

20. The process of treating wood, com-A prising placing the wood in a container. creating a vacuum therein, submerging the wood in boiling water, withdrawing the water, then creating a vacuum in said container while supplying heat therein 'to evaporate moisture and create expansion in the wood.

21 The process of treating wood, comprising treating the wood in superheatedwater. to soften its structure and dissolve water soluble constitutents, subsequently Withsoften its fibers and dissolve the Water soluble constituents and finally drying the Wood while maintaining heat suiicient to induce evaporation and prevent hardening of the resins.

23. The process of treating wood comprising subjecting the wood to a vacuum toeX- pel a. portion of the air therefrom, then treating the Wood in superheated Water to permeate the same to dissolve and remove its water soluble constituents, and arresting the treatment before deterioration of the wood occurs.

24. The process of treating wood comprising subjecting the Wood to superheated water until its struc-ture is softened and Water soluble constituents are dissolved, removing the vater from around the wood, then subjecting the Wood to a vacuum to evaporate moisture and cause expansion in the Wood, drying the, wood While maintaining heat sufficient to induce evaporation and prevent hardening of the resins to permit them to replace the removed substances.

25. The process of treating Wood Which comprises subjecting wood to the action of super-heated water for a period of time to melt the resins of the Wood and dissolve its water soluble constituents, then removing the water and subjecting the wood to heat sufficient to cause evaporation of the Water in the wood and prevent hardening of the resins of the. wood and insure a permeation of the fibrous structure .of the wood by its resins. f

Q6. rlie process of treating Wood comprising subjecting the wood to superheated water until its structuri is thoroughly softened and its water soluble constituents are dissolved, removing the water. then subjecting the wood to a vacuum until a portion of its moisture is withdrawn and expansion is created in the wood. then subjecting the Wood to steam to raise the temperature of the Wood and evaporate a vportion of its moisture.

27. The process of treating wood comprising the subjection of the Wood to superheated water until its soluble constituentsl and sap matter are dissolved and largely removed and the wood thoroughly sterilized throughout, arresting the treatment before any sul'istantial deterioration of the wood occurs. removing thefivater and subjecting the wood to steam under pressure to raise the temperature and evaporate a portion of -in'g subjecting the Wood' to superheated Wathe moisture, and finally subjecting the wood to heat sufficient -to induce evaporation and preventing hardening of the resins. n 28. The )rocess of treating wood comprising the su jection of the Wood to super-, heated water until its soluble constituents]v and sap matters are dissolved and largelyremoved and the Wood thoroughly sterilized' throughout, arresting 4the treatment before any. substantial deterioration of the wood occurs, removing the water, and subjecting the' wood to steam: to raise the temperature and evaporate a4 portion ot its moisture.

29. The process of treating wood compris-v ing subjecting the wood to superheated iva-v ter until its structure is thoroughly softened jsure, to raise the temperature ot' the wood andevaporate a portion of its moisture, then creating a vacuum While applying heatto further evaporate moisture, then drying thel'wood While maintaining heat suflicient Ato induce evaporation and prevent hardening of thefres'il.- Q Y Y 30. The process' of 'treating wood compris-V ter until itsstructure isthoroughly softened vand its water soluble constituents are dissolved, removing the water, then subjecting the Wood to a vacuum until a portion of its moisture is withdrawn, then subjecting the Wood to 4steam to raise the temperature of the wood and evaporate a portion of its moisture, then creating a vacuum while applying heat to further evaporate moisture. 31. The process of treating Wood, coinpiising subjecting the wood to -a vacuum, then submerging the ivood in boiling water and raising the pressure thereof and treating the wood in superheated water, removing the Water and substituting therefor a vacuum; then subjecting the wood to steam While creating a high temperature around the Wood, finally drying 'the wood at about atmospheric. pressure and in the presence of heat u'hile periodic-ally removing the accumulat-ing moisture -from the atmosphere surrounding the Wood.

32. The process of treating wood comprising subject-ing u'ood to a vacuum, to expel a. portion ot' the air therefrom. treating lthe wood to superheate-d water to soften its structure and dissolve the Water soluble constituents, removing the water, then subjecting the wood to a vacuum to evaporate the moisture from the wood, and inally treating the Wood with steam to induceevaporation j and prevent hardening of the resins.

33. The process of treating wood comprising subjecting the wood to superheated water until its structure is thoroughly softened and its water soluble constituents are dissolved, removing the Water. subjecting the Wood to steam under pressure to raise the temperature of the Wood and evaporate a portion of its moisture, then creating a vacuum to evaporate moisture and cause expansion in the wood, then drying the ivood while maintaining hea-tsuiiieient to induce evaporation and prevent Vhardening ot' the sa. The'l ter and thereafter superlieating the ivater, then 'removingl the water and substituting therefor a vacuum; then replacing this vacuum bysteam then replacing the steam with a vacuum; and finally finishing the drying at about atmospheric pressure and in the presence of heat\vhile periodically removing the accumulating moisture from the atmosphere surroundingtlie wood.

Y 35. The process of treating Wood, comprising subjecting the wood to boiling water to soften its structure, open up its pores and dissolve its sap; then subjecting the Wood to successive. vacuum treatments with an iiitervening raising of the pressure around the Wood; the temperature of the wood duringv these steps being maintained sufficient toinduce evaporation and prevent hardening of the resins, the wood being finally dried at about atmospheric pressure. t

'96. The process of treating Wood, coniprising boiling the ivood to soften its structure, open up its pores and dissolve its sap; then subjecting the wood to a. plurality of vacuum treatments alternated with steam, the temj'ieraturc of the wood during these steps being maintained sufficient. to induce evaporation and prevent hardening ot the resins; the wood being finally dried by heat at about atmospheric pressure, the temperature being lnaintained sufficient 'to prevent hardening ot the. resins and permeate the fibers ofthe wood with its resins.

37. The process of treating wood, comprising subjecting the Wood to a vacuum, then replacing the vacuum by boiling Water and raising the pressure above atmospheric, removing the water, and treating the wood with steam under pressuregthen creating a vacuum; and linishing the driving at about atmospheric pressure with heat while periodic-ally removing the accumulating moisture surrounding the Wood'.

3S. The process of treating Wood, coinprising subjecting the Wood to a vacuum and iinlnediately thereafter boiling it in Water until its structure becomes soft, its pores are opened and its guminy sap matters are dissolved; then vwithdrawing the Water and subprocess ottreating u'ood, com-V prising subjecting the wood to a vacuum; thenreplac'ing the vacuum with boiling iva.-

jecting the Wood to steam and heat and'raising the pressure surrounding it; 'then subjecting it to a vacuum,-`mally drying the Wood at about atmospheric pressure.

39. rlhe process of treating Wood, comprising placing the wood in a container, surrounding the Wood with boiling Water until its pores are opened up, its structure thorremoving the Water, treating the Wood to steam under pressure to increase the internal heat of the Wood and evaporate a portion of the moisture, then subjecting the wood to a vacuum while applying heat to evaporate moisture and cause expansion in the wood.

41. The process of treating Wood, comprising boiling the Wood to soften its structure, open up 1ts pores, and dissolve its sap, then subjecting the Wood to aplurality' of vacuum treatments alternated With steam, the temperature of the wood during these steps being maintained up to a degree suilicient to induce evaporation and prevent hardening of the resins and drying 'while periodically removing accumulating moisture surrounding the woodl 4t2. The process of treating Wood comprising submerging the Wood in heated Water to dissolve and remove soluble gums and sap, removing the Water, and subjecting wood to steam under pressure and simultaneously introducing dry heat to maintain the temperature of the steam to evaporate the moisture in the wood.

43. The process of treating Wood, comprising subjecting the wood to heated water uny der pressure until the pores of the Wood are" opened up, its structure thoroughly softened and "its gummy Vsap matter dissolved, and largely removed, removing the Water; subsequently subjecting the wood to a'vacuum while applying heat to evaporate moisture. j

44. The process of treating wood, comprising boiling the Wood to soften its structure,' open up itspores and dissolve its sap, then subjecting the Wood to heat and steam under pressure; the wood being finally dried.

' at a temperature suliicient to'cause evaporation of the moisture from the Wood and prevent hardening of the resins and cause,

permeation of the wood fibers with its'resins.

' 45. The process of treating Woodcompris- A ing subjecting the wood' to boiling water until its structure is thoroughly softened and 'water soluble' constituents are dissolved and removed, removing the Water, treating the Wood with steamunder pressure to increase the internal heat` of the Wood, and evaporate a portion of the moisture and then drying the Wood.

46. The process of treating Wood, comprising boiling the Wood to soften its structure, open up its pores and dissolve its sap; then subjecting the Wood to a plurality of vacuum treatments alternated with a raising of the pressure around the wood; the temperatureof the Wood during these steps being maintained up to a degree sufficient to induce evaporation and prevent hardening of the resins and cause a permeation of the bers of the Wood by its resins.

4J?. rlhe process of treating Wood, comprising boiling the Wood to soften its structure, open up its pores and dissolve its sap; then subjecting the Wood to a plurality of v2 enum treatments alternated with live steam, the

last of said vacuum treatments being varied in. its intensity; the temperature of the Wood during these steps being maintained up to adegree suliicient to induce evaporation and preventhardening of the resins; the wood being finally dried at about atmospheric pressure.

48. The process of treating Wood comprising subjecting wood to a vacuum to expel a portion of the air therefrom, treating the Wood 'with steam, then a vacuum to evaporate moisture, and then subjecting. the Wood to heat at about atmospheric pressure While periodically removing the accumulating moisture surrounding the Wood.

49.' The process of treating Wood comprising thewood to steam, to increase its internal temperature and evaporate moisture, then to a vacuum to evaporate moisture from .the Wood and expand the Wood and tlien'subjecting the wood to heat While peing subjecting the Wood to a vacuum, treatriodically removing the accumulating moisture and subjecting the Wood to a vcurrent Oifair- Y .50. The process of treating wood comprisingsubmerging the Wood in 'su erlieated water to dissolve and remove solulble gums and sap, removing the Water, subsequently drying the Wood in a moderately heated atinosphere with moisture sufl'icient to prevent Y too superficial 51. The process of treating -Wood comprising subjecting thewood to a vacuum to expel a portion of theair therefrom, treating the Wood with steam and heat to increase itsinternal temperature and evaporate moisture therefrom, finally drying the Wood at about atmospheric pressure to induce evaporation. 452. The process of treatingiwood, comprising subjecting .the Wood vto a vacuum, and thereafter boiling it until its structure becomes soft, its pores are opened and its Lemmer gunnny sap matters are dissolved; then subjecting the Wood to a plurality of vacuum treatments alternated with a treatment 0f steaii under pressure, and finally drying the woo 53. The process of treating Wood comprising subjecting the wood to a' vacuum to expel a portion of the air therefrom, treating the wood with steam and` heat to increase its internal temperature, then to 'a vacuum to evaporate moisture froml the wood, then subjecting the Woodto heat at about atmospheric pressure. sufficient toevaporate moisture therefrom while peri-A odically removing moisturefrom the wood.

54. The process of treating wood,`com prising subjecting the wood to vacuum and thereafter boiling it until its structure becomes soft, its pores are opened and its gummy sap matters are dissolved; then subjecting the wood to a vacuum; then, while maintaining the internal heat of the wood, raising the pressure surrounding it; then subjecting it to vacuum and finally drying the wood at about atmospheric 4pressure while periodically removing the accumulating moisture surrounding the wood. i

55. The process of treatin prising subjecting the Wood to the action'of a vacuum to remove the air therefrom, then submerging the wood in water Vunder pressure todissolve and extract the soluble gums andsap water, arresting the treatment, and

subsequently drying the wood.

56. The process .of treating wood, com'- prising subjecting the wood to a vacuum and thereafter to heated water until its structure becomes soft, its pores are opened and its mmy sap matters are dissolved; then sub ecting the wood to vacuum; then, while maintainingv the internal heat of the wood, raising the pressure rsurrounding it; subsequently subjecting it. to lvacuum and inally drying the wood at about atmospheric pressure. o

57. The process of treating wood, coinprising submerging the wood in water under pressure and heatlng the water to dissolve and extract the soluble gums and sap and meltv the resins, removing the water and subsequently subjecting the wood 'to a temperaturefsucient to induce' evaporation of the moisture in the wood and prevent hardening of the resins, thereby causing the resins to permeate the fibers of the wood.

58. The process of treating wood which comprises placing wood in a container submerglng said wood in water previously used in a similar treatment of Wood to dissolveand remove Water soluble constituents, and by pressure forcing the water into said wood to uniformly permeate the fibers and dilute the sap, withdrawing the water from the wood, and subjecting the wood to treatment to evaporate the moisture in the wood.

wood comv `59.'The process of treating wood, comprising subjecting the wood to heated water under pressure until its structure is thoroughly softened and its sap matters are dissolved; then subjecting it to a vacuum until a portion of its moisture is withdrawn; .then subjecting it to steam under pressure; then subjecting it to a vacuum of increasing intensity while applying heat.

60.*The rocess of treating wood, comprising subjecting the wood to heated water under pressure until its pores are opened and its gummy sap matters dissolved, subsequently 'subjecting the wood to a vacuum to evaporate moisture and cause expansion in the wood and subsequently surrounding the wood with 'a body of dryin heat suficient to prevent the hardening o the resins of the wood.

61. The process of treating wood, comprising submerging the wood in` water at a temperature and at a pressure suiiicient to open its pores andv dissolve its gummy sap matters, then creating a vacuum around the wood to evaporate moisture and create expansion in the wood, and finally subjectingL the water and subsequently subjecting the wood to steam under pressure and applying heat; then subjecting the wood to a vacuum,

and finally drying the wood at or about atmospheric pressure.

63. The process of treating wood, comprising` subjecting the wood to heated water under pressure to soften its structure, open up its pores and dissolve its. water soluble constituents; subsequently subjecting the wood to steam under ressure: the temperature 'of the wood' being maintained up to a-degree suiicient to induce evaporation and prevent hardening of the resins.

64. The process of treating wood, comprising immersing the Wood in Water under pressure until the wood is softened, the pores opened up and the Water soluble con- `vstitutents dissolved, then applying heat suficient to evaporate the moisture from the wood, and periodically removing the accumulating moisture from around the wood and intermittently passing a current of air over the wood. t

65. The process of `treating wood, comprising subjecting the wood to heated water to soften its structure, open up its pores and dissolve its saps; then subjecting the wood to a plurality of vacuum' treatments alternated with a raising of the pressure aroundv the wood; the temperature of the wood during these steps being maintained up to a degree sufficient to induce ready evaporation and prevent hardening of the resins. I

66. The process of treating wood which comprises placing wood in a container, submerging said wood in water and by pressure suflicient to force the water into said wood to permeate its fibers and to dissolve and remove the water soluble constituents, withdrawing the water, and subjecting the wood to treatment to evaporate the moisture.

67. The process of treating wood `comprising submerging wood in heated Water under pressure, then subjecting the wood to the action of a vacuum, and subjecting the wood to heat at a temperature to induce evaporation of moisture of the wood and prevent hardening of the resins thereby causing the resins to permeate the individual fibers of the wood. i

68. The process of treating wood, which comprises placing wood -in a container submerging said wood in a Xed body of water and by pressure forcing the water into said. wood to permeate the wood fibers and dilute the sap of the wood, withdrawing the water from the wood, and subjecting the wood to heat to evaporate the moisture in the wood,

and cause the resins to permeate the fibers. i

69. The herein described process of treating wood comprising the subjection of the wood to a vacuum to withdraw air from the wood, then subjecting the wood to heated water to dissolve its water soluble substances.

and open up its pores and expand the wood, removing the wat-er, again subjecting the Wood to a vacuum to evaporate moisture, from the wood, the wood being held in fixed position to prevent warping while being subjected to treatment, and subsequently dr ing the wood.

0. The process of treating wood, comprising boiling the wood to soften itsstruci ture, open up its pores and dissolve and remove Water solubleiconstituents, and then subjecting the wood to heat and steam under pressure to evaporate moisture from the wood. Y

71. The process of treating woodl comprising boiling the wood to soften its structure, open up its pores and dissolve and remove Water soluble constituents, then subjecting the wood to a vacuum, thereafter treating the wood to steam under pressure, and then treating the woodto a vacuum to evaporate moisture.

72. The process of treating wood, comprising subjecting the wood to boiling water to soften its structure, open up its pores and dissolve and remove water soluble constitu-- ents, then subjecting the wood to a vacuum, and thereafter treating the wood to steam under pressure to evaporate the moisture.

73. The process of treating wood, comprising subjecting the wood to boiling water to soften its structure, open up its pores and dissolve and remove water soluble constituents and thereafter subjecting the wood to a vacuum and to heatjto evaporate moisture from the wood and prevent hardening of the resins.

74. The process of treating/wood comprising subjecting the wood to a vacuum to expel air therefrom, then subjecting the wood to boiling Water to dissolvethe water soluble constituents, then to avacuum, thereafter subjecting the woodto steam under pressure, and then dryingv the wood at about atmospheric pressure while periodically removing accumulating moisture from the atmosphere surrounding the Wood.

T5. The process of treating wood comprising subjecting the Wood to a vacuum to expel air therefrom, then subjecting the wood to boilingwater to dissolve 4and remove water soluble constituents, then to a vacuum, then subjecting the Wood to steam under pressure to evaporate the moisture. 76. The process of treating wood comprising treating the wood in boiling water, applying pressure to the boiling water to force the latter into the wood to dissolve and remove the major portion of water soluble constituents, arresting the treatment before removal of the preservative elements, and then applying heat to dry the wood.

77. The process of treating wood comprising subjecting the wood to boiling water to open the pores and dissolve and remove the major portion of the water soluble constituents, and then drying the wood at about atmospheric pressure While periodically removing accumulating Inoisture from the atmosphere surrounding the wood.

78. The process of treating wood comprising boiling the wood to open its pores and dissolve and remove the major portion of the water soluble constituents, and melt and diffuse the contained resins, thereafter drying the wood at a temperature to cause evaporation 'of moisture from the wood,

prevent hardening ofthe resins and cause permeation of the fibers of the wood by its resins.

79. The process of treating wood com--` prising boilin the wood, to open its pore-.a and. dissolve'tie sap, thereafter subjecting the wood to steam under pressure, then to the action of a vacuum, `and then drying the Wood at a temperature to cause evaporation of moisture from the wood, prevent hardening of the resins and cause permeation of the fibers of the Wood by its resins.

80. The process of treating Wood comprising boiling the wood to open itsv pores and dissolve the sap, then subjecting the wood to a vacuum, then to steam under pressure, then to a vacuum, and thereafter subjecting the Wood to a temperature sulficient to evaporate moisture from the Wood and permeate the fibers with its resins.

81. The process of drying Wood comprising subjecting the Wood to heat sufficient to evaporate the moisture, and periodically removing the accumulating moisture from around the Wood and intermittently passing a current of air over the Wood to cause uniform evaporation.

82. The process of treating and drying wood comprising heating the Wood to cause evaporation ofthe moisture from the Wood While preventing the removal of the moisture from the drying chamber to create around the Wood a humid condition above saturation, then relieving the humidity and periodically passing a current of air around the Wood, the internal temperature of the Wood being maintained at a temperature sufficient to vaporize the interior moisture of the wood.

83. The process of treating and drying Wood comprising heating the Wood to cause evaporation of the moisture from the Wood While preventing the removal of the moisture from the drying chamber to create around the wood, a humid condition above saturation, then relieving the humidity and passing a current of air around the Wood,

the internal temperature of the Wood beingV maintained at a temperature sufficient to vaporize the interior moisture of the Wood.

84. The process of drying wood comprising subjecting the Wood to a temperature in a substantially xed air until the humidity i approaches saturation to Ja deposition of moisture on the surface of the Wood, and

then relieving the humidity to evaporatey such moisture, the interior of the Wood being maintained at a temperature suiicient to vaporize the interior moisture.v

85. The process of treating Wood comprising subjecting the Wood to steam under pressure and to temperature for sufiicient time to melt its resins, dilute its'sap and raise the interior temperature of the Wood, then to a vacuum to remove vapor therefrom, and then to heat and about atmospheric pressure, While periodically subjecting the wood to a current of air.

86. The process of treating and ldrying Wood comprising subjecting Wood to steam While maintaining heat to `raise the temperature throughout the Wood and evaporate vapor therefrom, then to a vacuum to cause moisture and sap to move towardLthe surface of the Wood and to remove moisture therefrom, and then subjecting the Wood to heat at about atmospheric pressure sutlieient to cause evaporation While periodically removing accumulating moisture from the atmosphere surrounding the Wood.

S7. The process of drying and treating .vood comprising forcing Water into the wood to dissolve and remove the major portion of the Water soluble constituents, the water being heated to raise the vinterior temperature of the Wood, arresting the treatment before deterioration of the wood occurs, and thereafter subjecting the Wood to heat to dry it Without degrading it.

SSQThe process of treating wood comprising subjecting the wood to alternating vacuum and Water treatment under pressure, said Water being at a temperature above the boiling point, and thereafter drying the Wood.

89. The process of treating Wood comprising subjecting'the Wood to steam under pressure, and to temperature for sufficient time to melt its resins, dilute its sap and aise the interior temperature of the Wood, then to a vacuum to remove vapor therefrom, and then to heat and about atmospheric pressure While subjecting the Wood to a current of air.

90. The process of treating wood comprising subjecting the Wood to steam under pressure, and to temperature for suiicient time to melt its resins, dilute its sap and raise the interior temperature of the Wood, then to a vacuum to remove vapor therefrom, and then to heat and about atmospheric pressure While subjecting the Wood to a current of air to complete the drying.

91. The process of treating Wood comprising subjecting the Wood to steam under pressure and to temperature for suflicient time to `melt its resins, dilute its sap and raise the interior temperature of the Wood, then to a vacuum torcause the moisture in the Wood to move surface-wise.

92. The process of treating Wood comprising subjecting the' Wood to a vacuum, thereafter treating the Wood to steam under pressure and to temperature for sufficient time to melt its resins dilute its sap and reinove moisture, then to a vacuum to remove vapor, therefrom, and then to a current of air.

In testimony whereof I aix my signature.

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