US1915410A - Manufacture of wood pulp - Google Patents

Description

June 27, 1933. 1 B. DECKER MANUFACTURE OF WOOD PULP 2 Sheets-Sheet ,Filed Oct. 50, 1930 JeifiZZeLEFecke/ Inventor B% I I W I Attorneys June 27, 1933. DECKER 1,915,410

MANUFACTURE OF WOOD PULP Filed Oct. 30. 1930 2 Sheets-Sheet 2 Zemzzelfifleafier Invent By v - Attorneys Patented June 27, 1933 UNITED STATES LEIV IUEL B. DECKER, OF KENOGAMI, QUEBEC, CANADA MANUFACTURE OF WOOD PULP Application filed October 30, 1930. Serial No. 492,263.

The present invention relates to the manufacture of wood pulp and has particular reference to a process for handling pulpwood blocks before and after treatment.

An important object of the invention is the provision of a process of charging a treating vessel with pulpwood blocks and discharging the blocks therefrom.

A further object of the invention is the m provision of means for charging a treating vessel with wood blocks and discharging the blocks therefrom through the medium of a liquidto be injected into the vessel disposed to buoyantly support the wood blocks. 15 Other objects and advantages of the invention will become apparent as the description progresses.

In the accompanyingdrawings forming a part of this specification and in which like reference characters are employed to desigs nate corresponding parts throughout the same:

Figure 1 is a fragmentary sectional view through-a treating vessel showing the manner of charging the same with wood blocks, Figure 2 is a similar View illustrating the discharging operation,

Figure 3 is a fragmentary section showing the introduction of a cleansing liquid,

Figure 4 is a perspective view of'the apparatus for conveying the blocks from the treating vessel, and

Figure 5 is a perspective view of a fiting adapted to be connected with the bottom of the vessel to be used during the cleaning op eration. I

Referring to the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the numeral 10 generally designates a vessel, similar in construction to what is known as the digester, designed to accommodate a suitable quantity of wood blocks in order to subject the same to a preliminary treatment prior to grinding or other subsequent treatment. At the top, the vessel 10 is formed with a restricted material receiving opening '11, preferably formed with an outwardly directed peripheral flange 1 2.

During the cooking or other treatment of the blocks in the vessel the receiving aperture 11 is closed by a fiat cover plate 15 bolted or otherwise connected with the flange 12 and provided with a central threaded aperture designed to accommodate therein posed a laterally projecting apron 18 assuming a downwardly inclined arrangement and over which the blocks are discharged during removal from the container.

At the bottom end of the vessel 10 is formed a restricted aperture 20 about which is formed a peripheral outwardly projecting flange 21.

A special strainer fitting 25 is also attached to the bottom of the vessel 10, this fitting embodying an annular base plate26 the peripheral margin of which is disposed to be connected with the flange 21 of the vessel and having a relatively small central aperture to which is connected a conduit section 27 Projecting upwardly from the base plate 26 is a cylindrical strainer body 28 enclosed by a' top plate 29. The side wall and top plate of the strainer are provided with a plurality of relatively small apertures 30, the purpose of which will be later described. When connected with the vessel, the body portion of the fitting 25 extends upwardly within the bottom thereof, as shown to advantage in Figures 1 and 2.

During the unloading of the vessel, that is, during the discharge of the wood blocks therefrom, a conveyor chute 33 isconnected with the special fitting 17 this chute being provided with side boards 34 and having its upper extremity arranged so that the apron 18 of the fitting will overlie a portion thereof. The chute 33 is disposed so as to incline downwardly from the fitting, having the lower end terminating immediately above one end of a conveyor which may comprise and endless belt or other form of carrier. At the intermediate portion, the chute 33 is provided with a section having a plurality of relatively small apertures 36-below which is formed a tapered receiver 37 adapted to collect the liquid matter dripping from the wood blocks as they are conducted downwardly on the chute.

A conduit 40 connects the receiver 37 with a liquid reservoir'41 in which the liquid from the wood blocks is recovered. I

Above the vessel 10 is disposed a horizontally extending conduit having disposed therein a T fitting 45'. To the lower outlet of the T fitting is connected the removable pipe section 16. Qn one side of the T fitting 45 is mounted a control valve 46. Upon the opposed side of the T fittlng 1s mounted a control valve 46. Thus, one side of the line is to be employed as a wash liquid feed line while the opposed side can, if desirable, be employed as an exhaust for the gases and liquid'in the vessel.

To the conduit section 27, depending from the lower extremity of the vessel fitting 25,

is, connected a T fitting 48 to the lower branch of which is connected a discharge liquid conduit 49 provided with a control valve 50. To the side branch of the T 48 is connected a steam conduit 51 provided with a control valve 52 by means of which steam is introduced into the interior of the vessel.

To one side of the vessel, adjacent the bottom, is connected a conduit 53 having a control valve 54 through the medium of which the treating liquid is delivered into the cooking vessel. At the opposed side, adjacent the bottom, is connected a conduit 55 provided with a control valve 56 through which the treating liquid is discharged from the vessel. The inner end of the conduit 55 is referably covered by a perforated strainer 5 to avoid the discharge of foreign matter with the liquid. Immediately below the conduit 55 is mounted an additional conduit 58 connected with the vessel and communicating with the interior thereof and controlled by a valve 59. The opposed end of the conduit 58 connects with a force pump which is also connected with the, reservoir 41 by a connecting section 61. Thus, the pump 60, which may be of any preferred character, is interposed in a line embodying the conduit sections 58 and 61 extending between the reservoir 41 and the lower portion of the vessel and having communication therewith for conducting a fluid between these containers.

In order to charge the vessel 10 with wood blocks, the cover 15 and preferably the pipe section 16 are disconnected from the vessel and the conduit 45 respectively. The vessel is then substantially filled with water or other suitable liquid, which may be effected by opening the valve 59 and, by operation of the pump 60 delivering the liquid from the reservoir 41, or other source of supply, through the conduit sections 58 and 61 into the vessel. The wood blocks are then conveyed to a position above the vessel opening by means of an endless belt conveyor 65 or other suitable carrier means and dropped through the top opening into the liquid within the vessel. During the charging operation, the liquid is withdrawn in correspondence with the entry of the blocks and returned to the reservoir tank 41 until the vessel is entirely filled with the blocks and substantially all the liquid withdrawn therefrom.

When the vessel is completely charged with the blocks, the valve 59 is closed and the cover 15 secured in position to enclose the top opening, the valve 16 also being closed.

The treating liquid is then introduced into the bottom of the vessel by opening the valve 54 and feeding through the conduit 53 an acid solution or other preferred liquid under suitable pressure so as to treat the wood blocks packed in the vessel. The cooking operation is then carried out by opening the valve 52 and introducing steam through the steam conduit 51, this operation being effected for a suitable period of time to suitably treat the blocks. When the blocks have been sufliciently treated, the liquid is removed or exhausted from the vessel through the outlet conduit 55 by opening the valve 56 for this purpose.

When desirable, however, the valves 16 and 46 can be opened to afi'ord an exhaust for the gases and superfluous liquid. When the treating process is completed the liquid and steam conduit valves are closed and the water control valves 46 and 16 are opened so that water is delivered through the conduit 45 and the section 16 into the top of the vessel under suitable pressure to thoroughly wash and cleanse the blocks and remove the cookin solution and foreign matter therefrom. %uring the cleansing operation, the wash water is discharged through the perforated strainer 28 which, projecting upwardly through the bottom portion of the vessel, obviates clogging of the discharge opening and permits efl'ective removal of the matter washed from the blocks. Thus, by opening the valve 50, the'wash water may be discharged through the outlet conduit 49 to a sewer or other receiver.

Upon completion of the washing operation, thewater control valves are closed and the pipe section 16 and cover 15 are removed. The special block discharge fitting 17 is then secured on the flange 12 in registration with the top opening of the vessel. Water or other liquid is then forced into the bottom of the vessel from the reservoir 41 through the conduit sections 58 and 61 through the operation of the pump 60.

Due to the buoyancy of the woodblocks, the liquid introduced into the vessel elevates the same and forces the blocks through the fitting 17, the liquid being injected at a predetermined pressure so that the blocks may be discharged at a controllable rate of speed. As the blocks are forced outwardly through the fitting 17 they are directed on to the slide member or chute 33, sliding downwardly thereon to a suitable carrier such as the endless belt conveyor 35. During the passage of the wood blocks down the chute, the water or other liquid matter dripping therefrom will be mainly recovered in the reservoir 41 through the. medium of the apertures 36 in the chute through which the liquid will be conveyed into the trough 37 and conducting pipe 40.

As will be readily apparent, the foregoing process and apparatus will greatly facilitate the handling and treatment of the wood blocks preparatory to grinding or other subsequent treatment thereof, rendering the treating of the blocks very practical and completely eflicient. One of the great difliculties heretofore encountered has been the slow, ineffective manner of charging and discharging the vessels in which the blocks are subjected to preliminary treatment, rendermg the vessels inactive for a substantial period of time and consequently rendering the treatment a relatively expensive procedure.

It is to be understood that the form of my invention herein shown and described is to be taken as a preferred example of the same, and that various changes as to the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the- 'invention or the scope of the subjoined claims.

Having thus described .my invention, I claim:

1. A process of handling wood for the manufacture of pulp which consists in filling a receiving vessel with a liquid, introducing wood blocks into the vessel on to the liquid, discharging the liquid from the vessel in cor: respondence with the introduction of the blocks to substantially fill the vessel, treating the blocks, injecting a liquid into the container so as to buoyantly raise the blocks and discharge the same from the vessel. y

2. A process of charging and discharging a vessel fortreating wood blocks which consists in filling the vessel with a liquid, introducing the blocks through an opening in the top of the vessel on to the liquid, gradually exhausting the liquid from the vessel till the same is filled with blocks, and discharging the blocks from the vessel by injecting a liquid which will force the blocks through the upper opening therein.

3. The process of charging and discharging wood block" cooking vessels consisting in injecting a liquid into the vessel adjacent the lower end, introducing blocks through the upper open end into the liquid, gradually exhausting the liquid until entirely removed and the vessel is filled with blocks, treating the blocks, and introducing a. liquid into the bottom portion of the vessel so as to force the block'sthrough the upper open end to discharge the vessel. I

4. The process of handling and treating wood blocks consisting in filling a cooking vessel with a liquid, introducing the blocks through the upper open end into the liquid, exhausting the liquid gradually from the vessel and filling the same with wood blocks, subjecting the blocks-to a cooking treatment, introducing a liquid into the vessel so as to discharge the blocks through the upper open portion thereof.

5. The process of handling and treating wood blocks consisting in filling a.cooking vessel with a liquid, introducing the blocks through the upper open'end into the liquid, exhausting the liquid gradually from the vessel and filling the same with wood blocks, subjecting the blocks to a cooking treatment, introducing a liquid into the vessel so as to discharge the blocks through the upper open portion thereof, and recovering the liquid dripping from the blocks as they are discharged from the vessel.

6. The process of handling and treating wood blocks consisting in injecting a liquid into the bottom portion of a receiving vessel, introducing wood blocks through the upper open end of the vessel on to the liquid, exhausting the liquid from the vessel, covering the vessel and subjecting the blocks to a cooking treatment, introducing a washing liquid in the upper portion of the vessel and exhausting the same through a strainer fitting in the lower portion thereof, introducing a liquid into the bottom portion of the vessel and discharging the wood blocks by the buoyancy thereof in the said liquid.

7. A process of handling wood for the'manufacture of pulp which consists in filling a receiving vessel with a liquid, introducing wood blocks into the vessel on to the liquid, discharging the liquid from the vessel in correspondence with the introduction of the blocks to substantially fillthe vessel, then on completion of an impregnating treatment and after removal of treating medium, injecting a liquid into the receiving vessel so as to buoyant ly raise the blocks and discharge the same from the vessel.

8. In a process of charging a vessel with wood blocks, the steps which consist in injecting a. liquid into a vessel through the lower portion thereof, introducing wood blocks into the vessel through an opening in the upper portion thereof and onto the liquid in the vessel, and gradually discharging the liquid during the introduction of the woodblocks,

until a suitable charge of blocks has been placed in the vessel.

9. In a process of discharging wood blocks from a treating vessel, the step which consists in introducing a liquid into the lower portion of the vessel so as to buoyantly raise the blocks for discharge through an opening in the upper portion thereof.

10. In a process of discharging wood blocks y from a treating vessel, the steps which consist in introducing a liquid into the lower portion of the vessel to buo antly raise the blocks for removal through t e upper portionthereof, and continuing the in ection of the liquid during the discharging operation in correspondence with the removal of the blocks.

11. In a process of charging a vessel with wood blocks in the manufacture of pulp, the steps which consist in injecting a liquid into the vessel introducing wood blocks into the vessel onto the liquid, and removing the liquid in correspondence with the block filling operation until a suitable charge of blocks has been placed in the vessel.

12. In a process of discharging wood blocks from a treating vessel, the step which consists in introducing a liquid into'the vessel so as to buoyantly raise the blocks for discharge from the vessel, the said liquid to be introduced at a rate conforming with the removal of the blocks.

In witness whereof I have hereunto set my hand.

LEMUEL B. DECKER.

Images