US1035395A - Apparatus for the production of pulp. - Google Patents

Description

G. A. STEBBINS.

APPARATUS FOR THE PRODUOTION OF PULP.

APPLICATION FILED APR. 15, 1910.

Patented Aug. 13, 1912.

Witnesses Attorneys COLUMBIA PLANOGIAPN CO" WASHINGTON. D C

UNITED STATES PATENT OFFICE.

GEORGE A. STEBBINS, OF WATERTOWN, NEW YORK.

APPARATUS FOR THE PRODUCTION OF PULP.

To all whom it may concern:

Be it known that I, Gnonon A. Srnnnnvs, a citizen of the United States, residing at lVatertown, in the county of J e'tlerson and State of New York, have invented a new and useful Apparatus for the Production of Pulp, of which the following is a specification.

This invention relates to a process and apparatus for the production of pulp such as is used in the manufacture of paper and the like.

l'leretofore, two methods have been employed in the production of pulp. These methods are known as the direct and the indirect. The direct method is carried out by feeding the chips or other material to the digester and then feeding steam to them while in the digester so as to cook them by the direct action or contact of the steam. This direct method, while it is rapid in its results, is attended by certain disadvantages. The condensation of the steam dilutes the acid liquor, and in order to counteract this dilution, the acid liquor is usually made stronger than is necessary to produce the best effects, and the resulting pulp is accordingly of an inferior character. The indirect method is carried out by heating the product in the digester in an indirect manner such for example, as by supplying the steam to pipes or coils located around the interior of the digester so that the heat from the steam is radiated to the material in the digester, but the steam itself does not com-e in direct contact therewith and consequently does not dilute the acid liquor. This method has the advantage, over the direct method, of producing a very much better grade of pulp, for the reason that a weaker acid liquor can be employed and the quality of the pulp is accordingly not injuriously afi'ected. The indirect method, however, has the disadvantage that it c0n sumes a very much greater period of time than the direct method. In fact, the gain resulting from the superior grade of pulp produced by the indirect method, is practically off-set by the loss occasioned by the great length of time necessary for carrying out the method. It is apparent therefore that the manufacturer of pulp has been put to the necessity of deciding whether he would sacrifice the quality of his pulp by using the direct method or sacrifice his time by using the indirect method.

Specification of Letters Patent.

Application filed April 15, 1910.

Patented A11 13, 1912.

Serial No. 555,644.

The object of the present invention is to provide a process and apparatus by means of which the rapidity of the direct method and the superior product of the indirect method may be approximated.

\Vith the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the process and apparatus hereinafter described and claimed, it being understood that changes in the embodiment of invention herein disclosed can be made within the scope of the claims without departing from the spirit of the invention.

In the accompanying drawings forming part of this specification :Thc figure is a vertical section of the novel form of apparatus by means of which the process of the present invention may be carried into effect.

The process of the present invention, briefly outlined, consists in rapidly raising the temperature of the products in the digester to the desired degree wit-h the aid of the direct method, and then maintaining the product at said temperature, by means of the indirect method, until the pulp is produced. The resulting pulp is very much superior to that resulting from the direct process and almost as superior as that obtained from the indirect method, and the time consumed is very much shorter than that necessitated by the indirect method, and only three or four hours longer than that consumed by the direct method. The present process, therefore, approximates the advantages of both the direct and the indirect methods, without the disadvantages.

of either.

The novel form of apparatus, by means of which the process of the present invention can be carried into effect, includes a digester or shell 1 having the usual acid proof lining 2. Arranged at the upper end of the digester is the entrance opening 3. At the lower end of the digester is the T 4 by means of which the pulp may be blown or drawn off by steam after the process has been completed. Extending through the digester 1 and lining 2 at any suitable point is a bushing 5 with which is connected a steam pipe or radiator 6 supported in any suitable manner such for example as by means of the spider arms 7 and 8 suitably connected with the interior of the digester in such manner as not to interfere with the action of the acid proof lining. Steam is admitted to the radiator 6 in any suitable manner such for example as by means of the pipe 8 located on the outside of the digester. The water of condensation is withdrawn from the pipe 6 in any suitable manner such as by means of the valve 9. Extending longitudinally through the radiator 6 is a pipe 10 which is supported in any suitable manner as by means of the spider arm 11. The pipe 10 terminates adjacent the upper end of the radiator 6 and is open at that point. At its lower end the pipe 10 extends through a bushing 12 and is provided with a valve 13. The pipe 10 is used to draw off any air which may be trapped in the upper end of the radiator 6. Steam is admitted to the interior of the digester in any suit-able manner such as by means of the inlet l t of the T 4. The novel form of apparatus described, or any other form of apparatus falling within the terms of the following claims is used, in carrying out the process of the present invention, in the manner which will now be described. The digester is filled with the material which is to be converted into pulp and the acid liquor. The cover plate atthe top (not shown) is secured in position and steam is then admitted in the usual manner at the point it until a pressure of approximately 85 pounds is reached. In the meantime, steam has been admitted at 8 to the radia-- tor 6 for the purpose of aiding and hastening the raising of the pressure to 85 pounds. l/Vhen this pressure is reached, the steam at 14 is cut cit and the steam at 8 is maintained so as to continue the cooking process within the digester until the contents of the same have been entirely treated, after which the pulp is discharged at 4.

It is found in practice that the contents of the digester can be readily raised to the temperature desired in the manner described by supplying the steam directly and indirectly to the digester, and after said temperature has been reached, the indirect action of the steam in the radiator 6 serves rapidly to complete the process.

The form of apparatus herein described, has many advantages. The costly arrangement of supporting coils adjacent the shell of the digester is entirely avoided. Old forms of direct method digesters can. be readily equipped with the improvements of the present invent-ion in order to adapt them for use in carrying out the methods herein disclosed. in the event that the di gester gets out of order, it can be readily repaired without necessitating the great loss of time and labor which results when it is necessary to repair a digester which is equipped with internal coils. The time during which coil digesters are thrown out of operation pending repairs is, a very considerable item, and the loss in lining is also material in removing and replacing coil arrangements. These disadvantages are almost entirely obviated in the present form of apparatus.

l/Vhat is claimed is 1. A vertically disposed digester having a centrally located vertically extending ra diator, one end of said radiator extending at an angle and joining the adjacentwall of the digester, and upper and lower feed and outlet openings for said digester.

2. A vertically disposed digester'having a tapered lower end and upper and lower feed openings, and a centrally disposedvertically extending radiator in alinement with said openings, the lower end of said radiator extending at an angle and connecting with the tapered port-ion of said digester, whereby to provide a clearance for the lower opening of the digester.

3. A. digester having a centrally disposed vertically extending steam pipe closed at its upper end and provided adjacent its lower end with a'condensation valve, and a vertically extending vent pipe located in said radiator and being open at its upper end and provided with a valve at its lower end.

4. A digester having an inlet at its upper end an outlet at its lower end, a vertically extending centrally disposed steam pipe closed at its upper end and provided with a condensation valve and a steam inlet at its lower end, a centrally disposed vertically extending vent pipe in said steam pipe, said vent pipe being open at its upper end and being provided with a valve at its lower end, spiders for supporting said steam pipe in said digester, and spiders for supporting said vent pipe in said steam pipe.

in testimony that I claim the foregoing as my own, I have hereto aflixed my signature in the presence of two witnesses.

GEORGE A. STEBBINS.

Witnesses H. O. Mnrzonu, N. G. BARONE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. C.

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