US797970A - Process of reducing paper-stock to pulp. - Google Patents

Description

No. 797,970. PATEMBD AUG. 22, 19.05. F. P. MILLER.

PROCESS OF REDUCING PAPER STOCK T0 PU LP.

APPLICATION rum) MAR. 13. 1902:.

1 UNITED STATES PATENT QFFICE.

FRANK Pe -MILLER, OF DOWNINGTOWN, PENNSYLVANIA.

PROCESS OF REDUCING PAPER-STOCK TO PULP.

Specification of Letters Patent.

Patented Aug. 22, 1905.

Application filed March 13, 1902- Serial No. 98,011.

To all whmn it may concern:

Beit known that I, FRANK P. MILLER, a citizen of the United States, and a resident of Downingtown, Pennsylvania, have invented certain Improvements in the Process of Reducing Paper-Stock to Pulp, of which the following is a specification.

The object of my invention is to reduce paper-stock and separate the ground stock from material in circulation without interrupting the flow of the said material, so that the finished stock'can be carried from the machine and new stock added for making the process continuous.

In the accompanying drawings, Figure 1 is a longitudinal sectional View of an improved beating-engine used in carrying out my process. Fig. 2 is a section on the line 2 2, Fig. 1, with the shaking mechanism for the screen removed, and Fig. 3 is an enlarged view of a portion of Fig. 1, showing the screen in detail.

A is the vat, separated by the usual midfeather a, forming two channels through which the paper-pulp is traversed. In one of these channels is a beating-roll B, mounted on a shaft B, carried by suitable bearings and having knives 6.

C C are knives mounted in the frame of the machine, between which and the beating-roll the pulp is passed.

A is the back-fall over which the pulp is carried by the beating-roll B, and directly back of the back-fall is ascreen D. This screen is suspended from a shake-frame D, which can be constructed in any suitable manner, and any means may be provided for shaking the frame, so as to agitate the screen. The screen in the present instance is made up of a number of plates, each plate being recessed on each side to form narrow slots, so that when the plates are assembled they form narrow slots for the passage of the pulp, as shown in Fig. 2. This screen may be perforated with circular holes or slots of any shape, and the slots may be formed in any manner. The perforations are of such size as to allow the finished product of the machine to readily pass through the plate into the chest E, which is directly under the screen and from which the product is withdrawn, either by gravity or by means of a pump through the outlet-passage e.

Beyond the screen D is a continuation A of the back-fall A. The unfinished product passes over the screen and over the back-fall and circulates through the channels, to be acted upon again by the beating-roll. In the present instance the screen D is arranged on an incline from the back-fall A, so that the unfinished material will more readily pass over it; but it will be understood that it may be horizontal or at any incline desired, depending greatly upon the material being treated.

When certain classes of paper-stock are being treated, particularly old paper, cardboard, books, 860., I provide means for catching the strings and like material, and this means consists in the present instance of a transverse shaft F, having a number of curved forks f arranged directly back of the screen D and in the present instance having their tips resting upon the upper portion of the continuation A of the back-fall. These forks are so arranged that the ordinary stock will pass between them, while the strings and similar material will be caught by the forks, and when these strings accumulate the operator simply turns a shaft F and raises the forks and removes the strings, which can either be collected for other paper-stock or reduced in another machine. The shaft F in the present instance is suspended from a shaft F by arms f, and this shaft is operated by a lever f so that the shaft F and its forks can be moved out of the way when desired.

While any suitable means may be provided to shake the screen D, in the present instance I have shown one form of shaking means which I will now proceed to describe.

Mounted on pedestals K K on each side of the vat are spring members is h, from which is suspended by bars 7. the screen D.

I is a driven shaft having cams a thereon, which act against plates '6, carried by the spring memberslsis. The shaft I is mounted in suitable bearings, and the shaft may be driven from the beater-shaft B, if desired, or it may be independently driven.

The back-fall A may be provided with a yielding lip a, which will overlap the frame of the screen D, so as to prevent the material from entering the chest E except through the screen. A like lip 60 may be provided at the opposite end of the screen, which will overlap the portion A of the back-fall, Fig. 3.

The material to be reduced into paper-pulp is placed in a vat with a suflicient amount of water. The beating-drum is set in motion,

The material is reduced by passing between the beating-roll and knives until it is in condition to be removed from the engine.

In its passage through the vat the material passes over my improved screen, and there is sufiicient suction caused by the agitation of the screen to draw certain particles of the material through the screen. These particles are those that have been reduced to the desired condition, and they pass into the chamber under the screen and are drawn out through any suitable pipe connected with any suction device, either gravity or pump, as desired. The balance of the stock circulates through the vat, passing under the roll until it is finally reduced to the desired condition, when it will pass through the screen into the chamber E. This processiscontinuous, and new stock can be added without stopping the machine. In fact, after the machine is once charged with paper-stock the finished stock can be removed and additional stock added.

By my improved apparatus, which forms the subject of a separate application, Serial No. 110,523, filed June 6, 1902, the rags, strings, and similar material can be collected by the forks placed directly back of the screen, while wires, nails, and other heavy foreign matter will collect in the bottom of the vat, and pockets m may be provided for this pur pose.

My invention is especially adapted for grinding and reducing old paper and paper-stock; but it will be understood that it may be used in connection with any material which can be ground to a pulp to form paper.

In reducing some classes of paper-stock it has been the practice to work the beating-engine until all the stock is reduced to such a consistency than it can be transferred to a paper-making machine. It has been found in reducing the paper-stock in this manner that a great portion of/the material was reduced to such an extent that the fiber was destroyed, and consequently the paper which was made from the pulp was not strong. This is entirely obviated by my invention, and the pulp as soon as it is in condition to be removed from the machine passes through the screen and away from the pulping mechanism. The machine can be either used as a continuous machine or as an intermittently-operating machine, according to the desire of the operator.

I claim as my invention 1. The process herein described of reducing paperstock to pulp, said process consisting in continuously circulating the stock, heating it during such circulation, positively grading the coarse and fine stock during the circulation, and withdrawing the fine stock from the circulation without interrupting the uniform flow of the coarser stock, substantially as specified.

2. The process herein described of reducing paper-stock to pulp, said process consisting in continuously circulating the stock, heating it during such circulation, positively grading the coarse and fine stock during the circulation, and withdrawing the fine stock from the circulation by suction without interrupting the uniform flow of the coarser stock,substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FRANK P. MILLER.

Witnesses:

WILL. A. BARR, Jos. H. KLEIN.

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