US1722693A - Extractor - Google Patents

Description

July 30, 1929. G. s. WITHAM, JR

EXTRACTOR Filed April 28, 1927 I 1\ 'llllln wmullllll fir ATTORN Y Fatented July 361 192$.

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GEORGE STANFORD WITHAItLJ'R, 0E HUDSON FALLS, NEW YORK.

:EXTBAGTOR.

Application filed April 28, 1927. Serial No. 187,333.

My invention relates to the art of paper making and particularly to devices for continuously selecting and segregating, from a mass of paper stock which is undergoing a hydrating or disintegrating treatment, particles of a predetermined size or which have reached a predetermined stage in the treatment. It is particularly adapted for use with a beating engine but may be used, in connection with suitable means for spraying or projecting a-liquid, to extract particles of stock from any liquid mixture.

The usual, present practice in the preparation of paper stock is to place a definite charge in the beating engine and to subject all of this stock to the same beating process for the same length of time. Before the stock is placed in the beater it has been subjected to a preliminary treatment and when placed in the machine comprises many unbroken lumps, separated groups of a few fibers, and often times individual fibers then ready for the paper making machine. This entire mass is beaten until all of the stock is in proper condition without regard to the fact that as the beating operation progresses a constantly increasing proportion of the mass is becoming ready for the paper machine.

As a result of this method of operation, a great part of the mass is excessively over treated representing an enormous waste of power, and requiring a very large equipment to produce the amount of stock necessary for the paper machine proper.

The disadvantages inherent to this method of operating have been recognized, and various means have been devised with varying degrees of success whereby fully treated stock may be extracted from the beater, or whereby the beating operation has been made substantially continuous in other ways. a For example, perforated cylinders revolving slowly in the mass of stock have been used to extract the prepared fibers. and it has also been proposed to perforate a portion of the hood about the beater roll through which particles of stock will be projected from the revolving roll. Extractors of the latter type are easily plugged and for this reason the perforations must be of such large size that these devices are onlyadapted to disintegrate or reduce broke and the like to half stock which is usually circulated in the beatersat a low consistency and is therefore easily disintegrated. Furthermore, itis not possible to extract the finer fibers and particles alone because in this condition they are not projected against the necessarily finely perforated plates or screens with sufiicient force to carry them through.

The primary object of this invention is to provide an extractorwhich will operate in connection with a beatin engine or thelike running at a high consistency, and which will, without clogging, separate and segregate the finest particles or fibers from the general mass of stock. Another object is to provide a device of this character which may be readily adjusted to extract particles of stock up to any predetermined'size. A further object of my invention is to provide 'a device of this character as an assembled unit adapted for attachment to existing beating engines or the like without any substantial alterations therein, and which may be cut out of operation without interfering with the operation of the heater or other device to which it is attached. And a still further object is to provide, in connection with the above general objects, a device which will be self cleaning.

My invention therefore includes the novel elements and the combinations and arrangements of elements described below and illuswhich- Fig. l is a fragmentary section of a beating engine at a point somewhat behind the backfall and shows the attachment of my extractor to the hood above the beater roll; portions of the extractor casings being broken away for the purpose of showing the inner construction; and

Fig. 2 is a section of Fig. 1 in the broken planes 22.

. Referring particularly to the drawings, 1 represents the tub having the usual midfeather, 2, backfall, 3, and beater roll,4, provided with the hood or cover, 5. Y

The beater roll, 4, revolves in the direction of the arrow shown in Fig. 2 and the bars or natural that the finer particles of stock- Y those which are nearest complete hydrationwill be carried over by the roll and will be sprayed or projected therefrom by centrifugal force.

In attaching my device to a beating engine, a portion of the hood or cover over the roll is cut out as shown at, 7. Mounted upon the top of the hood or cover, 5, and over the opening, 7, is my extractor. This device comprises a casing, 8, having a perforated screen portion, 9, and an impeller or paddle, 10, ax-

ially mounted within the casing, '8. The

screen, ,9, is preferably cylindrical and the gate, as shown at 12, and to generally regulate the opening between the extractor compartment and the beater roll. Below the perforated portion, 9, of the casing is a trough or gutter, 16, into which fall the particles of stock extruded through the perforations in plate, 9, by the impeller, 10. In the drawings, I have shown a screw conveyor, 17, operating in the trough which conveys the particles of stock to the chute, 18, through which they may be carried with the assistance of water, air or gravity for delivery at some other point. It is obvious that a screw conveyor is not the only means which may be employed to force the stock from the trough, 16, but that either water or air alone, or in conjunction with such a conveyor, may be employed where desirable. The impeller, 10, may be turned b a motor driven reduction unit, 19, attache directly to the shaft, and the screw conveyor, where employed, may be operated by a chain, 20, running over suitable gear wheels on the impellor shaft and the screw conveyor shaft.

The operation of my device on a beater is ,as follows: As the beater roll, 4, revolves,

particles of stock are projected therefrom through the opening, 7, in the hood and into the compartment, 8, in the form of a spray. Some of this stock is intercepted directly by the impeller and some accumulates in the compartment from which it is later picked up by t e impeller, 10, carried around, and extruded through the perforated portion, 9. The screen, 9, is detachable by simply removmg bolts, 21 and 22, so that screens having di erent size openings therein may be easily substituted. The extruded material falls by gravity into the trough, 16, and flows thence to the chute, 18. l

In addition to mechanically extruding particles of stock through the screen, the impeller, at certain positions, tends to com ress or force air through the perforated p ates, and, in other positions, to draw air through the perforated plates, thereby giving a slight,-

pulsating action similar to the present types making machine.

of centrifugal screens. This action automatically tends toprevent clogging of the perforations in the screen and to produce a steady flow of selected stock. By reason of this action the screen portion, 9, may be made very thin and the perforations therein may be made much smaller than is possible with the present types of extractors.

One of the great advantages of my form of extractor is that it is possible to use a screen or perforated plate of such fineness that stock delivered therefrom is all of the proper size and in proper condition for the paper making machine proper. This is obviously not possible where the stock is projected directly on the screen. 1

Where a mill is equipped with several beaters it is possible, with my device, to provide a continuous supply of stock to the paper To make a, continuous system, the first extractor is provided with a' screen having comparatively coarse openings. The product of this extractor is directed through other heaters having extractors pro vided with finer screens until the stock from the last heater is of the proper size and has been sufficiently treated for delivery to the web forming machine. In such a system no time is lost in dumping a tub after it has been charged and the expense of a large equipment is considerably reduced because of the increased capacity of each beater.

While I have illustrated and described my device as attached to a beating engine it is 'to be understood that my invention is not necessarily limited to such a combination. It will be perfectly clear to those versed in the art of paper making, and to others, that my extractor may be used for. removing stock of selected size from any vat or tub where suitable means is provided for spraying, forcing or projecting the particles of stock into the extractor compartment." Furthermore, it is wholly immaterial whether the extractor be arranged over the opening, 7, with the screen, 9, to t e rear or the front of opening, 7.

It is therefore to be understood that the words which I have used herein are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention in its broader aspects.

What I claim is 1. In a stock extractor, the combination with a easing into which the stock is sprayed, of a screen, and means within the casing adapted to intercept part of the sprayed stock and extrude it through said screen.

2. In a stock extractor, the combination with a casing having an opening therein for the admission of stock, of a screen in said casing, means for positively extruding stock through said screen, and means for varying the size of the opening in said casing.

agitator adapted -toreceive stock thrown therefrom by centrifugal force, a screen, and

means intermediate the agitator and screen for forcing the stock from said compartment through said screen.

4. In a beating engine or the like, the combination with a rotating stock agitator, of means forming a compartment adjacent said agitator adapted to receive stock thrown therefrom by centrifugal force,'and revolving means for extruding the stock through a perforated portion of said compartment.

5. In a beating engine or the like, the combination with a stock agitator, of a screen, and revolving means intermediate said agitator and screen adapted to receive stock from the agitator and extrude the same through said screen.

6. In a beating engine or the like, the combination with a rotating stock agitator, of means forming a compartment adjacent said agitator adapted to receive stock projected therefrom by centrifugal force, means for positively forcing the-stock from said compartment and means for regulating the quantity of stock projected into said compart- 'ment. 1

. 7 In a beating engine or the like, the combination with a stock agitator, of a screen,

revolving means intermediate the agitator and screen adapted to receive stock from the agitator and extrude the same through said screen, and means for regulating the quantity of stock passing from the agitator to said revolving means.

8. In a beating englne or the like, the combination with a rotating stock'agitator, of a stock extractor adapted to receive stock projected from said agitator by centrifugal force, and means for regulating the passage of stock between the agitator and extractor.

9. In a beating engine or the like, the combination with a stock projector, of means forming a compartment adjacent said projector adapted to receive stock thrown therefrom, a screen in said compartment, means for stock from beneath the screen, and means for:

regulating the passage of stock from the projector to said compartment.

11. In a stock extractor, the combination with a screen, of means for spraying stock in the general direction of said screen, and means for maintaining a slight pulsatin movement of the stock particles passin t tough the openings in said screen where y said screen .is prevented from clogging.

12. In a stock extractor, the combination with a casing having a screen therein, of means for spraying stock into said casing, and means intermediate the screen and spraying means for conveying a portion of the spraye stock to said screen.

13. In a stock extractor, the combination with a casing having a screen therein, of

means for spraying stock intosaid casing,

means for extruding the sprayed stock v through said screen, and means for varying the quantity of stock sprayed into saidcasing.

'14. In a stock extractor, the combination with a screen, of an impeller for forcing stock through said screen; said impeller being provided with revolving blades barely clearing said screen.

15. In a stock extractor, the combination with a curved screen, of an impeller for positively forcing stock through said screen said impeller being provided with revolving blades barely clearing said screen.

16. In a stock extractor, the combination with a screen, of means for projecting stock in the general direction of said screen, and means intermediate the screen and projecting means for preventing ging the screen. .1

17. In a stock extractor, the combination the projected stock from clogwith a easing into which the stock is projected,

of a screen, means for picking up part of the stock projected into said casing and forcing'it through said screen, and means exterior of said casing and below the screen for conveying the screened stock away.

18. In a stock extractor, the combination with a screen, of a rotary stock impeller adapted to extru'de stock through said screen, and means operatively connected with said impeller for carrying away the extruded stock.

19. In a device of the character described including a stock vat, the combination with a casing, of a screen therein, means for conveying stock from the vat to the casing, and means for interceptinga portion of the stock conveyed to the casing and sweeping it over said screen.

' 20. In a stock extractor comprising a separate unit adapted for attachment to a heater or the like, the combination with a casing into which the stock is projected, of a cylindrical screen, and an impeller rotatively mounted in said casing and provided with a plurality of blades revolving in close proximity to said screen.

GEORGE STANFORD WITHAM, JR.

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