US1331587A

US1331587A - Centrifugal pulp-screen

Info

Publication number: US1331587A
Application number: US277727A
Authority: US
Inventors: George F Shevlin
Original assignee: Northern New York Foundry & Ma
Current assignee: Northern New York Foundry & Ma; Northern New York Foundry & Machine Co Inc
Priority date: 1919-02-18
Filing date: 1919-02-18
Publication date: 1920-02-24
Anticipated expiration: 1937-02-24

Description

G. F. SHEVLIN.

CENTRIFUGAL PULP SCREEN.

APPLICATION FILED FEB. 18, 1919.

1,331,587. Patented Feb. 24, 1920.

4 SHEETS-SHEET 1- ,FZQJ,

G. F. SHEVLIN.

CENTRIFUGAL PULP SCREEN.

APPLICATION FILED FEB. 18, 1919.

1 3 3 1 587 Patented Feb. 24, 1920.

4 SHEETS-SHEET 2.

G. F. SHEVLIN.

C E N T R I F U GAL P U L P SC R E E N APPLICATION FILED FEB. 18, 1919.

1,331,587, I Patented Feb. 24,1920.

4 SHEETS-SHEET 3- G. F. SHEVUN.

CEN-TRIFUGAL PULP SCREEN.

APPLICATION FILED FEB. 18, 1919.

1,331,587. Patented Feb. 24, 1920.

4 SHEETS-SHEET 4.

UNITED STATES PATENT OFFICE.

GEORGE E. SHEVLIN, 0F GLENS FALLS, NEW YOB-g, ASSIGNOB '10 NORTHERN NEW YORK FOUNDRY & MACHINE CO. INC., OF GLENS FALLS, NEW YORK, A CORPORA- TION OF NEW YORK.

CENTBIFUGAL PULP-SCREEN.

Specification of Illectcn Patent- Patented Feb. 24, 1920.

Application filed February 13, 1919. Serial Ira-277,127.

To all whom it may concern:

Be it known that I, GEORGE F. SHEVLIN, a

.citizen of the United States, residing at reticulated plates etachably connected with each other and supported on the frame of the machine. In such machines provision is made for separately collecting the screened stock, and the sliver, lumps, and other refuse and foreign matter, and the casing is made in detachable sections to provide for access to the screen plates when they require repairs or when it is necessary to replace them.

According to my present invention, I sim plif the construction of the machine and so change the relation of the beater blades with each other and to the discharge 0 nings in the cylinder as to increase their e ciency in discharging the pulp from the cylinder and against the screens and in discharging-the slivers, lumps and other foreign matters from the lower portion of the cylinder into the trough provided to receive them. I also so mount and connect the screens that they may be more readily separated and removed from the machine when they require repairs or it is necessary to replace them. Other 3--2. of Fig. 1.

features of the invention will be hereinafter In the accompanying drawings Figure 1 shows a vertical sectionthrough a centrifugal pulp screen embodfi riag my improvements on the line 1--1 of ig. 2.

Fig. 2 shows a transverse section on the line 22 of Fig. 1.

Fig. 3 shows a similar section on the line Fig. 4 is a side view of the cylinderor barrelcarrying the beater blades and the devices for discharging refuse or foreign matter.

Fig. 5 is a pers i 've view of a portion of the beater-carrying cylinder.

Fig. 6 is an end view of oneof the screen sections.

Fig. 7 is a perspective view showing portions of two of the screen sections.

Fig. 8 is a detail view In section, showing how .two adjacent screen sections are, connected with each other.

Fig. 9 is a perspective view of a single screen section.

Fig. 10 is a perspective view further illustrating how the screen sections are connected with each. other.

Fig. 11 is a sectional view of a modification, the section being similar to that shown in Fig. 2, but showing a slightly difierent arrangement of the beater blades.

Fig. 12 is a perspective view, showing partioularly'the devices for discharging foreign matter into the receivin trough, and

this figure of the drawings a so shows therelation of such devices with the cylinder and the beater blades carried thereby.

As my" improvements do not involve changes in all parts of the machine, I have shown only such portions thereof as are necessary to illustrate my invention. Unless otherwise specified the parts shown are of well known construction.

The paper stock is fed to the machine through an inlet A. The screened stock is received b a trou h B and the sliver or unstrained stock, inc uding all foreign matter, is received by a separate trough C. The shaft D is supported in suitable bearings and extends centrally through the beatercarrying cylinder or barrel E. The cylinder 1s formed with a narrow horizontal upper flange f and a wider downwardly inclined bottom flange f which latter extends artway over the inner edge of the troug O.

The cylinder is closed at its lower end, as

dicated at f.

Within the cylinder are arranged a series of vertical radially'arranged, curved beater blades 9 and similar beater blades g are arranged on the outside of the cylinder. Preferably the body of the cylinder, the flanges f,

f, bottom plate f and the blades 9, g are made in a single casting, the inner blade 9 being formed with a hub g which is secured to the shaft D so that the cylinder and the bladesrevolve with the shaft. The upper ends of the blades 9 are of the usual form,

as indicated in Fi 1, and said blades extend from the top of t e cylinder to the bottom thereof. Lateral o nings or slots h are formed in the oylin er to permit the liquid cases.

pulp to pass from the interior of the cylinder to the outside thereof and thus enter the annular chamber in which the blades 9' 'operate.

It will be observed, by reference to Fig. 2, that the outer blades 9 are not direct continuation of the inner blades 9 but are out of line therewith.

It will also be observed, by reference to Fig. 2, that whereas the convex sides of the blades 9 act upon the pulp within the cylinder the concave sides of the blades g act on the pulp outside the cylinder. The openings h in the side of the cylinder E are in front of the outer ends of the blades 9 and just behind the inner ends of the blades g, each opening being thus a considerable distance in advance of the first blade of the, outer series which actson the pulp flowing out of said opening. This is an important improvement made by me, for the reason that the pulp is prevented from flowing too rapidly through the apparatus because Inasmuch as it is thrown out through the openings h by action of the convex blades 9, as well as by centrifugal force, it is not immediately acted upon by the outer concave heaters but a short time elapses before the heaters act upon the pulp flowing through said openings. The pulp flowing downwardly through the cylinder E tends to continue its downward movement by gravity, but also tends to flow laterally through the openings h by centrifugal force and by the action of the beater blades 9 which being convex assist in throwing the pulp through said openings. The pulp is detained in the spaces between the heater blades 9 before passing through the openings 71, and thus is not immediately thrown out by centrifugal force. Some of the pulp is immediately thrown out by centrifugal force while other portions of the pulp descend and are then 'thrown out by centrifugal force, thus the output of the machine is increased and a larger surface of the screen is utilized. Furthermore, by employing outer beater blades of the kind shown, which present a concave surface to the pulp passing out of the cylinder, the pulp which enters the annular space traversed by the outer blades is prevented from passing too quickly against the screen and thus is made to distribute itself over an extended surface thereof so that practically the entire vertical surface of the screen is utilized.

The heaters g operate in an annular chamber formed between the cylinder E and the cylindrical screen K which surrounds the outer edges of the beaters but is arranged a short distance therefrom as is usual in such The particular construction of the screen will be hereinafter described, but the operation of the apparatus will now be clear. The pulp entering at A passes down into the cylinder E, and the fine pulp passes out through the openings h and is thrown by the outer heaters 9 against the cylindrical screen. The stock which passes through the screen is received by the trough B and is conveyed away in the usual way. Such stock as falls to the bottom of the machine outside the cylinder E and onto the inclined flange f passes therefrom into the trough C. Much of the stock and the lumps, chips and foreign matter does not pass through the openings 71. but drops to the bottom of the cylinder E. In order to discharge this stock and the refuse or foreign matter that may be mixed with it and prevent it from clogging the machine, openings m of large area are formed in the lower portion of the cylin-.

der above the flange f. Whatever material or substances reaches the bottom of the cylinder passes out through these openings and over the flange f into the trough C.

In order to properly direct the material passing through the openings m and to deliver it to the trough C, I provide hoods M which have upper closed sides m and curved vertical front faces m Fig. 12 of the drawings clearly illustrates the construction of these hoods and their relation with other parts of the apparatus.

It will be observed that the openings m are quite extended so as to permit unstraine stock and foreign matter to freely pass out from the bottom of the cylinder. The material thus passing through the openings m enters the hoods M and is delivered from the rear portions of the hoods. The front portion the apparatus is so clearly shown in the drawings that a detailed description of this feature of the invention is deemed unnecessary. The convex front sides of the hoods, as before stated, so act upon the material as to cause it to pass into the trough C without being thrown against the screen plates. This is an advantage inasmuch'as parts of machines, pieces of wood and other heavy material are often mixed with the pulp and it is desirable that suchmaterial should be delivered to the trough C without beingthrown against the screen plates.

The exterior casing N is madein sections as heretofore. No attempt has been made to illustrate the details of construction of the "casing and it need not be described further than to say that the sections are removable in order that access may be had to the screen plates or sections which are also removable in order that they may be repaired or replaced at proper times. I have,

owever, provided means for so supporting and joining the screen plates that they may be very quickly connected and disconnected and removed when the casing is opened and in like manner replaced. My improvements in this connection are most clearly illustrated in Figs. 6-10, inclusive, of the drawings. Each screen section is of the general form shown in Fig. 9. The reticulated part 0 may be made of perforated plates or other suitable reticulated material and the perforated portion of the screen is surrounded by a suitable frame 0'. The vertical sides of the frames are formed with key-hole slots 0 so constructed and arranged that the larger portion of each opening may easily pass over the head of a bolt. To connect the screen sections with each other, I employ bolts Q, carrying nuts 9. The bolts pass through the vertical side pieces of two adjacent screens, as illustrated in the drawings, and when the nuts are screwed home the screen sections are rigidly connected with each other, and form a cylindrical screen which rests on the vertical flange R which separates the troughs B and C. The screen is so supported that it may be turned about a vertical axis, so as to bring each section opposite an opening in the casing made by removing one of its sections and then each section or any section may be removed through this opening. In this way, it will be observed, it is not necessary to remove all sections ofthe casing when it is desired to romove the screen plates, and it will also be observed that it is not necessary to dismantle other parts of the machine when desiring to remove a screen section. When the screen sections are being assembled they are brought together in the manner indicated in Fig. 8 and bolts are passed through thelarger portions of the slots or openings 0 then the bolts are dropped into the narrower portions of the slots and the nuts are screwed home. When it is desired to remove the screen sections the nuts are loosened, the bolts are moved vertically into the larger portions of the slots and are then drawn laterally through said slots. In this way the screen sections are disconnected and any section may be removed without disturbing the others, or they may all be re-' moved if desired after the nuts have been lar to the section shown in Fig. 2, but it will be observed that the arran ement of the beater blades is slightly di erent. In this case the inner beater blades 8 are made concave on their front faces and their outer ends are in front of the adjacent openings in the cylinder. The, outer blades 8' are similar to those shown in Fig. 2, and the relation of these blades to the openings h is the same.

The construction shown in Fig. 11 works well but that shown in Fig. 2 is preferred. In both cases, it will be observed, the outer or exterior blades are concave and tend to detain the pulp and in each casethe inner end of each outer blade is in front of the adjacent opening in the cylinder. In both cases the blades for propelling the pulp through the slotted cylinder are used in connection with the devices particularly shown in Fig. 12 for expelling lumps, slivers and other larger and heavier material from the lower part of the cylinder.

I claim as my invention:

1. A centrifugal pulp screen, comprising a cylindrical screen, means for separately receiving the screened and unscreened stock, and a revolving cylinder within the screen having lateral openings and provided with interior blades having convex sides operating on the pulp within the cylinder and exterior blades having concave sides operating on the pulp outside the cylinder.

2. A centrifugal pulp screen, comprising a cylindrical screen, means for separately receiving the screened and unscreened stock, and a revolving cylinder within the screen having lateral openings and provided with convex interior blades o crating upon the pulp within the cylin er, and exterior blades, the inner ends of which are disposed 3. A centrifugal pulp screen, comprising a cylindrical screen, means for separately receiving the screened and unscreened stock, and a revolving cylinder within the screen having lateral openings and provided with interior blades operating upon the pulp within the cylinder, and exterior blades, the inner ends of which are disposed in advance of the adjacent openings on the cylinder and in advance of the outer ends ofthe next adjacent interior blades.

4. A centrifugal pulp screen, comprising a cylindrical screen, means for separately receiving the screened and unscreened stock, and a revolving cylinder within the screen having lateral openings and provided with interior blades, the outer end of each. of which is disposed close to and on one side of an opening in the cylinder, and exterior blades, the inner end of each of which is disposed close to and on the opposite side of each of said openings in advance of the outer end of an interior blade.

5. A centrifugal pulp screen, comprising a cylindrical screen, means for separately receiving the screened and unscreened stock,

and a revolving beater-carrying cylinder having side openings through which the pulp passes to the screen, a closed lower wall or bottom plate over which the pulp passes laterally, and enlarged side openings through which the pulp flows over said bottom plate from the cylinder, and hoods partially surrounding said openings and through which the stock passes laterally between the hoods.

6. A centrifugal pulp screen, comprising a cylinder screen, means for separately receiving the screened and unscreened stock, a revolving beater-carrying cylinder having side openings through which the pulp passes to the screen,'a closed lower wall or bottom plate and having enlarged side openings through which the pulp passes laterally from said bottom plate, a downwardly inclined flange extending from said bottom plate to the receiver for the unstrained stock, and hoods above said inclined flange having convex front faces acting en the material passing out of said side openings over said flange.

7. A centrifugal pulp screen, comprising a revolving beater-carrying cylinder having lateral openings through which the pulp is delivered, and a surrounding cylindrical screen mounted to turn about a vertical axis and made in sections detachably connected with each other.

8. A centrifugal pulp screen, comprising a revolving beater-carrying cylinder having lateral openings through which the pulp is delivered, a surrounding cylindrical screen rotatable about a vertical axis and made in sections detachably connected with each other, and a casing surrounding said screen having one or more removable sections.

10. A centrifugal pulp screen, comprising.

a revolving beater-carrying cylinder having lateral openings through which the pulp passes, and a surrounding screen made in detachable sections each of said sections being formed with key-hole slots in its vertical side portions and bolts carrying tightening nuts arranged insaid key-hole slots, said bolts being removable through the wider portions of said slots but being held from removal when in the narrower portions of said slots.

11; A centrifugal pulp screen, comprising a cylindrical screen, means for separately receiving the screened and unscreened stock, and a revolving cylinder within the screen having lateral openings and provided with interior blades operating upon the pulp in the cylinder to expel it through said openings, and exterior concave blades having concave sides operating on the pulp outside the cylinder to deliver it to the screen, said cylindrical screen having side openings in its lower portion provided with hoods having convex front sides operating upon the pulp delivered through said side openings to rotate it and to deliver it to the receptacle for unstrained stock.

In testimony whereof I have hereunto subscribed my name.

GEO. F. SHEVLIN.