US3040995A

US3040995A - Disc refiner

Info

Publication number: US3040995A
Application number: US767433A
Authority: US
Inventors: Herman W Steiniger
Original assignee: Bauer Brothers Co
Current assignee: Bauer Brothers Co
Priority date: 1958-10-15
Filing date: 1958-10-15
Publication date: 1962-06-26
Anticipated expiration: 1979-06-26

Description

`lune` 26, 1962 H. w. sTElNIGER DISC REFINER Filed Oct. l5, 1958 amb @MAT

M -v flq mw m NE M ET W5 n 1w M N m m l A m m 2.5m un whmu W. QAJMW United States Patent O 3,040,995 DISC REFlNER Herman W. Steiniger, Springfield, Chio, assigner to The Bauer Bros. Company, Springfield, Ohio, a corporation of Ohio Filed Oct. 15, 1958, Ser. No. 767,433 7 Claims. (Cl. 241-79) This invention -relates to disc refiners and more particularly to an improved pulp refining system for use on pulp suspensions which have Ia tendency to foam.

Certain types of pulp suspensions have a tendency to produce foam, either in the form of large air bubbles or small bubbles which produce a heavy lather. The foam can reach a thickness of several feet, the fibers being suspended in the foam. Since the foam is principally air, it is impossible for a conventional pumping system to handle it and the tanks and vats handling such a suspension have a tendency to overflow. This means that the air which creates the foam must be excluded or evacuated in order to make it possible to rene stock with a foaming tendency.

Previous devices for handling this type stock are relatively ineicient. They generally consist of slow speed refiners which are actually not suitable -for completing the defvbering of a pulp suspension since most of them have a tendency to cut the fibers. Moreover, their rotating elements generally operate submerged in the stock being refined, producing high friction and consuming large amounts of power in the process.

In the development of the invention recognition has been taken of the fact that a double disc refner operating at high speeds is an excellent device for defibering since the fiber bundles tend to align themselves in a radial direction and the teeth of the rotating disc tear off individual fibers from the bundles With little tendency for cutting. The system of the invention in its preferred form employs contained discs operating in a housing with a sealed feed and discharge, means being provided for excluding and evacuating `air from the stock being processed. 'Ihe discs are so related to the stock flow to enable their operation at high speeds ywith substantially no turbulence resulting. Substantial economy and efficiency of operation lresults in the use of the invention system and a high quality product is insured.

A primary object of the invention is to provide improvements in refining `systems for operating on pulp suspensions which have a tendency to foam whereby such systems may be more economically manufactured, more efficient and satisfactory in use, adaptable to wide variety of applications and be vunlikely to get out of repair.

A further object of the invention is to provide an improved rening system having a sealed feed land discharge which avoids entrainment of air in the stock being processed.

Another object of the invention is to provide a pulp refining system which effectively excludes and evacuates air from the pulp stock preliminary to deliver to ya paper making machine or the like.

An additional object of the invention is to provide an improved disc refiner system for producing high quality pulp at minimum cost wherein double refining discs are employed in conunction with a sealed feed and discharge.

Another object of the invention is to provide improvements in disc refiners by applying means for controlled evacuation of air from the refined stock.

A further object of the invention is to provide an improved refner and System possessing the advantageous structural features, the inherent meritorious characteristics and the mode of operation herein mentioned.

With the above and other incidental objects in View as will more fully appear in the specification, the invention intended to be protected by Letters Pate-nt consists of the features of construction, the parts and combinations thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings, or their equivalents.

Referring to the accompanying drawing wherein is shown one lbut obviously not necessarily the only form of embodiment of the invention,

FG. l is a `generally diagrammatic view illustrating a pulp refining system as provided by the invention; and

FIG. 2 is a diagrammatic illustration of a modification of the invention system as shown in FlG. l.

Like parts are indicated by `similar characters of reference throughout the several views.

The invention can be Vbest described with reference to the drawings. A double disc reliner 1 is shown to include opposed discs 2 and 3 which are rotatable in opposite directions. The disc 2 is centrally mounted about one end of a hollow shaft 4 which is the drive shaft of a motor 5. The reiiner base 6 has vertical standards 7 to either end of motor 5 which mount bearings 8 for the shaft 4.

The disc 3 is centrally mounted to the drive shaft 9 of a motor 10 coaxial with the shaft 4. The shaft 9 is similarly supported in bearings 11 in 'spaced vertical standards 12 on the base 6. Means 13 are diagrammatically illustrated in connection with the shaft 9 for axial adjustment of the shaft and connected disc 3 relative disc 2 in a manner which is obvious and which constitutes no part of the present invention.

The opposed faces of the discs 2 and 3 are dish shaped. The hollow shaft 4 communicates with the space between the discs 2 and 3 at its outlet end and is provided with a rotary union 15 at its inlet end through which stock is delivered under pressure.

A housing 16 contains the discs 2 and 3 and mounts about the respective shafts 4 and 9. The only outlet provided from the housing 16 is through an opening yat its bottom defined by a tube 17 sealed thereabout and extending to connect into a stock chest 18, which is pressure tight. Access panel 19 seals an opening to the chest 18. A vacuum pump 14, schematically shown, has an evacuation tube 21 opening into the top of the chest 1S. A centrifugal discharge pump 22 connects into the bottom of the chest 13, while a delivery ltube 23 leads from :the pump 22 to subsequent fiber treating equipment in the preferred application of the invention.

A recirculation tube 24 connects from the tube 23 into the upper portion of the stock chest. The tube 24 has' a valve 25 therein controlled by a level sensing device 26 which is float controlled to selectively maintain the valve 25 open or closed, depending on the level of the stock in the chest 18, as will be described.

In the use of the invention system stock is delivered through shaft 4 under pressure to the space intermediate oppositely rotating discs 2 and 3. Since the feed line is sealed, entrainment of air in the pulp slurry or stock is avoided. The pulp is passed between the discs which tear off individual fibers from the fiber bundles in the stock. The stock, thus modied, is slung radially into housing 16 to drop by gravity through the sealed feed passage 17 into the stock chest.

The level Isensing device 26 in the stock chest is so adjusted that a certain space is to be maintained above the refined stock falling into the chest. The connected vac- -uum pump 14 is operated to induce a partial vacuum in this space above the stock. As the refined stock falls into lthe chest, the vacuum induced therein causes the air within the fiber material to be drawn off. This is facilitated by the free fall of the refined material. If the level of the stock should fall, the device 26 operates to open valve 25 to bring `Sufficient refined material normally being delivered by the pump 22 to subsequent fiber treating equipment back into the chest 18 to re-establish the required level of the stock therein. The fact the discs 2 and 3 `are not immersed in the stock in `operation enables their high speed operation with minimum power loss. The sealed feed and discharge insures that no outside air is drawn in to cause undue foaming or turbulence as the stock is refined and delivered. Foaming is reduced to a minimum and the processing of the fibers is smooth and efficient. The controlled vacuum in the stock chest i11- sures maximum air evacuation.

The above system is particularly desirable when applied to the refining of pulp with tendencies to foam excessively but its application is, of course, not so limited. The smooth continuous flow operation which is provided for stock having inherent tendency -to foam enables the production of a pulp, both quantity-wise and quality-wise, representing a distinct advance in the art.

FIG. 2 of the drawings shows a modification of the system `of FIG. 1. In this embodiment the structure of the refiner proper is identical through to the discharge tube 17. Here a centrifugal separator 30 is connected in the discharge tube 17 preliminary to the delivery of the refined material from the discs to the stock chest 18. The centrifugal separator has a tube 31 in its top open to the atmosphere. The separator operates on material passing therethrough to evacuate whatever air is entrained through the tube 31. From the separator the refined material is delivered into the sealed stock chest 18 from which it is drawn and delivered to subsequent fiber treating equipment by a pump 22 connecting into the bottom of the stock chest by a tube 21.

Thus, it will be readily seen that the present system will positively and effectively control any stock that will be likely to produce problems of foaming in operation. It is ecient, simple and requires a minimum of power.

From the above decription it will be apparent that there is thus provided a device of the character `described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any 'of its advantages.

iWhile in order to comply with the statute the invention has been described in language more or less specific as to |structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but 'one of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, l claim:

1. A pulp refiner system including, a sealed housing having a feed and gravity discharge means sealingly connected therein, means for receiving stock from said feed means within said housing, refining it and delivering it to said gravity discharge means, a stock chest having a sealed connection to said discharge means and means for evacuating air from the refined stock as it is delivered from said discharge means to said chest, said last named means including a centrifugal separator means in said gravity discharge means intercepting the rened stock.

2. A pulp rener system including, a sealed housing, a pair of cooperative refiner discs` oppositely rotatable therein, a gravity discharge means having a sealed connection to said housing, a pressure feed means connected in said housing for delivery `of stock to said refiner discs to be refined thereby and gravity discharged through said discharge means, a sealed receptacle for the stock delivered through said discharge means having a pressure tight connection to said gravity discharge means, means for selectively recirculating stock withdrawn from said receptacle i for maintaining a predetermined stock level in said receptacle to maintain a predetermined space therein and vacuum creating means operatively connected into the space in the top of said receptacle to induce an evacuation of air entrained in said stock as it drops into said receptacle.

3. The structure as set forth in claim 2 characterized by drive means mounting said discs, one of said drive means being hollow and constituting feed means for delivery of stock between said discs for refining.

4. A pulp refining system including a sealed operating housing having a feed means connected therein in sealed relation thereto, a gravity discharge means from said housing, refiner means in said housing receiving stock from said feed means for delivery after refining through said gravity discharge means, a stock chest, said gravity discharge means delivering the refined stock to said stock chest, means selectively recirculating stock withdrawn from said stock chest for maintaining a predetermined stock level in said chest, providing a space in the upper portion thereof, said refined stock free falling through said space on delivery to said chest, and Ameans connected in said upper portion of said chest evacuating air from the refined stock during its free fall.

5. The structure as set forth in claim 4 wherein said refiner means are provided by opposed dish-shaped discs and said feed means connects intermediate said discs in the dished portions thereof.

6. A pulp refiner, including an enclosed housing, refiner means in said housing, means delivering stock under pressure to said refiner means in said housing, said housing having a single outlet, a stock chest in closed communication with said outlet, means selectively recirculating stock withdrawn from said stock chest for maintaining a predetermined high stock level in said chest providing for a free gravity fall of stock from said outlet through at least a portion of said chest, and means applying a vacuum to the space above the stock level in said chest.

7. A pulp refiner, including a housing having an enclosed chamber means to deliver stock under pressure to said chamber, a single outlet from said chamber, a double disc refiner in said chamber receiving the delivered stock under pressure between its discs and discharging it peripherally outward into said chamber, the varying fluids and solids comprising or accompanying the refined stock having a common escape from said chamber by way of said single outlet, a stock chest in closed communication with said outlet, and means applying a vacuum to the upper part of the interior of the stock chest, said vacuum being exerted upon the stock during free fall from said outlet into the chest.

References Cited in the file of this patent UNITED STATES PATENTS 1,603,534 Grafflin Oct. 19, 1926 1,704,728 De Cew Mar. 12, 1929 1,831,940 Wiener et al. Nov. 17, 1931 1,853,849 De Cew Apr. 12, 1932 1,875,045 Leshner et al Aug. 30, 1932 2,156,320 Sutherland May 2, 1939 2,285,973 Hopkins .Tune 9, 1942 2,591,106 Sutherland Apr, 1, 1952 2,642,950 Clark et al. June 23, 1953 2,823,868 Scherer Feb. 18, 1958 2,909,332 Brown Oct. 20, 1959 2,920,761 Freeman Jan. 12, 1960 OTHER REFERENCES Pulp and Paper Manufacture, volume 4, McGraw- Hill, New York, 1955, chapter 1, sections 195 and 206.