US1939747A - Fiber-stock refiner - Google Patents

Description

Dec. 19, 1933. J. A. WIENER 1,939,747

FIBER STOCK REFINER Filed June 29, 1933 2 Sheets-Sheet 1 Ihwentor.

Joan P\.N\ENER- Cttomeg Dec. 19, 1933. V J. A;WIENER 7 FIBER STOCK REFINER Filed June 29, 1953 2 Sheets-Sheet 2 Jnnentorx V dorm HWENER.

attorney I Patented Dec." 19, 1933 PATENT OFFICE v UNITED STATES FIBER-STOCK REFINER John A. .Wiener, Oswego, N. Y. Application June 29, 1933. Serial No. 678,140

' 8 Claims. '(01. 92-27) This invention relates to a combined refining and screening mechanism designed for reducin .coarse fibers to the consistency of acceptable stock and to screen the refined product concurrently with said reduction, the screening element being the stationary member of the refining couple.

' The invention relates particularly to improvements in the pulp refiners shown and described in my United States Patents Nos. 1,730,908 and The object of this invention'is to provide a pulp conditioning mechanism, wherein means is employed for refining and converting into acceptable stock such waste products of paper mills as tailings and other coarse and rejected fibers, said means being combined with novel facilities for screening the pulp concurrently with the' refining, thereby eliminating entirely the use of the well-known fiat,- inclined and other'screens in common use. A further object is to provide the usual Jordan type of frusto-conical longitudinally fiuted plug'or core that is rotatable axially within a frusto-conical shell, but instead of the shell being formed with longitudinal flutes that coincide with the flutes of the plug, the present shell comprisesa tapered cylinder whose inner surface is-plane and smooth, and whose walls.

are perforated to effect thecontinuous screening of therefined' pulp by mashing and forcing the stock through the perforations by the action ,of the blades of the plug, not unlike the Performance of the common kitchen colander; the

1 longitudinal flutes of the plug in 'the' instant caseserving to carry this unrefined stock preferably from the smaller to the larger end of,

the plug under pressure exerted bya series of propeller blades which are rigid to said smaller end; the refining being effected by the rapid rotation and relatively close spacing of the plug whose blades successively move past all of the perforations of the shell during each revolution of the plug. The plug in the present machine is preferably, operated at exceedingly high speeds which may range from 1500 to 3500 r. p. m.,'

and owing to the fact that the grooves of the plug are constantly ,fiooded with the unrefined stock, the latter is thrown radially by the centrifugal force against the inner surface of'the screening shell, and as the blades ofthe plug pass -over the perforations, they efiect the primary grinding throughout the screening zone. This produces a considerable amount of refined fibers which will be literally blown through the perforations and into a concentric chamber which only collects the acceptable stock. This primary grinding by the plug and screen naturally falls short of completely reducing the original tailings, and as the mass of unrefined stock is carried along the grooves of the plug towards its larger end, there is inevitably a continual discharge of tailings that escape complete reduction while passing through the screening zone. In is an object of the present invention to provide novel means for regrinding and refining this residue or waste beyond the larger end of the normal plug by means of detachable extensions of'the plug and screening-shell, wherein both of said extensions are formed with coinciding flutes definedby sharp grinding blades, the 70 same as in the Jordan and the machines of my; former patents. It will thus be'understood that as the tailing waste of the paper mills is primarily-being carried or forced along the relatively short plug, from toof the said waste fibers are reduced by the plug and screening shell to acceptable stock, which may be delivered directly to a forming machine and con verted into paper. It will also be understood that by adding the aforesaid extensions to the normal plug and screening shell, the remaining 40% to 50% of the unreduced waste fibers may be reground and refined before it leaves the machine, and that the product of this auxiliary grinder may be returned to the head-end of the machine and mixed with a fresh supply of the original tailings that constantly flows towards the machine.

In this way'the latter product may be run through the machine again and again and 0 thereby increase the percentage of recovery of acceptable stock to upwards 01' without waste of time, extra power or machine attendance. Within a few minutes after the starting of the present machine, the several perform- 5 combined pulp refining, screening and auxiliary coarse-fiber regrinding machine in a single unit that is capable of producing fifty'or more tons of acceptable stock per working day, and which is so compactly builtas to require a minimum of space, and may be operated continuously for long intervals without requiring any attention or care such as adjustment, overhauling or replacement.

I attain these objects bythe means set forth in the detailed description which follows, and

as illustrated by the accompanying drawings, in which- Figure 1 is a top plan view of a combined fiber-stock refining and screening apparatus, embodying the principles of my invention. Fig. 2 is a central vertical longitudinal section, the return conduit or pipe being shown in fragment in dotted lines taken on line 22 of Fig. 1. Fig. 3 is a head-end elevation. Fig. 4 is a side elevation of one of the rings of the regrinder. Fig. 5 is an end elevation of the same. Fig. 6 is a vertical cross section of the screening shell, taken on line 6-6 of Fig. 2. Fig. 7 is a broken top plan view of the screen-shell. And Fig. 8 is an end elevation ofthe impeller blade assembly, taken in the direction of the horizontal arrow in Fig. 2.

In the drawings, 2 represents an elongated base having pedestals 2'--2a that support. the whole of the composite machine. 3 represents the main driving shaft upon which is mounted the frusto-conical plug 4, which may be secured to the shaft by keys 3'. The external surface of the plug is preferably formed with parallel longitudinal grinding knives or blades, as 4, the said knives being accurately ground to the required pitch, in order to effect the desired degree of refining. Shaft 3 is preferably Journaled in ball-bearings 5-5 mounted upon blocks 5a supported by the pedestals 22a. The bearings 5' are secured in a cage 5b slidable in the adjacent block 511. 5c represents a threaded adjusting rod secured at one end to the cage 5b, and which passes through a head 5e, and has its outer end fitted with a handwheel b, which when maneuvered in the proper direction, adjusts the shaft 3 and the plug 4 axially for regulating the flneness of the grinding. A second handwheel b locks the shaft against longitudinal movement after each adjustment of the parts.

6 represents the head-end of the machine, having a chamber 6 concentric to the shaft 3 that receives the unrefined waste fibers through an inlet 6a, and 7 represents the tail-end, having a concentric chamber 7' that collects the products treated by the machine and discharges the same through an outlet 7a. The heads 6 and 7 are both bored, as at 6b7b to receive the shaft 3, the said openings being suitably packed by glands 60-70 to prevent leakage around the shaft. The heads 6--7 are spaced apart mainly by an outer cylindrical jacket 8 to the ends of which may be fitted several removable interlocking spacing ring-like segments, as 8', 8a, 8b, and 8c, the rings 8' and being directly interlocked with the heads 6 and '7 respectively, and after said parts are assembled, as shown in Fig. 2, they are securely clamped and held rigid by tierods a, which pass through flanges a'that may be cast with the heads. The opposite ends 01' Jacket 8 are thickened, as at 8d, to provide therebetween a circumferential recess 8f, and the inner face of the portions 8d are preferably tapered corresponding substantially to the taper of the core 4, as shown in Fig. 2.

9 represents a perforated frusto-conical cylinder or shell, which telescopes the jacket 8, and is inserted between the plug 4 and the jacket, its larger end being normally disposed flush with the corresponding ends of the Jacket and plug and being thickened, as at 9', to coincide with one of the portions 8d of the jacket. The smaller end 01' the cylinder 9 is also thickened at M to coincide with the other portion 8d of the Jacket, and beyond the portion 90, said end is expanded, as at 917, to provide a circular recess 90, in which is disposed a radial arrangement of impeller blades, as 10, that lie between spaced integral discs l0'l0a, the disc 10a being seated in a shallow socket 4a formed in the small end of the plug 4, to which the blades and related parts may be secured by screws 4b. The disc 10 of the impeller assembly is formed with an axial tubular extension 10b that loosely receives shaft 3, projects into the chamber 6', and serves to direct the unrefined contents of said chamber into the recess 90, from which the said contents are forced by the blades 10 longitudinally between the fluted surfaces of the plug 4 and the perforated portion a: of the cylinder 9 towards the end '7, as indicated by the arrows 10c in Fig. 2. The inner wall of the extension 9b is preferably slightly spaced from the tips of the blades 10 so as to permit the free rotation of said blades. The external surface of the cylinder 9 is recessed at 9d and combined with the recess 8f to form a cylindrical chamber 9e which serves to collect the acceptable stock that may be drawn oif through an outlet 9.1:.

The foregoing briefly describes that portion of the machine that effects the normal grinding as well as the simultaneous screening out of the acceptable stock ready for immediate conversion into paper. It has been found, however, that to limit the reduction of the coarse waste fibers to the normal plug 4 and the screen :1: results in the machine giving off a considerable percentage of coarse tailings which are unserviceable and ordinarily have to be discarded as waste. This restricts the actual recovery of the acceptable pulp from a given quantity of tailings to 50% to 60%, which is about the average for the Jordan type of reflners. In order therefore to reclaim a higher percentage of serviceable fiber, it has been found expedient to return by any well-known means the whole of the'tailings of the normal machine from the head '1 to the head 6 to be passed through the machine a second time, and so on, for. instance by means of a conduit or pipe 7a: connected at one end to outlet 7a and connected at its opposite end to a lateral inlet 6d of the head 6 shown more clearly in Figs. 1 and 6. To remedy this more or less wasteful tendency or condition, it is proposed to adopt novel and simple means for regrinding this inevitable waste before the tailings flnally leave the machine. To this end, I apply a fluted tapering extension 4a: to the larger end of the plug 4, and also a complementary extension to the corresponding. ends of the jacket 8 and the cylinder 9 by the insertion of the spacing segments or rings 8a, 8b and 80, as shown in Fig. 2, the said segments preferably being internally fluted, as at 8x, to coincide with theflutes of the core 4. These regrinding extensions virtually amount to a reversion to the construction of the Jordan, as well as that of my former patents, but they are nevertheless novel in their association with the combined refining and screening elements 4 and x, as herein shown. By this an rangement of the regrinding parts, the tailings discarded by the normal grinding and screening parts 4 and :c are passed uninterruptedly through the flutes of said extensions where they are subjected to a thorough regrinding without requiring attention from the machine tender, and without necessitating any increase of the power or variamachine.

will be appreciated when it is recalled that the normal machine at best effects the recovery of but 50% to 60% of the acceptable stock from the ordinary paper. mill tailings, as compared with a recovery of upwards of by the same machine equipped with the regrinding extensions.

In practice, the unrefined-fibrous stock supplied by the head 6 is forced longitudinally between the plug 4 and the screen a: by the impeller blades 10, during which operation, the stock passes freely through the flutes of plug 4 in a continuous stream. The plug 4 is normally operated at a high speed and centrifugal action is depended upon to force the highly diluted fine fibers or acceptable stock laterally through the perforations a: of the cylinder 9. The screen is preferably formed with several series of perforations a; which range in diameter from one sixteenth to three sixteenths of an inch, the smaller perforations being disposed adjacent the small end of the-screen and are then followed by the larger perforations, as shown in Figs. 2 and 6. By this arrangement, as the fresh waste stock enters the primary refining section from head 6, the centrifugal force created by the revolving plug, as well as the supplementary pressure derived from the impeller blades 10, force the finer fibers together with an excess of the water through the smaller perforations :r. The remainder of the original stock, consisting largely of' the coarser fibers and a lower content of water, is thence forced along the grooves between the blades 4 of the plug past the eighth and three-sixteenths holes, and being more or less ground throughout the said travel, produces a considerable amount of fine fibers which readily escape through said larger perforations, but owing to the high speed of the rotor 4 and their splinter-like shapes, practically noneof the coarse fibers are given time to veer and enter or pass through even the larger perforations a: beforethey are brushed and dislodged by the blades 4' of the plug, and although the coarse'fibers may be greatly reduced by continual grinding between the knives 4' and the inner surface of the screen, even such partially reduced fibers, owing to the high speed of the plug, fail to pass through the screen openings 3: while being forced through the normal machine. It is to be noted, as explained, that during the primary screening and recovery of the accepted stock, an excess of the water escapes with the fine fibers. This leaves the remaining coarse fibers deficient in water content, which not only tends to abnormally thicken the residual stock, but also slows down its movement towards the tail-end 7 cf the This slower moving mass is therefore subjected to longer regrinding which results, in

greatly increasing the reduction of the coarse tailings, especially when the reground stock returned to the head-end 6 has been again forced through the machine by the blades. 10, which enables the finer fibers of said stock to be driven through the perforations a; without further grinding. But the slightly coarser fibers, not being so readily screenable, are thrown by the centrifugal force of the rapidly revolving plug against the surface of the screen at, where they are crushed and ground by the rubbing action of the sharp knives of the plug and the relatively sharp circular edges of the perforations with the result that the latter fibers become so reduced as to enable them to be screened before blades rotatable in the bore of said shell, im-

they pass beyond the screening zone. The still coarser fibers are also somewhat reduced while passing through the said zone, but being unable to escape through the screen, these fibers continue on until they enter the regrinding section, where they are so. greatly reduced that when they again return with a. fresh supply of origv inal tailings to the head 6 of the machine, the subsequent normal grinding thereof yields enough additional screenable fibers to bring the total recovery of acceptable stock to upwards of 90%, as described. I

Obviously, the extensions 41: and 8ae-8b.8c mayeach be made in one part instead of several segments, as shown in Fig. 2.

Ordinarily, shaft 3 is driven by an electric mot-or (not shown) through a flexible coupling 1 Having thus described my invention,what I claim, is

1. In a fiber-stock refining and screening apparatus a foraminous shell having a frusto-conical shaped bore, a frusto-conical plug having longitudinal flutes defined by parallel grinding peller blades mounted on the smaller end of said plug to force the stock through said flutes towards the larger end of the plug, said grinding blades supplemented byv the centrifugal force of the plug adapted to'mash the fibrous mass and force the refined fibers through the mesh of said plug to force the stock through said fiuates larger end of the plug and the corresponding end of the shell to regrind and condition the tailings for rescreening by said shell.

2. In a fiber-stock refining and screening apparatus the combination with a main driving shaft, of a frusto-conical plug having longitudinal flutes defined by parallel grinding blades rigidly mounted on said shaft, a foraminous shell having a frusto-conical shaped bore telescoped by said plug to continuously screen the stock refined by said plug and shell, impeller blades adjacent the head-end to force the stock longitudinally between the plug and shell towards the tail-end of the machine, a cylindrical jacket to receive and grip said shell to prevent rotation thereof, and means disposed adjacent-the tail-end of the machine for repeatedly regrinding the tailings from the screening portion of the machine.

- 3..In a combined fiber-stock refining and screening apparatus, a shell having afrusto-- conical bore and graduated screening openings, a fluted frusto-conical plug rotatable in said shell, impeller blades secured to the smaller end of the plug to force the stock between the shell and plug towards the larger end of the plug, a cylindrical jacket to receive the shell, means to regrind the tailings from the screening zone beyond the larger end of the plug comprising an externally fluted extension rigidly mounted on the larger-end of the plug and a plurality of annular segments formed with internal flutes that coincide with-the flutes of said extension,

and means to rotatesaid plug.

, Acombinedfiber-stock grinding'and screening machine including a 'frusto-conical plug having flutes defined by parallel longitudinal grinding blades,'a perforated shell comprising the stationary element of the-primary grinding couple having a frusto-conical bore to'rotatably receive said plug, impeller blades in the headend of the machine to force the stock longithe centrifugal force exerted radially by the plug effects the continuous screening of the refined fibers, means to regrind the coarse portions of the stock after it passes beyond the plug, and means to return the reground product to said head-end to screen out the acceptable stock resulting from said regrinding.

5. In a fiber-stock refining and screening apparatus the combination with a main driving shaft, of a frusto-conical plug having longitudinal flutes defined by parallel grinding blades rigidly mounted on said shaft, a perforated cylinder having a frusto-conical shaped bore to rotatably receive said plug and to continuously screen the stock refined between the plug and cylinder, means to force the stock between the surfaces of the plug and shell towards the larger end of the plug, a Jacket to receivesaid cylinder having interlocking end portions, and means extending beyond the larger end of the plug interlocking with said jacket and cooperating with a fluted extension of the plug for continuously regrinding the tailings rejected by the screen until substantially total recovery of acceptable fibers is attained.

6. In a combined fiber-stock refining and screening apparatus a frusto-conical shell having screening openings of different size arranged in series, a frusto-conical plug rotatable in said shell, impeller blades secured to one end of the plug to force the stock between the shell and plug towards the opposite end of the plug, a cylindrical Jacket having a frusto-conical bore to receive the shell, means to regrind the tailings from the screening zone beyond said opposite end comprising an externally fluted ex-- tension rigidly mounted on said opposite end, and a plurality of concentric rings interlocked with the jacket and formed with internal flutes fined by said grinding blades, impeller blades mounted on the smaller end of said plug to force the unrefined stock between the facing surfaces of the plug and shell towards the larger end of the plug, a cylindrical jacket to receive said shell, and complementary means comprising extensions of the normal plug and jacket to regrind the unscreened product excluded by said shell.

8. A combined fiber-stock grinding and screening apparatus including a frusto-conical perforated sheli, a i'rusto-conical plug rotatable in said shell having longitudinal flutes defined by parallel grinding blades, impeller blades carried by the smaller end of the plug to force the stock longitudinally between the plug and shell, the centrifugal action of the plug forcing the stock radially against the shell and enabling the grinding blades to mash the stock and force the finer fibers through said perforations while the coarser fibers continue on towards the larger end of the plug, complementary means comprising extensions of the plug and shell to regrind said coarser fibers beyond the larger ends of the plug and shell, and means to return the product of said regrinding' to the screening zone to effect the recovery of the remainder of the finer fibers.

" JOHN A. WIENER.

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