US3073535A

US3073535A - Paper machinery

Info

Publication number: US3073535A
Application number: US17282A
Authority: US
Inventors: Robert F Vokes
Original assignee: Black Clawson Co
Current assignee: Black Clawson Co
Priority date: 1960-03-24
Filing date: 1960-03-24
Publication date: 1963-01-15
Anticipated expiration: 1980-01-15

Description

Jan. 15, 1963 R. F. VOKES PAPER MACHINERY 2 Sheets-Sheet 1 Filed March 24, 1960 INVENTOR.

ROBERT F. VOKES ATTORNEYS Jan. 15, 1963 R. F. VOKES 3,07 35 PAPER MACHINERY Filed March 24, 1960 2 SheetS -Sheet 2 lo 1 I05 FIG-1O m i \r 11! Fl; 8 8

a ma 92 INVENTOR.

ROBERT F. VOKES ATTORNEYS United States Patent ()fifice 3,673,535 Patented Jan. 15, 1963 3,073,535 PAFER MACHINERY Robert F. Vohes, Middletown, Ohio, assignor to The Black-Clawson Company, Hamilton, Ulric, a corporation of Ohio Filed Mar. 24, 1960, Ser. No. 17,282 6 Claims. (Cl. 241-46) 7 This application relates to pulping apparatus for liquid slurry stocks such as paper making stock.

The invention has special relation to pulping'apparatus of the type' wherein the stock to be pulped is contained in a tub which is provided with a rotor or impeller mounted in the bottom or side wall thereof for rotation on an axis causing outward circulatory movement of the stock in a generally vortical pattern which creates hydraulic shearing forces in the stock and thereby effects the desired pulping or defibering action. Pulping apparatus of this general type is employed in both batch and continuous operations, and the invention is equally applicable to both types of operation.

It is a primary object of this invention to provide pulping apparatus of the above general type wherein the rotor is of novel and improved structural characteristics which not only give increased general efficiency of operation but which in particular make it possible to obtain effective slushing and defibering simultaneously on even the hardest pressed pulp and stocks such as wet strength, unbleached kraft and hard White stock.

A further object of the invention is to provide pulping apparatus as outlined above wherein the improved operational characteristics are obtained by a novel construction and mode of cooperation of the rotor with a bedplate having a grooved working surface which assure that substantially all the particles in the stock will be forced repeatedly into rubbing engagement with the working surface of the bedplate.

It is a special object of the invention to provide a rotor as outlined above wherein a plurality of outwardly projecting blades each includes a leading edge surface of substantial area which is inclined toward the working surface of the bedplate in operation in such a manner as to urge the stock toward the bedplate as the rotor rotates.

It is also an object of the invention to provide a rotor as outlined above which is of essentially smooth construction over its upper surface and includes no pumping vanes other than the leading edge surfaces of the vanes as noted above so that the entire pumping action of the rotor derives from these leading edge surfaces.

A still further object of the invention is to provide pulping apparatus having one or more of the features noted above and which in addition incorporates a bedplate of perforate construction through which extraction of the refined stock can take place.

Additional objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims.

In the drawings FlG. 1 is a view partly in side elevation and partly broken away in vertical section showing pulping apparatus embodying a rotor constructed in accordance with the invention; I

FIG. 2 is a plan view of the rotor in FIG. 1 and a fragment of the associated screen or extractor plate;

FIG. 3 is an enlarged fragmentary view in radial section on the line 3-3 of H6. 2 with the vane shown in elevation;

FIG. 4 is an enlarged detail view in plan of one of the 7 component vanes of the rotor of FIG. 2;

FIG. 5 is a sectional view taken on the line 55 of FIG. 4 and including a fragment of the associated bedplate;

FIG. 6 is a fragmentary view in perspective showing another construction of bedplate which incorporates a screen section or extractor plate and is adapted for use in the apparatus of FIG. 1;

FIG. 7 is a fragmentary View of the face of still am other construction of bedplate which incorporates slots for the extraction of refined stock;

HG. 8 is an enlarged fragmentary section on the line 8 8 of FIG. 7;

FIG. 9 is a front view of a rotor and bedplate assembly constructed in accordance with the invention and mounted on the side wall of the tub;

PEG. 10 is a section on the line -10 of FIG. 9; and

FIG. 11 is an enlarged fragmentary section on the line llill of FIG. 10.

Referring to the drawing, which illustrates a preferred embodiment of the invention, PEG. 1 shows pulping apparatus which is generally of the construction disclosed in Martindale Patent No. 2,371,837 issued March 20, 1945 to the assignee of this application. This pulper includes a tub or vat having a cylindrically extending upper wall portion lib, an inwardly tapered lower wall portion fl and a bottom Wall 12, and it is carried by supports 13 of any suitable character. Arranged below the tub is a gear drive 15 shown as driven by a pulley 16 from a suitably located motor (not shown) and the gear drive 1 5 drives a vertical shaft 17 which supports a rotor 20 for rotation centrally of the bottom portion of the tub.

In operation, the rotor 20 provides an effective circulation outwardly and then upwardly along the outer portions of the tub in a generally vortical pattern providing a return flow-towards the impeller, as indicated by the arrows in FIG. 1, and stationary guide plates 21 are mounted on the wall portion 11 to guide the upward flow of the partially pulped stock. Adjacent the bottom of the tub is an annular chamber or compartment 22 partitioned from the space above the impeller by a perforate screen or extractor plate 25 of frustoconical form which permits the passage to the compartment 22 of pulped particles which have been sufficiently reduced in'size to pass through the perforations of this screen 25. This pulped stock may be withdrawn from the compartment 22 continuously or batch-wise, by way of the conduit 26 and control valve 27.

The present invention is concerned particularly with the construction of the rotor 2t and the cooperating bedplate 30 as now described. Referring to FIGS. 2 and 3, an annular bottom support 31 is secured as by bolts 32 to the annular flange portion 33 of the tub It A circular wall member 35 which defines the inner wall of the compartment 22 is mounted on the flange 33 at the Y periphery of the support 31 and supports the ring 36 which in turn supports the inner periphery of the screen 25.

The bedplate 36 comprises a plurality of segments 40 which are secured as by bolts 41 to the ring 36 and to the outer periphery of a support plate 42, andthe connections between the segments 40' and the ring 36 and support plate 42 are sealed by suitable gaskets 43. As best seen in FIG. 5, the segments 40 are provided with grooves 44 extending radially of the surface of the segments and alternating with smooth areas or lands 45 to form a grooved or ribbed working surface, and the grooves 44 are also configured as shown to provide relatively sharp edges on the lands 45. g

The rotor Zll includes a rotor body 5*!) having a depending skirt 51 which is received over the upper end of plate 41 and carries a packing gland 56 as shown in FIG. 3.

The rotor body 50 carries a plurality of vanes 60 which project outwardly therefrom in overhanging relation with the working surface 44 of the bedplate. As best seen in FIGS. 3 and 4, each vane 60 includes a flange portion 61 by which it is bolted at 62 to the annular surface portion 63 of the rotor body 50. A rotor cap 65 covers the top of the rotor body 50 and is secured thereto as by bolts 66, and it extends over the flanges 61 to form an essentially smooth outline on the rotor limiting its pumping action to the leading edge surfaces of the several vanes 60 as now described.

Referring particularly to FIGS. 3 and 5, the working portion of the vane 60 which projects beyond the rotor body 50 has a substantially flat undersurface area '70 which is parallel with the working surface of the bedplate 30. In assembling the rotor, the vanes 60 may be located in predetermined spaced relation with the surface of the bedplate by means of one or more shims 71 positioned between the underside of the vanes and the upper surface of the rotor body portion 63 as shown, or a similar arrangement of shims may be provided at the mounting of the bedplate segments 40, in the same location as the gasket 43. A spacing of the order of .010 inch between the surfaces 70 and the areas 45 has provided satisfactory results in practice, and adjustment of such spacing as may prove desirable for different materials may be effected by varying the shim arrangement as described.

The leading edge surface 72 of each vane 60 is essentially fiat in vertical section and of substantial area, extending along the vane inwardly to the flange 61. In addition, this leading edge surface 72 is arranged to incline toward the working surface of the bedplate so that as the vane rotates with the rotor, the surface 72 will not only produce a pumping action urging the stock tangentially outwardly, but it will force the stock downwardly toward the working surface of the bedplate. Satisfactory results from this standpoint have been obtained with the vane surface inclined at an angle of the order of as shown. The trailing end portion 73 of the vane curves upwardly from the area 70 as shown in FIG. 5 to exert a lifting action on the stock away from the surface of the bedplate in response to rotation of the vane.

With this construction of the rotor and vanes as just described, it will be seen that the vanes 60 are essentially the only elements having a pumping action on the stock. Since the upper surface of the rotor provided by the cap 65 is essentially smooth and does not include the up-standing vanes which have been conventionally used in apparatus of this general character as shown, for example, in the above Martindale patent. As a result, instead of having the stock lifted away from the bedplate as would be the tendency if the rotor included pumping vanes, the pumping action on the stock is maintained in close proximity to the bedplate, and the desired rubbing action of the stock on the bedplate is enhanced by the forwardly inclined edge surfaces 72 of the vanes as described.

The combination shown in FIGS. 1-5 is subject to modification within the scope of the invention. For ex ample, it may be desired in some installations to eliminate the extractor plate 25 and to carry out extraction of the pulped stock through the bedplate itself. FIG. 6 shows a bedplate suitable for such installation, and it includes an annular frame 80 provided with a perforate intermediate annular section 81. A plurality of bars 82 overlie the annular surface 81 and are welded or otherwise secured to the frame 80. This unit 80-82 can be mounted in the wall of a tub similarly to the arrangement in FIG. 2 with the unit 80-82 taking the place of the parts 40-42 in FIG. 2, and the only other modification neces sary would be to complete the enclosure of the space immediately above the support 31 and to convert it into an extraction chamber similar to the chamber 22 as de-- scribed and to which a suitable discharge pipe may be connected. The same rotor 20 as already described may be used with the extracting bedplate 30-82 and will produce similar results, and it is also possible with either rotor to omit the bars 82 and use the perforate surface 81 as the working surface of the bedplate.

FIGS. 7 and 8 show a further modification of a bedplate construction which could be substituted for the seg' ments 40 described. The bedplate segment in FIGS. 7 and 8 is similar to the segments 30, including similar grooves 91 providing ribs 92 therebetween. Certain of these grooves 91, however, are continued through the surface of the plate to form slots 93 through which the pulped stock can be extracted, and it will be noted that these slots 93 are tapered to enlarge downwardly in order to facilititate the discharge therethrough. These segments 90 may be utilized in the same manner as described for the unit ill-82 in the assembly of FIG. 2, requiring only conversion of the space immediately below the bedplate into the chamber for the extracted stock.

FIGS. 9-10 show another rotor construction in accordance with the invention, and they also illustrate the mounting of the rotor and bedplate on the side wall on a pulp tub, such for example as the tub disclosed in Stark Patent 2,696,766 issued December 14, 1954, to the same assignee as this application. Thus in FIGS. 9 and 10, the rotor is mounted on a shaft 101 extending horizontally through the side wall 102 of the tub. The bedplate segments 105 have grooves 106 and ribs 107 forming their working surfaces, and they are mounted on a support plate 108 which may be secured in any suitable way to the tub wall 102.

The body 110 of the rotor 100 carries a plurality of vanes 111 which are of somewhat curved shape as best seen in FIG. 11 but otherwise operate in the same manner as the vanes 60. Thus the vane includes an undersurface 112 which moves in close parallel clearance to the surface of the bedplate segment 105, and the leading edge surface 115 of each vane 111 is inclined forwardly toward the surface of the bedplate at a substantial angle, satisfactory results having been obtained with this surface arranged to define an angle of the order of 10 as shown. The underside 116 of the trailing edge of each vane 111 is curved away from the surface of the bedplate to produce a lifting action as already described by the vane 60.

The vanes 111 may be secured to the rotor body 110 by welding or other suitable means, and it will be seen that they form the only pumping elements on the rotor. This rotor construction accordingly operates similarly to the rotor 20 as already described, and it has been found particularly desirable for installations where increased circulation of the stock in the tub is desired, while the straight vane construction of FIGS. l-S appears to give somewhat decreased circulation but even better defibering action than the curved vane construction of FIG. 9.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of stock and a bedplate mounted in a wall of the tub and having an annular working surface composed of spaced smooth areas having grooves therebetween providing edges on said smooth areas, the combination of a rotor including a body mounted for rotation concentrically of said bedplate, a plurality of vanes on said rotor body projecting outwardly therefrom in overhanging rela tion with a substantial portion of said bedplate, means maintaining each said vanes spaced a predetermined relatively small distance from the plane defined by said smooth areas of said working surface to define a stock working space therebetween, means for rotating said rotor in the direction to cause said vanes to produce discharge of the stock outwardly of said bedplate, means forming a leading edge surface along a substantial portion of each of said vanes which is inclined towards the plane of said working surface to define an angle of less than 90 as measured between said plane and said leading edge surface of each said vane for forcing the stock towards said working surface of said bedplate and into said working area in response to rotation of said rotor, and said leading edge of each said vane cooperating with said bedplate to produce a predominately rubbing action on the stock between the vanes and the bed plate while creating hydraulic pressure and turbulence operative to provide highly effective pulping and defibering with a minimum of cutting action on the solid matter in the stock.

2. In pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of stock and a bedplate mounted in a wall of the tub and having an annular working surface composed of spaced smooth areas having grooves therebetween' providing edges on said smooth areas, the combination of a rotor including a body mounted for rotation concentrically of said bedplate, a pluarlity of vanes on said rotor body projecting outwardly therefrom in overhanging relation with a substantial portion of said bedplate, means maintaining each said vane spaced a predetermined relatively small distance from the plane defined by said smooth areas of said working surface to define a stock working space therebetween, means for rotating said rotor in the direction to cause said vanes to produce discharge of the stock outwardly of said bedplate, each of said vanes having an under surface portion of substantial area arranged in parallel and closely space relation with said Working surface of said bedplate, each of said vanes having a leading edge surface intersecting said under surface portion and arranged in inclined relation toward said bedplate to define an angle less 90 as measured between said plane and said leading edge surface of each said vane for forcing the stock towards said working surface of said bedplate and into said working area in response to rotation of said rotor, and said leading edge surface of each said vane cooperating with said bedplate to produce a predominately rubbing action on the pulp between the vanes and the bedplate while creating hydraulic pressure and turbulence operative to provide highly effective pulping and defibering with a minimum of cutting action on the pulp.

3. In pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of stock and a bedplate mounted in a Wall of the tub and having an annular working surface composed of spaced smooth areas having grooves therebetween providing edges on said smooth areas, the combination of a rotor including a body mounted for rotation concentrically of said bedplate, a plurality of vanes on said rotor body projecting outwardly therefrom in overhanging relation with a substantial portion of said bedplate, each of said vanes having an under surface of substantial area including a portion arranged in parallel and closely spaced relation with said working surface of said bedplate, each of said vanes having a leading edge surface of substantial width in the direction intersecting said working surface, means maintaining each said vane spaced a predetermined relatively small distance from the plane defined by said smooth areas of said working surface to define a stock working space therebetween, means for rotating said rotor inthe direction to cause said leading edge surface of said vanes to produce discharge of the stock outwardly of said bedplate,

said leading edge surface on each of said vanes being arranged to incline toward said working surface and defining an angle less than as measured between said plane and said leading edge surface of each said vane for forcing the stock between said working surface and said under surface portion of said vane in response to rotation of said rotor, said vane including an under surface portion trailing the first named said portion thereof and arranged to diverge from said bedplate and thereby to exert a lifting action on the stock away from said bedplate, and said leading surface of each said vane cooperating with said bedplate to produce a predominately rubbing action on the pulp between the vanes and the bedplate while creating hydraulic pressure and turbulence operative to provide highly effective pulping and defibering with a minimum of cutting action on the pulp.

4. In pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of stock and a bedplate mounted in a wall of the tub and having an annular working surface composed of spaced smooth areas having grooves therebetween providing edges on said smooth areas, the combination of a rotor including a body mounted for rotation concentrically of said bed plate, a plurality of vanes on said rotor body projecting outwardly therefrom in overhanging relation with said bedplate, means maintaining each said vane spaced a predetermined relatively small distance from the plane defined by said smooth areas of said working surface to define a stock working space therebetween, each of said vanes having a flat leading edge surface of substantial width in the direction intersecting said working surface, means for rotating said rotor in the direction to cause said leading edge surface of said vanes to produce discharge of the stock outwardly of said bedplate, said rotor having a substantially smooth surface radially inwardly of said vanes and being substantially free of portions projecting axially outwardly thereof to confine the pumping action thereof to said leading edge surfaces of said vanes, said leading edge surface on each of said vanes being arranged to incline towards said working surface and defining an angle less than 90 as measured between said plane and said leading edge surface of each said vane thereby to force the stock towards said working surface and into said working area in response to rotation of said rotor, and said leading surface of each said vane cooperating with said bedplate to produce a predominately rubbing action on the pulp between the vanes and the bedplate while creating hydraulic pressure and turbulence operative to provide highly effective pulping and defibering with a minimum of cutting action on the pulp.

' 5. A rotor assembly for use in pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of stock and a'bedplate mounted in a wall of the tub and having a working surface, comprising a rotor body adapted to be mounted for rotation concentrically of the bedplate, a plurality of vanes on said rotor body projecting outwardly therefrom in angularly spaced relation, each of said vanes having an under surface portion of substantial area defining a plane extending radially of the central axis of said body, means forming a leading edge surface of substantial area on each of said vanes, and each said leading edge surface being arranged in inclined relation toward said plane and defining therewith an angle less than 90 as measured directly between said plane and said surface to force the stock toward said plane and to urge said vanes away from said plane in response to rotation of said rotor.

6. A rotor assembly for use in pulping apparatus of the character described for liquid slurry stock including a tub for receiving a quantity of stock and a bedplate mounted in a wall of the tub and having a working surface, comprising a rotor body adapted to be mounted for rotation concentrically of the bedplate, a plurality of vanes on said rotor body projecting outwardly from the periphery thereof in angularly spaced relation, each of said vanes having memes r) an under surface of substantial area defining a plane extending radially of said body, means forming a leading edge surface of substantial area on each of said vanes which is inclined at an angle of less than 93 toward said plane and which intersects said under surface of said vane 5 at an angle correspondingly greater than 90 to force the stock toward said plane and to urge said vanes away from said plane in response to rotation of said rotor, and the upper surface of said vanes and said body being substantially smooth to confine the pumping action of said 10 rotor assembly to said leading edge surfaces of said vanes.

References Iited in the file of this patent UNITED STATES PATENTS Valentine May 12, 1931 Cowles June 13, 1944 Martindale Mar. 20, 1945 Morden Oct. 6, 1953 Cowles Mar. 8, 1955 Lee Feb. 25, 1958 Honeyman Nov. 4, 1958

Claims

1. IN PULPING APPARATUS OF THE CHARACTER DESCRIBED FOR LIQUID SLURRY STOCK INCLUDING A TUB FOR RECEIVING A QUANTITY OF STOCK AND A BEDPLATE MOUNTED IN A WALL OF THE TUB AND HAVING AN ANNULAR WORKING SURFACE COMPOSED OF SPACED SMOOTH AREAS HAVING GROOVES THEREBETWEEN PROVIDING EDGES ON SAID SMOOTH AREAS, THE COMBINATION OF A ROTOR INCLUDING A BODY MOUNTED FOR ROTATION CONCENTRICALLY OF SAID BEDPLATE, A PLURALITY OF VANES ON SAID ROTOR BODY PROJECTING OUTWARDLY THEREFROM IN OVERHANGING RELATION WITH A SUBSTANTIAL PORTION OF SAID BEDPLATE, MEANS MAINTAINING EACH SAID VANES SPACED A PREDETERMINED RELATIVELY SMALL DISTANCE FROM THE PLANE DEFINED BY SAID SMOOTH AREAS OF SAID WORKING SURFACE TO DEFINE A STOCK WORKING SPACE THEREBETWEEN, MEANS FOR ROTATING SAID ROTOR IN THE DIRECTION TO CAUSE SAID VANES TO PRODUCE DISCHARGE OF THE STOCK OUTWARDLY OF SAID BEDPLATE, MEANS FORMING A LEADING EDGE SURFACE ALONG A SUBSTANTIAL PORTION OF EACH OF SAID VANES WHICH IS INCLINED TOWARDS THE PLANE OF SAID WORKING SURFACE TO DEFINE AN ANGLE OF LESS THAN 90* AS MEASURED BETWEEN SAID PLANE AND SAID LEADING EDGE SURFACE OF EACH SAID VANE FOR FORCING THE STOCK TOWARDS SAID WORKING SURFACE OF SAID BEDPLATE AND INTO SAID WORKING AREA IN RESPONSE TO ROTATION OF SAID ROTOR, AND SAID LEADING EDGE OF EACH SAID VANE COOPERATING WITH SAID BEDPLATE TO PRODUCE A PREDOMINATELY RUBBING ACTION ON THE STOCK BETWEEN THE VANES AND THE BED PLATE WHILE CREATING HYDRAULIC PRESSURE AND TURBULENCE OPERATIVE TO PROVIDE HIGHLY EFFECTIVE PULPING AND DEFIBERING WITH A MINIMUM OF CUTTING ACTION ON THE SOLID MATTER IN THE STOCK.