US3023972A - Rotor assembly and pulp treating machine - Google Patents

Description

March 6, 1962 R. B. HONEYMAN ROTOR ASSEMBLY AND PULP TREATING MACHINE Filed May 25, 1959 4 Sheets-Sheet l ATTORNEY March 6, 1962 R. B. HONEYMAN 3,023,972

ROTOR ASSEMBLY AND PULP TREATING MACHINE Filed May 25, 1959 4 Sheets-Sheet 2 J J g: 5

INVENTOR. ROB E RT B. HON EYMAN Fig: 4 i

ATTORNEY March 6, 1962 R. B. HONEYMAN ROTOR ASSEMBLY AND PULP TREATING MACHINE 4 Sheets-Sheet 3 Filed May 25, 1959 IIIIIH F1 Illl u INVENTOR. ROBERT E. HON EYIVIAN ATTORNEY March 6, 1962 R. B. HONEYMAN 3,023,972

ROTOR ASSEMBLY AND PULP TREATING MACHINE Filed May 25, 1959 4 Sheets-Sheet 4 INVENTOR. ROBERT B. HONEYMAN ATTORNEY Unite States Robert Blakeley Honeyman, Portland, reg., assignor to Morden Machines Company, Portland, Oreg., a corporation of Oregon Filed May 25, 1959, Ser. No. 815,464

Claims. (Cl. 241-255) The invention relates to treating and refining machines for pulp and the like wherein a driven rotating element co operates with a nonrotating element or stator, such as a shell or plate, in producing the desired treatment on the pulp or other material as such material passes between the opposed faces of the two elements, the opposed faces having suitable attritioning means on their surfaces. In such machines it is customary to provide means for enabling the rotating element to be adjusted axially with respect to the non-rotating element, or vice versa for adjusting the nomrotating element axially with respect to the rotating element, in order to have the proper spacing between the opposed attritioning or treating surfaces for the particular material being treated, and also to compensate for wear on the two surfaces. As is well-known, the spacing between the -two attritioning surfaces must be very carefully adjusted and controlled since a difference of only a few thousandths of an inch in such spacing can make a considerable difference in the result produced by the machine.

However, a slight variation laterally in the position of the axis of one element with respect to the other, such as a very slight angular deviation of the axis of the rotating element with respect to that of the non-rotating element, will cause the opposed attritioning surfaces to be unevenly spaced from each other and to be closer together in one portion of their effective area than in another. This prevents absolute uniformity in the treatment given the pulp passing between the opposed attritioning surfaces, since the treatment varies with the pressure to which the pulp is subjected between the opposed elements. Also it soon produces uneven wear on the attritioning surfaces, particularly on that of the non-rotating element, and, as will be readily understood, the adjustment of one surface with respect to the other in an axial direction, as provided for in the machine, does not take care of the situation or remedy the defect. On the other hand, in the customary types of large pulp refining machines, in which a heavy rotating element and a heavy non-rotating element are mounted on axes which are substantially horizontal and intended to be in alignment with each other, it is inevitable that they should become slightly out of mutual alignment with continued operation of the machine.

An object of the present invention is to provide an improved pulp treating machine, ineluding the rotating and non-rotating elements, in which a limited amount of deviation in the axis of one element with respect to its alignment with the axis of the other element will have only a minimum effect on the spacing between the opposed attritioning surfaces.

Another object of the invention is to provide an improved pulp treating machine of the type indicated in which some self-adjustment of the alignment of the rotating element with respect to the non-rotating element will occur when required.

It is common practice to use pressurized refining to develop maximum strength and other qualities from papermaking fibers by developing or increasing fibrilation and hydration. Similarly it is common practice to use nonpressurized or free-delivery refining to defiber and reduce particle size or to cut and shorten paper-making fibers. Consequently, it is a further object of the invention to provide a pulp treating and refining machine in which such an improved rotor assembly can be used either for atent O which the attritioning surfaces of both elements constitute- 3,023,972 Patented Mar. 6, 1962 pressurized refining and thus for the treatment of material maintained under pressure, or for non-pressurized refining with the treatment of material delivered freely to the treating elements, and which will be adapted for treatment of pulp flowing either in one direction or in the reverse direction through the machine.

These objects and other advantages are attained with the assembly of the present invention in which the attritioning surfaces of both elements constitute either conical surfaces or portions of concentric spherical surfaces, with provision made for slight variance in the alignment of the axes, of the two elements, and with the surrounding housing for both elements arranged as explained and described in the following specification with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a sectional elevation of the rotor assembly and surrounding housing, taken longitudinally substantially on the vertical plane passing through the rotor axis, showing the carrying out of the invention with an assembly in portions of concentric spherical surfaces and illustrating the rotor assembly arranged for the treatment of pulp delivered under pressure;

FIG. 2 is a fragmentary sectional elevation, similar in part to FIG. 1, showing the rotor assembly slightly modified for the treatment of pulp not under pressure;

FIG. 3 is an end elevation partly in section taken on line 3-3 of FIG. 1, but drawn to a larger scale;

FIG. 4 is a section on line 44 of FIG. 1 drawn to a much smaller scale;

FIG. 5 is a fragmentary sectional elevation similar in part to FIGS. 1 and 2 but showing the two elements provided with attritioning surfaces which are conical instead of being parts of spherical surfaces;

FIG. 6 is a diagram illustrating the principle of the invention when the two elements have attritioning surfaces constituting portions of concentric spheres; and

FIG. 7 is a similar diagram illustrating conical attritioning surfaces.

Referring first to FIG. 1, a rotor 10 is keyed on the rotor shaft 11 and held thereon by a suitable cap nut 12. The shaft 11 is driven by connection with a motor (not shown) as usual. The shaft 11 is mounted in a pair of bearing assemblies indicated in general by the reference characters 13 and 14, which bearing assemblies are mounted on suitable bases secured to a main base support indicated in part at 15. The rotor is located within a housing designated in general by the reference character 16, this housing 16 also being secured to the base support 15.

The rotor 19 is shaped substantially as shown in FIG. 1 and its attritioning surface is provided by a face plate 17 which fits a recessed conical portion on the Working face of the rotor and is secured to the rotor by recessed screws, one of which is shown at 18. The outer surface of the face plate 17 has the shape of a segment or zone of a sphere, the exact center of which is the point on the axis of the shaft 11 within the bearing assembly 13, to which reference will be made later. The rotor face plate 17 is provided with attritioning bars 17', the outer edges of which lie in this concentric spherical surface. The attritioning bars 17' may be of various design as long as their outer edges or faces lie in the same spherical surface. A non-rotating but axially adjustable cooperating attritioning member 19 has a replaceable attritioning face plate 19A which forms part of the surface of a sphere which is concentric with that of the spherical working surface of the rotor, and this face plate 19A of the non-rotating attritioning member 19 also has attritioning bars 19' on its working face. The central portion of this nonrotating attritioning member 19 is formed into a cylindrical channel 20 which extends beyond the end of the rotor and rotor shaft, is substantially co-axial with the rotor shaft and is slidable within a surrounding cylindrical portion 20A of the housing 16. The housing 16 has an outlet opening 21 co-axial with the cylindrical channel 20 and this outlet is connected to a flow pipe 22, which houses a valve (not shown) controlling the flow out from the housing through the pipe 22.

The housing 16 has a lower chamber 24 which is closed by a removable closure plate 25. An inlet channel 26 is provided for the housing and the material to be treated is delivered by pressure or by gravity through this channel into the machine from a suitable source (not shown). The rotor has a plurality of vanes 27 on the periphery of its rear face which act in the nature of blades in a centrifugal pump to cause the material delivered through the channel 26 to be discharged into the space surrounding the periphery of the rotor with suflicient pressure to force the material to pass inwardly between the attritioning surfaces of the rotor element and the cooperating non-rotating element 19, and finally to pass out through the pipe 22.

With rotation of the rotor 10 and its peripheral pumping vanes 27, foreign particles, particularly so called tramp metal, will be centrifugally thrown out against the housing 16 thence passing beyond the periphery of the nonrotating member 19 and settling in the chamber 24 and be collected there. The collected tramp metal and other trash may then be periodically disposed of by removing a cover plate 25 or by means of a suitable valve (not shown) in place of the cover plate 25.

The non-rotating attritioning member 19 has a plurality of integral, symmetrically positioned, support brackets (there being three such support brackets for this member in the machine illustrated), one of which is shown at 28 in FIG. 1. Each support bracket is connected with a slidable guide 29 which rides in a semi-cylindrical guide channel 23, provided on the inner wall of the housing 16, and is slidable therein. Each support bracket 28 is secured to a positioning screw 30 which has a reduced end portion extending through the guide 29 and the support bracket and which carries a clamping nut 31. The positioning screws 30 are parallel to the common axis of the cylindrical housing and of the member 19 and extend out through the holes 32 in the housing, being slidable in these holes. A suitable sealing ring 33 is. provided for each positioning screw to prevent material in the housing 16 from leaking through the holes 32. An adjusting nut 34 is carried on each positioning screw 30. The periphery of each nut 34 is provided with, gear teeth for meshing with a worm.

The three adjusting nuts 34 are enclosed in supplemental housings 35, 36 and 37 (FIG. 3) secured on the main housing 16, which supplemental housings hold the nuts 34 against axial travel while permitting them to be rotated. A master adjusting shaft 38 is rotatably mounted in the supplemental housing 35 (FIG. 3) and carries a worm 39 which meshes with the external gear teeth of one of the adjusting nuts, as apparent from FIG. 3. The shaft 38 also carries a pair of bevel gears 40 and 41 which mesh with bevel gears on the ends of cooperating shafts 42 and 43 respectively, and these cooperating shafts carry worms which are identical to the worm 39 and which mesh with external gear teeth on the other two adjusting nuts respectively. A hand wheel 44 is keyed on the master adjusting shaft 38. The arrangement is such that rotation of the hand wheel 44 will cause the three adjusting nuts 34 for the three positioning screws 30 to be rotated in unison, thus producing identical axial movement of the three positioning screws 30. In this Way the non-rotating attritioning element 19 can be adi ied x l y a and wh n res sted A. ocki g de i e or thumb screw 45 serves to hold the master adjusting shaft 38, and therewith the cooperating shafts 42 and 43 and the adjusting nuts for the positioning screws 30, against any inadvertent rotation. Motor-driven means may of course be substituted in place of manual means for rotating the master shaft 38.

Referring again to FIG. 1, the bearing assembly 13 for the rotor shaft 11 includes an outer bearing ring or race 46 carried in the bearing housing sections 47 and 48 (see also FIG. 4), an inner bearing race 49, held in place against a shoulder on the shaft 11 by a lock nut 50, and the sets of bearing rollers 51 with their correspondingly curved bearing surfaces; thus together forming a self aligning spherical roller and thrust hearing.

The center of curvature of the inner face of the outer bearing race 46, and thus the effective center of the spherical bearing assembly, is the point on the axis of the rotor shaft 11 indicated at O in FIG. 1. However, as previously mentioned, this same point 0 is also the center of the concentric spherical sections which form the attritioning surfaces for the rotating element 10 and the stationary element 19. The spherical bearing 13, which serves also as a thrust bearing, becomes self-centering under thrust load. Consequently the point 0 is a fixed point under normal conditions of operation.

The second bearing assembly 14 for the rotor shaft 11 may be any suitable anti-friction hearing, such as the conventional type of roller or ball bearing illustrated in FIG. 1. This second bearing assembly allows the normal small clearance customary in such bearings and accordingly permits slight play for the shaft at that location, thus permitting any very slight tilting of the shaft axis centered at the point 0 in the spherical bearing assembly 13. A sealsupporting ring 52 is mounted in the wall of the housing 16, having a loose fit around the shaft 11, and carries a compressible packing 53 of more or less standard type, arranged so as to prevent leakage from the housing out around the shaft 11.

Should a slight tilting of the axis of the shaft 11 occur about the point 0 at the center of the spherical bearing assembly 13, thus causing the axes of the rotating and of the non-rotating elements to become slightly out of alignment with respect to each other, this would not affect the spacing between the opposed attritioning surfaces inasmuch as both of these surfaces are sections of concentric spherical surfaces centered at the point 0. Also, under operating conditions, with the pressure existing between the opposed attritioning surfaces, the reaction of the rotating element to such pressure will exert a force tending to bring the axis of the shaft 11 centered at the point 0 into such position as to cause the pressure on all sides of the working surface of the rotating element to be equalized. Thus, to a limited extent, the rotating element is self-adjusting and the spherical bearing assembly 13 is self-centering under the thrust load.

In the diagram of FIG. 6 the attritioning surfaces of the non-rotating element and of the rotating element are indicated at 19' and 17' respectively. The axis of the rotating element in normal position is indicated by the line 63. The attritioning surfaces of both elements are portions of concentric spherical surfaces having their center at 0. It will be obvious that if the axis of the rotating element should become tilted slightly, as indicated by the broken line 63' the spacing between the two opposed attritioning surfaces would not be affected.

In the modified arrangement of the rotor assembly shown in FIG. 2, the rotating element 54 is the same as the rotating element 10 of FIG. 1 except that the pumping vanes 27 are omitted. The rotating element is carried on a rotor shaft 55 mounted in exactly the same manner as the shaft 11 in FIG. 1, and the rotating element 54, includes. a face, plate similar to the face plate 17 in FIG. 1 and similarly presenting a working surface constituting a section of a spherical surface having its center at the center of the spherical bearing assembly 56 for the shaft 55. The non-rotating element 57 is identical to the non-rotating element 1.9 in FIG. 1, includes a face plate similar to the face plate BA in FIG. 1, and is mounted in the identical manner for axial adjustment.

The housing 58 for the assembly in FIG. 2 is connected to a central pipe 60, corresponding to the pipe 22 in FIG. 1, but in this case the pipe 64) delivers the material to be treated into the housing from a suitable outside source. In this modified arrangement the material to be treated may or may not be delivered to the rotor assembly under pressure, as in the case of the arrangement in FIG. 1. The housing 58 in FIG. 2 is similar to the housing 16 of FIG. 1 with the exception that the inlet channel 26 of housing 16 is omitted, since the pipe 60' and the central cylindrical portion 59 of the non-rotating element 57 now provide the inlet channel.

The material to be treated is drawn outwardly by centrifugal force between the two attritioning surfaces, as indicated by the arrows in FIG. 2, with the operation of the rotating element. The housing 58 has a lower passageway 61, identical to the closed passageway which forms a chamber 24 in FIG. 1, but in this case the passageway 61, instead of being closed off by a sealing plate or valve, is connected to an external pipe 62 through which the material is delivered from the rotor assembly after treatment. As the material is discharged outwardly by centrifugal force from the attritioning surfaces it is forced into the surrounding space in the housing and thus into the passageway 61 and finally out through the pipe 62, as indicated by the arrows.

Thus, by dispensing with the intake 26 of FIG. 1, and omitting the vanes 27 from the rotating element of FIG. 1, and substituting the discharge pipe 62 of FIG. 1 for the closure plate 25 (or valve) of FIG. 1, the rotor assembly of FIG. 1 can be converted from a machine for treating material delivered under pressure to a machine for treating material delivered freely. In both cases the features and advantages of the specially shaped attritioning surfaces, and the related and cooperating support mounting for the rotating element are the same.

The pulp treating machine of FIG. is the same as that of FIG. 2 and similar to FIG. 1, except that the rotor 64, keyed on the shaft 65, has a face plate 66 which is frusto-conical instead of being part of a spherical surface, this face place carrying attritioning bars 66, the outer edges of which also lie in a corresponding frusto-conical surface. The slope of the surface of the face plate 66 with respect to the axis of the rotor shaft 65, however, is such that the maximum and minimum diameter peripheries of this frusto-conical surface will be equidistant from the center (indicated at O' in FIG. 5) of the spherical bearing assembly for the shaft 65.

Similarly the non-rotating element has a face plate 67 which is frusto-conical and the maximum and minimum diameter peripheries of which are also equidistant from the center 0 of the spherical bearing, the face plate of this non-rotating element being provided with attritioning bars 67'.

Referring now to the diagram of FIG. 7, the frustoconical surface of the attritioning bars 66' of the rotor will have a maximum diameter periphery comprising a circle passing through the points 66A, and a minimum diameter periphery comprising a circle passing through the points 668. All points on both circles or peripheries are equidistant from the bearing center 0'. In other words, the lines O66A and O'-66B are equal, and the frusto-conical surface may be considered as being generated by the rotation of a chord of spherical section which 6. has its center at O', the generating chord extending in the same plane as the axis of the rotor shaft and rotated about such axis.

Similarly the frusto-conical surface of the attritioning bars 67 on the non-rotating element will have the maximum diameter periphery constituting a circle passing through the points 67A, and a minimum diameter periphery constituting a circle passing through the points 678, and all points on both circles or peripheries will also be equidistant from the center point 0.

For purposes of clarity the outer edges of the attritioning bars 66 and 67' fall in attritioning surfaces which are each defined as a single frusto-conical surface as distin guished from a surface that includes a plurality of conic portions.

When the two frusto-conical attritioning surfaces defined as above are so positioned with respect to the spherical bearing center 0' it will be apparent from the diagram of FIG. 7 that, a constant gap, or spacing, is provided between said attritioning surfaces and when a slight tilting of the rotor axis about the point 0' occurs (with the rotor axis then being shifted to some such position as indicated by the broken line 65' and with the rotor attritioning surface 66' shifted as indicated by the broken lines in FIG. 7), the variation in the spacing between the attritioning surfaces 66' and 67 will be practically negligible compared to what the variation would be if the two peripheries were located at considerably different distances from the point 0'.

Thus the invention may be carried out either by having the attritioning surfaces of the two elements comprise sections of concentric spherical surfaces with their center at the center of the spherical bearing for the rotor axis, or by having the attritioning surfaces comprise frustoconical surfaces generated by the chords of such spherical surfaces, the chords being located in the same plane as the rotor axis and rotated about the rotor axis.

I claim:

1. In a pulp treating machine including a rotating element and a cooperating non-rotating element substantially co-axial with said rotating element and means for adjusting one of said elements axially with respect to the other, a driven shaft carrying said rotating element, a pair of bearing assemblies supporting said shaft, the bearing assembly nearest said rotating element being a spherical type thrust bearing and providing for a slight tilting of said shaft about the center of said spherical bearing, an attritioning surface on said rotating clement, said attritioning surface having a maximum diameter periphery and a minimum diameter periphery with all points on both peripheries being exactly the same fixed distance at all times from the center of said spherical bearing, and a similar opposed attritioning surface on said non-rotating element having maximum and minimum diameter peripheries with all points of the latter pair of peripheries being exactly equidistant from the center of said spherical hearing at all times, said attritioning surfaces providing a constant gap throughout their operating surfaces from said maximum to said minimum peripheries, whereby a slight deviation in the axis of said rotating element with respect to its alignment with the axis of said non-rotating element will have only a minimum effect on the spacing between said opposed attritioning surfaces.

2. The machine of claim 1 in which each of said attritioning surfaces is a single frusto-conical surface.

3. The machine of claim 1 in which said attritioning surfaces are spherical.

4. In a pulp treating machine including a rotating element and a cooperating non-rotating element substantially co-axial with said rotating element and means for adjusting one of said elements axially with respect to the other, a driven shaft carrying said rotating element, a

pair of bearing assemblies supporting said shaft, the bearing assembly nearest said rotating element being a spherical type thrust bearing and providing for a very slight tilting of said shaft about the center of said spherical bearing, an attritioning surface on said rotating element, said attritioning surface constituting a zone of a spherical surface having its center at a fixed radial distance from the center of said spherical bearing at all times, and a similar opposed attritioning surface on said non-rotating element constituting a zone of a separate spherical surface concentric with said first mentioned spherical surface at all times, whereby a slight deviation in the axis of said rotating element with respect to its alignment with the axis of said non-rotating element will have no appreciable effect on the spacing between said opposed attritioning surfaces.

UNITED STATES PATENTS Fowler May 19, 1925 Austin June 1, 1926 Tolman July 20, 1937 Sullivan Nov. 7, 1944 Wells Mar. 13, 1951 Smith Mar. 3, 1953 Sutherland Oct. 9, 1956 Asplund June 23, 1959 Eirich et al. May 24, 1960 FOREIGN PATENTS Great Britain Mar. 8, 1934 -M v va-1w

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