US3073498A

US3073498A - Supporting and conveying means for pulp grinders

Info

Publication number: US3073498A
Application number: US850303A
Authority: US
Inventors: Hornbostel Lloyd
Original assignee: Beloit Iron Works Inc
Current assignee: Beloit Iron Works Inc
Priority date: 1959-11-02
Filing date: 1959-11-02
Publication date: 1963-01-15
Anticipated expiration: 1980-01-15

Description

Jan. 15, 1963 HORNBOSTEL 3,073,498

SUPPORTING AND CONVEYING MEANS FOR PULP GRINDERS Filed Nov. 2, 1959 3 Sheets-Sheet 1 0 w w k H W [W 1 l 1 d w. 1 ,wi- W m% I. N s Ifi V E. mm KN ,U, N |L Jan. 15, 1963 HORNBOSTEL 3,073,493

SUPPORTING AND CONVEYING MEANS FOR PULP GRINDERS Filed NOV. 2, 1959 3 Sheets-Sheet 2 76 3 I 'L/ yd Hornbosfe/ y M' wad/W &

Jan. 15, 1963 HORNBOSTEL 3,073,498

SUPPORTING AND CONVEYING MEANS FOR PULP GRINDERS Filed Nov. 2, 1959 3 Sheets-Sheet 3 Eran 2271" Lloyd Harnbosfe/ MVM@M 1% Na l" Patented Jan. 15, 1983 3,073,498 SUPPORTMG AND CONVEYING MEANS FUR PULP GRINDERS Lloyd Horuhostel, Beloit, Wis, assignor to Beloit Iron Works, Beloit, Wis, a corporation of Wisconsin Filed Nov. 2, 1959, Ser. No. 850,303 3 Claims. (till. 226-98) The present invention relates broadly to the art of log processing, and is more particularly concerned with new and improved means for advancing logs during the grinding thereof for production of pulp in the manufacture of paper.

It has recently been found that improved stock quality results and the power requirements are reduced when individual logs are subjected to a rotational helical grinding with a series of conical grinding stones. In this proc ess, the logs during grinding are directed forwardly along a plurality of sets of cylindrical supporting rollers the diameters of which gradually decrease from the inlet to the outlet end of the machine. The grinding stones are arranged in a longitudinal series and each presents a conical grinding face to the rotating supported log to make a helical grinding sweep thereon, effecting a diameter reduction as the log advances through the machine. The grinding stones diminish in diameter from the inlet to the outlet end of the machine, and the stone diameters is dependent upon the particular diameter of the log being ground. The grinding stones are mounted for pivotal swinging movement toward and away from the logs supported therebeneath upon the rotatable cylindrical rollers, and experience has shown that logs processed in the described apparatus can be ground to a higher and more uniform freeness, the strength properties of the pulp fibers obtained are improved, and the process has a relatively low specific energy consumption measured in horsepower per day per ton.

It has been observed, however, that the diameters of the rejects obtained from this process are quite substantial. One important cause of this is the relatively large diameter of the supporting rolls at the reject or outlet end of the machine, and this arises by reason of the use of rollers of a cylindrical cross-section. To explain, since the rollers must be supported at opposite ends and drive means are normally required, the necessary diameter at opposite ends of the rollers must be substantial in order to accommodate the drive and support means. Accordingly, the minimum diameter to which the log can be ground by the described machine is not less than 1 inch.

Additionally, while the described machine efiectively grinds logs of a uniformly round cross-section, major irregularities along the log length, such as large knots, cannot be accommodated. It is therefore necessary that the logs to be ground must be completely debarked and processed to a uniform cylindrical configuration prior to passing beneath the conical grinding stones of the described apparatus.

It is accordingly an important aim of the present invention to provide conveying means for logs and the like which permits the logs to be ground to a substantially reduced diameter to thereby increase the grinding machine output.

Another object of this invention lies in the provision of conveying and supporting means for logs and which are constructed to accommodate major irregularities along the log and which maintains the angle between the grinding surface and the log essentially uniform so that constant stock freeness is obtained.

Still another object of this invention is to provide apparatus for conveying and supporting logs and the like, comprising a pair of transversely spaced conical rollers each having a relatively large diameter end first receiving the log and a reduced diameter end discharging the log, support means for the rollers at the reduced diameter ends thereof, and drive means for the rollers at the relatively large diameter ends thereof, whereby the log is continuously supported and rotated during advancement along the rollers and during processing thereon.

A further object of the instant invention is to provide apparatus for supporting logs during the processing thereof and which features a plurality of transversely spaced resilient tire members each contacting the log along the underside thereof and each being sufficiently deformable to accommodate major irregularities along the log without permitting said log to be deflected substantially from a horizontal plane during advancement along said tire members.

A still further object of the invention lies in the provision of a method of grinding logs to produce pulp therefrom, and which comprises advancing a log forwardly along an essentially straight line path to a grinding station, resiliently supporting the log at said station and along the underside of said log to permit accommodation of major irregularities on the log without permitting deflection thereof from a horizontal plane, and conveying the log to another grinding station and continuously supporting the log from beneath by a pair of conical rollers during conveyance through said station whereby the log diameter is reduced to substantially a minimum and maximum pulp is obtained therefrom.

Other objects and advantages of the invention will become more apparent during the course of the following description, particularly when taken in connection with the accompanying drawings.

In the drawings, wherein like numerals designate like parts throughout the same:

FIGURE 1 is a side elevational view, with parts broken away, showing in particular conveying and supporting means downstream of the inlet end of the grinding apparatus and related means in the form of conical rollers at the outlet end of said apparatus;

FIGURE 2 is a vertical sectional view, with parts in elevation, and taken substantially along the line II-II of FIGURE 1;

FIGURE 3 is a vertical sectional view taken substantially along the line III--III of FIGURE 1, and showing the relatively larger diameter ends of the conical supporting rollers;

FIGURE 4 is a vertical sectional view taken substantially along the line IV-IV of FIGURE 1 to show the reduced diameter ends of the conical rollers and the rela- 'vely small diameter log end in nip-defining relationship therewith;

FIGURE 5 is a top plan view of the apparatus of FIGURE 1;

FIGURE 6 is a side elevational view of one form of resilient supporting means for accommodating thereon logs having major irregularities, and showing in section an exemplary inflatable tire arrangement;

FIGURE 7 is a top plan view, with parts in section, illustrative of another form of resilient log supporting and conveying means;

FIGURE 8 is a fragmentary sectional view of a form of resilient supporting means of the general character illustrated in FIGURE 6, and departing therefrom by its provision of conical contours; and

FIGURE 9 is an end elevational view of an exemplary mounting arrangement for supporting rolls to accommodate major irregularities on logs carried thereby.

Referring now to FIGURES l and 2 of the drawings, there is shown grinding apparatus generally designated by the legend A and incorporating a plurality of individ ually driven and independently adjustable grinding units mounted for pivotal movement by a supporting framework 11, and effecting successive diameter reductions upon a plurality of axially advancing logs 12 supported during initial grinding by a plurality of pairs of

spaced rollers

13 and 14 mounted by a longtitudinally extending central portion 15 of the supporting framework 11. Adjacent the outlet or discharge end of the apparatus A, or in the right hand portion of FlGURE l, the logs 12 are supported and conveyed by a pair of

conical rollers

16 and 17, constructed in a novel manner to be later described for the purpose of continuously presenting to the grinding units 10 a substantial peripheral portion of the logs for diametral reductions by the grinding units.

Each grinding unit 10, as illustrated in FIGURE 2, comprises motor means 19 provided with a shaft 20 carrying a conical grinding wheel 21 thereon. While other configurations of abrasive surfaces may be employed, a conical grinding wheel canted in the direction of log travel is at present preferred, since the illustrated grinding wheel not only imparts rotative and axial movement to the logs 12, but also provides a much improved grinding action by, in effect, lifting relatively long fibers from the advancing logs. This action is enhanced by utilization of the spaced supporting

rollers

13 and 14 which, together with contact of the grinding wheel 21 with the log periphery, effect a compression on the log to loosen the fibers for removal by the abrasive elements 21. As is now known, fiber removal is facilitated during grinding by dissolving the lignins, and this is effected by partially immersing the logs 12 and essentially completely submerging the

rollers

13 and 14 in a liquid bath 22 containing a suitable lignin solvent.

The motor 19 for each of the individual grinders is connected to mounting means 23 and 24, which may take the form of relatively movable plate means embodying therein means to tilt, extend and vertically adjust the motor means 19 and grinding wheels 21 relative to the logs 12. The mounting means 24 may attach to bracket structure 25 pivotally mounted as at 26 to a supporting member 27 erected from base portion 28 forming a part of the supporting framework 11. The base portion 28 may be constructed of concrete, and is shaped to provide a pair of spaced longitudinally extending

channels

29 and 30, Within which may be located screw conveyor means to facilitate pulp removal.

The supporting base 28 is further shaped to provide the earlier described longitudinally extending central portion 15 and supported thereon is a pedestal 31 having an upper plate portion 32 mounting the roller or supporting

means

13 and 14. 'The

rollers

13 and 14 are rotatably carried by

shafts

33 and 34 received in bracket means 35 and 36 at opposite ends thereof.

In order to accommodate logs 12 of varying diameters to properly elevate said logs to effective grinding contact with the abrasive surfaces 21, the

rollers

13 and 14 are vertically and horizontally adjustable. For this purpose, the supporting

brackets

35 and 36 are provided with

flange portions

35a and 36a, respectively, and between said flange portions and the supporting plate 32 on the pedestal 31 there may be located shims 37, as required. To effect horizontal adjustment of the bracket means 35 and 36, the flange portions thereon and the shims are transversely slotted as shown. The bracket means 35 and 36 are, of course, secured to the supporting plate 32 in any suitable manner, and this may include bolt means 38 passing through the

flange portions

35a and 36a and through the shims 37.

The supporting

rollers

13 and 14 may be employed in all stages of the grinding operation up to the final grinding stations defined by the

conical rollers

16 and 17. The

rollers

13 and 14 may be helically grooved, as indicated at 39 in FlGURES l and 5, to facilitate axial advancement of the logs 12. Drive means may be utilized for the

rollers

13 and 14, although generally these rollers will be freely rotatable since rotational and axial movement is imparted to the logs 12 by the conical grinding elements 21. To initiate movement of the logs 12 into the grinding apparatus A, pusher means or the like may be employed at the entry end to the apparatus, in the manner generally known to the art.

As earlier stated, one of the problems encountered in connection with the helical pulp grinding method recently developed is presenting a sufficiently extensive peripheral surface to the grinding elements so that the logs are reduced in diameter the maximum amount and the size of the rejects reduced. The known practice is to support the logs throughout all grinding stations on cylindrical rollers, and as is believed now quite apparent, utilization of cylindrical rollers does not sufficiently elevate the log in the final stages of grinding, and accordingly, substantial waste results by reason of the relatively large diameter of the stick obtained at the exit end of the machine. As was also pointed out, the necessity of utilizing drive means at opposite ends of the cylindrical rollers precluded reducing the diameters of these rollers sufficiently to effect maximum grinding in the final stages of the operation.

However, the stated problems have been essentially entirely eliminated by provision of the conical supporting and conveying

means

16 and 17 shown in the drawings. The

conical grinding rollers

16 and 17 may be noted to each have a relatively large diameter end 16a17a and a reduced diameter end 16b-17b discharging the log or stick, which may have a diameter not substantially greater than that of a lead pencil. As appears in FIGURES 1, 3 and 4, the

rollers

16 and 17 are supported at their relatively

large diameter ends

16a and 17a upon stub shafts 40 received in bracket means 41 and 42, while the reduced diameter ends 16b and 17b of the supporting and conveying rollers receive shaft means 43. The shaft means 43 are supported by bracket means 44 which elevates the reduced diameter ends 16b and 17b and disposes the axis of each

roller

16 and 17 in an upwardly inclined plane from the relatively

large diameter ends

16a and 17a so as to maintain the logs being processed on an essentially horizontal plane. The bracket means 44 is attached by bolts or the like 45 through a flange portion 44a to the supporting structure 11, while the bracket means 41 and 42 at the inlet ends of the

rollers

16 and 17 are secured to supporting structure in essentially the same manner as the bracket means 35 and 36 of FIGURES l and 2.

Accordingly, like numerals with suffix a appended thereto have been applied to the bolt and shim means of FIGURE 3.

The

coned rollers

16 and 17 are preferably positively driven to facilitate longitudinal advancement of the log 12 therealong, and it is to be noted in this connection that the

rollers

16 and 17 are supported and driven at their relatively larger diameter ends 1611-1711 and are supported for rotation at their reduced diameter ends 16b-17b. By provision of conical rollers, no supporting means intermediate the opposite ends thereof are required, and effective drive means can be utilized, accurate control of the linear speed of the log is accomplished, and as noted, the diameter of the final stick obtained is markedly reduced over the prior art. The

rollers

16 and 17 may be fabricated of a suitable steel, and helical grooving or ridging may be provided thereon in order to promote the longitudinal movement of the log being ground.

One form of drive means for the

conical rollers

16 and 17 is shown in FIGURES 1 and 3, and such drive means may be seen to comprise a crown gear 46 suitably secured to the relatively larger diameter ends 16a17a of each of the

rollers

16 and 17, the crown gears 46 being in meshing relationship with pinion gears 47 carried upon shaft means 48 supported for rotation by the bracket means 41 and 42 and driven by motor means or the like (not shown). It is now apparent that application of a driving force to the shaft 48 rotates the

rollers

16 and 17 through the meshing gears 47 and 46, and by reason largely of the existing frictional forces, the supported logs 12 are axially fed beneath the grinding units by the

conical rollers

16 and 17.

It may now be seen upon reference to FIGURES 3, 4 and 5 that the logs 12 are continuously supported in a substantially elevated position from their point of entrance upon the

conical rollers

16 and 17 to their points of discharge at the reduced diameter ends l6b-17b of said rollers. By the conical configuration herein disclosed, there is provided between opposite ends of the

rollers

16 and 17 a transverse spacing or gap 5t} which gradually diminishes in width from the inlet to the discharge ends of the rollers, and this is of course controlled by proper location of the bracket means 41 and 42 and an initial predetermined spacing of the stub shafts 43. Of course, adjustment can be provided between the latter shafts if particular applications should so dictate.

It is to be further observed from FIGURES 1 and 5 that as the logs 1?. pass beneath the successive and longitudinally spaced grinder units 21 a stepped diameter reduction is accomplished. This is indicated in FIGURES 1 and 5 by the numeral 12a being appended to the tapering sections connecting each generally cylindrical section 12!) between said tapering sections being acted upon by the conical grinding faces. As is apparent, as the logs 12 are axially advanced and simultaneously rotated, a generally helical cut is made upon the logs, and in effect, the tapering log sections 12a continuously move axially rearwardly until the maximum diameter reduction is accomplished at the discharge end of the apparatus A. Each grinding unit It is desirably pressure actuated by pneumatic or other means, supplementing the weight of each unit, in order that the conical grinding wheels 21 engage the logs 12 with sufficient pressure to effect controlled diameter reductions. Further, as is shown in FIGURE 1, the diameter of the grinding wheels 21 at the discharge end of the apparatus is relatively less than the diameter of said Wheels upstream therefrom and in the inlet region of the apparatus A.

It has been found that attainment of uniform stock freeness requires that the angle between the grinding stone surface and the log remain essentially the same throughout axial advancement of the log in grinding cont-act with the stone surfaces. Accordingly, heretofore it has not been possible to effectively grind logs with knots or major irregularities thereon, and it has been necessary to remove knots in an earlier processing operation so that the log to be subjected to helical grinding was of generally uniform cylindrical shape throughout. Now, however, such earlier processing is not required, since there is provided by this invention resilient supporting means which accommodate major irregularities on the log without permitting deflection of said log from a horizontal plane.

One form of resilient supporting means for use at the end of the apparatus A is shown in FIGURE 6 and is designated generally therein by the numeral 51. The resilient supporting means 51 may comprise an axle portion 52 receiving at opposite ends shaft means 53 and 54, which may be mounted by the bracket means and 36 in the manner shown in FIGURES l and 2 of the drawings. The axle or Wheel portion 52 mounts thereon a plurality of axially spaced tire members 55 defining therein an annular air receiving chamber 56, and the axle portion 52 may be formed on its outer diameter with a plurality of axially spaced circumferential ribs 57 engageable with outwardly turned annular flange portions 58 and 59 on said tire members 55.

The air receiving chambers 56 of each tire member 55 are pressurized a predetermined amount in accordance with the degree of deformability desired for particular applications, and for this purpose the axle portion 52 of the supporting mechanism 51 is provided with an axial passage 69 and radial passages 61 communicating with each chamber 56. The axial passage connects to a suitable source of pressurized air, and in FIGURE 6 the source is identified by the numeral 62. By provision of communicating air chambers 56, as contrasted with individually inflatable chambers, there is obtained etfective control over stiffness in a particular location, since there exists the same volume of air in all chambers 56 even though one chamber may be deformed by contact With a knot or the like.

The tire members or rolls 55 may be seen to have an essentially straight-walled outer diameter, and this particular configuration can be varied substantially. As for example, the outer diameter of the tire members may slope downwardly in the direction of log movement, or as otherwise stated, the tire members may be generally conical as shown in FIGURE 8. The tire members in FIGURE 8 are identified by the numeral 63, and it may be seen that each tire member has an outer Wall 64 connecting with side walls 65 and 66, the latter Wall being of relatively lesser length than the Wall 65 to provide generally conical tire members 63. The tire members define therewithin air receiving chambers 67 and each chamber in the direction of log travel decreases somewhat in volume. The conical tire members 63 are supported and supplied with air in essentially the same manner as the resilient supporting means 51 of FIGURE 6, and accordingly, like numerals have been appended to like parts. In the manner of the

conical rollers

16 and 17 earlier described, the resilient conically shaped supporting means 63 have as one advantage thereof permitting increased diameter reductions of the logs supported thereby. The resilient supporting means 51 of FIGURE 6 and the conical supporting means 68 of FlGURE 8 may be freely rotatable or may be positively driven, as was described in connection With the supporting

rollers

13 and 14 of FIGURES 1 and 2.

Another form of resilient supporting means is illustrated in FIGURE 7, and in this embodiment of the invention there is provided a plurality of tire members 70 longitudinally spaced along one side of the advancing log 12 and a second series of longitudinally spaced tire members '71 located along the opposite side of the log 12, the tire members 70 being transversely staggered With respect to the tire members 731 so that the log 12 is supported on opposite sides at axially spaced locations therealong. The tire member 7% and 71 preferably face downstream in the direction of log travel, and may be seen to be disposed essentially in a vertical plane. The tire members may be supported in generally the same manner, which may include a hub '72 connected to a bracket means 73 secured to a fixed structure as shown. A suitable air header '74 provides with an air flow passage 75 communicates with individual air lines 76 to the tire members 7% and '71. The

tire members

79 and 71 may be positively driven in any suitable manner, or may rotate freely as shown. By provision of the resilient supporting means 7t and 71 there is obtained the earlier described advantage of accommodating major irregularities along the log, without permitting said log to be deflected substantially from a horizontal plane during advancement along the supporting means 7s and 71. As is now apparent, the tire members 70 and '71 need not necessarily be disposed at the inlet end of the apparatus A, but may take a downstream position and still effectively carry the log 12 during the grinding operation.

It may under particular circumstances be desirable to limit vertical movement of the resilient supporting means 51 of FIGURE 6 or the conical supporting means 63 of FIGURE 8, or the

rollers

13 and 14 of FIGURES l and 2 when positioned at the inlet end of the apparatus, at which location major irregularities may be found on the entering logs. For this purpose, there is provided the structure illustrated in FIGURE 9, to which reference is now made.

As shown in FIGURE 9, a pair of supporting rollers 80 and $1 supported on shafts 82--82a carry during Y axial advancement a log 33 having a knot or other major irregularity 83a thereon. The shafts 82-82a mount generally L-shaped arm members 84-8411 at one end,

the arm members being pivotally mounted by suitable supporting structure at 85-85a and being resiliently mounted upon spring means, air cylinders or the like S6S6a. As shown, the air cylinders may bottom at one end against a leg of the arm members 8484a, and at their opposite ends upon a plate portion 87 of a supporting base 83.

It is now to be observed that when the knot 830 on the log 83 contacts one of the

rollers

80 or 81, the air cylinders 86-86(1 deform to a degree, and yet the log 33 is not substantially deflected from its generally horizontal plane during axial advancement. When the knot has been removed by grinding or has passed its nip with the

rollers

80 and 81, the air cylinders 86-86a of course extend as shown. In order, however, to limit the vertical movement of one roller when the other roller is contacted by the knot 83a, there may be provided stop means on the arm members 84-840, and this may take the form of bolt means or the like 89-45941 for contact with a block or the like 90-90;: attached to the supporting base 83.

It may now be seen that applicant has provided conveying and supporting means for logs and the like during the grinding thereof which have substantial advantages over the earlier structures. The disclosed conical rollers eliminate the need for intermediate supporting means for the rollers and said rollers can readily accommodate drive means at one end and supporting means at the opposite end. By use of the conical rollers the log may be ground to a much smaller diameter and the amount of rejects is substantially reduced. The various resilient supporting means eliminate knot removal problems, and it is no longer required that the logs to be ground be earlier processed to a generally uniform cylindrical shape. The instant invention accordingly is of importance in debarking, and the resilient supporting means permits the angle between the stone surfaces and the log to remain essentially constant, so that uniform stock freeness is attained.

As is now apparent, various changes and modifications may be efiected in the structures and procedures herein disclosed without departing from the novel concepts of the present invention.

I claim as my invention:

1. Apparatus for conveying and supporting logs and the like, comprising a pair of transversely spaced conical rollers which are so spaced so as to continuously support and convey the logs each of said conical rollers having a relatively large diameter end first receiving the log and a reduced diameter end discharging the log, support means for the rollers at the reduced diameter ends thereof, drive means for the rollers at the relatively large diameter ends thereof, and support means for said drive means, whereby the log is continuously supported and rotated during advancement along the rollers and during processing thereon, the reduced diameter ends of said conical rollers being elevated by said support means to dispose the axis of each roller in an upwardly inclined plane from the relatively large to the reduced diameter ends thereof, whereby the log during support thereon is maintained substantially elevated on said rollers and the axis of the log is maintained in an essentially horizontal plane to present a maximum peripheral surface on logs and the like supported by said rollers for grinding and related operations thereon.

2. Apparatus for conveying and supporting logs and the like during axial advancement beneath a plurality of longitudinally spaced working surfaces, comprising a plurality of individually deformable, spaced, and resilient roller means contacting and supporting the logs along the underside thereof at axially spaced locations and while said logs are being advanced beneath an initial group of working surfaces to direct said logs forwardly and to accommodate major irregularities on said logs during forward travel without substantially deflecting said logs from a generally horizontal plane, a pair of transversely spaced conical rollers located downstream from said resilient roller means said conical rollers being spaced so as to continuously support and convey the logs, each of said conical rollers having a relatively large diameter end first receiving the log and a reduced diameter end discharging the log, the relatively large diameter ends of the conical rollers being aligned with the resilient roller means so as to receive the logs free of major irregularities from the said resilient roller means, support means for the rollers at the reduced and relatively large diameter ends thereof, and drive means for the rollers at the relatively large diameter ends thereof, whereby the log is continuously supported and rotated during advancement along the rollers and during processing thereon.

3. Apparatus for conveying and supporting logs and the like during axial advancement beneath a plurality of longitudinally spaced working surfaces, comprising a plurality of individually deformable, spaced, and resilient roller means contacting and supporting the logs along the underside thereof, said resilient roller means comprising a first row of longitudinally spaced deformable and resilient tire members engaging the logs along one side thereof, a second row of longitudinally spaced deformable and resilient tire members for engaging the log along the other side thereof, the tire members in the first row being transversely staggered with respect to the tire members in the second row to support the logs on opposite sides at axially spaced locations therealong, each tire member facing downstream in the direction of travel of the logs and being disposed generally in a vertical plane, and support means for the tire members, the resilient means advancing the logs beneath an initial group of working surfaces to direct the logs forwardly and to accommodate major irregularities on said logs during forward travel without substantially deflecting said logs from a general horizontal plane, a pair of transversely spaced conical rollers located downstream from said resilient roller means, said conical rollers are spaced so as to continuously support and convey the logs, each of said conical rollers having a relatively large diameter end first receiving the logs and a reduced diameter end discharging logs, the relatively large diameters ends of the conical rollers being aligned with the resilient roller means so as to receive the logs free of major irregularities from the said resilient roller means, support means for the rollers at the reduced and relatively large diameter ends thereof, and drive means for the rollers at the relatively large diameter ends thereof, whereby the log is continuously supported and rotated during advancement along the rollers and during processing thereon.

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