US2536446A

US2536446A - Suction box for traveling screen filters

Info

Publication number: US2536446A
Application number: US645101A
Authority: US
Inventors: Irving C Jennings
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-02-02
Filing date: 1946-02-02
Publication date: 1951-01-02
Anticipated expiration: 1968-01-02

Description

Jan. 2, 1951 l. c. JENNINGS 2,536,446

SUCTION BOX F OR TRAVELING SCREEN FILTERS Filed Feb. 2, 1946 5 Sheets-Sheet l 3 wu cwvtom #1404 C. Jenn/figs I. C. JENNINGS SUCTION BOX FOR TRAVELING SCREEN FILTERS Jan, 2, 1951 5 Sheets-Sheet 2 Filed Feb. 2, 1946 'I'IllIIIlIllIIIIlIIllllI'l-If lrwhq C. Jen/712795 I. C. JENNINGS SUCTION BOX FOR TRAVELING SCREEN FILTERS Jan. 2, 1951 Jan; 2, 195-1 l. C. JENNINGS SUCTION BOX FOR TRAVELING SCREEN FILTERS Filed Feb. 2, 1946 5 Sheets-Sheet 4 lg. Z.

Mania/ a Jan. 2, 1951 l. c. JENNINGS SUCTION BOX FOR TRAVELING SCREEN FILTERS 5 Sheets-Sheet 5 Filed Feb. 2, 1946 Patented Jan. 2, 1951 UNITED STATES PATENT OFFICE SUCTION BOX FOR TRAVELING SCREEN FILTERS 10 Claims.

The invention is of utility in any art in which a filter screen, driven over a suction box would be useful for thickening material or extracting liquid. For simplicity of exposition, however, a paper making machine will be illustratively disclosed and referred to..

In the manufacture of paper and allied products, particularly on the wet end of a machine known as a Fourdrinier, difficulty has long been experienced with the rapid wear of the wire screens due to the friction between these screen belts" and the suction boxes used to remove the water from the pulp. It is necessary, particularly On high speed machines, to renew these screen belts very often, and as the screen belts are expensive this is an important item in the cost of manufacturing paper. Furthermore, the extra power required to operate the Fourdrinier due to this friction is considerable.

A Fourdrinier' screen is made in the form of an endless horizontal belt running over a driver drum, usually a suction roll, and idler drums to support and keep it tight. The top or tight side is further supported by free-running table rolls and by several flat boxes, which are boxes rectangular in ection in which is maintained a partial vacuum. Paper pulp mixed with a large percentageof water is fed ontothe'wires at one end. Some of this water drains through the wires as it passes along overthe table rolls and a large amount is drawn out by suction as the wires pass over the'fiat boxes. This screening and felting action forms the sheet of paper, which isfurther processed in subsequent operations. The tops of the flat boxes which are in contact with the wires are usually of hard wood, sometimes'impregnated withtallow or other like material to act as a lubricant in the presence ofwater. The heavy suction pressure, however, between the rapidly moving wires and the top of the boxesproduces'a considerable drag, which results in friction and wear; All this is well known in the art.

Many attempts have been made to produce flat boxes equipped with rollers under the wires to overcome these difficulties. These devices have been only partially successful on slow moving paper machines, and nothing has been produced as yet that is satisfactory for high'speed machines.

One of theprincipal troubles in making such a device lies in the fact that the flat box rollers supporting the wire must be close together, or too great a sag of the wire will occur between rollers. This requires rollers of small diameter arranged close to one another. It has heretofore been customary to support such rollers from end bearings only. As commercial paper machines are very wide, requiring rolls ranging from 8 ft. to 20 ft. or more in length, too great adefiectionresults when small diameter rollers are used. Difficulty has also been experienced in sealing the roller equipped boxes against air leakage.

It is a primary object of the present invention to provide a suction box which is equipped with small diameter rollers and which includes practical means for rotatably supporting rollers at frequent intervals to prevent sagging thereof.

To this end it is an important feature of the invention that the rollers, divided into short, hollow' segments, are rotatably supported from thin brackets interposed between" the segments, the supporting and bearing structure carried. by the brackets'being disposed internally of the rollers.

Other objects and advantages will hereinafter appear.

This application is a' continuation in part of my pending application, Serial No. 561,342, filed November l, 1944, for Fourdrinier Machine, now abandoned.

Figure I shows a fragmentary top view of my invention; I

Figure II is a section taken along the line 2-2 of Figure I, looking in the direction of the arrows;

Figures III and V are sectional views on difierent scales, taken upon the section line 3-3 of Fig. I, looking in the direction of the arrows, and showing two methods of supporting the rollers;

Figure IV is a sectional view taken upon the line 4-'5 of Figure II, looking in the direction of the arrows but with one of the brackets shown in section which is not in the section plane;

Figure VI shows one method of sealing the end of the rollers, this section being an enlarged view of the roller taken along the same; lines as in Figure II;

Figure VII is a fragmentary longitudinal section of the seal shown on Figure VI;

Figure VIII is a suction upon the line 8-8 of Figure III, looking in the direction of the arrows;

Figure IX is an elevationof a portion of the wet end of a paper machine showing the location of the flat box unit with relation to the wire;

Figure X is a fragmentary view in front elevation of a sealingdevice employed in the machine;

Figure XI is a sectional view taken upon the line Hll of Figure VII; and

Figure XII is a fragmentary, sectional view showing an arrangement in which solid roller segments are employed.

Referring to Figure IX, a roller equipped flat box unit A, is shown as applied to a Fourdrinier paper machine. The unit A is supported by a frame B. An endless screen belt C runs successively upon table rolls D and over rollers F of the unit A. The screen belt passes thence around a suction or couch roll E by which it is driven. The paper stock comes in from the right on top of the wire 0 and flows along C until it reaches the box unit A, the interior of which is maintained under a partial vacuum. Details of the suction box unit A are disclosed in Figures I to VIII inclusive. The box itself is a tightly closed structure desirably rectangular in section, consisting of longitudinal channel members i to the bottom of which a plate 2 is affixed.

The channel members l are connected to one another through cross braces l2 and i3 and by end wall members G. The members I and G have top flanges disposed in a common horizontal plane and on these flanges a roll carrying frame is mounted. Y The frame comprises longitudinal angle irons i and transverse angle irons 3. Several rows of relatively small articulated rollers F are supported in the frame. These rollers are sealed on the top by the wire C which is covered by the wet paper stock. The rollers are supported from the angle irons 3, the supporting means extending through the angie irons and having bearing therein. Cover plates Ed at the outer sides of the angle irons Bseal the openings thus provided in the angle irons. Seals 4 are provided on angle irons E5 to cooperate with the adjacent rollers F for completing the sealing of the suction box. The suction box is connected by pipe H to a vacuum pump not shown. The rollers F are placed as close together as possible while still allowing room for air and water removed from the stock to pass between them into the enclosure, and are made small in diameter.

The individual rollers which form the cornposite roller F are made short enough to prevent undue deflection. Each individual roller runs on bearings, desirably of the ball or roller type adjacent, its opposite ends.

Figures II, III, IV and VIII illustrate one method of mounting and supporting these bearings. In these figures the bearings 9 are mounted on the stationary shaft E fixed in end plates 3, and are supported between the rollers by intermediate brackets 5 which rest on the cross braces [2.

The webs 2B of the brackets 5 extend across the end faces of the rollers to form a partial seal and are made narrow so as to enable the ends of the rollers to extend into proximity with one another, thereby obviating sagging of the wires into the space between the ends of the rollers. Each web is continued as a wire-supporting flange at the upper side of the bearing and terminates just within the peripheral bounds of the associated roller segments. The webs 23 are stiffened by side plates 29 located outside the rollers,'the web and side plates being integral with one another and with a base 3%. The base 3E8 is secured to the cross brace l2 by screws 35.

The outer races of the bearings 9 are fixed in the rollers by threaded members it, which turn'with the rollers and are formed with drip grooves ii. The grooves H conduct water away from the bearing enclosures when the rollers are stationary, and also act as slingers in conjunction 'with the ends of the rollers to exclude water bearings 9 and hold the rollers in close running relation without contact with the webs 28 and the end angle irons 3. Proper clearances may readily be secured by first fixing and locking one end bushing 3| and shaft 1 in proper relation by a set screw 33 and then adjusting and locking bushing 32 with set screw 34. After this, brackets 5 may be moved to divide the clearance between the rolls and then locked in place by the screws 35. It will be observed (see Fig. III) that the shanks of the screws 35 pass through slots formed in the upper faces of the cross braces 52.

An alternative structure for mounting and supporting the roller bearings is shown in Fig. V. In this structure the rollers are mounted on the shaft 22 by means of collars 25 fixed in the ends of each roller. These coliars may be adjusted longitudinally of the shaft and locked in position by any suitable means such as set screws 25a.

The shafts 22 and rollers F mounted thereon are'supported by, and turn on, roller bearings 23. The outer bearing members for the end roller are carried by end plates 3 and the intermediate bearings are located in brackets 6. The brackets 6 are fastened to cross-braces l2. A thrust bearing 24 is fixed to one end of the shaft 22 to hold the rollers in proper axial relation with the end plates 3 and the brackets 6. Interior bearing caps 27 are provided which form bearing closures and hold the hearings in place. These caps are formed with grooves 2i. Slingers 25 are provided on the collars 25 and these together with the grooves 27' effectively exclude water from the bearings.

A further alternative structure .is shown in Figure XII. In this structure the braces l2, the

brackets 61, the interior bearing caps 27:, and the with the rod 22 divided lengthwise at the middle.

of each intermediate'bearing 23.

Figure XII illustrates the joint between two roller segments. nular recess 52 is divided by an annular flange 53 corresponding ,to the slinger flanges 26 of Figure V. Each solid roller segment is formed with a central hub portion 54 which substantially meets the likehub'portion of the neighboring roller segment at the middle of the roller bearing 23. In the case of terminal roller segments, an extended hub portion 54 is. provided at one end for cooperation with a bearing in one of the frame members .3. In one instance the extended hub portion has the structure shown at the right-hand end of the shaft 22 of Fig. V for cooperating with a ball bearing 24 and a nut 2% as shown in Fig. V.

At each end of the rollers, members l4 supported on the end frame members ii-(see Figures I and II) extend under the screen belt C to a point just inside the edge 36 of the paper stock on the wire. These members are desirably made ofv synthetic resin or some similar. material and their upper faces are formed with a curvature slightly less than that of the sagging wires to permit these members to be worn in by contact with the wire during the initial'period of operation, Thereafter a running clearance will be It will be observed that the an- V automatically maintained at this point, which clearance will be sealed by water which comes along with the paper stock or is separately supplied.

The sealing member 4 adjacent to the composite rollers is shown in detail in Figures VI and VII. A member I6 which may be'composed of a single piece of material or of several pieces of material fitted together to form a, tight joint is fastened to the angle beam I5. A plate 40, Figs. II and IV, is interposed between the members l5 and'l and between the members 3 and G. The angle beams i5 are held down snugly but movably on the plate 49 by screws [5a which are passed through the plate and through members I. The beams also fit snugly between the end members 3. Piece I 6 partially surrounds the outside ofthe outer composite roller F and has a running clearance therewith. The plate 48 is formed with upturned arms dlla through each of which an adjusting screw 4% is threaded. The stud 49b is fixed in an abutment 400 on the angle beam I5 and may be operated when the associated screw I 5a is loosened to move the angle beam [5 and the seal member it which is carried thereby toward the adjacent roller F. After the desired adjustment has been secured, the screw [5a is again tightened and the screw 491) may be retained in adjusted position by lock nuts 4011.

Piece It is provided intermediate between its upper and lower margins with a space or channel I? which extends lengthwise of the piece l6, but is interrupted in the regions opposite the supporting brackets where solid portions 3? are provided. Above the space I! there is provided a rib portion Ila, and above the rib portion Ila there is provided a channel is having discharge openings 2a which extend outward through the angle beam i5. The space I! is subdivided by partitions I lb through which openings l'lc are formed.

Below the space [I there are successively a rib portion i'id, a channel We, a rib portion III, a channel 2! and a rib llg. As illustrated, the channels I9, lie, and 2| are all coterminous with the channel ii. The solid portions 31 are formed at either side of a roller segment junction with drain passages 38 which lead into the lower part of the suction box. The parts described are repeated for each roller segment.

Water is forced under slight pressure through a conduit i8, being delivered to the space ll through ports 53a. Water is forced in under suflicient pressure to fill the space or channels lie, 2! and i9, and to cause a slight surplus 01": water to escape through drain openings 2%?" that communicate with the channels it. In this way,

film of water is maintained between the memher it and the adjacent roller F to seal the suction box against ingress of air. A limited quantity of water is continuousl drawn into the suction box from the space between the member 15 and the adjacent roller F, but the water flows less freely than air, and its volume represents only a minute fraction of the volume of air which would be drawn in between the member it and the roller F if the water seal were not provided.

Although the invention as described herein is embodied in a Fourdrinier machine it is evident that the utility of the invention is not limited to paper making. The invention may find utility in any art in which a filter screen driven over a suction box would be useful for thickening material or for extracting liquid. For example, the invention might be used to advantage in the 6 sugar making industry for withdrawing liquors from the mash.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. In a traveling screen filter, a suction box including a series of closely spaced small diameter rollers on which the screen wire runs, each roller being composed of a plurality of hollow, imperforate roller segments arranged end to end, a stationary rod extending continuously through each roller for supporting the same without sagging, supporting means for the rod comprising end supports and intermediate supporting brackets disposed between adjacent roller segments, said brackets comprising. thin upstanding webs between adjacent end faces of. said segments, anti-friction bearings. mounted within each: roller segment adjacent opposite ends of the latter for supporting the segment rotatively on the rod, and end closure seals disposed within the opposite ends of each roller segment for preventing access of water to the bearing, the adjacent ends of roller segments being separated from on another by spaces not substantially greater than the thicknesses of the thin intervening supporting brackets, and each roller segment with its bearings and end seals forming a unit through which the supporting rod may be passed.

2. In a traveling screen filter, a suction box including a series of. closely spaced small diameter rollers on which the screen wire runs, each roller being composed of a plurality of hollcw, imperforate roller segments arranged end to end, a rod extending continuously through each roller for supporting the same without sagging, supporting means for the rod comprising end supports and intermediate supporting brackets dis" posed between adjacent roller segments, said brackets comprising thin upstanding webs between adjacent end. faces of said segments, and

.-- anti-friction bearings mounted within each roller segment adjacent opposite ends of the latter'for supporting the segment rotativel on the. rod, and sealing plugs threaded into the opposite ends of each roller segment for obstructing access of water to the bearings, the sealing plugs being contained within the roller segments, the adjacent ends of roller segments. being separated from one another by spaces not substantiall greater than the thicknesses of their intervening supporting brackets, and each roller segment with its bearings and end seals forming a unit through which the supporting rod may be passed.

3. In a traveling screen filter, a suction box including a series ofclosely spaced small diameter rollers on which the screen wire runs, each roller being composed of a plurality of hollow roller segments arranged end to end, a rod extending continuously through the successive seaments of each roller for supporting the same without sagging, supporting means for the rod comprising end supports and intermediate supporting brackets disposed between adjacent roller segments, each bracket including a broad bearing portion adapted to be received within end portions of adjacent roller segments, and a thin upstanding web portion disposed between adjacent end faces of said segments and carrying said broad bearing portion, each bearing portion carrying a roller bearing through which the rod is rotatively supported from the bracket, sealing members secured to opposite sides of the bearings to protect and correctly posit-ion the bearings, and means rigidly connecting each roller segment to the associated rod, the adjacent ends of the roller segments being separated from one another by spaces not substantially wider than the thickness of the thin Web portion of the intervening bracket.

4. A suction box as set forth in claim 3, in which the web of each bracket is continued as a flange at the upper side of the bearingand terminates just within the peripheral bounds of the associated roller segments.

5. In a traveling. screen filter, a suction box including a series of closely spaced, small diameter rollers on which the screen wire runs, and a sealing member cooperating with a terminal roller of the series, said sealing member having a face conforming generally to the contour of a wide sector of the roller but being formed with a series of longitudinally extending parallel channels or pockets, said box further including end walls and side walls, the latter including a sec tion movable bodily toward and from an adjacent roller, upon which the sealing member is carried, and cooperative with the associated wall portions, of the box to maintain the wall unbroken when it is moved toward and from the roller, and adjusting means for shifting said movable wall section to provide a desired clearance tween the sealing member and the roller.

6. A suction box as set forth in claim in which a water conduit is connected through said movable wall section to discharge water under pressure into an intermediate channel of the sealing member.

7. In a traveling screen filter, a suction box including a series of closel spaced, small diameter rollers on which the screen wire runs, each roller being composed of roller segments arranged end to end, and each segment having a hollow portion in which a bearing is received, and supporting means for the bearing comprising a wire-supporting bracket interposed between adjacent roller segments, the peripheries of the adjacent ends of roller segments being separated by a space of substantially less width than the width of the associated bearing portion, said bracket including a thin upstandingrweb disposed between adjacentend faces of said segments. 8. In a, traveling screen filter, a suction box including a series of closely spaced, small diameter rollers on which the screen wire runs, each roller being composed of a plurality of roller segments arranged end to end, supporting means for the segments comprising end supports and intermediate supporting brackets disposed between adjacent roller segments, each bracket including a thin upstanding web disposed between adjacent end faces and a broad bearing portion adapted to be received within end portions of adjacent roller segments, and each carrying a roller bearing through which the roller is rotatably supported, the peripheries of the adja- 8 a 7 cent ends of roller segments being separatedby a space of substantially less width than the Width of the associated bearing portion.

9. In a traveling screen filter, a suction box including a series of closely spaced, small diameter rollers on which the screen wire runs, each roller being composed of a plurality of roller segments arranged end to end, supporting means for the segments comprising end supports and intermediate supporting brackets disposed between adjacent roller segments, each bracket including a broad bearing portion adapted to be received within end portions of adjacent roller segments, and each carrying a, roller bearing through which the roller is rotatabl supported, each bracket including a thin web portion disposed between adjacent end faces of said segments and through which the relatively broad roller bearing is carried, said web'being continued as a flange at the upper side of the bearing and terminating just within peripheral bounds of the associated roller segments, the peripheries of the adjacent ends of roller segments being separated by a space of substantially less width than the width of the associated bearing portion.

10. In a traveling screen filter, a, suction box including a series of closely spaced small diameter rollers on which the screen wire runs, and a sealing member cooperating with a terminal roller of the series, said sealing member being composed of segments arranged end to end, each segment having a face conforming generally to the contour of a wide sector of the roller and having a series of longitudinally extending parallel channels in said face terminating short of the ends of the segment, the box including side walls having an upper longitudinal section carrying said sealing member, said section and sealing member being movable toward and from said terminal roller and adjusting means for shifting said movable wall section and sealing member to provide a desired clearance between the sealing member and the terminal roller.

IRVING C. JENNINGS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 200,369 Young Feb. 12,1878 989,195 Sager Apr. 11, 1911 1,071,021 Bauer Aug. 26, 1913 7 1,171,999 Witham Feb. 15, 1916 1,572,238 Jones Feb. 9, 1926 1,678,083 Russell et a1 July 24, 1928 1,831,334 Wenzel Nov. 10, 1931 2,428,921 Scofield Oct. 14, 1947 FOREIGN PATENTS Number Country Date 7 10,880 Great Britain of 1905 401,935 'Germany' Sept. 15, 1924 700,623 Germany Dec. 24, 1940 Certificate of Correction Patent No. 2,536,446 January 2, 1951 IRVING 0. JENNINGS It is hereby certified that error appears in the printed specification oi? the above numbered patent requiring correction as follows:

Column 7, line 46, after the word and comma segments, insert said bracket including a thin upstanding we?) disposed between adjacent end faces of said segments,; line 49, beginning with the comma and word said strike out all to and including segments in line 51;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice. Signed and sealed this 27th day of February, A. D. 1951.

THOMAS F. MURPHY,

Assistant Uommissioner of Patents;