US 3201066 A
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Aug. 17, 1965 n. w. DANFORTH MACHINE AND METHOD FOR DISPOSING OF BROKE Filed Nov. 29, 1962 2 Sheets-Sheet l INVENTOR. DONALD W. DANFORTH ATTORNEYS Aug. 17, 1965 D. w. DANFORTH 3,201,066'
MACHINE AND METHOD FOR DISPOSING OF BROKE Filed Nov. 29, 1962 2 Sheets-Sheet 2 INVENTOR. DONALD W. DAN FORTH Rea/wow r PM ATTORNEYS United States Patent Thisinvention relates to an apparatus and method for disposing. of broke in a paper making machine.
It has heretofore been proposed to provide means for disposing of narrow edge trim from the paper machine wire, or for disposing of a narrow lead strip used to thread therolls. of a paper machine. The capacity of such devices is not sufiicient to receive and dispose of a full width paper web which has broken and is accumulating at the production speed of the machine.
It is conventional in the art to handle the broke of. a full width paper web by guiding it downwardly through a floor opening into a full size conventional pulper mounted on the fioor below. Such pulpersmay take the form of al-Iollander type beater as in US. Patent 2,696,766 to Stark of December 14, 1954 or the form of a round vortical typepulper as .in U.S Patent 2,667,106 to Hyman of January 26, 1954. The web of dry broke may be slit and wetted by jets of liquid, as in the above mentioned patents, or the Web of dry broke may be shredded into dry fragments by toothed rolls, as disclosed in US. Patent 1,052,495 to McClellan of February 11, 1913.
In some paper machine installations there is no floor below the floor. of the paper machine and no headroom capable of accommodating a full size pulper. In addition, such conventional pulpers are relatively costly and not primarily designed to handle broke. It may, therefore, be ineflicient and uneconomical to devote such a pulper entirely to the purpose of disposing of broke it and when a break occurs.
It is highly undesirable to stop a paper making machine, whenever a break in the web occurs and the paper maker will attempt to correct the situation while the machine is running. Usually in order to be able to cope withthe rapidly accumulating paper, another break is purposely made at another location more suited for the removal of the paper. selected location is a severe problem which requires considerable manpower and which will eventually lead to a shutdown of the machine.
The principal object of this invention is to provide an apparatus and method for disposing of paper web broke directly under the paper making machine by converting the dry broke to wet macerated fragments and then to screened wet pulp, as fast as it is received and in a single pass, and pumping the wet pulp away from under the machine.
Another object of the invention is to provide a broke pulper capable of handling dry broke as rapidly as it accumulates from the machine, the broke pulper being elongated, shallow and narrow and mounted close to the level of the floor on which the machine is supported.
A further object of the invention is to provide a low height, or shallow, wet broke disposal apparatus which can be mounted under any paper machine with a minimum of installation. problems, the pulper having a toothed nip accepting and drawing broke away from the machine at -such speed as will keep the machine free=and clear of broke and prevent accumulation of the broken paper web.
Still another object of the invention is to provide an under-machine broke pulper which hydrates the dry broke, shreds it into fragments, macerates it into pulp and screens out the pumpable pulp right at the point of breakage and The removal of the paper at the "ice then pumps the screened pulp away from under the machine from under the machine in a single pass and without requiring recirculation through the broke pulper.
A still further object of the invention is to provide a broke pulper in which a pair of toothed rolls have a toothed nip for shredding the broke and in which a screen encircles the rolls, except at the nip, the rotating teeth being. aligned with the meshes of the screen and having predetermined clearance from the other roll and from the screen to macerate the broke fragments while centrifugally driving the pulp through the meshes into a pulp collection chamber.
Other objects and advantages of the invention will be apparent from the claims, the description of the drawings and from the drawings in which:
FIG. 1 is a side elevation or a typical paper making machine showing the broke pulper of the invention mounted under the machine close to machine floor level.
FIG. 2 is an enlarged side elevation of the pulper of theinvention together with a diagrammatic view of the preferred control system.
FIG. 3 is a still further enlarged side elevation, in section on line 3-3 of-FIG. 4, of the broke pulper of the invention.
FIG. 4 is a rear elevation of the machine shown in FIG. 3, looking from therear, or delivery end of a paper making machine, and
FIG. 5 is a plan view of the pulper shown in FIGURES 3 and 4.
As shown in FIG. 1, a typical paper making machine 25, may include a Fourdrinier wire section 26, press section 27, dryer sections 28 and 28a, size press section 29, calender section 30 and reel section 31. The machine 25 is supported on the floor-32, and the usual full size broke pulpers are conventionally supported on the floor 33, if there is suflicient headroom in the space 34 between the floors. The machine 25 may be two or three hundred feet in length, withthe wire traveling at twelve hundred feet a minutetto produce a relatively dry, continuous web of paper 36, about fifteen feet in width, at the press section 27.
It will be understood that the paper web 36 is supported by felt and thelike through much of its path through the machine. However, there is an unsupported stretch 37, between the press section 27 and the dryer section 28and there are unsupported stretches 38 and 39 in advance Of,aIld in rear of the calender section 30. If the paper web 36 breaks in a supported stretch it will normally be carried through to one of the unsupported stretches where it will accumulate on the floor at the production rate ofthe machine. However, if broke is generated at an inaccessible location, the paper maker may break the web deliberately at a point such as 37,
. 38 or 39 where the accumulationcan be handled more effectively.
As shown, in accordance with this invention, slots 41, 42 and 43 are formed in the floor 32, beneath the stretches 37, 38 and 39 and extending the full Width of the ma chine 25 for receiving paper web broke. Similar slots 142 and 143 are provided under the press section 29.
A broke pulper 44, is suspended from the ceiling 45, by suitable hangers 46, beneath slot 41, an identical-pulper 147 is similarly suspended beneath slots 142 and 143 and an identical pulper. 47 is similarly suspended beneath slots 42 and .43, so that the pulpers are directly under the machine and close to the level of floor 32. The pulpers 44, 147 and 47 could be supported on floor 32, in the space beneath the rolls of the machine, but it is preferred that they berecessed into the floor, or just below floor level, to provide room for an initial accumution 31 will be directed into the slot 43.
As shown diagrammatically in FIG. 2 paper web broke 48, from the calender section 30, will be directed into the slot 42 and paper web broke 49 from the reel sec- Paper web broke 51, from the size press section 29 may be directed into either slot 142 or slot 143, in each case being received into the pulper 147.
Each broke pulper, such as 47, includes elongated receptacle means 52 of narrow width and low height, at least equal in length to the width of the paper web 36 and extending transversely of the machine 25. In the embodiment illustrated the receptacle means 52 includes a forward wall 53, a rearward wall 54 and opposite end walls 55 and 56, theforward and rearward walls being at least fifteen feet in length and several feet in height to define a horizontal, broke-receiving, upper opening 57 capable of accommodating broke such as at 48, 49 or 51. A pulping chamber 58 is provided at the bottom of pulper 47, divided for convenience into an upper portion 59 and a lower, pulp collection portion 60, all coextensive in length with the width of the web 36, slots 42 and 43 and the opening. The bottom 61 of the pulping chamber 58 is preferably inclined downwardly and inwardly to a central outlet 62.
Pulping means 65 is mounted in the upper portion 59 i of pulping chamber 58 and includes a pair of toothed rolls 66 and 67, each carried on a shaft such as 68 passing through stuffing boxes 69 and 70 in the end walls 55 and 56 and journalled in bearings 71 and 72 mounted on the pulper outside the receptacle means 52.
Drive means 74, including the pulley 75, or an electric motor and reducer, or any other suitable source of power, is provided to rotate the roll 67, there being suitable gearing 76 to rotate the roll 66 in the opposite direction so that the toothed nip 77 receives the broke in its entrance throatand feeds the broke from its exit throat away from the machine and downwardly into the pulper 47. Preferably the drive means 74 is controlled by the drive of machine 25 so that the surface speed of the teeth at the nip 77 will always be slightly greater than the production speed of the machine to thereby prevent accumulation of broke and tend to quickly clear the 1 machine of broke.
Each toothed roll such as 67 is preferably formed by a stack of identical toothed rings such as 80, 81 and 82,
each having about eight angularly spaced teeth thereon and each keyed as at 83 to the cylindrical face 84 of the roll in a different angular position to stagger the teeth. In the embodiment shown, each ring has eight teeth and every other ring is displaced twenty-two and one half degrees relative to the adjacent rings, whereby sixteen teeth are seen from the end of the roll.
The teeth 85 and 86 on each pair of adjacent rings 80 and 81 on the same roll 67 are arranged in circular, circumferential rows with a space between the rows slightly greater than tooth Width to accommodate the circular row of teeth on the ring of the other roll 66. The centre distance between the rolls is less than roll diameter so that the teeth intermesh and overlap with a predetermined clearance along the sides of the teeth and between the teeth and the face of the other roll, but the teeth do not strike each other. The leading edge 87 of each tooth 85 or 86 is preferably sharp to shred the broke into small substantially uniform size fragments in cooperation with the adjacent teeth and the face of the opposite roll. The number of rings used will depend on the width of the machine and the pulper casing 92 is preferably divided into three units 88, 89 and 90 with mating flanges 91 in order to permit easy installation and removal of the rolls 66 and 67.
The liquid supply means 93, of the invention is located in advance of the toothed nip 77 and proximate the horizontal broke receiving opening 57. Means 93 preferably comprises a series of shower pipes such as 94, 95, 96
and 97, one above the other and lining the forward and rearward walls 53 and 54 of the pulper. The jet, or spray apertures 98 in each shower pipe are directed inwardly at the lower, outer edge portion 99 of one of a series of deflectors, or baffles, 101, 102, 103, 104 and 165 with the resulting jets of liquid, such as water, being deflected outwardly and downwardly to cascade down the inner faces of the deflectors as full width liquid curtains, sheets, or water falls. The forward and rearward walls 53 and 54 preferably form a funnel-like entrance to the pulper, by converging inwardly and downwardly from the opening 57 toward the nip 77.
Preferably also the series of showers and baffles lining each wall 55 and 56 are inclined, to provide a funnel entrance with wet, sloping forward and rearward walls which will contact dry broke festooning in the opening and hydrate the same in advance of the nip while urging the broke toward the nip.
Pulp extraction means 108 is provided in each broke pulper 44 and 47, including a pulp screen 189 extending across the pulping chamber 58, the screen 109 dividing the pulping chamber into the upper portion 59 and the lower pulp collection portion 60. The screen 109 is shaped and curved to conform to the path of the outer faces of the teeth and 86 on the rolls 66 and '77 at a predetermined spaced distance therefrom of about one sixteenth to one eighth inches. It is of substantially double cylindrical configuration with the central portion 110 just in rear of, or below, the exit throat of the toothed nip 77, thence extending around and substantially encircling each roll to terminate in advance of or above,
the entrance throat of the nip in a forward edge 111' spaced from a rearward edge 112 to define a restricted opening or throat 113. The edges 111 and 112 merge with the bottom edges of the forward and rearward funnellike liquid curtain walls so that broke is flushed into the throat 113 and thence into the entrance throat of the nip 77. The perforations 114, or meshes, of the screen 189 are spaced apart in spaced circumferential rows aligned with the tips 115 of the teeth of the rings so that the teeth continually clear the perforations of any large fragments and the hydrated fragments are macerated into slush, or pulp, between'the tips of the teeth and the screen 109.
In the embodiment illustrated, the speed of the web is about twelve hundred feet a minute and the surface speed at the tips 115 is thirteen hundred feet per minute, the rotational speed of the toothed rolls imparting considerable centrifugal force to the hydrated fragments carried around the screen thereby forming a centrifugal screen which forces pulp of the desired consistency through the perforations into the chamber 60. The teeth, of course, also tend to push or squeeze the fragments through the screen thereby reducing the size of the fragments to a pumpable slush-like consistency.
Pulp extraction means 108, also includes a suitable suction pump 116 and drive means 117, for continuously extracting the pulp, screened out of chamber 59 into chamber 60, through the outlet 62 and back into the stock supply system or into the broke chest 118.
As illustrated diagrammatically in FIG. 2, each pulper 4-4 or 47, includes a break sensing device such as the photo cell 120, whereby a broken paper web will actuate the automatic controller 121. Controller 121, through suitable electric circuits, energizes the drive means 74 to actuate the pulping means 65, energizes the drive means 117 of the pump 116 and actuates the valve 122 for supplying liquid to the shower pipes of the liquid supply means. A second pump 123 in a by-pass line 124 may be provided, there being suitable stock valves 125 and 126 in the pump lines operated by the controller 121 and a consistency regulator 127 in the line 124.
From a method single pass point of view, the invention makes use of a pair of toothed rolls, first by flushing the pre-wetted broke into the roll nip, then shredding,
bined centrifugal screening step and pulp extraction step whereby pulp of a pumpable consistency is collected and pumped away from under the machine.
1. A broke pulper for disposing of paper web broke in a paper making machine, said pulper comprising:
elongated receptacle means, of narrow width and low height, adapted to extend transversely of said machine, said means including a forward and rearward wall defining a horizontal, broke receiving, opening and including a pulping chamber at the bottom thereof, said opening and chamber being co-extensive in length with the width of said web; a pair of toothed rolls rotatably mounted in the upper portion of said pulping chamber, said rolls forming a toothed nip extending horizontally, lengthwise of said chamber and having an entrance throat for receiving and advancing broke from said opening through said nip downwardly into said chamber while shredding and macerating the same; means for rotating said rolls in opposite directions at a surface speed greater than the speed ofsaid web for preventing accumulation of said broke and for drawing said broke into said nip and away from said machine; liquid curtain supply means in advance of said nip proximate said opening for wetting said broke to convert the same into pulp in cooperation with said toothed rolls; r
and pulp extraction means, including a screen extending across said pulping chamber to form a pulp collection compartment in the lower portion thereof and including a pulp outlet in the compartment bottom for extracting pulp from said compartment.
2. A broke pulper as specified in claim 1 wherein each said toothed roll comprises a stack of identical rings keyed on a cylinder, each ring having a face with a plurality of radially projecting teeth, the teeth of each ring rotating in a path between the paths of the teeth of the adjacent rings on the opposite roll and at a spaced uniform distance therefrom to provide a predetermined clearance between the said teeth and the ring face of the other roll for shredding said broke into substantially identical short strips or fragments while macerating the same.
3. A broke pulper as specified in claim 1 wherein the screen of said extraction means is curved into double cylindrical configuration with circumferential rows of perforations aligned with, and extending substantially around, the path of the tips of the teeth of said rolls, at a uniform spaced distance therefrom for maceration of wet broke fragments therebetween.
4. A broke pulper as specified in claim l wherein the screen of said extraction means substantially encircles said toothed rolls at a spaced distance from the teeth thereof except for a throat in advance of said nip whereby broke, entering said entrance throat of said nip, is carried around said rolls and back into said entrance throat of nip.
5. A broke pulper as specified in claiml wherein said liquid curtain supply means includes a plurality of jet sprays and spray deflectors on each said forward and rearward wall for cascading continuous sheets of liquid down said walls toward said nip and pulping chamber and a valve in said supply means, responsive to web break sensing means, for actuating said liquid curtain supply means to wet said broke as it festoons into said pulper.
6. A broke pulper as specified in claim 1 wherein the forward and rearward wall of said receptacle means converge inwardly and downwardly toward said pulping chamber to'form a funnel-type opening and said liquid curtain supply means includes a plurality of showers, 'eachdirecting jet sprays inwardly, and a plurality of defiectors, each in the path of one of said showersfor directing the spray therefromdownwardly on each said forward and rearward wall thereby forming a liquid curtain leading into saidnip for wetting broke festooning into said pulper. t
7. A broke pulperas specified in claim 1 plus a pulp pump connected to the bottom outlet of said extraction means for extracting pulp therefrom, said pulppump directing said pulp away from under said machine back into the stock supply system of said paper machine.
8. A broke pulper as specified in claim 1 plus hanger means for suspending said pulper from the ceiling of the floor below the floor of said paper machine.
9. Broke disposal apparatus for use in converting broke to pulp directly under the location of a break in the web of a paper making machine, said apparatus comprising:
relatively shallow, elongated, funnel-like, receptacle means at least equal in length to the width of said web, said means including forward and rearward walls spaced apart to form a horizontal, upper, broke re ceiving opening, and including a lower, pulping chamber of nanrow width and shallow depth,
liquid curtain supply means on said forward and rearward walls, said means including showers directed inwardly of said opening and deflectors in the path of the sprays from said showers, a liquid curtain for urging broke downwardly into said pulping chamher while hydrating said broke;
a pair of toothed rolls rotatable in the upper portion of said pulping chamber, said rolls having a brokereceiving toothed nip for shredding said broke while advancing the same into said chamber;
pulp extraction means including a pulp screen of generally double cylindrical configuration in said pulping chamber conforming in shape to the path of said teeth, said screen and teeth cooperating to macerate said broke therebetween while driving pulp of selected consistency through the meshes of said screen, and means for rotating said toothed rolls in opposite directions at a surface speed greater than the speed of the webof said machine for preventing accumulation of broke in advance of said toothed nip while drawing said web into said nip and away from said machine.
10. In a paper making machine having unsupported stretches of a paper web advancing at a predetermined height above floor level and at a predetermined speed, the combination of a broke pulper, of narrow width and low height extending transversely of said machine under one of said unsupported stretches, said pulper having a funnel like, broke-receiving, upper opening and a pulping chamber in the bottom thereof;
a pair of toothed rolls, rotating in opposite directions in the upper portion of said pulping chamber on axes parallel to the axes of the rolls of said machine,'said rolls having a toothed nip for receiving and shredding broke and rotating at a greater surface speed than the speed of said web for drawing said web away from said machine;
a pulp screen extending across said pulping chamber, said screen conforming in shape to the path of said teeth, with a uniform clearance therebetween, for macerating broke while guiding the same around said rolls and back into said nip,
liquid supply means forming a liquid curtain on the inside face of said funnel-like opening for urging broke downwardly into said nip while hydrating the same,
and a pump connected to the lower portion of said 7 8 11. A method of disposing of broke in a paper making said fragments into pulp and screening out pulp of a machine by means of a pair of toothed rolls having a preselected consistency toothed nip, said method comprising the steps of and continuously pumping said screened-out pulp away flushing said broke downwardly on a curtain of liquid,\ from said paper making machine. a s fl to Said m i References Cited by the Examiner rotating said rolls in opposite dlrections at a surface speed greater than the speed of said web while shred- UNITED STATES PATENTS ding said wet broke into small wet fragments and 903,801 1/09 Ponsar 241-90 while drawing said broke away from said machine 1,9 0 10 5 34 Grewin 241 4 into the entrance throat of said nip; 10 2,23 ,9 9 4 41 Flatebue 241 23 guiding said wet fragments around said rolls and back a 7 into the entrance throat of said nip while macerating J. SPENCER OVERHOLSER, Primary Examiner.