Патент USA US2116168код для вставки
May 3, 1938. ‘ J. FISH ET AL 2,116,168 METHOD OF AND APPARATUS FOR FORMING A PULP_WEB Filed ’ July 11 , 1933 @ m/dZ?a/m ' 4206 Unkgbr, Patented May 3, 1938 2,116,168‘ ’ UNITED STATES PATENT OFFICE 2,116,168 METHOD OF AND APPARATUS FOR FORM ‘ ING’ A PULP WEB James Fish, Bristol,“ Pa. , and Arnold John vBarea, Berlin, N. H., assignors to Brown Company, Berlin, N. H., a corporation of Maine . Application July 11, 1933, Serial No. 679,906 6 Claims. (Cl. 92-45) This invention relates to a method of and ap water from its lowermost layer to form a pulp paratus for improving the formation of a pulp web against the wire While the upper layer of the web on a Fourdrinier wire of a paper-making stock still retains approximately its original con machine. sistency. The omission of a table roll leaves a Heretofore it has been common practice to im substantial stretch of unsupported wire at this part a lateral shake to the portion of the Four critical point ‘in the formation of the pulp ‘web. drinier wire extending over the table rolls. Thus, The unsupported stretch of wire magni?es the the ?bers in the pulp stock which ?ows over the vibrations received through the shake rails and “ breast roll onto the Fourdrinier wire, and which no tend to aline themselves withthe direction of ?ow, are agitated in such a way as to cause many of the ?bers to assume crisscross positions in the web whichvis formed on the wire by the drain age of white water from the stock deposited M thereon.) Under the best of conditions, however, adjacent table rolls so that the stock on this por tion-of the wire is strongly agitated in such a 10 manner as to form standing waves of a height many times the amplitude of the vibration. These waves‘ effectively prevent the formation of ?ber bunches in the liquid upper portion of the sheet, and break up any bunches of ?berswhich the paper sheet resulting from a web thus formed may have collected while traveling from the wet is subjected to ripples or non-uniformity of thick , end of the wire to the point of agitation. . ness of sheet, especially in the case of heavy For a more complete understanding of the sheets, or of free stock. This can readily be ob invention, reference may be had to the descrip 1servéed by holding the sheet of paper to the igh . Y tion thereof which follows and to the illustra- I tion of an embodiment thereof on the drawing, It is an object of the present invention to im prove the uniformity of a heavy paper sheet by the particular kind of agitation of the web ar ranged to take place at the particular stage in its formation. According to the invention, a liquid sheet of pulp stock is run onto the Four Fourdrinier paper-making machine, many of the customary parts being omitted to avoid confusion drinier wire in the usual manner and may be sub 1 on a larger scale. jected to the usual lateral shake. As the sheet 30 of stock progresses with the movement of the wire, the lowermost portion of the sheet directly against the face of the wire loses its white water ?rst so that an incipient layer or mat of ?ber is formed against the face of the wire before the 35 upper portion of the liquid sheet of stock has on which ' Figure l is a side elevation of the wet end of a of detail. , l ' I Figure 3 is a section on the line 3-3 of Fig ure 2. Figure 4 is a section on the line ‘fl-1i of Fig- 30 ‘ .ure 2. Figure 5 is a section on the line 5—5 of Fig ure-4. Figure 6 is a section on the line 6-43 of Fig- lost any appreciable amount of its white water. ‘ ure 2. At this stage in the formation of the web, the sheet is subjected to a vibration of such a nature as to set up a series of standing waves in the 40‘ aqueous upper portion of the sheet. This partic ular type of agitation has the effect of offsetting the tendency on the part of the ?bers in the liq uid upper portion of the sheet to collect in soft bunches before they are deposited in the pulp 45 web by the escape of the white water by which they are carried. Thus the. ?ber distribution in the upper portion of the sheet is such as to result in a substantially uniform paper sheet. Vibrations adaptedto attain these results may 50 be set up by imparting to the shake rails and the table rolls supported thereby a rapid vertical oscillation of small amplitude, say a few hun dredths of an inch. Furthermore, one or more of the table rolls may be omitted at the point where the sheet of stock has lost su?icient white 26 Figure 2 is an elevation of a portion of Figure 35 As illustrated in Figure 1, the invention may be embodied in the wet end of aFourdrinier paper making machine which includes a?xed base ID from which a number of supporting standards H extend upwardly to support a pair of ?xed side bars i2. These side bars support a pair of shake rails which, as indicated in Figure 1, may each consist of two separate parts l4, Ill. The part ll of each shake rail, which is nearer to the 45; breast roll I6, is loosely supported for limited vertical movement. To this end, each of the side bars I2 is provided with a number of hangers 11. Each han‘ger is vertically slotted as at l8 so as to receive therethrough a bolt 20 having a head 50 2|. A spacer block 22 is provided next to the head 2|. This spacer block, if desired, may be integral with the bolt itself. The spacer, block rides in an aperture 23 in the shake rail l4 and cooperates with a nut 25 on. the bolt 20 to clamp - . 2,116,168 2 the bolt ?rmly to the hanger H in a vertically adjusted position. The head 2| of the bolt over laps the sides of the aperture 23 so as to hold the rail M in position, but at the same time to allow a limited free vertical movement on the part of - the rail. The portions ii of the shake rails, remote from the breast roll l6, may be suitably ?xed to hangers IT. The shake rails are provided with '10 bearing members 30 for table rolls 3| over which a wire screen 32 extends. The apparatus may be provided vwith the usual head box 33 and with one or more slices 34. Vertical shaking. movement is imparted to the loosely mounted portions H of before they are deposited in the pulp web. Thus heavy sheets can be made of free stock with a high degree of uniformity of distribution of ?bers through the entire thickness of the sheet. Various ‘modi?cations and changes may made in the particular embodiment of the vention herein shown and described without parting from the spirit or scope thereof as ?ned by the following claims. be in de de 10 We claim: 1. In 'a paper-making machine, a breast roll, a pair of shake rails, a series of table rolls jour naled on said rails, said rolls being arranged with a substantial gap in the series near the breast 15 the shake rails by any suitable apparatus. As shown, a block 35 is ?xed to each shake rail por roll, and means for vertically oscillating the rails and table rolls in the vicinity of said gap. which is mounted on an eccentric member 4|. The eccentric member II is mounted on an ec at a point where a substantial fraction of the pulp 2. In a paper-making machine, a Fourdrinier tion l4. Each block contains a socket 36 which cooperates with the upper end 31 of a pitman 38 7 wire adapted to receive dilute pulp stock thereon, to form a ball and socket joint ‘so as to permit a pair of shake rails, a series of table rolls on 20 20 the customary lateral shake. The pitman 38 ~ said rails supporting said wire, said rolls being extends upwardly from an eccentric strap 40 arranged with a substantially greater than centric sleeve 42, which in turn is mounted von a drive shaft 43. Since both the members 4| and 42 are eccentric, the amplitude of vibration may be altered by adjusting the angular relation be tween the two eccentric members so that their eccentricities will either augment or neutralize 30 each other to a greater or less extent according to the angular relation. As indicated in Figures 1v andl2, one or more of the table rolls may be omitted. The particular roll or rolls to be omitted will, in any particular case, depend upon 35 the amount and characteristics of the pulp stock ‘supplied to the machine. It is desirable to omit a roll at the point where the lowermost stratum of vthe'stock on-the wire has lost enough of its white waterto form a web on the screen, but the upper stratum of stock is still liquid but is at the point of depositing its ?ber on the web which is forming. The location of the gap between suc cessive table rolls will depend upon the nature of-the stock employed, a web being formed more rapidly from pulps of somekinds than from pulps of other ‘kinds. In operating the mechanism, the usual horizontal shake may be imparted to the pulp stock by means well known in the art but not herein illustrated. In addition to the 50 customary lateral shake, a vertical shake may be imparted by the eccentric mechanism shown and described, the amplitude of such vibrations being of the order of a few hundredths of an inch. The frequency of vibLation may vary within con siderable limits and will in any particularcase depend upon the conditions of operation. In most cases frequencies between 600 and 2000 per customary. gap in the series near the breast roll stock on the wire, when the machine is in opera tion, has drained sufliciently to form a web next to the wire while the upper stratum of stock com prising a substantial fraction of the pulp is liquid, and means for imparting a rapid vertical oscilla tion to ‘the rails. - 3.<In a paper-making machine, a supporting 30 frame, a pair of side rails mounted on said frame for limited vertical movement, a series of table rolls j-ournaled on said rails and arranged with a gap in the series near the breast roll at least twice as wide as the usual space between suc 35 cessive rolls at the same place, and means for imparting a vertical oscillation to saidrails and to the table rolls carried thereby. 4. Ina paper-making machine having a breast roll,“a stationary support frame, a pair of shake 40 rails supported in said frame, each said rail hav ing two separate parts, the parts remote from‘the breast roll being adjustably ?xed to said frame, the parts near the breast roll being loosely sup ported by said frame for limited vertical move 45 ment, table rolls carried by said shake rails, the rolls on the loosely mounted portions of the rails being arranged with a substantial gap between two of the rolls, and means for imparting to said loosely mounted‘ rail portions a vertical vibration 50 of small amplitude. 5. In a paper-making machine, a series of table rolls, a pair of shake rails carrying said rolls and loosely mounted for limited vertical movement. said rolls being arranged with a substantial gap between two of the rolls, and means for impart ing vertical oscillation to said shake rails and the. -on either side of the gap- This wire screen is 65 under considerable longitudinal tension, and the rolls thereon, said means including a rotatable shaft, an eccentric mounted on said shaft, an eccentric strap on said eccentric, and a p‘itman connecting said strap and a shake rail. 6. A method of forming a relatively thick ‘pulp web, which comprises removing from a Four drinier machine one of the table rolls at a point where a substantial fraction of the stock on the wire has formed a mat and a substantial fraction through the shake rails and table rolls, become considerably ampli?ed in the unsupported stretch of the stock still retains its original consistency, operating the machine in the usual manner, and minute give satisfactory results. The vibrations are imparted to the loosely mounted portions ll 60 of the shake rails and tothe table rolls which are supported thereon. By omitting one or more of these table'rolls, a substantial unsupported stretch of wire screen ‘occurs between the rolls ‘vibrations, which are imparted to the screen of wire over the gap. The vibration of this 70 stretch sets up a train of standing waves in the watery upper layer of the stock on the wire. The resultingvagitation of the stock has the effect of uniformly distributing the individual ?bers through the upper layer of the stock immediately imparting rapid vertical vibrations of small amplitude to the side rails of the machine during 70 such operation. ‘ . ' JAMES FISH. ARNOLD JOHN BAREA.