US2782692A - Secondary headbox - Google Patents

Description

P. BORONOW ETAL SECONDARY HEDBOX Filed ned.' s, m52

3 Sheets-Sheet l @Wmv/eey@ Fe 26 3957 P. BoRoNow ETAL SECONDARY HEADBOX 3 Sheets-Sheet 2 Filed Dec. 8, 1952 INI ifm/alga Feb. 26, 1957 Filed Dec. 8, 1952 P. BORONOW EVAL SECONDARY HEADBOX 3 Sheets-Sheet 3 yn/aveu or; auf fia/mw SECGNDARY HEADBOX Paul Boronow, Appleton, and Willard C. Notbohm, Kaukarma, Wis., assignors to Valley Iron Works, Appleton, Wis., a corporation of Wisconsin Application December 8, 1952, Serial No. 324,708

3 Claims. (Cl. 92--39) This invention relates generally to paper making machines and, more particularly, relates to an improved paper making machine of a type which is adapted to lay two or more webs upon a single wire of the machine.

In the manufacture of paper, it has been the almost universal practice to initially form a sheet or web of fibers by flowing paper stock onto an endless wire screen, called the forming wire or wire, whereupon the water is drained from the fibers leaving a web which is then pressed and dried to form a sheet of paper. The means for flowing the paper stock onto the wire with the proper uniformity of mixture and motion, and at the desired velocity is generally referred to as the headbox.

It is known that in the forming of a sheet of paper a second headbox may be used for owing stockV onto a wire. When this is done, the second headbox is located downstream of a rst headbox and ilows stock, in superposed relation, onto the web formed on the wire by the first headbox. It will be seen that through the use of the second headbox, paper having opposite surfaces of different characteristics may be readily and economically manufactured.

While, as pointed out, it has been known that secondary headboxes are useful in manufacturing certain types of paper sheets and while such headboxes have been employed in the manufacture of various paper sheets, presently known secondary headboxes have not, in general, successfully provided satisfactory sheets' of paper having the second web firmly bonded and/or formed onto the initially laid web. We believe that this has resulted from a failure to appreciate that dilerent problems are involved in laying successive webs on a wire than are involved in laying a single web upon a wire.

A main object of the present invention is, therefore, the provision of an improved secondary headbox and a further object of the invention is the provision of a secondary headbox which is adapted to lay a uniform web upon an initially laid web in Isuch a manner that the superposed webs are integrally associated, one with the other. As will become more apparent hereinafter, these and other objects of the invention are accomplished through provision of a pressure type secondary headbox of a particular construction to be described.

The drawings illustrate the apparatus of the invention, and in the drawings:

Figure 1 is a diagrammatic illustration of the wet end of a paper making machine showing the position of the secondary headbox of the invention;

Figure 2 is a plan View of a secondary headbox embodying the features of the invention, certain parts being broken away to more clearly show the structure;

Figure 3 is an enlarged end view of the structure shown in Figure 2, and;

Figure 4 is an enlarged sectional view taken along line 4-4 in Figure 2.

Referring to Figure 1 of the drawings showing the wet end of a paper making machine, which may be of the Fourdrinier or cylinder type, the machine comprises a nited States Patent ice ' main or primary headbox 10 of the gravity ow type,

a breast roll 11 disposed at the outlet of the headbox it),v a couch roll 12 spaced in the machine direction of the web from the breast roll 11, table rolls 13 between the breast roll 11 and the couch roll 12, and a forming wire 15- which travels from the breast roll 11 over the table rolls 13 to the couch roll 12 and returns to the breast roll'. The machine also includes a secondary headbox 16 which, as pointed out, embodies the features of the invention.

The primary headboxV 10 includes a collecting trough 17 for receiving liquid stock from a supply chest (not shown), and a distributing rollv 18 over which the stock passes in. its flow to a vertically adjustable slice 20. As the stock leaves the headbox 10 it ilows onto the Wire 15 and isV carried downstream along the machine. The wire 15, well known as the Fourdrinier wire, comprises an endless belt of woven wire on which the fibers in the liquid stock are felted upon filtration of the liquid through the wire mesh.

The table rolls 13` are disposed downstream of the breast roll 11v and transversely of the wire 15, the rolls being spaced longitudinally of the machine to maintain the wire in a horizontalplane. The couch roll 12 is located at the downstream end of the path of the wire 15 and is driven by suitable means to provide the drive for the wire. A series of guide rolls 21 serve to suitably support and tension the wire in its return to breast roll 11.

The machine further includes suction boxes 22 which are disposed at the downstream. end of the wire, in underlying relation to the wire 15. The suction boxes serve to assist in removing the water from the felted stock material. The usual dandy roll 23 is located, in the illustrated structure, downstream of the secondary headbox 16.

The foregoing description is directed to conventional parts of a paper making machine and is set forth to more clearly disclose the relationship of the secondary headbox ofthe invention to a paper making machine, and since the present invention is directed primarily toward a particular secondary headbox structure in the illustrated paper making machine, a more detailed description of the remainder of the paper making machine is believed unnecessary,- and the following description will be directed, therefore, to the secondary headbox 16 which is located downstream of the primary headbox.

Figures 2 to 4 show the details of the secondary headbox and, as illustrated, the secondary headbox 16 comprises a housing 25 disposed above and extending across the Width of the wire 15. The housing communicates with a closed conduit system 26 which conducts stock under pressure, as by means of a pump, from a stock chest or other supply source (not shown). The headbox further comprises an adjustable slice 20a for controlling the ilow of stock from the housing 25 onto the forming wire 15.

Considering the housing in detail, it includes a generally flat bottom plate 2S which extends in a plane parallel to the wire 15, and a pair of transversely spaced side plates 30 which extend vertically from the bottom plate. The housing further includes a curved top member 31 which connects to the side plates 30 and which extends transversely of the wire 15. The upstream end of the housing 25 is provided with a series of transversely spaced flanged necks 32 for connecting the housing 25 to the conduit system 26.

Disposed in the housing 25 are a pair of transversely extending, longitudinally spaced base plates 41 and 42 (Figure 4) which are located above but adjacent the bottom plate 28 of the housing. Intermediate the base plates 41 and 42 is a weir defining section 43 which extends vertically into the housing 25 and also extends transversely to the paper making machine. This section, in cross-section, is inverted U shape and may be formed from suitable steel plate material. The wcir defining section is supported in the housing 25 by a transversely extending channel member 45, the web of the channel member being attached to the up stream side of the weir defining section 43 and one fiange being connected to the up stream base plate 41.

In order to provide a fluid tight housing, a liner 46 is provided which extends from the flanged necks 32, over the base plate 41, around the channel member 45, and across the top of the weir defining section 43. The liner 46 curves away from the section 43 and tangentially contacts the downstream base plate 42, the liner following this plate 42 to the downstream edge.

A series of transversely spaced rods 47 join the Weir defining section 43 with the top structure 31 of the headbox 16, and each rod 47 is preferably adjustably and detachably connected by means including an internally threaded block 48 which is attached to the weir defining section and which receives the lower end of the rod 47, this end being suitably threaded as shown. The upper end of each rod 47 is also threaded and extends through the top structure 31 of the housing 25. The rods 47 are carried by nuts 50 which seat on brackets 51a, the brackets being mounted on the top structure.

In order to insure proper uniformity of stock and of distribution of the stock, we have provided a pair of distributing rolls 51 and 52 which are disposed on opposite sides of the weir defining section 43. The distributing roll S1 is preferably placed adjacent the top of the weir defining member 43 on the upstream side and the other roll 52 is placed adjacent to the slice 20a with a portion of its surface closely aligned with the curved portion of the liner 46 on the downstream side of the weir defining member. The distributing rolls are each carried on a shaft 55, the shaft being journalled in suitable bearings 56 (Figure 2) carried by the side plates 30. Each of the rolls 51 and 52 includes a perforated cylindrical shell 57 supported on the shaft 55 by means of a series of axially spaced discs 58.

It is important that the shell be perforated in order to have proper distribution of the stock and to assure proper functioning of the secondary headbox 16. In this connection, the perforations preferably comprise circular openings having a diameter between about V2 and about l inch, the openings comprising between about 50 percent and percent open area and being uniformly spaced.

The distributing rolls 51 and 52 are driven at such a rate as to further assure uniform laying of a web upon a preformed web. We have found that the rolls 51 and 52 should be driven at between about 6 and 12 revolutions per minute, the speed being proportioned to the wire speed. In order to rotate the rolls 51 and 52, as required, drive means 60 is provided for the rolls, the drive means comprising a chain and sprocket arrangement including sprockets 61 and 62 which are keyed to corresponding ends of each of the shafts 55 and connected by a chain 63. A variable speed motor` 65 may be provided to drive the rolls 51 and 52, the motor rotating one of the shafts 55 by means of a chain 66. It will be understood, of course, that a gear or other drive arrangement may be employed.

In order to provide access to the interior portion of the housing in order to permit cleaning of the rolls 51 and 52, etc., a section 67 of the housing 25 is hingedly supported by hinges 68. This section 67 is located adjacent the top of the housing and permits ready access to the interior portion.

For smooth ow of the stock onto the preformed web, we have found it necessary to vent the housing 25 and for this purpose a series of vents 69 communicate with the housing 25 at points transversely of the housing. We have found, however, that in order to secure proper fiow control of the stock onto the preformed web by the secondary headbox, the headbox should not be ventilated freely, and therefore, vent control valves 70 are provided for limiting the degree of ventililation. As shown in the drawings, the vents 69 communicate with the atmosphere but it will be understood that these may connect to pipe lines or discharge into troughs for the purpose of disposing of any overflow.

The forward portion of the housing 25 carries the slice 20a, the slice comprising a vertical plate 71 which extends transversely along the upstream side of the housing. The plate 71 is vertically adjustable and carries a nozzle blade 72 along its lower edge, the nozzle blade 72 being connected by hinges 73 and also being adjustable. The vertical plate 71 is carried on a structure 74 mounted on the housing 25 and vertical adjustment of the plate 71 is effected by adjusting means 73a which is mounted on the structure 74.

The adjusting means comprises a pair of gear housings 74a which are supported upon the structure 74 by brackets 75. Each housing 74a journalsa gear 75 which is rotated by a worm 77 carried on a transversely extending shaft 78. The shaft is turned by a manually adjustable wheel 79. rThe gears 75, which are actuated by the worm 77, threadedly .engage rods 80 at their upper end and these rods'80 carry the vertically adjustable plate 71. Thus, by adjustment of the wheel 79 the plate 71 may be adjusted vertically as desired.

As was pointed out above, the `nozzle blade 7,2 is hingedly supported upon the lower end of the vertically adjustable plate 71 and is adjustable. The upstream end of the nozzle blade 72 may be adjusted by vertical positioning of the plate 71 while the downstream end may be adjusted by a blade adjusting means 81 which permits both coarse and fine adjustment of the nozzle blade in order to assure proper flowing of stock onto the initially formed web.

The blade adjusting means 81 is connected to the blade 72 by meansV of rods 82 which are connected, at their lower end, adjacent the downstream end of the blade 72 by means of brackets 82a. The rods 82 are adjustably lengthened or shortened, as desired. by means of adjusting screws 83 which make possible fine adjustment of the nozzle blade 72. At their upper end, the rods 82 are connected to lugs 84 carried on a rotatable beam 85.

In addition to the rods 82 and rotatable beam 85, the

l blade -adjusting means 81 includes a worm wheel 86 which is keyed to the rotatable beam 85 and which is driven by a worm gear 87, the worm gear being controlled by a hand wheel 88. For convenience of adjustment, a stationary indicator plate 89 may be used and a pointer 90 keyed to the rotatable beam so that the desired posi- 4tion of the nozzle blade may be rapidly adjusted.

The rotatable beam is journalled in brackets 91 carried on the housing 25, the brackets being bolted to the housing by means of bolts 92 which extend through slots (not shown) in the vertically adjustable plate 71.

It will be seen from the foregoing that the nozzle blade 72 may be adjusted by raising or lowering the adjustable plate 71 or byV adjustment of the blade adjusting means 81. It will be apparent that the nozzle blade may likewise be adjusted by control of both the plate 71 and adjusting means 81. This multiple adjustment of the blade is quite important in order to assure proper felting of the second web to the'initially'formed web.

The wide range of adjustment of the nozzle blade 72 is illustrated by the blade shown in dotted outline at 93 in Figure 4.at an extreme position. I

The nozzle blade 72 coacts with a lower nozzle blade 94' which is longitudinally adjustable so as to permit proper laying of a secondary web upon an initially formed web. The' lower nozzle blade is slidably carried between the bottom'plate 28 of the housing 25 and the upstream greased base plate 42. For purposes of adjusting the position of the lower nozzle blade 94, racks 95 are carried on the rearward end of the blade, the racks engaging pinions 96 which are keyed to a transversely extending shaft 97 located in the weir defining member 43. The position of the shaft 97, and consequently the lower nozzle blade 94, is controlled by a segmental gear 98 Figure 3) which is keyed to the shaft and which is driven by a worm 99. The worm may be rotated by a crank (not shown).

As before pointed out, the housing connects to a closed conduit system 26 through flanged necks 32. It is important that the stock be uniformly supplied to the housing in order to assure proper forming of the secondary web. For this purpose, we have employed six necks of oval shape across a housing having a transverse length of 157 inches, each neck measuring! 5 inches along the minor axis and measuring 15 inches along the major axis.

The flanged necks 32 connect to flanged sections 100 through valve sections 103. The valve sectionsV 103 have butterfly valves 105 (Figures 3 and 4) disposed therein. These valves are connected by a linkage 107 to a lever 109 which may be adjusted to position the valves 105 at any desired position. it will be noted that these valves are located aw-ay from the opening into the main portion of the housing 25.

The fianged sections 100 communicate with a manifold H1 which is supplied by a feed conduit 113 located centrally of the manifold 111. It is important that the manifold be proportioned so that the pressure of the stock to each neck 32 is approximately equal and, for this purpose, the manifold converges toward opposite ends. in this connection, the diameter of the manifold has a diameter at lthe center of 14 inches and converges down to a diameter of inches at the ends.

As has been pointed out, the structure of the invention is particularly adapted for laying fibers onto an initially formed web and provides a sheet having two webs integrally bonded together. This is made possible through the particular arrangement of the structural elements of the headbox and through control of these elements. The coacting relation of the perforated rolls 51 and 52 in their particular relation in the headbox with the weir defining member 43 and with the adjustable nozzle blades 72 and 94 permits effective laying of a web onto an initially formed web.

ln operation of the secondary headbox, stock is supplied to the feed conduit 113 which discharges into the manifold 111. The stock enters the housing 25 through the butterliy valves 105. In the housing, the stock passes through the roll 51 and over the weir defining member 43. The second distributing roll 52 then acts upon the stock which is discharged between the nozzle blades 72 and 94 onto the forming wire 15.

The position of the butterfly valve 105 is adjusted and the speed of rotation of the rolls 51 and 52 are varied to `accommodate the headbox for different wire speeds and pressures in the feed conduit 113. Similarly, the weir forming member 43 and nozzle blades 72 and 94 are adjusted to properly lay a second web onto an initially formed web.

The various features of the invention which are believed to be new are set forth in the following claims.

We claim:

l. A secondary headbox for a paper making machine comprising, in combination, a base plate, a pressure tight housing on said base plate which extends transversely to the machine, said housing being generally semi-cylindrical in cross-section and opening downwardly, means for supplying stock at a uniform pressure across the upstream end of said housing, valve means in said supply means for controlling the supply of stock to said housing, a transversely extending, generally inverted U shaped weir defining member which extends into said housing and which is disposed intermediate the upstream and downstream end of said housing so as to define a generally semi-circular path for said stock, a pair of 4distributing rolls supported in said housing, said distributing rolls being disposed on opposite sides` of said weir defining member and extending transversely to the machine, the upstream roll being disposed adjacent the top of said weir defining member and Ithe downstream roll being located adjacent the bottom of said weir defining member, said distributing rolls being perforated so as to have uniform openings which comprise from 50 to 20 percent of the surface area of said rolls, and means for rotating said rolls.

2. A secondary headbox for a paper making machine comprising, in combination, a base plate, a housing on said base plate which. extends transversely to the machine, means for supplying stock horizontally to the upstream end of said housing, an adjustable, transversely extending nozzle blade hingedly attached to the downstream end of said housing and extending downstream from said housing, means for vertically adjusting the upstream end of said blade and means for adjusting the downstream end of said blade whereby said blade may be adjusted relative tov the fiow of stock from said housing, a second cooperating nozzle blade carried on said base plate below said adjustable nozzle blade, said second nozzle blade extending generally horizontally, means for moving said second nozzle blade in an upstream direction forwardly of the upstream end of said adjustable nozzle blade and in a downstream direction rearwardly of the upstream end of said adjustable nozzle blade, a transversely extending, generally inverted U-shaped weir defining member which is disposed in said housing intermediate the upstream and downstream ends of said housing, a pair of distributing rolls supported in said housing, said distributing rolls being disposed on opposite sides of said weir defining member and extending transversely to fthe machine, the upstream roll being disposed adjacent the top of said Weir defining member and the downstream roll being located adjacent the bottom of said weir defining member, a liner extending tangentially to said upstream roll, over :the top of said weir defining member and below said downstream roll to a point on said base plate downstream of said downstream roll, said distributing rolls being perforated so as to have uniform openings which comprise from 50 to 20 percent of the surface area of said rolls, and means for rotating said rolls.

3. A secondary headbox for a paper making machine comprising, in combination, a base plate which extends generally horizontally, a generaly semi-cylindrical, transversely extending housing on said base plate, a plurality of supply conduits connected to the upstream end of said housing, a manifold which communicates with said supply conduits and which is proportioned to supply stock to said supply conduits at a uniform pressure, valve means in said supply conduits for controlling the rate of flow of stock to said housing, a -transversely extending, substantially inverted U shaped weir defining member which is disposed intermediate the upstream end and downstream end of said housing to define a substantially semi-circular path for the stock, means for vertically adjusting said weir defining member, a pair of perforated distributing rolls disposed on opposite sides of said weir defining member, the upstream roll being disposed adjacent the top of said member and the downstream roll being located adjacent the bottom of said member, a liner extending tangentially to said upstream roll, over the top of said Weir defining member and below said downstream roll to a point on said base plate downstream of said downstream roll, an adjustable transversely extending nozzle blade hingedly attached to the downstream end of said housing and extending downstream from said housing, means for ver-tically adjusting the upstream end of said blade and means for adjusting the downstream end of said blade whereby said blade may be adjusted relative to the flow of stock from said housing, a second cooperating nozzle blade carried on said base plate below said adjustable nozzle blade, means for moving said second nozzle blade in an upstream direction forwardly of the upstream end of said adjustable nozzle blade and in a downstream direction rearwardly of the upstream end of said adjustable nozzle blade, a transversely/*extending Weir defining member which is disposed in said housing intermediate the upstream and downstream ends of said housing, a pair of distributing rolls supported in said housing, said distributing rolls being disposed on opposite sides of said weildefining member and extending transversely to the machine, said distributing rolls being perforated so as to have uniform openings which comprise from 50 to 20 percent of the surface area of said rolls, and means for rotating said rolls.

References Cited in the le of this patent UNITED STATES PATENTS 8 2,203,802 Thaler June 11, 1940. 2,225,435 Kellet Dec. 17, 1940 2,286,942. Y Tuten June 16, 1942 2,325,016 Warren July 20, 1943 2,329,799 Thorsen Sept. 21, 1943 2,381,286 Hornbostel et al. Aug. 7, 1945 2,384,912 Helin Sept. 18, 1945 2,521,261 Smith et al. Sept. 5, 1950 2,677,316 Heys May 4, 1954 FOREIGN PATENTS 1,078 Great Britain of 1895 758,709 France Jan. 22, 1934 OTHER REFERENCES McNaughton: Paper Trade I., December 26, 1940, pp. 30-33.

Tennent: Paper Ind. and Paper World, December 1945, pp. 1357 and 1358.

Fraser: Pulp & Pulp Mag. of Canada, March 1948, p. 74.

Images