US3649448A

US3649448A - Paper machine headbox with adjustable partitions therein to regulate stock flow

Info

Publication number: US3649448A
Application number: US889039A
Authority: US
Inventors: Tadashi Kobayashi
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-12-30
Filing date: 1969-12-30
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14

Abstract

A headbox with first and second partitions therein which are adjustable with respect to one another and the headbox to define a feed chamber, a holding chamber, and an outflow chamber, and which the function to regulate the rate at which stock flows from the slice. The partitions are moved by rack and pinions located externally of the headbox, the first partition pivoting around its upper end and the second partition pivoting at a point intermediate its ends. Perforated rolls are located in the feed chamber and outflow chamber to facilitate the entwining of stock fibers.

Description

March 14, 1972 TADASH; KOBAYA5H| 3,649,448

HWI-R MACHINE HEADBOX WITH ADJUSTABLE IAV'TITIONS 'FHEHEN 'VO REGUT'ATV. STOCK FLOW Z Sheets-Sheet Filed Dec. 30, 1969 Inllmwmll.. 1 l l l ||...1.---............-------- THD/91m ATTORNEY March 14, 1972 TADASHI KOBAYASHI 3,649,448

IHM( MACHLNL HUADBOX WITH ADJUSTABLE IARTITINS 'VHERETN TO REGULATE STOCK FLOW Film1 Dec. 160, ,1%0 3 Sheets-Sheet 2 FiQZ Fg ATTORNEY March 14, 1972 TADAsl-u KOBAYASHI 3,649,448

APEJR MACHINE HEADBOX WITH ADJUSTABLE PARTITIONS THEREIN TO REGULATE STOCK FLOW Flled Deo. 30, v19659 5 Sheets-Sheet 5 Fig4 ENTOR ATTORNEY 3,649,448 PAPER MACHINE HEADBOX WITH ADJUSTABLE gTITIONS THEREIN TO REGULATE STOCK W Tadashi Kobayashi, 227 Mitoshima, Fuji-shi, Shzuoka-ken, Tokyo, Japan Filed Dec. 30, 1969, Ser. No. 889,039 Int. Cl. D21f I/02 U.S. Cl. 162-343 5 Claims ABSTRACT OF THE DISCLOSURE A headbox with rst and second partitions therein which are adjustable with respect to one another and the headbox to dene a feed chamber, a holding chamber, and an outflow chamber, and which function to regulate the rate at which stock flows from the slice. The partitions are moved by rack and pinions located externally of the headbox, the first partition pivoting around its upper end and the second partition pivoting at a point intermediate its ends. Perforated rolls are located in the feed chamber and outtiow chamber to facilitate the entwining of stock fibers.

BACKGROUND OF THE 'INVENTION This invention relates to a headbox used to supply paper stock onto a Wire or a screen in a papermaking machine.

Generally, paper of best texture can be obtained when stock fibers are allowed to settle by gravity naturally and uniformly in all horizontal directions as it is dewatered on the wire. This happens only when the running speed of the wire is in agreement with the speed of stock flowing out of the slice. Especially, when the stock flow speed is higher than the Wire speed, stock fibers tend to stand up in relation to the surface of the wire, thus unfavorably affecting the structure of the paper layer.

Since the stock flow speed depends on the head of the stock in the headbox, it is essential that the stock maintain the head corresponding to the wire speed so that there is a more nearly random orientation of the fibres of the paper.

The desired stock ow from the headbox depends on the consistency of the stock. If the heaviness of the paper is to be constant, the stock ow from the slice must be greater when the stock consistency is lower, and vice versa. Consequently, the desired sectional area of the stock ow is dependent on the stock consistency. In other words, if the width of the wire in the transverse direction (or the direction of the paper width) is constant, the lvertical dimension of the slice should be larger when the stock consistency is low, and vice versa. Moreover, whether the slice is wide or narrow vertically, the stock must maintain the head corresponding to the wire speed.

OBJECT OF THE INVENTION Thus, the present invention contemplates arrangements to produce paper of particular weights and excellent quality by enabling one to vary the stock head in the head-box promptly, as desired, in accordance with wire speed changes so that the stock ow speed will agree with the wire speed; and also enabling one to vary the stock head in the headboX promptly, as desired, in accordance with slice opening changes due to stock consistency changes, so that the stock flow speed will agree with the wire speed, thus making it possible to produce good paper.

ted States Patent O 3,649,448 Patented Max'. 14, 1972 Fice SUMMARY OF THE INVENTION .To achieve the foregoing object, generally speaking, the present invention contemplates a headbox which is divided into three chambers, namely, a stock outflow chamber having a slice through which stock hows out, a holding chamber in which stock to be supplied to the outow chamber is held temporarily, and a feed chamber which has a stock inlet and which supplies stock to the holding chamber. The outflow chamber and holding chamber are separated from each other by a rst partition which enables one to adjust the stock flow from the holding chamber to the outflow chamber. The holding chamber and the feed chamber are separated from each other by a second partition which enables one to adjust the stock llow from the feed chamber to the holding chamber. By adjusting the openings of each of these partitions, it is possible to vary the stock head as desired in response to wire speed changes and stock consistency changes.

Other objects and advantages of the invention will be more readily apparent from the following detailed description, when taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. l is a vertical section of a headboX according to the invention;

FIG. 2 is a diagrammatic vertical section of the headbox with the stock head adjusted to meet an increase in wire speed;

FIG. 3 is a diagrammatic vertical section of the headbox with the stock head adjusted to meet a decrease in wire speed;

FIG. 4 is a diagrammatic vertical section of the head- Ibox with the stock head adjusted to meet an increase in stock consistency; and,

FIG. 5 is a diagrammatic vertical section of the headbox with the stock head adjusted to meet a decrease in stock consistency.

DETAILED DESCRIPTION A box 1, constituting the main body of a headbox according to the present invention, is divided into three chambers; namely, a stock outflow chamber A, a stock holding chamber B adjacent thereto, and a stock feed chamber C located above these chambers. The outow chamber A has a slice 2 through which stock flow out. The holding chamber B is adjacent to the outflow chamber A and separated therefrom by a partition a which permits a controlled stock ow from the holding chamber B to the outow chamber A. The feed chamber C, having a stock inlet 3 through which stock is introduced from an outside source, is so located as to feed the holding chamber B chiefly by gravity and separated therefrom by a partition b which permits of a controlled stock flow from the feed chamber C to the holding chamber B. The partition a has a pivot 5 at the top and can be turned right and left so that its lower end 4. will control the stock ow from the holding chamber B to the outflow chamber A. The partition b is held like a lever on a fulcrum 7 and can be turned right and left so that its lower end 6 will control the stock ow from the feed chamber C to the holding chamber B. Stock introduced through the stock inlet 3 enters the feed chamber C, passes a flow clearance T which can be adjusted by the partition b, flows into the holding chamber B, then passes a flow clearance S which can be adjusted by the partition a, and enters the outow box A. By adjusting the partitions a and b, therefore, it is possible to vary the stock head H as desired in accordance with the wire speed P, namely, so that the speed 3 of stock flowing out of a slice 2 when its vertical dimension is W will agree with the wire speed P.

Thus, the partition b is equipped at the top with a rack 8 and a pinion 9 by which the partition b can be controlled from outside the box 1. A similar means including rack S and pinion 9' and 5 enables one to control the partition a from outside the box 1. The outfiow chamber A and the holding chamber B have transparent graduated guage pipes 10 and 11 shown on FIG. l only, so that the stock head in each chamber can be seen from the outside, and thus the heads may be adjusted either manually or automatically.

The partition a is arcuate at the lower end 4, and runs smoothly and straightly therefrom to the pivot 5. A pin 4" and guide slot 4 may be provided to insure straight movement as is conventional. The partition b is arcuate at the lower end 6, and runs smoothly and straightly upward therefrom including the part around the fulcrum 7. The box 1 also contains

perforated rolls

12 and 13 installed behnd the slice 2 and above the stock inlet 3, respectively, to facilitate the entwinin'g of stock fibers, and an agitating roll 14 installed in an upper part of the outow chamber to prevent stock masses from forming. These are means facilitating a random arrangement of :fibres in the suspension. The slice 2 is nozzle-shaped, and its upper lip 2' is attached to the box 1 'via a pivot 15 and can be controlled by a rod 16 to vary the opening of the slice 2. Rod 16 may be moved by any conventional means 21 such as a piston-cylinder, rack and pinion, or the like.

The means of adjustment according to the present invention, are more particularly described by the following examples.

Example l When the wire speed P has increased or is desired to be increased While the stock consistency is to be kept constant, the stock head H can be increased to H accordingly by the following procedure: As shown in FIG. 2, widening the liow clearances S and T increases the stock flow into the holding chamber B and into the outiiow chamber A, respectively, resulting in an increase in stock head H. As soon as the head reaches the level H required for the increased wire speed P', the tiow clearances S and T :are reduced so that the inflow through them, will again equal the outflow through the vertical dimension W of the slice 2. Thus, with the stock head maintained at a higher level H', the stock will flow out of the slice 2 at the sarne speed as the increased lWire speed P'.

Example 2 When the vmre speed P has decreased or is desired to be decreased while the stock consistency is to be kept constant, the 'stock head I-I can be decreased accordingly by the following procedure: As shown in FIG. 3, reduce the ow clearance T and make it narrower than the flow clearance S and the vertical dimension W of the slice 2. This decreases the stock flow into the outflow chamber A and into the holding chamber B, resulting in a decrease in stock head H. As soon as the head reaches the level H" corresponding to the decreased wire speed P", Widen the flow clearance T so that the iiow through it will equal that through the flow clearance S and the vertical dimension W. Thus, with the stock head maintained at H", the stock will flow out of the slice 2 at the same speed as the decreased wire speed P".

Example 3 When the stock consistency has been reduced while the Wire speed P and the stock head H are to be kept constant, that is, when the vertical dimension of the slice 2 has lbeen increased from W to W', as 'shown in FIG. 4, Widen the flow clearance S to S', so that it will equal the increased vertical dimension W. This causes the stock head H to go down temporarily. Then increase the tiow clearance T and make it wider than the iiow clearance S and the vertical dimension W. This makes the stock low from the feed chamber `C to the vholding chamber B greater than the flow that goes out of the outflow chamber A, with the result that the stock head goes up again. As soon as the head reaches H, make the flow clearances T and S equal to that of the vertical dimension W'. Thus, with the stock head maintained at H, the stock will flow out of the slice 2 with the increased vertical dimension W' at the same speed as the wire speed P.

Example 4 When the stock consistency has been increased while the wire speed P and the stock head H are to be kept constant, that is, when the vertical dimension of the slice 2 has been reduced from W to W, as shown in FIG. 5, the stock head would go up if the headbox were kept in this condition. Therefore, reduce the flow clearance T and make it less than that of the vertical dimension W. This reduces the stock ow into the holding chamber B and into the outflow chamber A, resulting in a decrease in stock head. As soon as the stock head reaches H, bring the ow clearance from T to T and make it equal that of the vertical clearance W. Thus, with the stock head maintained at H, the stock will flow out of the slice 2 with the reduced vertical dimension W" at the same speed as the wire speed P.

In each of the above Examples l through 4, the flow of stock supplied from the stock inlet 3 is constant at all times. This need not always be the case, but is the usual case.

ln the present invention as described above, coordinated adjustment of the two partitions provided in the box makes it possible immediately to cause stock to ow out of the slice at the same speed as the Wire speed whenever a change has occurred in wire speed or a new wire speed has been used during a papermaking run; and when the opening of the stock feeding slice has been varied in accordance with the stock consistency, it is possible to adjust the stock flow in accordance with the slice opening so that the speed of stock from the slice will equal the wire speed, thus ensuring the production of highquality paper. Moreover, wire speed is simply related to the various spacings which are also simply related to each other. This facilitates adjustments.

It is to be observed therefore that the present invention provides for a headbox which comprises a vertical elongated box 1. There is a stock inlet 3 toward the upper portion of box 11 with a feed chamber (C) in said box including a trough 19 disposed over the stock inlet, receiving stock from said stock inlet, and a curved wall 20 with a lower outer end, guiding stock flowing upwards through said trough over said curved wall and into the lower portion of the feed chamber (A). There is a driven perforated roll 13 in the trough to entwine stock libres passing therethrough. In the feed chamber is located a first partition b with upper and lower ends, and a fulcrum 7 intermediate said ends, substantially vertically disposed for movement about said fulcrum 7, including a rack and pinion l8, 9 exterior to said first partition upper end for moving said partition. Below the feed chamber is located a holding chamber (B) with a curved flow clearance at the lower end thereof. A second partition a defines on one portion the holding chamber, and on the other portion the feed chamber, and a flow clearance between said iirst and second partitions, said second partition being substantially vertically disposed, pivoted at its upper end to said curved wall outer end, said lower end extending into said flow clearance and having an arcuate curvature matching that of said flow clearance, the pivoting of said first and second partitions regulating the passage of stock. Adjacent said holding chamber (B) is an exit chamber in said box lower section, including a slice 2 at the lower end thereof for disgorging stock onto paper forming means. A third partition 17, defines the outer wall of the holding chamber from the inner wall of the exit chamber, said third partition 17 being substantially vertically disposed. A slice upper lip 2 connected at its inner end to said third partition, e.g., by means of a pivot including a rod 16 extending outwards of said box, said rod serving to adjust the position of said slice upper lip 2 to vary the size of said slice opening. There is a driven lower perforated roll 12, in said exit chamber lower end, for entwining stock ibers; and, an upper driven agitator 14, in the upper part of said exit chamber, for breaking up aggregations of bers.

Although the present invention has been described in conjunction with an embodiment suggesting manual adjustment, the various adjustments necessary because of the liquid levels, Wire speed, etc. may be measured automatically, eg., by a light beam and photocell. These components can in turn adjust a cam which can act on the other components herein described.

What is claimed is:

1. In a paperrnaking machine, a headbox, said headbox having walls and 'being divided into a stock outilow chamber having a slice 'for feeding stock, a holding chamber communicating with said outflow chamber in which stock to be supplied to said outflow chamber is temporarily held, and a feed chamber communicating with said holding chamber equipped with a stock inlet for introducing stock from an outside source to the top portion of said headbox, said outiow chamber and holding chamber being separated from each other -by first rigid partition means capable of controlling the stock flow from the holding chamber to the outflow chamber, means for moving said rst partition means with respect to one of said headbox walls to adjust the space between the same to control stock flow therebetween, said rst partition means being pivoted at its upper end to said headbox, and the said holding chamber and feed chamber being separated from each other by second rigid partition means capable of controlling the stock flow from the feed chamber to the holding chamber, means for moving said second partition means -with respect to said iirst partition means to adjust the space between the same to control stock flow therebetween, said second partition means being pivoted intermediate its ends to said headbox, and the means for moving said second partition means causing the same to rotate about its pivot, the stock flow being adjusted so that the stock head will be set in accordance with changes in wire speed and in stock consistency.

2. In a paper making machine according to claim 1, wherein said means ifor moving said iirst and second partitions includes rack and pinion means external to said headbox mechanically connected to said first and second partitions.

3. A headbox, comprising in combination:

(a) a vertically elongated box (1);

(b) a stock inlet (3) opening into the upper portion of the box;

(c) a feed chamber (C) in said box including a trough connected to said stock inlet, receiving stock from said stock inlet, and a wall guiding stock flowing upwards through said trough into a lower section of said feed chamber (C);

(d) a rst partition (b) in said feed chamber, substantially vertically disposed for movement therein, including a rack and pinion (8, 9) exterior t0 said first partition connected to the upper end of said partition for moving said partition;

(e) a holding chamber (B) adjacent and below said feed chamber (C) with a lower flow clearance at the lower end thereof;

(f) a second partition (a) defining on its lower portion said holding chamber, and on the upper portion said feed chamber, and an upper flow clearance between said lirst and second partitions, said second partition being substantially vertically disposed, pivoted at its upper end to said box, said lower end extending into said lower flow clearance and being shaped to match said lower low clearance, the pivoting of said tirst and second partitions regulating the passage of stock;

(g) an outllow chamber (A), adjacent said holding chamber (B) in the lower portion of the box, including a slice (2) at the lower end thereof for disgorging stock onto paper forming means;

(h) a third partition (17), defining the outer wall of said holding chamber, said third partition (17) being substantially vertically disposed; and

(i) a slice upper lip (2) connected at its inner end to said third partition including adjusting means (16) extending out-wards of said box, actuating means for moving said adjusting means serving to adjust the position of said slice upper lip (2) to vary the size of said slice opening.

4. A headbox as claimed in claim 3, said third partition 17 having a pivot (15) at its lower end, said slice upper lip (2') being pivoted thereto, said adjusting means being a rod (16).

5. A headbox as claimed in claim 3, said trough being disposed over said stock inlet.

References Cited UNITED STATES PATENTS 3,236,725 2/1966 Goldsmith i 162--336 3,135,654 6/1964 Fair 162-336 3,164,513 l/1965 Calehuf 162-336 X FRANK W. MIGA, Primary Examiner R. H. TUSHIN, Assistant Examiner U.S. Cl. X.R. 162-336