US1969546A - Method and apparatus for showing uniformity of sheet formation in paper making machines - Google Patents

Description

1934- A. E. BROUGHTON 1,969,546

METHOD AND APPARATUS FOR SHOWING UNIFORMITY OF SHEET FORMATION IN PAPER MAKING MACHINES 5 Sheets-Sheet 1 Filed Dec. 26, 1933 IN V N TOIF. fl/fTl/U/i 5/700 GHTUN,

Au 7, 1934. A. E. BROUGHTON 1,969,546

METHOD AND APPARATUS FOR SHOWING UNI'FORMITY 0F SHEET FORMATION IN PAPER MAKING MACHINES Filed Dec. 26, 1953 3 Sheets-Sheet .2

Aug, 7, 1934. A. E. BROUGHTON METHOD AND APPARATUS FOR SHOWING UNIFORMITY OF SHEET FORMATION IN PAPER MAKING MACHINES Filed Dec. 26, 1933 3 Sheet-Sheet 5 IW/UQW/ZOT' wwfi w? fly 7065A Ziorrzegs Patented Aug. 7, 1934 PATENT OFFICE METHOD AND APPARATUS FOR SHOWING UNIFORMITY or SHEET FORMATION m PAPER MAKING MACHINES Arthur E. Broughton, Wisconsin Rapids, Wis.

Application December 26, 1933, Serial No. 703,939

13 Claims.

This invention relates to paper making machines and to methods and apparatus for determining the uniformity of sheet formation in such machines.

It is one of the general objects of the invention to provide a novel method for determining at all times whether a paper making machine is operating to produce uniform sheet formation or not.

Another object is to provide a novel apparatus for visually indicating to the paper making machine operator whether or not the machine is operating to produce uniform sheet formation.

The objects and advantages of the present invention will more fully appear from the following description, made in connection with the accompanying drawings, wherein one apparatus for carrying out my novel methods is illustrated and wherein like reference characters refer to the same or similar parts throughout the various views and, in which,

Fig. 1 is a view diagrammatically illustrating an apparatus embodying the invention operatively applied to certain portions of a paper making machine, the parts of the paper making machine being shown chiefly in side elevation;

Fig. 2 is a vertical section taken on the line 22 of Fig. 1, as indicated by the arrows;

Fig. 3 is a view in enlarged scale showing the main portion of the indicator;

Fig. 4 is a vertical section taken on the line 44 of Fig. 3; and

Fig. 5 is a view taken chiefly in vertical transverse section through the major part of one control mechanism, the view, being in enlarged scale.

Referring to the drawings, there are more or less diagrammatically illustrated certain parts of a paper making machine of standard construction. The first floor of a paper mill is designated by the numeral 5, while the basement floor is designated by the numeral 6. The Fourdrinier wire upon which the mat of paper is formed at the wet end of the paper making machine is designated by the numeral 7 and this wire runs over travels is shown as being connected by a flexible connection 15 to a four-way fitting 16 which I prefer to substitute for the usual T found in a paper making machine of usual construction. The water drawn from the paper web A, as it is carried over the fiat boxes 8 by the wire 7, is separated from the air drawn from the various fiat boxes in the various four-way fittings 16 and the water from each flat box runs downwardly from the fitting 16 connected thereto into a seal box 17 through a water leg or pipe 18 connected at its upper end to'the lower connection of the particular fitting 16. The water legs running downwardly from the fittings 16 connected to the first two fiat boxes 8 are preferably vertical pipes, in order that as the water passes down through these pipes, considerable suction will be created to assist in maintaining or to maintain without assistance the necessary vacuum in the first two flat boxes. The seal box 17 is provided with a weir 19 which empties into a tank 20 located usually on the basement floor 6. Air legs or pipes 21 are connected to the upper connections of the four-way fittings 16 and these air legs run upwardly therefrom to carry off the air separated from the water in the four-way fittings 16.

A conduit 22 runs from the couch roll 10 to the intake side of a couch pump and this couch pump is provided with an outlet 24 which in the illustrated embodiment is shown as draining into the seal box 17. It is the usual practice to have the outlet 24 from the couch pump drain directly into the tank 20 and this may be done in the present instance, although the drain 24 is shown as emptying into the seal box 17 for a purpose presently to appear.

In order to automatically accurately maintain uniformity of vacuum pressure on the fiat boxes 8, I utilize, with the fiat boxes, vacuum control mechanism embodying my invention entitled Vacuum control mechanism disclosed and claimed in United States application for patent Serial Number 687,139, filed August 28, 1933. Inasmuch as the said vacuum control mechanism is fully described in said above referred to appli cation for patent, it need only be briefly described here. There is provided a manifold 25 located well above the fiat boxes 8 and this manifold is connected by a pipe 26 to the conduit 22 running to couch pump 23. The air legs 21 are connected at their upper ends to valves 27 which are, in turn, connected to the manifold '25. Castings 28 are secured to the valves 27 and these castings support cylinders 29. The cylinders 29 are open at their lower ends and closed at their upper ends and mounted within each cylinder is a. piston 30 having a central aperture 30b through which loosely projects a sleeve 31. This sleeve is provided with an external flange 31a which cooperates with a downwardly extending ridge 300 on the piston 30 adjacent the aperture 3017 as do a valve member and a valve seat. Having screw threaded connection with the lower end of the sleeve 31 is a stud 32 connected as by a pin 33 to the upper end of the valve stem 270 of the adjacent valve 27. Guiding the stud 32 for movement to and from the valve 27 and preventing rotation of the stud are pins 34 which are mounted in the lower end of the stud and are received for sliding movement within pin openings in the casting 28 through which the valve stem 27c projects. A relatively heavy coiled compression spring 35 is disposed within the cylinder 29 and bears at one end against the closed end of the cylinder and at its other end against the piston 30. A collar 36 surrounds the sleeve 31 near the upper end of the sleeve and is held from removal 01f this end of the sleeve by means of a pin 37. A relatively light coiled spring 38 encircles the upper portion of the sleeve 31 and bears at one end against the collar 36 and at its other end against the piston 30. Each cylinder 29 has connected thereto between its closed end and the piston 30, a pressure equalizing pipe39 which runs downwardly from the cylinder and is connected to the fore-way fitting 16 for the fiat box 8 in connection with which the cylinder 29 is used. A'

pressure gauge 40 is preferably connected to the closed end of each cylinder 29.

' Each vacuum control mechanism just described aets automatically to maintain a sub-. stantially constant vacuum in the fiat box 8 in connection with which it is used when the paper making machine is in operation. Assuming that the proper vacuum is provided in a fiat box 8, when the valve 27 is partly opened, the parts of the control mechanism will assume approximately the position shown in Fig. 5. The pressure equalizing pipe 39, afiording communication between the four-way fitting l6 and the cylinder 29, will cause the air pressure in the cylinder to be the same as in the-flat box and the spring 38 will hold the flange 31a in tight engagement with the ridge 300, so as to maintain the opening 30b in the piston 30 closed. Of course, the position of the valve 27 determines whether or not the couch pump 36 will assist in maintaining the vacuum in the flat box. If for any reason the vacuum in the fiat box 8 is increased beyond the requisite degree, i. e. the pressure in the flat box is reduced, the pressure in the cylinder 29 will be correspondingly reduced and the piston 30 will raise against the tension of spring 35. As this occurs, the spring 38 which bears against the piston 30 will cause the sleeve 31 and the valve stem 270 to raise until the valve 27 is closed and, of course, as the valve closes, the suction on the flat box will be decreased. If the vacuum still remains too great after the valve 27 has closed, naturally the piston 30 will continue to raise against the pressure of the spring 38, thereby causing the piston to draw away from the flange 31a of the sleeve 31 to permit air to rush into the cylinder 29 through the opening 301) and break the vacuum in the 'flat box. Atmospheric air rushing int-o the cylinder 29 will then permit the spring 35 to again move the piston 30 downwardly until ridge 300 seats with the flange 31a of the sleeve, whereupon no further air can be admitted through the aperture 30b into the cylinder and.

the correct vacuum in the Hat box will be restored either through opening of the valve 27 or by vacuum created by the passage of water through the water leg 18 connected to the flat box. If for any reason the vacuum in the flat box 8 should fall beyond the level for which the control mechanism is .set, i. e. the pressure in the flat box should increase, then the pressure in the cylinder 29 will similarly increase and the spring 35 will force the piston 30 downwardly to push the sleeve 31 and valve stem 27c downwardly to open valve 27 farther, so that the couch pump 23 may draw greater quantities of air from the leg 21. The vacuum in the flat box accordingly is automatically controlled irrespective of outside fac tors that may tend to change the vacuum in the fiat box. Adjustment "of the control mechanism to maintain any desired vacuum in the fiat box can be made by merely screwing the sleeve 31 upwardly or downwardly farther on the stud 32.

As the control mechanism, briefly above described and forming the subject matter of my previously identified pending application for patent, maintains a substantially constant vacuum pressure on each fiat box to which the control, mechanism is applied, if the sheet of paper being made by the paper making machine is being uniformly formed, there will be uniformity in the rate of water flow from the various water legs 18 and from the couch pump 23. In other words, if there is uniformity of sheet formation in the machine and uniformity of vacuum pressure on the various flat boxes, water from the paper mat running over the flat boxes is withdrawn by each fiat box in uniform quantity at a uniform rate of speed and is discharged in uniform quantity and speed during a given period of time from the water legs 18 into the seal box 17. Similarly, there should be uniformity in the discharge of water from the couch pump 23. Further as water drains constantly from the weir 19 of seal box 17, the water level in the seal box 17 into which the water legs 18 from the fiat boxes empty and into which the outlet 24 from the couch pump 23 empties in the illustrated embodiment, will be maintained the same providing that the sheet is being uniformly formed by the machine. If, however, for any reason, the sheet being formed should become too free so that the fibers of the pulp do not mat properly on the wire 7, or if the sheet should become too slow by reason of the closer matting of the fibers of the pulp on the wire, or if the sheet should become too light or too heavy from the desired Weight basis, or if any other variance from normal in the sheet formation should take place, this will be reflected in the level of water.

in the seal box 17 by reason of the fact that as the sheet becomes freer or slower or lighter or heavier or otherwise varies from normal, greater or lesser quantities of water will be discharged into the seal box 17 from each water leg 18 and from the outlet 240i the couch pump 23. It is of.

great importance that any variation in sheet formation be immediately known by the operator of the machine, so that the condition causing the variation may be immediately remedied to again produce the right conditions for uniformity of sheet formation.

The method of my invention consists generally. 1

weir equipped box into which the water discharged from one or more suction heads, over which the paper web travels, empties. Yet more specifically my method consists in maintaining substantially constant vacuum pressure on one or more suction heads of the machine and measuring the variation from normal of rate of water flow from that head or those heads.

Although various apparatus may be utilized for carrying out my methods to detect changes in sheet formation, in a paper making machine, in the accompanying drawings I have illustrated a very simple indicating apparatus that I have found to be successful under actual working conditions.

Referring to Figs. 1, 3 and 4 of the drawings, the indicating apparatus shown includes a float 41 which is disposed within the seal box 17, so as to rise and fall with the level of water in that box, the water surface being designated by the letter B. Connected to and supported by this float 41 is a tube 42 which is preferably guided for vertical movement by means of a bracket 43 secured to the seal box 17 and a sleeve 44 running through the floor 5 and projecting above the same. Of course, the tube 42 extends through an opening in the bracket 43 and through the sleeve 44. A set screw 45 is preferably mounted in the tube 42 adjacent its upper end. I

A rod 46 is telescopically received at its lower end within the upper portion of the tube 42 and this rod is pivotally connected at its upper end to one arm 47a of a bell crank lever 47. This lever has a downwardly extending arm 47b equipped with a weight 48. The bell crank lever 47 is pivotally mounted for turning movement on a segment-shaped plate 49 which may be attached as by a bracket 50 as to one of the valves 27, the pivot for the bell cranklever being designated by the numeral 51. A pointer 52 is secured to the bell crank lever 47 and this pointer works over the face of the segment-shaped plate 49, there being calibrations 53 printed or painted along the arcuate edge of the plate for cooperation with the pointer 52'. The weight 48 is so adjusted on the arm 47b of the bell crank lever that when, the set screw 45 is loosened and the rod 46 has no positive connection with the tube 42, the arm 47b together with the weight 48 will counterbalance the weight of the arm 47a and the rod 46 with the pointer 52 pointing toward the middle calibration 53 on the plate 49.

In operating the paper making machine-the set screw 45 is allowed to remain loosened so that there is no positive connection between the tube 42 and the rod 46 until the paper making machine has been adjusted properly for producing a sheet of the desired type. After the sheet is being properly formed by the machine and the machine has run for a short period of time, the water level in the seal box 17 will not fluctuate. Of course, the pointer 52 when the rod 46 is not connected to the tube 42 will stand opposite the central calibration 53 on the plate 49. The set screw 45 .will then be tightened against the rod 46 to positively connect the rod 46 and tube 42, whereupon the indicator.

can be used for visually showing to the operator of the machine changes in uniformity of sheet formation.

If the sheet is being uniformly formed, the pointer 52 will remain opposite the central one of the calibrations 53 on the plate 49, thereby indicating the fact that the water level in the seal box 17 is the same as formerly to produce uniform formation of the sheet. If the pointer 52 should swing to the right or to the left of the central one of the calibrations 53, this will indicate to the operator of the machine that there has been a change in the sheet formation and the operator may quickly remedy the condition causing this change. Generally speaking, a movement of the pointer 52 to the left of its central position will show that the sheet being formed is either somewhat freer or somewhat lighter than formerly, or the sheet may be both freer and lighter than formerly. Movement of the pointer 50 to the right of the central position will generally indicate that the sheet is slower or heavier than formerly or both slower and heavier. Variations from normal in the formation of a sheet may be thus quickly checked by the machine operator merely by observing the position of the pointer 52.

It is, of course, not essential for the operation of the indicator that the outlet 24 from the couch pump 23 discharge into the seal box 17.

The indicator will be effective for use to show whether the sheet is being uniformly formed or not, if the float of the indicator is mounted in any weir equipped box into which one or more of the water legs 18 discharge, or into which the water from the couch pump 23 alone discharges. In other words, the indicator is effective for use to show variations from uniformity of sheet formation when it is used to measure the rate of flow of water from any one or more of the suction heads of the paper making machine.

It will be appreciated that many other types of apparatus than that shown may be utilized for measuring the rate of flow of water from one or more of the suction heads of a paper making machine in order to show whether or not the sheet is being uniformly formed by the machine. Although it is possible that an indicator showing variations in the rate of water flow through one or more of the water legs from one or more flat boxes or other suction heads, would provide some index to the uniformity of sheet formation in a paper making machine, even if the vacuum on the particular suction head or heads utilized with the indicator was not automatically stabilized as by means of my vacuum control mechanism disclosed and claimed in my above referred to application for patent, it is certainly true that without the vacuum control mechanism disclosed or some equivalent mechanism which maintains uniformity of vacuum pressure on the suction head or heads, the indicator could not be reliably counted on to show whether the sheet was being uniformly formed or not without taking other factors into consideration. Without the vacuum control mechanism, there would be considerable variance in the discharge of water from the suction head and this naturally would reflect in the operation of the indicator. My method of determining uniformity of sheet formation in a paper making machine therefor, although it primarily consists in measuring the continuous rate of water flow from, at least, one suction head over which the sheet passes in a machine, consists secondarily in automatically controlling and maintaining substantially constant the vacuum on one or more suction heads of the machine and at the same time measuring the continuous rate of water flow from that or those suction head or heads.

It will, of course, be understood that various changes may be made in the form, details, ar-

rangement and proportions of the various parts of my apparatus and that various changes may be made in my methods without departing from the scope of the present invention, which, generally stated, consists in the matter shown and described and set forth in the appended claims.

What is claimed is:-

l. The method of determining uniformity of sheet formation in a paper making machine which consists in measuring the rate of water fiow from weir equipped box into which the water emptiesv from at least one suction head over which the pulp web passes in the machine.

sheet formation in a paper making machine which consists in maintaining substantially constant f more suction heads over which the paper web =travels, a weir equipped container into which 'the water drawn from said suction head or heads discharges, and an indicator float controlled by vacuum pressure on at least one suction head over which the pulp web travels in the machine and measuring the rate of water flow from said suction head.

5. The method of determining uniformity of;

sheet formation in a paper making machine which consists in maintaining substantially constant, vacuum pressure on at least one suction head rate of water flow from said first mentioned means.

'7. In a paper making machine having one or more suction heads over which the pulp web travels, means for drawing off the water from said suction heads, control mechanism automatically maintaining substantially constant vacuum pressure on said suction heads and means for determining uniformity of sheet formation in the machine comprising a device registering changes in the rate of water flow from said first mentioned means.

8. In a paper making machine having one or more suction heads overwhich the pulp web travels, discharge means carrying off the water from said suction heads and indicating means controlled by the flow from said discharge means and indicating both increases and decreases in the rate of water flow from said discharge means. 9. Inapaper making machine having one or more suction heads over which the pulp web travels,. a'water leg connected, to each suction head and carrying' off the water therefrom and means recording changes in the rate of water flow from said waterleg or legs.

10. In a paper making machine, one or more suction heads over which the paper web travels,

a water leg connected to each suction head and carrying off the water therefrom, a weir equipped .box into which said water leg or legs discharge and an indicator showing the water level in said box.

11. In a paper making machine having one or the water level of said container and visibly showing a change in water level in said container.

more suction heads over which the paper web travels, control mechanism for automatically maintaining substantially constant vacuum pressure on said suction head or heads, a'water leg carrying off the water from each suction head, a weir equipped box into which said water leg or legs discharge and an indicator showing the water level of said box.

ARTHUR E. BROUGHTON.

Images