US3245872A - Automatic shower for removing a broken web from a fourdrinier wire - Google Patents

Description

April 12, 1966 G. 1.. NELSON 3,

AUTOMATIC SHOWER FOR REMOVING A BROKEN WEB FROM A FOURDRINIER WIRE Filed June 6, 1963 2 Sheets-Sheet 1 A ril 12, 1966 e. L. NELSON 3,245,872

AUTOMATIC SHOWER FOR REMOVING A BROKEN WEB FROM A FOURDRINIER WIRE Filed June 6, 1965 2 Sheets-Sheet 2 United States Patent 3,245,872 AUTOMATIC SHOWER FGR REMDVING A BRO- KEN WEB FROM A FOURDRINIER WIRE George L. Nelson, Westwood, Mass., assignor to Bird Machine Company, South Walpole, Mass, a corporation of Massachusetts Filed June 6, 1963, Ser. No. 286,005 10 Claims. (Ql. 162-255) This invention relates to intermittently operable fluid jets and in particular to apparatus for rapidly init1ating the flow of a number of spaced-apart fluid jets. It is a principal aim of the invention to enable the construction ofv a simple apparatus incorporating a large number of jet nozzles, e.g. as many as 30 or 60, that are spaced apart along a fluid supply conduit, for example, at intervals of 5 inches, in which the nozzles can be all converted from completely sealed condition to full flowing condition within a fraction of a second.

The invention has particular application to Fourdrinier paper-making machines which have endless, traveling, web-forming wires. In such machines, after formation the web is normally removed from the wire at the couch roll and thereafter processed. Occasionally, due to the failure of the removal or processing machinery or due to imperfections in the web, the web breaks and adheres to the wire. The web then moves downwardly with the wire about the couch roll and rearwardly toward the outer rolls that support the bottom length of the wire. It is well known that this broken web, if allowed to remain upon the wire, can cause damage to the wire as it passes over the outer support rolls, and will foul the machine.

To avoid such difficulties with a broken web a series of water jets have been directed from within the wire loop downwardly through the bottom length of the wire to dislodge or knock-01f the web, and cause it to fall into the couch pit. But continual operation of the water jets is very disadvantageous in that large amounts of water are continually admitted to the system which causes extreme dilution and cooling, and requires substantial pump ing capacity. Hence there has been a need for an intermittent fluid jet apparatus which can normally be sealed, but which can rapidly be initiated upon the occurrence of a break in the web to remove the web from the traveling wire. But no intermittent jet apparatus has been available that adequately provides the number of features necessary for use with paper machines.

One of the needed features is that the fluid jet must be actuatable very quickly. The length of traveling wire that extends from the couch roll to the first outer support roll for the wire is only on the order of 8 to 10 feet while the wire may travel at speeds on the order of 2500 feet per minute or higher. Such short distances and high speeds impose the limitation that the break must be detected and fluid jets across the full width of the wire must be initiataed within as little as /5 of a second if the web is to be removed before it is compressed against the wire by the first outer support roll.

Another needed feature is that the jet apparatus must be mountable within the loop of the traveling wire, and must be substantially self-supporting. In a typical installation the traveling wire may have a width of 200 inches, and, for example, where the fluid employed is water and the nozzles have an adequate effect if spaced on 5 inch centers, 40 jet nozzles are required. To be practical with such a large width wire, the nozzles and the pipe must be lightweight and small, for otherwise extremely heavy and expensive piping or complicated supporting structure within the loop of the traveling wire would be required.

Other needed features are that the intermittent jet nozzles be simple and inexpensive to manufacture and maintain.

Accordingly, it is a principal object of this invention to provide an intermittent jet apparatus for a Fourdrinier paper-making machine in which the nozzles are normally sealed against any flow, but in which the nozzles throughout the width of the paper-making machine can be actuated within a fraction of a second, preferably within /5 of a second.

Another object of the invention is to provide a jet apparatus which can employ a single control valve for the rapid actuation of the entire apparatus, and only one moving member in each of the valve nozzles.

Another object of the invention is to provide a jet apparatus which, after actuation is completely self-sealing and reset by the mere closing of a single control valve.

Another object of the invention is to provide a jet apparatus in which a single seal member seals completely the only outlet passage of each nozzle with no secondary outer seal or other complicated mechanism extending beyond the first seal, and with no leaking from the apparatus.

Other objects of the invention are to provide a jet apparatus which is small and lightweight, is simple to manufacture, has few machined surfaces and few parts that can wear out, is noncri-tical with respect to machining tolerances and is selfadjusting.

While from one point of view the invention is a substantial and important improvement in the rapid removal of broken webs from a paper machine wire, the apparatus inherently has advantages which may be called upon for other applications in the paper and pulp industry, and indeed for other uses.

The invention lies in part in the realization that for a passage that has a reasonable cross-sectional area and that is as long as the width of the traveling wire of a paper machine, if the passage already is charged with pressurized fluid, the pressure drop produced by dumping the passage from an end thereof can propagate through the length of the passage so effectively that said pressure drop can be used to unseal a series of nozzles very quickly; furthermore, in part the invention lies in a simple structure that efficiently utilizes this principle.

Broadly, the structure of the invention includes a series of spaced-apart nozzles each having a movable means which can move to seal and unseal the nozzle outlet with respect to a fluid supply, an extended control manifold adapted to be filled with fluid under pressure, and dump means to drop the pressure in the manifold when desired. Propagation of the pressure drop in the control manifold causes all of the movable means to move to their unsealed positions. Various movements of the movable means, pivotal as well as translational, are comprehended by the invention in its broadest scope, but an important aspect of the invention is that a single, reciprocating member can be employed for each nozzle with a working surface exposed to the control manifold pressure. Various means such as springs can be employed to keep the movable means in the fully sealed position when the control manifold pressure is not dropped, but it is also an important aspect of the invention that simple fluid pressure can be employed for this purpose while obtaining fast action.

Advantageously, the dump means includes a detector that senses the condition that requires the fluid jets and a dump valve that responds to the detector to dump the control manifold. In the context of the Fourdrinier papermaking machine, a web break detector is positioned near the couch roll for monitoring the normal removal of the web from the wire. When normal removal fails, the detector transmits a signal to open the dump valve to suddenly decrease the pressure in the control manifold.

' These and other important features and advantages of the invention will be explained in conjunction with the drawings wherein:

FIG. 1 is a side view, partially broken away, of the preferred embodiment of an intermittent jet apparatus according to the invention;

FIG. 2 is a transverse cross-sectional view taken on line 22 of FIG. 1 showing one of the nozzles thereof partly in cross-section;

FIG. 3 is a diagrammatic side view of part of a papermaking machine employing the apparatus of FIGS. 1 and 2;

FIG. 4 is a perspective view, partially broken away, of the jet apparatus and traveling wire of the machine of FIG. 3;

FIG. 5 is a diagrammatic side view, similar to FIG. 3 of another embodiment of a paper-making machine employing the present invention;

FIG. 6 is a vertical cross-sectional view of another embodiment of the invention.

Referring to the embodiment of FIG. 1, the fluid jet apparatus 10 comprises a multiplicity of fluid jet nozzles 11 mounted in a spaced-apart relation along elongated pipe 12. An elongated dividing wall 14 extends within the pipe substantially the entire length thereof. At one end of the dividing wall 14, a tranverse wall 16 seals dividing wall 14 to one side of pipe 12 and at the opposite end of transverse wall 18 seals the dividing wall 14 to the other side of the pipe 12, whereby elongated zones on opposite side of the dividing wall 14 are substantially sealed from each other. The first zone comprises an elongated supply conduit 20 for the nozzles 11, and communicates with a pipe extension 22 terminating at flange 24 that is adapted to be connected to a source 26 of pressurized fluid. The second zone comprises an elongated control manifold 28 which communicates with a pipe extension 32 forming a reservoir 34. A dump valve 36 is connected to reservoir 34 and dump piping 37. End supports 38 and 40 are connected to the ends of the pipe for supporting an extended length of pipe therebetween, for instance, within the loop of a traveling paper machine wire.

In this embodiment the filling means for the control manifold 28 comprises a leakage path from supply conduit 20, defined here by a restricted opening 41 in the dividing wall 14, although a means entirely separate from the fluid supply could be employed.

Referring to FIG. 2, in conjunction with FIG. 1, each nozzle 11 of this preferred embodiment has means defining an outlet passage 42, means defining one or more supply passages 44 communicating with supply conduit 20, means defining a movable piston 48 for moving the seal surface 46 and guide means 50 for guiding the movement of the piston.

In this embodiment the means that defines the outlet passage 42 comprises a nozzle head 52, the outlet passage beginning at a hollow conical valve seat 54, the large end of which communicates with supply passage 44, and the smaller end of which communicates directly with flow governing passage 56, the latter aligned to discharge against jet deflector surface 58 from which the fluid jet is emitted.

In this embodiment the guide 50 for the piston 48 comprises the surfaces bonding a chamber 59 defined by tubular member 60. This tubular member extends from the outlet passage transversely through the supply conduit 20, having its inner end 62 in communication with control manifold 28. An outer portion 64 of the tubular member 60 projects through the portion of the pipe wall that defines the supply conduit 20, being sealed by a weld 66 to the pipe wall. Threads 67 on the outer end of tubular portion 64 cooperate with a means 65 for connecting the nozzle head 52 to the tubular member 60. The supply passage 44 is provided by one or more holes 68 extending through the side wall of the tubular member 60.

In this embodiment the means defining the seal surface 46 is of spherical configuration, an annular surface portion 76 of which is adapted to engage a circular por tion of the conical seat 54 with the end surface portion 78 then exposed to the flow governing passage 56 through the only outlet of the nozzle. The seal surface 46 is closed and adapted to seal the outlet completely, the area of end surface 78 being greater than the crosssectional area of flow governing passage 56.

In this embodiment the movable piston 48 has a work-' ing surface 72 directed toward the control manifold 28. The sides 74 of the piston 48 preferably fit closely to the walls of the tubular member 60 to define a restriction to the flow of fluid between the supply passage 44 and the control manifold 28 to enhance the effect of pressure drop upon the working surface 72.

The working surface 72' of the piston member disposed in the opposite direction from working surface 72 is exposed to fluid in the nozzle, and the end surface 46 is exposed to the atmosphere when sealed. The piston surfaces are constructed and arranged so that drop inpressure in the control manifold 28 from a first level will unseat the piston from the sealed position (solid lines FIG. 2) to the unsealed position (dotted lines FIG. 2} and restoration of the pressure will restore the piston to the sealed position. Advantageously, when employing the leakage path 41 to fill the control manifold 28, the first pressure level for sealing is substantially equal to the supply pressure for conduit 20. Atmospheric pressure acts through outlet passage 42 upon end surface 78 to cause annular surface 76 to engage the conical seat 54. Decrease of the fluid pressure in the control manifold 28 unbalances the forces acting upon the piston 48, and the piston 48 is displaced in straight line-movement toward the control manifold 28, unsealing said outlet passage 42 relative to said supply passage 44.

Advantageously, the working end of piston 48 has an annular, spherical portion 73 and the tubular member 60 has a narrowed portion 61 of smaller diameter than piston 48 which serves two functions. First, portion 61 defines a secondary valve seat 63 to be engaged by piston 48 to positively seal the nozzle from control manifold 28 when the piston 48 moves to the unsealed position (dotted lines FIG. 3). This prevents leakage into the control manifold 28, quickening the propagation of the pressure drop throughout the elongated control manifold 28. The second function of the narrowed portion 61 is to limit the movement of the piston toward the control manifold 28.

To rapidly initiate the drop in pressure in the control manifold 28 when a fluid such as water is employed, it is advantageous that the flow cross-section of the dump valve 36 be greater than that of the control manifold 28, that the reservoir 34 be provided with a flow cross-section greater than that of said control manifold 28, that the dump valve 36 be connected to the reservoir 34 and have downwardly sloping drain piping 37 to take advantage of the gravity effect for aiding the movement of the fluid. The dump valve 36 is suitable for remote actuation and is advantageously combined with a detector 35 that is adapted to sense the conditions of the process with which the jet apparatus 10 is to be used, the detector 35 adapted when a predetermined condition is sensed to cause the dump valve 36 to open.

Referring to FIGS. 3 and 4, the jet apparatus 10 is adapted to be used with a Fourdrinier paper machine 80. In such a machine the Fourdrinier wire 84 has a straight upper section upon which a web is formed, the wire turning downwardly about couch roll 85 and proceeding through a return path to the head box 86 to complete its loop, passing over a first outer support roll 87 and thence over a number of further support rolls before reaching head box 86. The formed web 88 is removed from the wire in the vicinity of the couch roll 85 by a suction pickup roll 90 and upper and lower traveling felts 92 and 94, respectively. If the web 88 breaks or the removal means 90 fails to normally remove the web 88 for some other reason, the web 88 travels along with the wire 84 rearwardly toward the first outer support roll 87. Before the broken web reaches outer support roll 87 the web must be dislodged from the wire, preferably deposited in couch pit 96 below the couch roll 85.

Referring to FIGS. 3 and 4, the elongated pipe of apparatus of FIGS. 1 and 2 is mounted by its end brackets 38 and 40 within the loop of the endless traveling wire 84, with the nozzles 11 positioned to direct fluid jets through the wire 84, which is perforate, to direct broken web into the couch pit 96. The flange 24 is connected to a source 26 of pressurized fluid and the dump valve 36 is mounted to discharge to the atmosphere. The detector 35 in this embodiment comprises a photoelectric system comprising a light beam source 97 located within the loop of the wire 84 and a light-sensitive device 98 aligned therewith, located outside the loop. The detector is quiescent when the light beam passes through the perforate wire 84 and impinges on the light-sensitive device 98, which occurs whenever the web is being normally removed by the removal means 90. In the event the web 88 is not removed in the normal manner from the wire, the light beam is interrupted by the broken web which adheres to the wire. A relay 100 is actuated by the lightsensitive device 98 upon the interruption of the light beam, and the relay 100 activates a solenoid 102 which opens dump valve 36.

In preparing for normal operation, the dump valve 36 is closed and leakage from the supply conduit through the restricted opening 41 to the control manifold 28 causes the control manifold 28 to be charged with pressurized fluid. When the fluid employed is a liquid, a float valve can be connected to the upper part of control manifold 28 to release entrapped air and close when the manifold is filled, or a fluid flow can be initiated through the control manifold to purge it of air before closing the dump valve. When the static pressure in the control manifold 28 reaches substantially the total supply pressure from source 26, the force upon the working surface 72 of each of the pistons 48 forces the piston towards the outlet passage 42 and causes the seal surface 46 to engage conical seat surface 54 to seal the outlet passage 42 from the supply passage 44. The jet apparatus is then ready for operation.

When a break occurs in the web 88, the web 88 moves with the wire 84 past the light beam emitted by light source 97, the failure of normal web removal is sensed by the interruption of the light beam, the light-sensitive device 98 generates a signal which through relay 100 actuates solenoid 102 to quickly open dump valve 36. Such opening of the dump valve releases the pressure of the fluid in the control manifold 28 at the dump valve 36,

and this pressure drop quickly propagates throughout the length of the manifold 28. As the pressure drop reaches each nozzle 11, the total force acting upon working surface 72 is overcome by forces acting oppositely which drives the piston 48 towards the control manifold 28 unseating seal surface 46 from the conical seat 54, initiating a jet of liquid through the outlet passage 42.

The jet of fluid from all of the nozzles blast through the wire 84 and dislodge the full width of the web 88, discharging it into the couch pit 96. The jets continue until the operators of the paper-making machine correct the condition and again cause the removal means 90 to properly remove the web 88 from the wire 84, then the dump valve 36 is closed, the pressure allowed to build up in the control manifold 28 again by leakage through restricted opening 41 and the jets stop as the pistons 48 are returned to their sealing position, the jet apparatus remaining sealed against even slight leakage, until the next break occurs.

In a typical example, the paper machine wire 84 may be 200 inches wide, the pipe 12 may have a diameter of 3 inches and extend the full width of the wire, 40 liquid nozzles may be mounted on the pipe spaced on 5-inch centers, the cross-sectional area of the elongated control manifold may be on the order of 40 percent of the total cross-sectional area of the pipe, the valve 36 may be a 2 /2 inch solenoid-operated quick-acting valve, the solenoid being operable in about 1 to 5 cycles of 60-cycle current, and the light source and light-sensing device 97 and 98 or a series of them across the width of the wire may comprise a standard photoelectric system capable of actuating a relay in .06 second after the light beam is interrupted. From the time the light beam is interrupted until all of the nozzles are actuated, approximately /5 of a second will elapse.

Actual running tests of the pipe and nozzles alone when filled with water have yielded a full width jet action Within of a second from the start of opening the dump valve 36.

Referring to FIG. 5, unlike the embodiment of FIGS. 3 and 4, the web 88 is not covered by a felt immediately upon being removed from the couch roll and the photoelectric system 97', 98' is positioned to sense the web itself, the light-sensitive device 98 being quiescent when no light beam reaches it. Upon the breaking of the web, the web adheres to the wire 84 and does not pass between the light devices. The light beam from source 97' then reaches light-sensitive device 98' which actuates the dump valve in substantially the same manner as in the embodiment of FIGS. 3 and 4.

Referring to the embodiment of FIG. 6, the most significant difference from the apparatus already described is the complete isolation of the control manifold 28 from the supply conduit 20'. In this embodiment a bullet shaped movable member 108 is employed having a working surface 110 disposed in passage 112 that communicates through a working surface port 113 with the control manifold 28. The rounded end 109 of movable member 108 is adapted to engage a conical seat with the peripheral portion of the rounded end exposed to the pressure of the supply conduit 20' through supply port 117 and with the inner portion exposed to the atmosphere when sealed. Guides 114, 116 constrain the movable member to reciprocal movement. A rubber tubular diaphram 120 of the type that turns upon itself is secured to the movable member and to the wall 122 of the passage 112, absolutely sealing the control manifold from the supply passage while permitting reciprocal movement of member 108. A valve 124 communicates with control manifold 28 to fill it with inexpensive fluid such as water or even compressed air, a dump valve 126 is provided to produce the flow from control manifold 28 and a supply valve 128 is provided for supply conduit 20', adapted to supply relatively expensive or dangerous fluid, e.g. perfume, to the nozzles. The operation of this em- ;bodiment is the same as above, the movable member movable to upper and lower positions in accordance with the conditions at the working surface port relative to the conditions at the supply port.

It will be understood that numerous of the specific details and the mode of use can be varied within the spirit and teachings of the invention.

What is claimed is:

1. Apparatus for use in a process that requires, when a predetermined condition occurs, the rapid automatic initiation of normally sealed spaced apart fluid jets, said apparatus comprising a multiplicity of spaced-apart nozzles, a fluid supply manifold for continuously furnishing fluid under supply pressure to said nozzles, an extended rigid-walled control manifold normally filled with fluid under pressure when said jets are not initiated, and dump means to drop the fluid pressure in said control manifold; each of said nozzles defining an outlet passage through which a jet of fluid can pass, each of said nozzles having independent piston means movable relative to said control manifold, said piston means having oppositely directed working surfaces and movable between sealed and unsealed positions with respect to said outlet passage, said control manifold being in direct fluid communication with one working surface of said piston means of each of the nozzles and said supply manifold being in direct fluid communication with the oppositely directed working surface of said piston means, said manifolds and said working surfaces of said piston means arranged to cause fluid pressure to act directly on said piston means to move said piston means to said sealed and unsealed positions, the piston means being maintained in said sealed position when the pressure in said control manifold is not dropped and in unsealed position when the pressure in said control manifold is dropped, and a dump means actuator for receiving a signal from a detector for said predetermined condition and automatically actuating said dump means upon receipt of said signal.

2. The apparatus of claim 1 wherein said manifold and nozzle structure is adapted for rapidly and automatically initiating said jets through the wire of a Fourdrinier webforming machine to dislodge the web therefrom in the event said web is not normally removed, said dump means comprising a remotely actuatable dump valve connected to said control manifold, and a web break detector means for actuating said dump valve, said detector constructed and positioned to sense the failure of normal removal of said web from said traveling wire and upon such occurrence to open said dump valve.

3. The apparatus of claim 1 including in combination a detector to sense the occurrence of said predetermined condition and activate said dump means.

4. The apparatus of claim 1 wherein said control manifold is in direct limited fluid communication with said supply manifold, said apparatus thereby operated with a single source of pressurized fluid.

5. The apparatus of claim 1 wherein each of said piston means has a secondary sealing surface, means defining a secondary valve seat positioned to be contacted by said secondary sealing surface when said piston means is in said unsealed position, thereby preventing the fluid in said supply manifold from entering said control manifold.

6. The apparatus of claim 1 wherein each of said nozzles includes a metering passage independent from said piston means and located in said outlet passage at a point spaced from said piston means in said sealed position, said metering passage sized smaller than the sealing portion of said piston means to control the fluid flow out of said nozzle.

7. The apparatus of claim 1 wherein said extended control manifold communicates with a source of pressurized liquid and dump piping is provided to conduct liquid from said dump means, said dump piping directed downwardly to enable gravity effect upon said liquid flowing from said dump means to aid in producing a pressure drop in said control manifold.

8. The apparatus of claim 1 wherein a reservoir is provided in open communication with said control manifold, said reservoir having a flow cross-section greater than that of said control manifold.

9. The apparatus of claim 1 wherein said piston means operates through a seal to prevent fluid communication between said control manifold and said supply manifold.

10. The apparatus of claim 9 wherein said seal is a flexible diaphram.

References Cited by the Examiner UNITED STATES PATENTS 1,057,780 4/1913 Sheldon 239108 2,803,499 8/1957 Goyette et a1. 239l09 2,829,005 4/1958 Broughton 239113 3,073,529 1/1963 Baker 239-1 13 3,097,992 7/1963 Strempel 162-255 3,097,993 7/1963 Goddard 162--255 DONALL H. SYLVESTER, Primary Examiner.

MORRIS O. WOLK, Examiner.

Claims (1)

1. APPARATUS FOR USE IN A PROCESS THAT REQUIRES, WHEN A PREDETERMINED CONDITION OCCURS, THE RAPID AUTOMATIC INITIATION OF NORMALLY SEALED SPACED APART FLUID JETS, SAID APPARATUS COMPRISING A MULTIPLICITY OF SPACED-APART NOZZLES, A FLUID SUPPLY MANIFOLD FOR CONTINUOUSLY FURNISHING FLUID UNDER SUPPLY PRESSURE TO SAID NOZZLES, AN EXTENDED RIGID-WALLED CONTROL MANIFOLD NORMALLY FILLED WITH FLUID UNDER PRESSURE WHEN SADI JETS ARE NOT INITIATED, AND DUMP MEANS TO DROP THE FLUID PRESSURE IN SAID CONTROL MANIFOLD; EACH OF SAID NOZZLES DEFINING AN OUTLET PASSAGE THROUGH WHICH A JET OF FLUID CAN PASS, EACH OF SAID NOZZLES HAVING INDEPENDENT PISTON MENS MOVABLE RELATIVE TO SAID CONTROL MANIFOLD, SAID PISTON MEANS HAVING OPPOSITELY DIRECTED WORKING SURFACES AND MOVABLE BETWEEN SEALED AND UNSEALED POSITIONS WITH RESPECT TO SAID OUTLET PASSAGE, SAID CONTROL MANIFOLD BEING IN DIRECT FLUID COMMUNICATION WITH ONE WORKING SURFACE OF SAID PISTON MEANS OF EACH OF THE NOZZLES AND SAID SUPPLY MANIFOLD BEING IN DIRECT FLUID COMMUNICATION WITH THE OPPOSITELY DIRECTED WORKING SURFACE OF SAID PISTON MEANS, SAID MANIFOLDS AND SAID WORKING SURFACES OF SAID PISTON MEANS ARRANGED TO CAUSE FLUID PRESSURE TO ACT DIRECTLY ON SAID PISTON MEANS TO MOVE SAID PISTON MEANS TO SAID SEALED AND UNSEALED POSITIONS, THE PISTON MEANS BEING MAINTAINED IN SAID SEALED POSITION WHEN THE PRESSURE IN SAID CONTROL MANIFOLD IS NOT DROPPED AND IN UNSEALED POSITION WHEN THE PRESSURE IN SAID CONTROL MANIFOLD IS DROPPED, AND A DUMP MEANS ACTUATOR FOR RECEIVING A SIGNAL FROM A DETECTOR FOR SAID PREDETERMINED CONDITION AND AUTOMATICALLY ACTUATING SAID DUMP MEANS UPON RECEIPT OF SAID SIGNAL.

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