US3468341A

US3468341A - Precision vacuum controller

Info

Publication number: US3468341A
Application number: US412370A
Authority: US
Inventors: Douglas H Newcomb; Charles B Nicholson Jr
Original assignee: Broughton Corp
Current assignee: Broughton Corp
Priority date: 1964-11-19
Filing date: 1964-11-19
Publication date: 1969-09-23
Anticipated expiration: 1986-09-23

Description

Sept. 23, 1969 D. H. NEWCOMB ET PRECISION VACUUM CONTROLLER Filed NOV. 19, 1964 2 Sheets-Sheet 1 cm S 1.1% H w \X' INVENTORS Dal/6145' 6f It'A/COHB BY 64 4x1553. Mayozsuk MSYW Anon/5y:

p 1969 o. H. NEWCOMB ET AL 3,468,341

PREC IS ION VACUUM CONTROLLER Filed Nov. 19, 1964 2 Sheets-Sheet I\'\'E.\'TOR. Dal/c445 ll IVEk/COMB BY CHARLES E. MCI/060A! I;

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firm/ ivers United States Patent 3,468,341 PRECISION VACUUM CONTROLLER Douglas H. Newcomb, Hudson Falls, and Charles B. Nicholson, Jr., Glen Falls, N .Y., assignors to Broughton gorpioration, Glen Falls, N.Y., a corporation of New Filed Nov. 19, 1964, Ser. No. 412,370 Int. Cl. F16k 31/145, 31/365 US. Cl. 137625.3 1 Claim This invention relates generally to pressure control equipment and more specifically to a precision vacuum control mechanism particularly constructed for use in controlling the vacuum supplied to a suction head for a paper making machine.

In paper making operations the paper pulp is deosited in a layer on the upper run of a Fourdrinier wire and the water in the pulp drains therefrom through the wire and is sucked out of the pulp by means of a plurality of suction heads or fiat boxes. When making particular types of paper such as a thin carbonized paper the vacuum on the first flat boxes must be particularly low and precisely controlled. The vacuum in the next succeeding boxes may be increased since the paper has progressively more strength as the water is removed therefrom. It is and has been difiicult in the past to provide a concise control at the low vacuum boxes and for this reason applicant has provided a new and unique valve member for a vacuum controller which enables him to precisely control this vacuum.

A general arrangement of these fiat box systems is to provide a vacuum header with a control valve between the header and the suction box. The control valve modified in this invention is adjusted through a pressure diaphragm arrangement and a second constant vacuum control likewise communicates with the diaphragm arrangement such that the vacuum in the suction head is maintained at a constant. The major modification to this valve provides precise control at low vacuums and thus insures a more constant pressure at the suction boxes at these low pressures.

Although this valve is illustrated in a vacuum control operation, it should be obvious that it would be useable with many pressure systems where it is necessary to slowly introduce the pressure into a system.

It is therefore an object of applicants invention to provide a precision vacuum controller for controlling the pressure of the fiat boxes in a paper making machine.

It is a further object of applicants invention to provide a vacuum control mechanism arranged to precisely control the pressure in flat boxes of paper making machine which depends on a unique valve aperture arrangement wherein the valve opening may be progressively enlarged through a series of progressively opening valve apertures.

It is a further object of applicants invention to provide a precise vacuum control mechanism for paper making machines and the like wherein a precise spring balance arrangement permits accuracy of control at low vacuums and which balance arrangement is deleted from operation when the valve is operating under high vacuum.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawing,

3,468,341 Patented Sept. 23, 1969 ice wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is a diagrammatic illustration of the control mechanism as it would be arranged in a paper making machine;

FIG. 2 is a vertical section taken centrally of the vacuum controller and illustrating a portion of the adjustment mechanism in two positions;

FIG. 3 is a horizontal section taken substantially along line 33 of FIG. 2 illustrating the valve aperture construction;

FIG. 4 is a portion of FIG. 2 drawn to an enlarged scale;

FIG. 5 is a vertical section taken substantially along line 55 of FIG. 4.

As shown in FIG. 1 of the accompanying drawings the vacuum controller 10 of this invention is illustrated in operative position wherein the suction side 10a thereof is attached to a vacuum manifold V and the other side 10b termed the inlet side is attached to a flat box B of a paper making system through an upright conduit C. A tee member T divides conduit C to permit vacuum to be applied to the fiat box B and provide discharge conduit D extending downwardly therefrom through which water drawn from fiat box B may be discharged into sealing tank S. A control pressure line L is provided to control valve 10 and likewise an equalizing pressure line P is provided to the control 10, the purposes of which will be described hereinafter.

Valve member 10 is best illustrated in the cross section of FIG. 2 and in the form shown comprises a valving portion 11 and a control portion 12 separated by an actuating diaphragm 13. The valving portion 11 is maintained in a housing and includes a pair of connected valve members comprising a balanced vacuum supply valve 14 and a balanced air relief valve 15, both of which control supply to a vacuum chamber 16 communicating with the inlet or flat box B end 10b of the valve 10. A vacuum supply conduit 17 extends inward to the cavity 16 and in the form shown is provided with a pair of aligned valve seats 17a-17b on the Walls thereof such that the vacuum supply valve 14 may operate therein and afford communication to vacuum chamber 16. Air relief valve 15 operates within valve seat 15a arranged on the valve housing and is open to the atmosphere and to vacuum chamber 16. Relief valve 15 is normally biased upward into closed position by -a balancing spring 18. Relief valve 15 and vacuum supply valve 14 are arranged on a common shaft 19 which in turn is operatively associated with diaphragm 13 through an upper 20 and lower 21 diaphragm confining arrangement for actuation thereby such that as diaphragm 13 moves upwardly valve 14 is opened upwardly and valve 15 is biased upwardly into closed position. Depression of diaphragm 13 of course reverses the procedure and a stop nut 19a opens valve 15 downwardly while a balancing spring 22 operates against valve 14 to insure downward closure thereof. An additional balance spring member 23 operates between the upper diaphragm plate 20 and a portion of the valve housing to insure proper positioning of the diaphragm. It should be noted that the upper portion of diaphragm 13 is open to the atmosphere by at least a pair of openings 24a-24b provided in the housing. Through this valving arrangement it should be obvious that when the vacuum control valve 14 is opened the air relief valve will be biased into closed position and when vacuum control valve 14 is closed the air relief valve 15 is forced downwardly into open position, thus increasing or decreasing the vacuum in flat box B.

The structure of the vacuum supply valve 14 to provide precision control at low vacuum is illustrated in FIGS. 3, 4 and 5 wherein valve 14 is provided with a pair of longitudinally spaced cylindrical seats 1441-14!) for seating respectively in valve seats 17a17b of conduit 17. Directly adjacent each of the seats 14a14b is provided a tapered opening portion 14c14d which taper allows the valve 14 to open progressively larger as valve 14 is urged upwardly.

To provide the desired precision control at low vacuum a plurality of longitudinally extending slots, three of which are designated 14c, the remaining being designated 14f, 14g, and 1411, are provided in the outer surface of valve 14 such that one end of each slot will be arranged on the cylindrical surface 14a and will extend longitudinally along valve 14 across the first tapered portion 14c with the other end thereof located on the second cylindrical portion 14b. The cross sectional shape of the slots is shown in FIGS. 3 and 5 and the purpose of the slots is to provide a series of openings which will provide progressively increasing cross sections to provide gradually increasing communication of vacuum to the flat box B. As shown in FIG. 5 this progressive opening is provided by changing the dimension X such that as the valve 14 is moved upwardly the introduction ends of the slots will come into staggered communication with the flat box conduit C. For example and in the form applicant has found most successful the slots 14s are spaced at a particular dimension, X and slots 147, 14g and 14h are each spaced respectively X-linch, X+ /s inch and X+ inch. This dimension naturally is arbitrary and would vary upon the size and application for the valve.

As seen in FIG. 4 the slots are generally elliptical in shape with sides converging to a smoothly radiused bottom as seen in FIG. 5. This configuration provides a cross sectional opening increasing in dimension as the valve 14 is moved upwardly. Movement of the valve 14 upwardly then allows communication between the vacuum and the flat box initially through the ends of the slots 14a arranged on cylindrical surface 14a. Progression of the valve upwardly progressively disposes slots 141, 14g and 1412 in communicating position. As the tapered portions 14c-14d of the valve 14 passes through the valve seats 17a-17b the cross sectional dimension of the disposed slots increase the total communication area and thus on the last portion of valve travel a much larger opening is presented.

The control portion of the valve 12 is arranged below the diaphragm 13 and as shown in FIG. 2 a longitudinal adjustable diaphragm tensioning member is arranged for longitudinal reciprocation about a center guide 31. For clarity of operation the adjustable member 30 is shown in two positions. Positioning member 30 comprises a generally arcuate cylinder 32 receivable about the upstanding center guide member 31 with a boot 33 arranged sealingly therebetween; one end 33a of the boot 33 being sealed to guide member 31 and the other end 33b of the boot 33 being sealed to cylinder 32. A central guide rod 34 is arranged in sliding relation within guide 31 and has one end thereof 34a attached to a top closure plate of cylinder 32.

Pressure is introduced through a passage 31a in guide member 31 from control line L and will cause the cylinder 32 to project upwardly as shown in FIG. 2 whereby the diaphragm 13 position and hence the valve 14 position may be controlled. An arcuate shoulder 35 is arranged around cylinder 32 and a first tensioning adjustment spring 36 is seated thereon. The upper end of the adjustment spring 36 is received against and surrounds a spring retainer 37 which is in operating alignment with the bottom diaphragm plate 21. A second adjustment memher such as resilient spring 38 is disposed between the spring retainer 37 and the bottom diaphragm plate 21 such that initial movement of the first tensioning spring 36 by the adjustment cylinder 32 will be transmitted to adjustment spring .38 providing a particularly delicate spring tensioning system to diaphragm 13. This delicate adjustment is particularly important when operating at the desired low vacuums.

It is possible to cancel out the eifect of the second tensioning spring 38 which cancellation is also shown in FIG. 3 wherein the spring retaining member 37 operates directly against the lower diaphragm capturing plate 21. This arrangement will be used at high vacuum requirements.

Sensing conduit P connects the control chamber 12 with conduit C and flat box B whereby the vacuum in the box 8 will be communicated to the control chamber 12. This sensing conduit P provides automatic means to actuate the diaphragm 13 in response to changes in the vacuum within the flat box B and thus will control the vacuum in the flat box B. Sensing conduit P provides automatic adjustment to the valves 14-15 such that pressure in the fiat box B will be kept at a constant.

At extremely low vacuums the combination of the progressively opening slots on valve 14 with the second tensioning spring member 38 provides particularly delicate adjustment such that the vacuum in the flat box B may be maintained within critical levels. At high vacuum the cancellation of the second tensioning device 38 and the cooperation of the slots on the tapered portion 14c of valve 13 allows greater communication area to the fiat box B.

It should be obvious that applicant has provided a unique progressively opening valve member in order to break the vacuum to a fiat box very gently and to delicately and precisely control the vacuum at these low vacuums.

It should be obvious that although a plicant has illustrated the use of this valve for controlling vacuum introduction to fiat boxes of a paper making machine the principle of progressive openings on the valve member would be easily adaptable and may be useable in this specific form on many other pressure applications.

It will, of course, be understood that various changes may be made in the form, details, arrangements and proportion of parts without departing from the scope of my invention, which generally stated consists in the matter set forth in the appended claim.

What is claimed is:

1. A vacuum control valve including:

(a) a housing defining a chamber therein;

(b) a suction conduit having a sealed end communicating with said chamber and having a generally arcuate diametrically aligned passage through the walls thereof to provide valve seats and to provide communication between the interior thereof and said chamber;

(c) an inlet communicating with said chamber;

(d) a valve member arranged for sealing with said seats including:

(1) a pair of longitudinally spaced generally arcuate sealing portions receivably into said seats for sealing therewith against the outer periphery thereof;

(2) an opening portion adjacent each of said sealing portions being tapered to provide progressively increasing communication between the inlet and said chamber;

13) a plurality of slots extending longitudinally of said valve member arranged on one of said arcuate sealing portions and extending therefrom onto the adjacent tapered portion, the ends pf at least certain of the slots on the arcuate portion being spaced longitudinally of the valve to provide a plurality of progressively increasing and successively opening communication passages as the valve is moved through said seats 6 such that the ends of the slots may be arranged References Cited respectively on eithenside of the wall of the UNITED STATES PATENTS suction conduit affording the only communication between the suction conduit and the cham- 1,942,426 1/1934 Hunter 137625'3 her; 2,969,809 1/1961 Kllngler 137615.3 (e) a control chamber defined by said housing and 5 3,221,767 12/1965 McCarty having a pressure responsive diaphragm member therein, said diaphragm being connected to said valve HOWARD WEAKLEY Pnmary Examiner member for actuation thereby; and

(f) means for applying valve positioning pressure to 10 said diaphragm for initially opening the same. 711 05.13; 51282

Claims

1. A VACUUM CONTROL VALVE INCLUDING: (A) A HOUSING DEFINING A CHAMBER THEREIN; (B) A SUCTION CONDUIT HAVING A SEALED END COMMUNICATING WITH SAID CHAMBER AND HAVING A GENERALLY ARCUATE DIAMETRICALLY ALIGNED PASSAGE THROUGH THE WALLS THEREOF TO PROVIDE VALVE SEATS AND TO PROVIDE COMMUNICATION BETWEEN THE INTERIOR THEREOF AND SAID CHAMBER; (C) AN INLET COMMUNICATING WITH SAID CHAMBER; (D) A VALVE MEMBER ARRANGED FOR SEALING WITH SAID SEATS INCLUDING: (1) A PAIR OF LONGITUDINALLY SPACED GENERALLY ARCUATE SEALING PORTIONS RECEIVABLY INTO SAID SEATS FOR SEALING THEREWITH AGAINST THE OUTER PERIPHERY THEREOF; (2) AN OPENING PORTION ADJACENT EACH OF SAID SEALING PORTIONS BEING TAPERED TO PROVIDE PROGRESSIVELY INCREASING COMMUNICATION BETWEEN THE INLET AND SAID CHAMBER; (3) A PLURALITY OF SLOTS EXTENDING LONGITUDINALLY OF SAID VALVE MEMBER ARRANGED ON ONE OF SAID ARCUTE SEALING PORTIONS AND EXTENDING THEREFROM ONTO THE ADJACENT TAPERED PORTION, THE ENDS OF AT LEAST CERTAIN OF THE SLOTS ON THE ARCUATE PORTION BEING SPACED LONGITUDINALLY OF THE VALVE TO PROVIDE A PLURALITY OF PROGRESSIVELY INCREASING AND SUCCESSIVELY OPENING COMMUNICATION PASSAGES AS THE VALVE IS MOVED THROUGH SAID SEATS SUCH THAT THE ENDS OF THE SLOTS MAY BE ARRANGED RESPECTIVELY ON EITHER SIDE OF THE WALL OF THE SUCTION CONDUIT AFFORDING THE ONLY COMMUNICATION BETWEEN THE SUCTION CONDUIT AND THE CHAMBER; (E) A CONTROL CHAMBER DEFINED BY SAID HOUSING AND HAVING A PRESSURE RESPONSIVE DIAPHRAGM MEMBER THEREIN, SAID DIAPHHRAGM BEING CONNECTED TO SAID VALVE MEMBER FOR ACTUATION THEREBY; AND (F) MEANS FOR APPLYING VALVE POSITIONING PRESSURE TO SAID DIAPHRAGM FOR INITIALLY OPENING THE SAME.