US2204644A - Pulp density regulator - Google Patents

Description

June 18, 1940. J. A. ADAMS PULP DENSITY REGULATOR Filed Sept. 7, 1937 3 Sheets-Sheet 1 INV ENT OR.

June 18, 1940.

J. A. ADAMS 2,204,644

PULP DENSITY REGULATOR Filed Sept. '7, 1937 5 Sheets-Sheet I5 INVENTOR. QZ4ME S 4. A DAM 5 Patented June 18, 1946 UNITED STATES PATENT OFFICE PULP DENSITY REGULATOR Application September "I, 1937, Serial No. 162,741

9Claims.

This invention relates to improvements 'in automatic pulp-density regulators.

In certain industrial processes such as, for instance, ore concentrating, paper making, and the like, material being treated is embodied in a pulp. This pulp usually is composed of the material in a finely divided condition carried in a liquid, usually water, with perhaps other inradients in addition.

It is important that this pulp be formed and kept at a constant density so that the next step in the processing will be accomplished at maximum eillciency. Since the pulp usually comprises a" plurality of components, care must always be exercised in the mixing to maintain that constant density factor. The mixing of components to form the pulp often is a continuous process and the present invention provides apparatus that is effective for automatically varying a fluid component of the pulp in response to density variations, to maintain a substantially constant density.

Therefore it is an object of this invention to provide apparatus that will respond automatically to sustained pulp-density variations and thereby A further object is to provide apparatus that is simple and positive in action.

A still further object is the provision of apparatus of this character that may be installed, optionally, in a. convenient position either at, above or below the normal pulp-level.

Stiilanother object is to provide apparatus for this purpose that will respond in degree and time in a manner corresponding to the degree and duration of the density variation to thereby eillciently correct it.

Other objects and advantages will be more fully disclosed in the following description and in the drawings wherein like parts have been similarly designated and in which:

Figure 1 is a vertical sectional view of apparatus built according to this invention;

Figure 2 is a diagrammatic view of a modified arrangement of the apparatus;

- Figure 3 is a fragmentary sectional view on line 3-4 of Figure l and drawn on a larger scale and including certain details that were purposely omitted from Figure 1 for purposes of clarity;

Figure 4 is a wiring diagram of electrical circuits that are well adapted to be used with the apparatus;

Figure 5 is a fragmentary elevation partly in section and illustrates apparatus built according to a further modified form of the invention; and 5 Figure 6 is a fragmentary plan view, drawn to a smaller scale, of the apparatus shown in Figure 5.

In the drawings reference character l2 denotes a body of pulp. At l3 are shown bodies of fluid, 10 preferably water, the supply of which may be renewed at a selected rate through a conduit I4 and valves l5. Two expansion fluidchambers l6 and H are closed respectively by flexible diaphragms l3 and Ma. A pair of flexible conduits I9 are in fluid conductive connection between the bodies of fluid I3 and the fluid chambers l6 and II respectively, and flexible discharge conduits connect the respective chambers to points of fluid discharge 2 and 22 respectively, which 20 are located in thebody of pulp at different depths below the surface.

A rigid yoke 23 connects the two diaphragms by passing around the outside of the chambers so that, in the form shown in Figure 1, the diaphragms are held in fixed spaced relation to each other.

A partition 24 completely seals the chambers I6 and I! from each other so that there is no flow of fluid therebetween. The yoke 23 is connected by means of a rod 25 to a beam 26 which is fulcrumed at 21 on a standard 28. On one side of the fulcrum the beam carries a slidablq counter-weight 23 and the beam terminates in a point 30 adjacent an arcuate calibrated scale 3|. To the right of the fulcrum'the beam carries a pair of mercury switches 32 and 33 which, as shown in diagrammatic detail in Figure 4, together serve as a motor-reversing switch. 0n the extreme right end of the beam is a hinged member 34 which is pivoted to the beam by means of a pin 35 and is normally held in alinement with the beam by a spring element 36.

Adjacent the right extremity of this assembly is a cam element 31 mounted for rotation on a vertical shaft 33 journalled in bearings 39 and 40.

. The shaft is driven by any convenient source of power, not shown, through an intermediary of a belt ll over a pulley 42 on the shaft. Adjacent its center thecain/element 31 has a symmetrical 5o concentric track 31a above and below which are the eccentric s 371).

, The two exp, nsion fluid chambers l6 and II are supported at their perimeters one. pair of standards 43 in a manner to permit free movement of the diaphragms l8, and it will be understood that the conduit I4 is connected with a source of fluid such as any common watersupply system, which is not shown.

Referring to thedetails shown in Figure 3, a grooved pulley 44 is mounted adjacent the cam element 31 and a mercury type switch is shown at 45. The switch is pivoted at 46 on a standard 41 and the left end of the switch is urged downwardly by means of a spring element 48. A belt or cord 49 is connected with a band 50 around the switch, and passes over the pulley 44, downwardly in close proximity to the hinged member 34 and is anchored permanently to an arm 5|. The mercury'switch 45 is used 'to open and close an electrical conductor 52 which is part of an electrical circuit shown in diagrammatic detail in Figure 4.

In the form, as shown in Figure 1, the two fluid chambers are mounted in superposed relation so that their respective diaphragms are in axial alinement with each other and oppose each other in their movements.

In Figure 2 a modified arrangement is shown wherein the fluid chambers, which are designated as Mia and Na, are positioned in lateral relation, each with its diaphragm in a downward position as shown at lib and He. The diaphragms are connected by means of rods 25a and 251) respectively, with a fulcrumed beam 53 which in turn is connected by means of a rod 54 to a second fulcrumed beam 26a which corresponds to the beam 26 in Figure l. The beam 28a is provided with a depending bar 55 adjacent and below its fulcrum, and a compensate ing weight 58 is adjustably carried on the bar.

In the form shown in Figure 2 it will be noted that the fluid chambers [6a and Ila are located above the surface of the body of pulp, whereas in the preferred form shown in Figure l, the fluid chambers 16 and ll are located below the surface of the pulp body I2. It will be understood that the various conduits are intended to be flexible so that the relative altitude of the fluid chambers, with reference to the body of pulp, may be varied, as will be explained hereinbelow.

In Figure 4, a wiring diagram is shown which illustrates certain electrical circuits that are well adapted to be used in connection with either form of the apparatus.

The switches 32 and 33 each comprises a metallic conductive tube 63 containing a body of mercury 81 and plugged at each end with insulating material 85. A source of power, as shown at 66, is conducted along a main conductor 6'! to switch 33 and along the main conductor 52 to switch 32. Conductive contactors 68 pass through the respective insulating plugs 65 so that when the tubes 63 are tipped in either direction from the horizontal, the mercury therein will flow to the lowermost end of each tube and thereby close an electrical conductive circuit between each tube and its respective contact point. The our contact points are cross-connected and are also connected with suitable leads to a motor 69 so that when the beam 26 tips in one direction, contacts will be made to operate the motor in one direction and when the beam 25 tips the other direction the motor will be reversed.

The motor is in driving relation with a speed reducer 10, the output of which is transmitted by means of a sprocket-chain H to a sprocket 12 that engages a valve hand-wheel 13 by means 5 of prongs 14 to open or close a valve 15 according to the direction of rotation of the motor. The valve 15 controls a flow denslty-aflecting fluid from a source, 16a, through a conduit 16 to the body of pulp l2. The electrically-conductive tubes 63 are carried on blocks of insulating material 11 that are attached to the beam element 26.

Operation In operation a flow of fluid is established from the fluid bodies I: through the conduits it, through the respective fluid chambers l6 and I1 and discharged through conduits 20 at different points at difierent depths below the surface of the pulp body [2. By adjusting the sliding weight 29 on the beam element 26 a condition of stabilization of the beam in a normal horizontal position may be eifected. Any change in the pulp level will affect the hydraulic pressure against each diaphragm to a like degree but any change in the pulp density will produce a diiferential pressure change on the respective diaphragms which will impart a movement to the beam element 26 which will, in turn, actuate the motorreversing switches 32 and 33 thereon. Movement of the beam element 26 may be observed at its pointed end 30 with reference to the callbrated scale 3 l.

The hinged element 34 on the right end of the beam element is normally in close proximity to the concentric central part of the cam element ll. This normal position is clearly shown in Figures 1 and 3. When the beam element undergoes angular movement about its pivotal axis or fulcrum 21 the right end thereof will move I up or down from its normal position as the cam element permits it to do so when the cams 3117 are rotated to the side away from the beam.

On the next revolution of the cam element 31, either one of the cams 311) will engage the hinged portion 34 of the beam element as they rotate in the direction of the arrow D in Figure 3. This will move the hinged end 34 laterally to contact the belt or cord 49, as shown in broken lines in Figure 3. This movement will raise the pivoted mercury switch 45 to its dotted line position to close the electrical conductor 52 which will in turn permit power to flow from the source 68 through the reversing switches 32 and $3 to the motor 69 to drive it in the direction called for by the position of the beam 28. The motor thus actuated will operate the mechanism to control the flow of density-affecting fluid to the body of pulp. The operation of the cam element 31 will introduce a certain desirable factor of delay in the operation of the density-affecting mechanism so that the resultant action will not be too severe.

Obviously and inherently, the cam-element will intermittently move the part 34 of the beam-element, when said beam-element is in position to be contacted by the cam.

It will be seen that due to the angular shape of the cams 31b, the farther from normal that the hinged end 34 of the beam element 26 is moved, the longer period of time the beam will be held in its lateral position and the longer the circuit-breaking switch 45 will remain closed. It will thus be apparent that the greater the variation in the pulp density the greater the automatic response will be to correct that variation and bring the pulp density back to normal.

Obviously the raised portions of the cam 31b 88 of the lower chamber.

vide contact periods with the beam-element of varying time duration.

In the arrangement shown in Figure 1 the flow of fluid through the chambers l6 and II will normally exert a pressure on the diaphragms l8 and Ila that is above atmospheric pressure. In the arrangement shown in Figure 2 the flow through the chambers I61: and Ila becomes a syphon system so that a pressure below normal atmospheric is usually exerted on the inner surface of the diaphragms Ill) and I80. In this arrangement any difierential change in the pressure exerted on the diaphragms will move the fulcrumed beam 83 to actuate the beam element 26a as hereinabove described.

The form of the apparatus as illustrated in Figures 5 and 6 makes use of a source of gas under pressure, that discharges simultaneously into two opposed chambers, 88 and 8| respectively, a conduit 82 leading from the source, not shown, to the upper chamber and a second conduit 83 leading fromthe source to the lower chamber 8|. A rigid plate 84 is positioned between a flexible diaphragm closure 85 of the upper chamber and a similar diaphragm closure A discharge conduit 81 leads to a point of gas discharge 88 in a pulp container I21: and another discharge conduit 88 leads to another point of gas discharge 98 at a different depth in the container Ila.

The plate 84 is connected with a yoke 8| which in turn is pivoted to the fulcrumed beam 26 that carries the elements as above deflned. The two expansion chambers 88 and 8| are rigidly supported at 82 on a frame 88 and it will be understood that variations in the density of the pulp I2 into which' the two discharge conduits are immersed, will diflerentially affect the pressures in the expansion chambers 8|! and 8| which will move the plate 84, the yoke 8| and the Iulcrumed beam 26. The beam may govern and be governed as hereinabove described and as illustrated in Figures 1, 3 and 4.

The diaphragms in all forms of the apparatus preferably have an area of many square inches so that even a small diiferential change per unit of area on the diaphragms will be multiplied to a very considerable total effective force on the mechanism actuated by the diaphragms. It will be understood that the movement of the diaphragms, due to a diflerential change in the pressure exerted thereon, may be utilized in various ways to actuate density-governing mechanism. The mechanism illustrated and described herein is a typical example. It is to be further understood that the term pulp as herein used, means any semi-liquid or solution or mixture of liquid and solid matter. I

What I claim and desire to secure by Letters Patent is:

1. In apparatus for automatic pulp-density control, a plurality of expansible chambers, fluid flow means associated with said chambers and discharging into a body of pulp at two different depths therein for expanding and contracting said chambers according to pulp-density ,variations, an element connected with a movable portion of at least one of the chambers for movement thereby, a continuously operating member positioned adjacent said element for reciprocating a portion thereof in directions other than its first said movement, and a motor-operating switch positioned to be actuated by the reciprocating movement of the element.

2. In apparatus for automatic pulp-density control, a plurality of'expansible chambers, fluid flow means associated with said chambers and discharging into a body of pulp at two different depths therein for expanding and contracting said chambers according to pulp density variations, an element connected with a movable portion of at least one of the chambers for movement thereby, means adjacent the element for intermittently moving the same in a direction other than its first said movement, and a motoroperating switch positioned to be actuated by the intermittent movement of the element.

3. In apparatus for automatic pulp-density control, a plurality of expansible chambers, means for discharging flows of fluid at different depths in a body of pulp, said means being also connected with the respective chambers whereby they are expanded and contracted according to pulp-density variations, a beam-element connected with a movable part of at least one of the chambers and fulcrumed for arcuate movement thereby, means adjacent the beam-element for reciprocating a portion thereof laterally of its arcuate path, and a motor-operating switch actuated by such lateral movement according to the arcuate position of said beam-element.

4. In apparatus for automatic pulp-density control, a plurality of expansible chambers, means for discharging flows of fluid at different depths in a body of pulp. said means being also connected with the respective chambers whereby they are expanded and contracted according to pulp-density variations, a beam-element connected with a movable part of at least one of the chambers and fulcrumed for arcuate movement thereby, means adjacent the beam-element for intermittently movinga portion thereof laterally of its arcuate path, and a motor-operating switch actuated by such lateral movement according to the arcuate position of said beam-element.

5. In apparatus for automatic pulp-density control, a plurality oi expansible chambers, means for maintaining a flow oi fluid simultaneously through the chambers, means for discharging the respective flows of fluid at different depths in a body of pulp, whereby the chambers are expanded or contracted according to pulpdensity variations, 9. beam-element connected with the chambers and fulcrumed for arcuate movement thereby, a motor-reversing switch operated by the arcuate movement of the beamelement, a cam-element positioned adjacent the beam-element for moving a portion thereof laterally of its arcuate path, and a motor-operating switch actuated by said lateral movement. 6. In apparatus for automatic pulp-density control, a plurality of expansible chambers, means for maintaining a flow of fluid simultaneously through the chambers, means for discharging the respective flows of fluid at different depths in a body of pulp, whereby the chambers are expanded or contracted according to pulpously through the chambers, means for discharging the respective flows of fluid at different depths in a body of pulp, whereby the chambers are expanded or contracted according to pulpdensity variations, a beam-element connected with the chambers and fulcrumed for arcuate movement thereby, a portion of said beamelement being capable of movement laterally of its arcuate path, a motor-operating switch actuated by such lateral movement, according to v the arcuate position of said beam-element, and a tently moving a portion thereof laterally of its arcuate path, and a motor-operating switch actuated by said lateral movement, according to the arcuate position of said beam-element.

9. In apparatus for automatic pulp-density control, a plurality oi expansible chambers, means for maintaining a flow of fluid simultane ously through the chambers, means for discharging the respective flows of fluid at different depths in a body of pulp, whereby the chambers are expanded or contracted according to pulpdensity variations, a beam-element connected with the chambers and fulcrumed for arcuate movement thereby, a portion of the beamelement being capable of lateral movement, with reference to its arcuate path, a motor-operating switch actuated by such lateral movement, according to the arcuate position of said beamelement, and a variable cam-element positioned adjacent the beam-element for moving a portion thereof laterally,

JAMES A. ADAMS.

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