US2024480A

US2024480A - Proportioning device for fluids

Info

Publication number: US2024480A
Application number: US734269A
Authority: US
Inventors: Robert J Short
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1934-07-09
Filing date: 1934-07-09
Publication date: 1935-12-17
Anticipated expiration: 1952-12-17

Description

Dec. 17, 1935. R J, SHORT 2,024,480

PROPORTIONING DEVICE FOR FLUIDS Filed Jul 9, i934 2 Sheets-Sheet 1 I2 3 2'} ll 1 '1 I III m INVENTOR. RQBE/PTJ 5710/??? ATTORNEYS.

Patented Dec. 17, 1935 PATENT OFFICE PROPORTIONING DEVICE FOR FLUIDS Robert J. Short, Cincinnati, Ohio, assignor to The Procter & Gamble Company, Cincinnati, Ohio,

a corporation of Ohio Application July 9, 1934, Serial No. 734,269

12 Claims. (01. 137-165) This invention relates to a device for delivering two or more fluids simultaneously in definite proportions to each other, which can be varied at will, and is particularly adapted to the proportionlng of several liquids, although the physical condition of the fluid is not a limitation upon my invention, since one or more may be gaseous, and others liquid.

The object of the invention is to provide a device of this character which will be smooth, positive, and-reliable in operation, adjustable to deliver diiferent proportions as desired within reasonable limits, and which will stop all flow automatically if for any reason one fluid falls below or exceeds a predetermined limit.

This application is related to my copending applications, Serial No. 702,266, filed December 13, 1933, and Serial No. 729,277, filed June 6, 1934.

In many industrial operations it is desirable to continuously mix two or more fluids in definite and sometimes variable proportions. The continuous proportioning of molten kettle soap and silicate of soda or sal soda solution in soap making, of crude vegetable oil and caustic soda solutions for use in the continuous refining of vegetable oils, or of petroleum oils and sulfuric acid, are examples of the application of this device; and many others might be mentioned. Various devices have been proposed for accomplishing this object, but all are objectionable for one reason or another; some give a pulsating flow instead of a smooth, continuous flow; some of the devices cannotbe closely controlled or cannot be readily adjusted to change from one proportion to another, and none, as far as I am aware, will automatically stop the flow if the flow of one of the fluids becomes interrupted. It is an object of my invention, therefore, to overcome all these difliculties.

The device herein described is especially applicable in cases where a pump is more desirable for measuring and delivering the secondary fluid, in contrast to the used a meter. This is particularly true when the ratio of the secondary fluid to the primary fluid is extremely small.

My device in its simplest form as applied to two fluids consists essentially in the use of a suitable differential, one of whose primary shafts is caused to rotate by a rotatable member in the line of flow of the primary fluid; the other of whose primary shafts is caused to rotate by a variable speed motive means. The secondary member of the differential, whose action depends on the speed relation of the two primary shafts, actuates a valve or other suitable control device controlling the speed of the variable speed motivemeans so that the rotation of said motive means is always in fixed relation to the rotation of the primary rotatable member. In addition to operating the secondary primary shaft of the 5 diiferential the variable speed motive means'operates a rotary gear pump which delivers the secondary fluid in proportion to its speed. The above interrelated parts are so connected that when the two primary shafts of the differential 10 are operating at the proper speed relation, the secondary pump will be operating at the speed required to deliver the correct proportion of the secondary fluid. An electrically operated valve or other suitable device, so arranged as to stop 15 the flow of the primary fluid whenever the secondary fluid falls below or exceeds a desired limit, is inserted in the line of flow of either the primary fluid or of the mixture of primary and secondary fluids. A stopping of the primary 20 fluid will in any event automatically stop the entire device. Various modifications of this principle may be used, and for the purpose of an exemplary disclosure, some of the preferred forms of the device and methods of applying the same are more fully set forth herein. The accompanying drawings will make these parts and their interrelated action clear.

Reference is now made to the drawings which form a part hereof, and in which- Figure 1 shows a plan view of one form of my device, and

Figure 2 shows a plan view of a modification thereof.

Referring first to the general layout of the apparatus as shown in Figure 1, a pump I, which may be any suitable form of positive acting pump, such as a gear pump, has an inlet 2 which is understood to lead from the primary fluid supply, and has an outlet 3; and leading from the outlet 3 to the inlet 2 is a by-pass 4, controlled by a yielding valve 5. A pump of this type will maintain a positive pressure depending upon its rate of operation, and upon the setting of the yielding valve 5. If its outlet is restricted to a certain ex- 45 tent, the by-pass valve 5 will open, so that there will be no overload upon the pump driving mechanism, such as a motor. If the outlet should be entirely closed, the entire amount of fluid passed by the pump gears will flow back through the 50 by-pass. At the same time it will be seen that for a given rate of operation the pressure at the outlet end of the pump will remain constant as determined by the pressure on the valve in the by-pass. If the outlet is open, fluid will flow 55 under this pressure; if the outlet is completely closed, the flow of fluid will be stopped, but the static pressure at the outlet end will be maintained.

A pump such as above described is preferable because it can be used with the aforementioned results, and the output of the apparatus can be controlled and determined by stopping the flow at the outlet end of the apparatus if desired.

The pipe line 55 conducts the primary fluid from the outlet of the rotary pump to the inlet of a device 5 having a rotatable member which is caused to rotate at a speed proportionate to the flow of the fluid through it. This device may conveniently be a meter of known type, having a counter I to indicate the quantity of fluid passing through the device in a given time. The shaft 8 of the rotatable member, which is caused to extend from the casing of the meter, is connected to one of the primary shafts 9 of the differential device III. N indicates the pipe through which the primary fluid leaves the device 6 and flows through a suitable check valve H to join the secondary fluid.

The second primary shaft l3 of the differential is driven through suitable means by shaft H of a fluid motor l5, which may be of any well known type, whose speed of rotation is dependent on the volume of fluid passing through it. The external fluid l6 employed to drive the fluid motor may be water, mineral oil, or any similar material. A drum I1 is provided as a reservoir for the external fluid. |8 designates the delivery line leading from the drum I to the intake 9 of the pump 20 which is of any well known, positive delivery type similar to the pump I described above, and which is driven by a motor 2|. The discharge of the pump 20 flows through a pipe 22 which is then divided into branches 23 and 24. The portion of the fluid conducted by the branch 23 passes through a check valve 25 and then to the fluid motor IS, the discharge line 26 of the said fluid motor returning the fluid to the reservoir II. The branch 24 conducts the remaining portion of the fluid through a balanced control valve 21 operated by the secondary member of the differential to the reservoir l1. Although the external fluid system, as I have shown it, is an open system, it may well be a closed system, provided of course there are no leaks.

The shaft I4 which has been said to drive the second primary shaft l3 of the differential, also drives, through suitable connections, the shaft 33 of the secondary pump 28 which is also of the positive delivery type previously mentioned. The secondary fluid is conducted through a pipe 23 from a source of supply to the pump 28 which discharges into a line 3|), the secondary fluid passingthrough a check valve 3| to a conduit I, there joining with the primary fluid. The mixture of proportioned primary and secondary fluids is then conducted to a mixer or elsewhere as desired.

Figure 2 shows a somewhat different arrangement of my invention, adapted to the proportioning of three fluids, in which the pump shafts of the secondary and tertiary fluids, 33 and 34 respectively, and the secondary primary shaft i3 of the differential, are operated by the variable speed shaft |4 actuated by the variable speed motor 35. The arm 39 of the rheostat is caused to move by the arm 48 of the secondary member of the differential, through suitable connecting means, to increase or decrease the speed of the motor so as to obtain the proper speed relation between the two primary shafts.

Inthe drawingsIhaveshown a chain and sprocket means of connecting the variable speed shaft H to the shafts of the'rotary pumps delivering the controlled fluid. This method of connection is quite desirable when the proportion of the ingredients is relatively constant. However, in some operations it is desirable to change readily from-one proportion to another and in this case a. variable speed transmission of any well known type may be used in place of the chain and sprocket shown. In this manner the proportions may be varied at will from time to time.

The particular type of differential mechanism is not a limitation upon my invention. In my specific embodiment the first primary shaft 9 of the differential is threaded as shown, the threads extending substantially from end to end thereof inside the housing of the differential. Mounted on the said threaded shaft 9 is a gear or secondary port not shown. The lever 40 is connected through a suitable linkage and lever to the arm of the rheostat 38. 41 indicates diagrammatically an electrical switch or switches arranged to be moved by the lever 40 against

abutments

48 and 49 respectively so that an electrical contact will be made when the lever moves in extreme position either to the right or to the left. The closing of these contacts can be made to operate means for stopping the flow of fluids and/or suitable signals in any well known manner. For this purpose I have shown a switch 41 connected by leads 5!! and 5|, in one of which a source of current 52 is inserted, to the solenoid 53 of the magnetically operated valve 54 in the inlet line 55 of the device 6. naling means 56 connected in parallel with the solenoid. This device will operate if for any reason the proper speed relation between the secondary pump and the primary rotatable member cannot be maintained. Any other known device for stopping the flow of the fluids may be used. An additional safety device may be inserted in the discharge line of the secondary fluid, preferably including a pressure gauge 51 which in addition to having a dial to indicate the pressure of the supply of the ingredients, also includes a pair of

electrical contact elements

58 and 59 by means of which an element 60 moved by the pressure gauge will complete a circuit through the

connections

58 and 59 and the coil of the solenoid 53. The parts are adjusted so that if the pressure in the secondary ingredient supply falls below a desired given value the gauge will make the contact and the solenoid will act to close the valve 54 and stop the flow of the primary fluid, the pump by-passing as has been described, when this happens. By this means it is insured that the primary fluid will not be passed through the apparatus without the supply of the secondary fluid. The combined action of the dif- The hub of the I have likewise shown a sigferential and the external motive means for moving the secondary pump insures proper correspondence of the quantities of the primary and secondary fluids so long as the pump 28 and the other parts of the secondary fluid system are in proper working order. This provision would not function, however, should the pump 28 for any of these reasons fail to supp y the rated amount of secondary fluid, notwithstanding that its proper speed was maintained through the operation of the diiferential and external motive means.

The principle of operation of the device shown in Figure 1 is as follows, assuming that two fluids are to be mixed:

The flow of the primary fluid causes the rotating member of the meter 6 to rotate in direct relation to the mount of fluid flowing, and through suitable connections causes the primary shaft 9 of the differential to operate at a certain speed. The primary fluid then flows through the pipe II to meet the secondary fluid which is being introduced into the pipe line at some other point 6|. The second primary shaft |3 of thedifferential is caused to operate, through suitable connections, by the fluid motor |5, its speed depending on the amount of external fluid flowing therethrough. The control valve 21 is inserted in a line by-passing the fluid motor, so that any proportion of the external fluid pumped from the reservoir throughthe line 22 may be allowed to by-pass the fluid motor IS. The shaft l4 of the fluid motor also drives, through a chain and sprocket, variable speed transmission, gears, or any other suitable means, the rotary pump 28 for supplying the secondary fluid. Since this secondary rotary pump is of the positive acting type, similar to the pump described before, the amount of secondary fluid discharged into the primary fluid will depend on its speed of rotation. As long as the primary rotatable member and the secondary pump operate at the required speed relation, the flrst and second primary shafts 9 and I3, respectively, will operate at their required speed relation, in which event the secondary member 4| will maintain its position without lateral movement along the shaft 9; but if the primary shafts fail to rotate at the required speed relation indicating that the primary rotatable member and the secondary pump are not operating at the required speed relation, the member 4| will move in a lateral direction to the right or to the left along the threaded shaft, the direction of motion depending on which shaft is moving faster. The lever attached to this secondary member 4| is thereby caused to move in the same direction as the member 4| and in combination with a suitable fulcrum will operate the stem of the balanced control valve 21 to open or close the said valve as required, thus decreasing or increasing respectively the flow of the external fluid through the fluid motor, until the desired speed relation is again restored, whereupon the two primary shafts of the differential, the secondary pump, and the primary rotatable member will again rotate at the required speed relation, with the member 4| in a position of equilibrium. By suitably adjusting the length or position of the lever arms a proper setting is obtainable, so that the gear 4| in its lateral movement disengages from the gear 42 at the maximum and minimum openings, respectively, of the valve 21. If the rate of flow of the primary fluid is changed by throttling at any point in the system, it is obvious that the device will automatically compensate for this through the differential, by causing the rate of flow of the external fluid through the fluid motor to change so that the speed relation between the two primary shafts of the differential is maintained. Likewise any throttling of the discharge line carrying the mixed fluids will reduce the total flow without permitting the proportions of the two fluids to vary.

The operation of the device shown in Figure 2 is the same as that of Figure 1, except that the 10 required speed relation of the various rotating parts is maintained by increasing or decreasing the power supplied to the variable speed motor through the rheostat which is actuated by suitable means connected to the secondary member of the differential.

It is, of course, possible to design this type of differential so that the two primary shafts, instead of rotating at identical speeds, will rotate at different speeds while maintaining the secondary member 4| in its proper lateral stationary position of equilibrium. This could be the case, for example, if the gear 42 were made with a different diameter and different number of teeth from the secondary member 4|. Such a variation, however, would be considered equivalent to the differential as described for all intents and purposes. It is also obvious that any other type of differential may be used, providedonly that it has two. primary driven members co-acting on a sec- 0 ondary member in such a way that the motion of the latter, whether rotary or lateral, can be used to control the secondary fluid. My invention is not limited to the type of differential shown, but covers the use of any diiferential in substantially 5 the manner described in connection with a suitable means of control.

It is to be understood also that means of power transmission other than a lever or levers, as shown and described may be used between the secondary 40 member of the differential and the stem of the control valve or other control means. A rotary screw motion or a worm gear type of transmission may be used, or any other of the well known mechanical means for accomplishing this object. My invention is not limited to the use of the lever, therefore, but is intended to cover any means of transmitting motion from the secondary member of the differential to the stem of the control valve, or to the pump, or to the rheostat, or to other control means in such a way as to control the speed of the variable speed shaft 4.

The relative proportions of the two fluids can readily be changed to any desired figure within the limits of the apparatus, by changing the size 5 of the sprockets or by changing the setting of the variable speed transmission apparatus as desired. It is hereby understood that the relative sizes of the rotatable member or meter, pipe lines, pumps, fluid motors, and valves willnaturally be 0 selected in accordance with the relative amounts of the different fluids to be handled, so as to obtain suitable speeds of rotation of the shafts within the desired range for use in this device.

Three or more fluids may be mixed or deliv- 5 ered proportionally in the same way that two are mixed, as shown in Figure 2, by extending the variable speed shaft i4 and by connecting to it, through chain and sprockets or through variable speed transmissions, another rotary pump for each added fluid being proportioned, it being understood that the choice of the size of the sprockets, or the setting of the variable speed transmissions, be such that each added pump operates at the required speed to deliver the correct proportion of corresponding fluid when the primary shafts of the differential are operating at the required speed relation. It is, of course, preferable that a gauge, containing the elecirlcal contacts previously described, be inserted in the discharge line carrying each added fluid, and that the said contacts be connected in parallel to the solenoid 53 and/or to the signaling means 56.

In order to prevent the continued flow of the primary fluid when the flow of the secondary fluid is interrupted for any reason, or when the required proportions cannot be maintained, suitable electrical safety devices are provided. These devices may include an electrical switch conveniently placed on the lever operating the balanced control valve and/or a gauge which contains adjustable electrical contacts and which is inserted in the discharge line of the pump delvering the secondary fluid. If the speed-of the secondary pump exceeds or falls below the set limit, the secondary member ll of the differential will then automatically travel in a lateral direction along the shaft 9 far enough to operate the electrical switch which will then operate a suitable electrically controlled valve, stopping the flow of the primary fluid or of both fluids. The electrical contacts located on the gauge are prov'ded to complete the electrical circuit when the secondary pump, although it may be operating at the required speed, is not delivering the required amount of secondary fluid, and therefore is not maintaining the pressure in the discharge lne within the set limit. These electrical devices may conveniently be connected in parallel with the electrically controlled valve and/or the signaling means. The safety device may also be arranged to cut oil the current supplying the motor which operates the pump supplying the primary fluid. Either method, therefore, stops the apparatus entirely, and it will not resume operat.on until the trouble is corrected. This feature is important and, I believe, has never been accomplished in any prior proportioning device.

This apparatus is easily constructed at a moderate cost, is simple in its action, gives a smooth flow of both fluids without pulsations, can, be readily adjusted to any desired proportion of two or more fluids, and will not permit any flow if the desired proportion for any reason cannot be maintained above a set limit.

Fluids of practically any kind or degree of viscosity can be handled satisfactorily in this device. Even liquids containing suspended matter forming a so-called sludge will operate satisfactorily provided the said materials will flow like a liquid.

It is to be understood that different forms of my preferred embodiment may be made without departing from the spirit of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

1. A device for controlling the flow of a fluid in definite proportion to the flow of a primary fluid, comprising in combination a rotatable memher in the line of flow of the primary fluid adapted to rotate in definite relation to the amount of fluid flowing, a pump for delivering the secondary fluid adapted to discharge said secondary fluid in definite relation to its speed of rotation, a suitable differential comprising a plurality of primary shafts and a secondary member, an external fluid delivery means, a fluid motor adapted to rotate in definite relation to the amount of external fluid flowing therethrough, and power transmitting means between the different elements so arranged that the said rotatable member causes one primary shaft of said differential to operate and that the variable speed fluid motor causes both the second primary shaft of said differential and said pump to operate, said primary shafts being caused to rotate at such a ratio of speed to each other as will hold the secondary member in a stationary position when the two fluids are flowing in the desired proportions but will cause movement in the secondary member of said differential when said ratio is disturbed; said movement being of such nature as to vary the speed of said fluid motor byvarying the flow of the external fluid therethrough so as to cause the secondary fluid to flow again in the desired proportion.

2. A device for controlling the flow of a fluid in definite proportion to the flow of a primary fluid and for stopping the flow of the primary fluid when the'flow of the secondary fluid falls below or exceeds predetermined limits, comprising the device described in claim 1 combined with a device comprising'an electrical switch actuated by the movement of the secondary member of the differential and an electrically operated valve on a line carrying the primary fluid, so arranged that when the flow of the secondary fluid falls below or exceeds predetermined pro- 1 portions, the movement of the secondary member of the diiferential will actuate the electrical switch causing an electrical current to close a valve in the line carrying the primary fluid.

3. A device for controlling the flow of a fluid in definite proportion to the flow of a primary fluid and for stopping the flow of the primary fluid when the flow of the secondary fluid falls below predetermined limits, comprising the device described in claim 1 combined with a control mechanism comprising means responsive to a control device located in the discharge line of the pump for the secondary fluid and an electrically operated valve in a line carrying the primary fluid so arranged that when the flow of the secondary fluid falls below a predetermined limit, the control device will close an electrical circuit causing an electrical current to close a valve in the line carrying the primary fluid.

4. In a device for proportioning the flow of fluids, means for delivering a controlling fluid, motive means actuated by the flow of said fluid in said delivery means in proportion to said flow, means for delivering a controlled fluid, motive means in said second delivery means adapted to discharge the controlled fluid into said second delivery means in proportion to the operation of said motive means, an equilibrium motion device having a plurality of primary driven parts and a secondary part adapted for movement upon the disturbance of a. given relationship of motion of the primary driven parts, a variable speed motive means, individual motion transmitting means between the variable speed motive means and both the motive means for delivering the controlled fluid and one of said primary driven parts, motion transmitting means between the motive means actuated by the controlling fluid and the other of said primary driven parts, a connection between said secondary part and the variable speed motive means, valve means in delivery means of said controlling fluid and means actuated by said secondary part for closing said valve means when said secondary part exceeds a given range of movement.

5. In a device for proportioning two or more liquids, a differential device having a plurality of primary moving parts and a secondary part which maintains a position of equilibrium as long as the several primary parts are moving in a definite speed relation, but which is adapted to move as soon as this relation is disturbed, means causing one of said primary parts to move in direct proportion to the flow of one of the liquids, an external fluid delivery means, a fluid motor adapted to rotate in definite relation to the amount of external fluid flowing therethrough, means causing other of said primary parts to move in direct proportion to the speed of said fluid motor, means driven by said fluid motor adapted to cause a flow of other of the liquids, and means responsive to the action of said secondary part to vary the speed of said fluid motor.

6. In a. device according to claim 5, means for stopping the flow of the first mentioned liquid when the flow oi the other several liquids falls below or exceeds predetermined limits, comprising an electrically operated valve in the line of flow of said first mentioned liquid, a switch actuated by the said secondary member at either extremity of its movement, and an electrical connection between the said switch and the said electrically operated valve.

7. In a device according to claim 5, means for stopping the flow of the first mentioned liquid when the flow of any of the several other liquids falls below predetermined limits, comprising an electrically operated valve in the line of flow of said first mentioned liquid, control devices in the lines of discharge of each of the other liquids, and means associated with the said control devices adapted to close an electrical circuit to the said electrically operated valve.

8.; In a proportioning device whereby a primary fluid flow controls a secondary fluid flow, the combination of a power drive for the primary fluid flow, a device responsive to the pressure of secondary fluid flow, and connections whereby movements of said flow responsive device beyond a prescribed range will cut off the power from said power drive.

9. In a proportioning device whereby a primary fluid flow controls a secondary fluid flow, the combination of an electric motor drive for the 5 primary fluid flow, a device moving in accordance with the pressure of the secondary fluid flow, and connections whereby movements of said flow responsive device beyond a prescribed range .will cut off the electric current from said electric motor drive.

10. In a liquid proportioning device having a diflerential with a plurality of primary parts and a secondary part, a prime mover which operates a pump for a secondary liquid and also one primary part of the diflerential, and a rotatable member in the line of flow of a primary liquid to operate another primary shaft of the differential, said prime mover comprising a fluid motor, and a valve for regulating the amount of fluid delivered to said fluid motor, said valve being controlled by the secondary part of the diiierential.

11. In a device according to claim 10, means for stopping the flow of the primary liquid when the flow of a secondary liquid falls below or exceeds predetermined limits, comprising an electrically I operated valve in the line of flow of said primary liquid, an electrical device actuated by the said secondary member at either extremity of its movement, and an electrical connection between the said electrical device and the said electrically operated valve.

12. In a device according to claim 10, means for stopping the flow of the primary liquid when the flow o! the secondary liquid falls below predetermined limits, comprising an electrically operated valve in the line of flow of said primary liquid, a control device in the line of discharge of said secondary liquid, and electrical means associated with the said control device suitably connected to 0 said electrically operated valve and adapted to operate same.

ROBERT J. SHORT.