US2873889A

US2873889A - Fluid proportioning apparatus

Info

Publication number: US2873889A
Authority: US
Inventors: Ernest A Mori
Original assignee: Gulf Research and Development Co
Current assignee: Gulf Research and Development Co
Priority date: 1956-12-31
Filing date: 1956-12-31
Publication date: 1959-02-17
Anticipated expiration: 1976-02-17

Description

Feb. 17, 1959 EA. MORl FLUID PROPORTIONING APPARATUS 3 Sheets-Shet 1- Filed Dec. 51, 1956 hill}! INVENTOR.

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Feb. 17, 1959 E. A. MORI 2,873,889

\ FLUID PROPORTIONING APPARATUS Filed Dec. 31, 1956 n IN V EN TOR. P 5" 4 501/557 .4. we/ BY Feb. 17, 1959 E. A. Mom 2,873,889

FLUID PROPORTIONING APPARATUS Filed Dec. 51, 1956 5 Sheets-Sheet 3 ,k ff,

VENTOR. Raga? fave-s7 .4. M021 2,873,889 I FLUID PROPORTIONING APPARATUS Ernest A. Moi-i, Pittsburgh, Pa., assignor to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware Application December 31, 1956, Serial N0.' 631,672 7 Claims.' (Cl. 222-434) This invention relates to a fluid proportioning system and more particularly to a fluid proportioning system adapted for blending and dispensing a plurality of gasolines in gasoline service stations. 7

Most gasoline service stations have for some time ofler ed for sale only two grades of gasoline, each having a relatively difierent octane number rating The better quality gasoline ordinarily possesses an octane rating sufiicient-to avoid knocking in'the relatively fewauto engines'th'at exhibitthe most extreme knocking tendencies, while the lower grade gasoline is adapted to func- :tion withoutknocking in auto engines having substantially less severe knocking tendencies. The spread'be- 'tween the octane number requirement forthenewest 'auto models and that for the much greater number of "earlier model autos that are capable of using the lower grade of gasoline marketed in service stations has now" -become quite large, so that a substantial number of motorists whose auto engines have octane requirements between-the twogrades of gasoline normally marketed -mu'st, to ayoid'knocking in their engines,-purchase gasolineof considerably better grade than the minimum grade required. In order to alleviate this condition, several manufacturers have considered it desirable to market a -'third grade ofgasoline intermediate in c 7 quality between the'two gradesnormally marketed." j

Although at bird grade of gasoline can be marketed by installing a third set of storage and pumping facilities "in existing service stations, bulk plants and refineries,- a considerablesaving can be effected by utilizing existing dual-storagefacilities and by marketing a blend of the present higher andlower octane gasolines blended at service station at the time of'purchase.

It has been heretofore proposed to accomplish blending of gasolines in the service stations by the use of adthe -' 'justable proportioning valve devices, but 'difliculty is -ordiriarily encounteredin such systems in maintaining. -a*co'nstantproportion of component gasolines in the blend. This is duetoan independentvariation in pressuredifferential across the respective proportioning valves that results primarily from independent variation in the j respective tank levels; Specially designed gasoline proportioning and dispensing pumps have also been proposed as a solution to blending-of gasolines at the service station, but such pumps are normally relatively expensive since they usually involve several'duplicate parts and inthat they are sufiiciently unconventional as to present substantial-problems of manufacture and supply.

According to the present invention there is provided a relatively low cost proportioning and dispensing system that'is-adapted for use in combination with the standard gasoline dispensing pumps currently used and offered to 1 the: trade, without substantial alteration or redesign of 2,873,889 Patented Feb. 17, 1959 "ice pump means associated with each of the branch supply conduits and adapted to cause flow through the branch supply conduits in the direction of the main supply conduit; A positive displacement dispensing pump is connected on its suction side to the main supply conduit and to a dispensing conduit on its discharge side. Bypass means is provided for recirculating pumped fluid in excess of the amount that can be discharged from the dispensing pump into the dispensing conduit, said fluid 1O being bypassed from the discharge side of the pump to the suction side of the pump. A substantially constant speed motor is provided for driving the dispensing pump. The invention further includes a hydraulic motor operatively associated with the dispensing conduit and means associated with said hydraulic motor and adapted to drive the proportioning means in a manner such that a total of one volume of fluid is caused to flow through the proportioning means for each volume of fluid passed through the hydraulic motor. The invention also includes a valve in the dispensing conduit adapted to control fluid flow therethrough.

Referring now briefly to the drawings there is shown in Figure 1 a schematic flow diagram, partly in section,

of a gasoline proportioning and dispensing system embodying the principles of this invention. Figures 2 and 3 comprise respectively front and side elevations, in section, of the rotary spur gear proportioning device of Figure 1.

'Figure 4 is a sectional plan view of another rotary spur gear proportioning device suitable for use in the combination of Figure 1, the device of this figure being especially characterized by the provision of means for varying the =flow proportion through the respective sides thereof.

Figure 5 comprises a schematic side view of another proportioning device of the type shown in Figure 4 but embodying a ditierent variable transmission means between the respective sides of the device. Figure 6 is a sectional side elevation of a rotary internal-external gear pump that can be used in parallel in place of the proportioning device in the combination of Figure 1. Figure 7 is a sectional side elevation of a vaned blending pump that can be substituted for the proportioning device of Figure 1.

- Referring now to Figure 1 in greater detail, operation ofrotary type positive, displacement dispensing pump 12 causes a reduction in pressure on the inlet or suction side of the pump; Atmospheric pressure acting on the gasolines in tanks A and B, not shown, causes flow ofthese gasolines from the tanks, through branch supply conduits 2 and 4, toward pump 12. The gasolines from tanks A and B are caused to flow in a fixed proportion shaft 8, which is common to one gear on each side of means 6.

In the illustrated embodiment, shaft 8 comprises means connecting the positive displacement pumps and controlling the ratio of flow therethrough. Where the rotary spur gear pumps are of the same size and possess a common connecting shaft, as in the illustrated embodiment, the volume proportion of the component gasolines delivered to the outlet of means 6 will be substantially equal.

The gasolines from tanks A and B are blended at the discharge side of the proportioning device 6, and the mixture then passes into main supply conduit 10 toward the suction side of dispensing pump 12, which is con nected in series in line 10. Pump 12 is driven at an essentially constant speed by electric motor 14 which also operates at a substantially constantrspeed. 1 The blended gasoline is conveyed from the suction side of pump 12 3 by rotation of vaned pump rotor 22 into the discharge side of the pump and then into dispensing conduit 24. Dispensing pump 12 has a capacity such that it will pump gasoline at least as rapidly as, and usually more rapidly 'than, the maximum rate at which it is dispensed from the system. T he volume of gasoline that ispassed through the pump in excess of the volume dispensed from the system is recirculated through bypass conduit 18, through spring-loaded, pressure relief valve and to the suction side of pump rotor 22.

Connected in series in dispensing conduit 24 is an air eliminator 26 which comprises essentially a battle chamber designed to facilitate separation of air bubbles from the gasoline before the latter is passed through meter 28, also connected in series in dispensing conduit 24 down stream of the air eliminator. Air bubbles separated from the gasoline in air eliminator 26 pass through a small diameter conduit, not numbered, into chamber 46 from which the air is vented to the atmosphere. The gasoline level in chamber 46 is controlled by a float controlled valve as illustrated. As the gasoline level in chamber 46 rises, the float controlled valve opens, and excess gasoline recirculates to the inlet side of dispensing pump 12.

Returning now to the description of liquid flow through the system, the volume of gasoline passed through dispensing conduit 24 is measured by passage through meter 28 which comprises a hydraulic motor having a rotary shaft 30 Whose rotation is directly proportional to the volume of liquid passed therethrough. The rotation of shaft 30 is translated into total gallons and total sale price by a system of gears in variator 32 and computercounter 34. The rotation of meter shaft 30 drives the connected, rotary spur gear pumps that comprise proportioning device 6 through a pair of beveled gears 36 and a drive shaft 38. In the illustrated embodiment, drive shaft 38 and beveled gears 36 comprise the means associated with the hydraulic motor (meter 28) adapted to drive the positive displacement pumps of the proportioning device. The rotations of the spur gear pumps of proportioning device 6 and the rotation of meter shaft 30 are so interrelated that for each unit volume of gasoline that is caused to flow through meter 28, a total of one unit volume of gasoline will be caused to flow from branch supply conduits 2 and 4, through proportioning device 6, to main supply conduit 10.

The provision of means associated with meter 28 adapted to drive the connected spur gear pumps of means 6 is important to the present invention, since otherwise, the pressure difierential across the main supply conduit 10 and one or both of branch supply conduits 2 and 4 due to the friction of the spur gear pumps would tend to promote partial vaporization of one or both of the component gasolines, together With other attendant difficulties. For example, partial vaporization of one of the gasolines only, or unequal vaporization of both gasolines, would produce blending in proportions other than those produced when the gasolines are blended in liquid form only.

Continuing with the detailed discussion of the system shown in Figure l, the blended gasoline passes downstream from meter 23 through a check valve, not numbered, through visi-gauge 40 and out of the system through dispensing nozzle 42 at a rate controlled by manually operated, spring-loaded dispensing valve 44.

Dispensing pump 12, air eliminator 26, meter 28, variator 32, computer-counter 34, visi-gauge 40 and dispensing nozzle 42 are suitably of any conventional kindand, as such, they form no part of this invention. ample, the listed items can be of the type illustrated in brochure P-494 of the Gilbert and Barker Manufacturing Company of West Springfield, Massachusetts.

For a clearer understanding of the structure and operto Figures 2 and3. In these figures, like parts have For exation of proportioning device 6, reference is now had been designated by the same numerals. As will be seen from reference to these figures spur gears 7 and 7' are axially mounted on shaft 8. Behind spur gears 7 and 7' and meshing therewith there is disposed a pair of independently mounted, axially aligned spur gears. The sectional end view shown in Figure 3 illustrates the relationship of spur gear 7' with its meshing, independently mounted spur gear 7. A similar relationship exists with spur gear 7 and its meshing gear, not shown.

In operation, rotation of shaft 8 in a clockwise direction causes clockwise rotation of spur gears 7 and 7 and counterclockwise rotation of the spur gears meshing therewith, whereupon liquid is caused to flow from the respective inlet lines around the inner periphery of the proportioning device housing. As will be seen, the pressure differentials across main supply conduit 10 and branch supply conduits 2 and 4 can vary quite widely without causing any change in the proportion of liquids delivered. A greater pressure differential across one pair of spur gears than across the other, that is, a pressure differential between branch supply conduits 2 and 4, tends to cause one spur gear pump to act as a motor and the other as a pump. Since both pairs of spur gears rotate in a fixed ratio, the liquid proportion is maintained constant.

Although in the embodiment of the invention illustrated in Figure l the means associated with meter 28 and adapted todrive the connected spur gear pumps of proportioning device 6 has been shown as a shaft 38, the invention is not limited to such structure. Any other suitable means for transmitting the rotary motion of shaft 30, either directly or indirectly, to the spur gear pumps of proportioning device 6 can be used. For example, where the proportioning -device 6 is relatively remote from meter 28, it is advantageous that the rotary motion be transmitted over most of the distance between the meter and the proportioning device by means of a pair of self-synchronous, or so-called selsyn, electric motors, or means having equivalent function. Such motors can be interposed in conventional fashion in place ofshaft 38.

Although the hydraulic motor shown in the embodiment of Figure 1 comprises the flow meter of the system, as is advantageous and preferred, this is not essential to the invention in its broadest form. A separate hydraulic motor adapted to drive the proportioning device 6 can be connected in the dispensing conduit between the dispensing pump 12 and the dispensing nozzle 42, preferably between the dispensing pump -12 and meter 28. Nor is it necessary that the power take-off be connected with the standard metershaft, astshown. If desired, a separate shaft fordrivingthe proportioning device can be provided as shownin dotted lines in Figure -1. I

Instead of the proportioning device 6shown in Figures 1, '2 and 3, other devices capable ofperforming the same function can be used. -'For example, the devices shown in Figures 4, 5; 6 and 7 can be used. In theembodiment illustrated in Figure 4, the spur gears mounted on

shafts

50 and 52 mesh with each other as do the spur gears mounted on

shafts

50 and 52. The gear mounted on shaft 50 is rotationally connected with the gear mounted on shaft 50 through a frictional drive train comprising disks58 and 58', mounted respectively on shafts 50' and Y50, and disk 56, axially mounted in an annular recess on threaded screw 54. The disk 56 frictionally engagesdisks 58 and 58' and determines the ratio of revolutions of the gears mounted on shafts 50 and 50', and as a consequence, of the gears-meshing therewith. Theratio of revolutions of the respective spur gear pumps is varied by varying the position of disk 56., The position-of disk 56 is controlled byadjustmentot threaded screw 54.

ln the modification of-Figure 5 the respective .sides of the spur gear pump means are connected by means of a pair of truncated .cones 60 and 60' and a friction disc-62 adapted to drive both cones and the respective spur gear pump'means that are connected therewith. Driving gear 612a? in turn mounted upon shaft 63 which engages keyed 's t 38.

In the illustrated embodiment the ratio of revolutions of the respective spur gear pumps, and therefore of the fluid passed therethrough, can be varied by moving driving gear 62 toward the apex of one or the other of cones 60 and 60'. In this embodiment, one or the other of the spur gear pumps can be completely disengaged from the power take-01f of the hydraulic motor by moving drive gear 62 until-it engages only one cone at its apex end. When the device is employed in this fashion, suitable locking means, not shown, will be provided to prevent the disengaged pump from turning.

In Figure 6 there is shown another means for controlling the proportion of liquids blended, comprising a rotary, variable flow volume, internal-external gear pump. Two of these pumps can be substituted for the two spur gear pumps employed in the embodiment illustrated in Figure 1. In operation, the internal or driving gear 70 at its lowest elevation meshes with and drives the external or ring gear 72. The quantity of liquid that the internal-external gear pump will pass depends upon the position of side plate 74 in relation to fixed abutment 76. The position of plate 74 is controlled by rotation of screw 78 which in turn meshes with and rotates the rack gear 80 attached to side plate 74. Downward movement of plate 74 permits less fluid to be trapped between the internal gear 70 and external gear 72. Conversely, upward movement of plate 74 causes more liquid to be trapped in the internal and external gears and an increased amount of liquid to be discharged. When a pair of connected internal'external gear pumps is employed as the proportioning device, it is preferred that the flow adjustment means of the respective pumps be mechanically linked so that adjustment of the flow through one gear pump will simultaneously cause an opposite adjustment of flow in the other pump. Because of the variable volume feature of the pump of Figure 6, various fluid proportions can be obtained without the use of a variable transmission.

In Figure 7 there is shown still another means for controlling the proportion of liquids blended. The blending pump in this instance comprises a vaned rotary pump having alternate inlet conduits and outlet conduits spaced about the periphery of the elliptically shaped pump chamber, with the outlet conduits being joined to form a common discharge line. In operation clockwise rotation of vaned rotor 82 causes liquid to be conveyed continuously from inlet line 4 between the vanes of the vaned rotor 82 to line 83. At the same time, liquid is continuously conveyed in the space between adjacent vanes of rotor 82, from inlet line 2 to outlet line 10, where the discharge is blended with the discharge from line 83. The vanes referred to are urged into frictional contact with the pump housing, thus forming a liquid seal, by means of resilient spring members, not shown. The proportions of liquid from line 2 and from line 4 can be adjusted by changing the relative position of rotor 82 in the elliptically shaped pump chamber along the major axis of said chamber. The rotor 82 is driven by rotation of shaft 38.

As indicated, in all of the embodiments described it will be understood that the rotations of shaft 38 are interrelated to the capacity of the proportioning device through choice of a proper gear ratio so that the total volume of liquid passed by the proportioning device is just equal to that passed by the hydraulic motor. In a specific embodiment, assuming the proportioning pump structure shown in Figures 1 to 3, a fluid displacement for the meter of 57.75 cubic inches per revolution of the meter shaft, and a 1:20 ratio of revolutions for the meter and the proportioning pump, a suitable spur gear proportioning pump might involve a pitch diameter of 1.125 inches per pair of gears, 7 teeth per gear, an addendum (difierence between the pitch radius and the O. D. of the gear) of 0.1875 inch, and a tooth face width of about 1.125 inches.

A pair of connected spur gear pumps having the fore going dimensions will pass a total of.2.888 cubic inches per revolution.

It will be appreciated that placing of the proportioning device upstream of the dispensing pump is advantageous in that such placement permits use of standard gasoline dispensingpumps as blending pumps, without substantial redesign. It will also be appreciated that the herein disclosed invention permits passage of the entire blended product through. the dispensing pump, thereby avoiding abnormal loading of the bypass system attendant to placing the proportioning device downstream of the dispensing pump. The herein disclosed invention also permits pumping of two liquids in varying proportions using both a single dispensing pump and a single flow meter. The disposition of the proportioning means upstream of the dispensing pump and of the driving means downstream of the dispensing pump affords a major advantage. Such structure permits the proportioning means to act as a booster pump, thereby reducing the lift requirements of the dispensing pump. This is important from the standpoint of minimizing the possibility of cavitation.

Many modifications of the herein described proportioning system will suggest themselves to those skilled in the art. For example, an auxiliary meter shaft and beveled gear elements shown in dotted lines in Figure 1 can be used for driving shaft 38 instead of beveled gears 36. Other positive displacement pumps than those illustrated can be employed in the proportioning means. Also, the disclosed system is adaptable in an obvious manner to the blending of more than two fluids.- It will also be apparent that two or more fluids other than gasoline can be blended in a fixed, predetermined proportion using the herein described invention. For example, lubricating oil blends, solvent blends, various liquid-liquid systems and even gaseous blends can be formed using the herein described invention or modifications thereof. In addition, various changes in form, size, arrangement of parts, operation and mechanical details can be made.

These and other modifications of the herein described invention can be resorted to without departing from the spirit or scope thereof. Accordingly, only such limitations should be imposed as are specifically set forth in the claims appended hereto.

I claim:

1. A fluid proportioning apparatus comprising a main supply conduit, a plurality of branch supply conduits connected to said main supply conduit and to separate sources of supply, proportioning means comprising positive displacement pump means associated with each of said branch supply conduits and adapted to cause flow in the direction of the main supply conduit, a positive displacement dispensing pump connected on its suction side to said main supply conduit and connected to a dispensing conduit on its discharge side, bypass means for recirculating pumped fluid in excess of the volume dispensed from the system from the discharge side of the dispensing pump to the suction side of the pump, a substantially constant speed motor for driving said dispensing pump, a hydraulic motor operatively associated with said dispensing conduit, means associated with said hydraulic motor adapted to drive the proportioning means whereby a total of one volume of fluid is caused to flow through the proportioning means for each volume of fluid that is caused to flow through the hydraulic motor, and a delivery valve in said dispensing conduit adapted to control flow through said conduit.

2. The apparatus of claim 1 where the proportioning means comprises a vaned positive displacement pump connected successively at the periphery of the pump chamber to one of said branch supply conduits, a first discharge conduit, a second branch supply conduit, and a second discharge conduit, said first and second discharge conduits being adapted to discharge into said main supply conduit.

3. The apparatus of claim 1 where the proportioning ge /sees means comprises a positive displacement pump connected to each of the branch supply conduits and adapted to cause flow in the direction of the main supply conduit, and means connecting said pumps and controlling the ratio of rotation thereof.

4. The apparatus of claim 2 where each of the positive displacement pumps comprising the proportioning means comprises a pair of meshing spur gears.

5. The apparatus of claim 2 where the positive displacement pump comprising the proportioning means comprises a pair of coaxially mounted internal-external gear pumps provided with adjustable means for controlling flow therethrough.

6. The apparatus of claim 2 where the means connectcomprises a fluid flow meter.

References Cited in the file of this patent UNITED STATES PATENTS 1,964,028 Boynton et a1 June 26-, 1934 1,985,918 De Lacey Jan. 1, 1935 2,057,226 Bleecker Oct. 13, 1936 2,600,477 Burt June 17, 1952 2,743,843 Bliss May 13, 1956