US2223112A - Apparatus for pumping and separating gas and liquid bodies - Google Patents

Description

NOV. 26, 1940. J D LEAR 2,223,112

APPARATUS FOR PUMPING AND SEPARATING GAS AND LIQUID BODIES ATTORNEY Nov. 26, 1940. J. D. LEAR 2,223,112

APPARATUS FOR PUMPING AND- SEPARATING GAS AND LIQUID BODIES Filed Oct. 26, 1958 2 Sheets-Sheet 2 Fun-,.3

/59 Y i 60 66 Y d INVENTOR 6l 7:5506 D Lear af BW@ 6 63 ATTORNEY ratented Nov. 26, 1940 uNlTED STATES APPARATUS Fon PUMPmG AND SEPARAT- ING GAS AND LIQUID BODIES Joseph D. Lear, Buiialo, N. Y.. assigner, by mesne assignments, to Martin t Schwartz, Inc., a corporation ci' Maryland lApplication October 26, 1938, Serial No. 237,003

2Claims.

'I'his invention relates to the pumping of mixed gas and liquid bodies with the concurrent separation of the gas from the liquid, and it has particular reference to a novel combination of pump- 5 ing and separating instrumentalities, whereby separation may be effected under all normal running conditions of the pump.

In the retail dispensing of gasoline, it has heretofore been proposed to draw the gasoline, with l air entrained therein, from a low level reservoir by means of a displacement pump, whose eiiluent was delivered to a separating chamber to remove the air, prior to the passage of the liquid to a meter and'dispensing hose and nozzle. It has l also been proposed. in such apparatus, to drain recovered liquid, separated from `the air in a second stage, to the reservoir or directly to the pump inlet.

This proposal, while extensively used for a 20 number of years, has certain serious disadvantages, which are corrected by the present invention. For example, in the prior system just referred to, and because of the diiliculties in tightly closing the return line with a valve, there is fre- 25 quently a direct passage from the atmosphere to the pump inlet, thereby causing a :dow of air to the pump, instead of a ilow of liquid, which results in decreased pump capacity. Another disadvantage arises in such system during periods 30 of by-passing, which are encountered when the pump is running, but the dispensing nozzle is closed. During such periods, the pump not only may draw in air at the suction side, but it also recirculates whatever amounts of mixed air and 35 liquid may be passing through it. Accordingly, when the suction line is air-bound, as may occur with a faulty foot valve in the suction line, van appreciable time interval may elapse, after the pump isv started and the dispensing nozzle is 40 opened, before the pump will deliver its full liquid capacity. While this time interval may be measured in seconds, it is nevertheless significant, because the average motorist becomes very impatient at the least delay at the service station.

According to the present invention, there is effected a complete reorganization of the elements heretofore employed, so that, irrespective of whether the dispensing nozzle is open or closed, the pump, so long as it is driven by its motor, nevertheless is pumping liquid, with only such air as may be entrapped in the suction line, and is not drawing in any atmospheric air through the separator drain line. That is to say. accord- 55 ing to the present invention, means are provided whereby the suction side'of the pump is lconstantly protected from atmospheric air, and also the necessity of recirculating liquid re-f covered in the second stage of the separator, therebyincreasing 'the liquid capacity of the pump, and permitting it to prime itself in a shorter interval of time.

Such reorganization, as hereinafter more fully explained, is accomplished by causing the eiiiuent of the pump to become, in eifect, a secondary pump for returning recovered liquid to the main body of liquid which has already passed the pump, and for diverting any air which may be entrapped in such recovered liquid, or which may flow through the drain lines therefor, from the suction side of the main pump and back into the separator. More speciiically, the present invention provides for the discharge of the pump eiiluent through a Venturi passage, whose throat is connected to the recovery line, and whose discharge orifice is connected to the separator.

My invention further provides, in order to make this principle practically effective, that the main pump shall be provided with a by-pass, so that it may continue to run even though the dispensing nozzle be wholly or partially closed, and in order to make such provision practical, the bypass must be located at a point in the system beyond the discharge orifice of the venturi. That is to say, the components of my improved system must be so arranged that the secondary pump, or venturi, is constantly functioning so long as the main pump is running, and such constancy must be maintained whether the dispensing nozzle is open or. closed. Otherwise, the principle of the invention cannot be satisfactorily applied, as conditions of impossible or impractical operation would be encountered.

The invention therefore prevents the return of air or liquid to the inlet of the main pump, and also provides for the tertiary separation of any small amounts of air re-entering the primary separator, by permitting it to flow directly to the second separating stage. The overall capacity of the pump is therefore increased, and the entire system may be built without expensive parts vor iittings, and in a size satisfactory for inclusion in a dispensing unit.

A typical embodiment of the invention, as just described, is illustrated in the accompanying drawings, wherein:

Fig. 1 is a schematic view of a gasoline dis-- penser including the features of the present invention:

Fig. 2 is a view, partly in elevation and partly in section, showing the pump and separating units;

Fig. 3 is a section on the line 3-3 of Fig. 2, showing particularly the secondary pump or venturi; and

Fg. 4 is a fragmentary view, partly in section; on theline 4-4 of Fig. 3, showing the by-pass arrangement.

Fig. 1 shows schematically a gasoline dispensing unit, to which the present invention may be applied. Such units, as installed at service stations, comprise a casing C, in which is disposed an electric motor M, connected to a liquid pump P. The suction side of the pump is connected, by means of a pipe I8, toa reservoir (not shown) containing the gasoline to be dispensed, and wherein the gasoline becomes admixed with appreciable amounts of air. The discharge side of the pump is connected to a separator S, to effect the removal of the air, and the clarified liquid then iiows through a pipe II to a ow meter R., and thence to a dispensing hose D terminating in aV valved nozzle N. The electric circuit for the motor M istaken through a switch operable by a hook H, on which the nozzle is hung when not in use. When the attendant dispenses gasoline, he removes the nozzle from the hook H, moves the hook to start the motor M and pump P, but of course refrains from opening the nozzle until it is placed inthe automobile tank. With this general understanding of a setting for the invention, consideration will now be given to the novel pump and separator adapted to be `em-f ployed therein, and illustrated in the remaining figures of the drawings.

The pump P is preferably mounted on a vertical axis, and its inlet port I5 communicates with a supply source through the pipe I8, fitting I6, and pipe I1. The tting I6, which will be more particularly described later, contains a valved inlet 11a which acts to prevent gravity return of the gasoline in the system to its source during idle periods of the dispenser. y

The housing of the separator S is formed with a cylindrical separating chamberv 20, having tangential inlet and outlet bosses 24, 25 formed` in its upper and lower portions respectively. The outlet port 26 of the pump P is connected to the boss 24 by a coupling fitting 21, which, as will be observed in Fig. 3, is internally machined to provide a venturi passage 28. The entire discharge of the pump is thus directed through the Venturi passage 28, whence it enters the cylindrical chamber 28 tangentially, and then swirls vortical-A ly downward to the outlet boss 25.

The fitting I 6 is formed with a lateral extension 3| in the shape of an angle tting for connecting the boss 25 to the discharge conduit I I.\

A cylindrical baille 32 is formed in the upper wall 33 of the separator chamber 28, and it serves to shield an air escape fitting 34, located in the center of the wall 33, from the entrant liquid. The tting 34 contains an orice 30 through which air separated vthrough centrifugal and gravitational effects in the chamber 20 escapes via an attached pipe 35 to an overlying cylindrical float chamber 48.

The side wall 36 of the chamber 48 is formed integrally with the separator housing,'and `its open top is closed by a secured cap member 31. A vent pipe 38, secured to the cap member 31, establishes communication between the chamber 48 and the outside atmosphere for the escape of air and non-condensable gases discharged from the chamber 20 into the chamber 48.

A liquid return vent in the form of an externally connected tting 4I is located in the lower portion of the chamber 48. A bell crank 42 is mounted for pivotal movement on a stud 43 carried by a xture 44 secured within the cham. ber 48, and the arms 45, 46 of the bell crank carry respectively a float 41 and a valve'48. The tting 4I is formed with a seat portion 5I for the valve 48, and its external portion is connected to a tube 58 which communicates with an orice 58a in the throat 28a of the venturi passage 28.

'I'he pipe 35 of the previously mentioned air escape fitting 34 is .secured in a block 52 which contains a seat 53 and a cage portion 54 for a ball valve 55. The block is secured to the bottom of the chamber 48 ina position adjacent the right 'side of the bell crank arm 46. The arm 46 is fcapes through the orifice 38, and gradually fills the chamber 48, finally raising the float 41 to 'unseat the valve 48. The liquid in the chamber 48 is immediately withdrawn to the outlet side of the pump by the suction action of the venturi, and the iioat once more drops to seat the valve 48.

Simultaneously with the opening of the valve 48, the opposed ball valve 55 is moved toward its seat 53 in a progressive throttling action, which automatically decreases the rate of fluid iniiux during the slow opening movement of the valve 48.

The operation of the apparatus as thus far described is directed to an operative condition of the dispenser where the valve of the nozzle N is wide open, and consequently the full discharge of the deaerated liquid is directed through the meter. As oftenV occurs in gasoline pumping equipment, the nozzle valve is permitted to remain closed for considerable periods .while the pump is in operation, thus bringing into action a by-pass device for the pump. In the present instance, a pressure-responsive by-pass valve unit 51 bridges the suction line of the pump and the chamber of the separator.

As shown in Figs. 3 and 4, the unit 51 is conveniently organized with the inlet iitting I6, and it includes a cylindrical piston chamber 58 formed integrally with the fitting and having a port 59 communicating with the extension 3l, and lthus the discharge side of the separator chamber. in the form of a valve seat 68 communicates with the suction side of the pump, and it is normally closed by a valve 6I.

'I'he valve carries a stem 62 to which is attached a large piston 63. The piston 63 is slidably carried within the chamber 58, and it isolates the end portion 64 of such chamber from the liquid stream. The portion or sub-chamber 64 is closed by a head 65, and it is retained under atmospheric pressure by a pipe connection 66 with the oat chamber 48. A compression spring 68 in the sub-chamber 64 thrusts the piston 63 A second opening in the chamber 58 inward and constantly urges the valve 6I toward its seat 60.

The piston 63 and valve 6I are so proportioned that pressures above a predetermined normal in v the separator chamber exert sufllcient force on the piston face to offset the opposing forces of the spring 68 and pressure on valve 6 I The valve Bl is thus forced open and it is held in such open position until pressures drop below normal, due to opening of the nozzle valve or stopping of the pump motor.

It will be observed that, during the periods of by-passing operation, the pump P nevertheless continues to deliver a full volume of vliquid to the separator, and hence, if there be any eX- cess quantities of air in the pump or suction line, such air may be eliminated during non-dispensing periods of operation. It will also be observed that no air is returned to the pump inlet, nor is any recovered liquid returned to the inlet, but,

on the contrary, is sent directly tothe separator. 1

It may be noted that, with the pump, separator, and discharge line Il located at the relative levels indicated in the drawings, there need be no fear of a reverse iiow through the drain tube 50 of high pressure liquid passing the venturi` A very high vacuum may be obtained, even though the pipe Il extends above the chamber 40. It will, of course, be understood that While the invention has been illustrated in one particular form, and has been described withreference to its applicability to a gasoline dispenser, it is not to be limited thereto, but may be modied in form, or applied to general uses, without departure from the scope of the invention, as set forthv in the following claims.

I claim:

1. Liquid pumping and separating apparatus for pumping liquid from a reservoir through a delivery conduit provided with a closable outlet,

a primary separating chamber, a secondary separating chamber, a uid passage between said chambers for admitting gas and liquid from the primary chamber to the secondary chamber, an

open air vent connected to the secondary chamber, a liquid drain chamber, a valve for line from the secondary closing said drain, liquid responsive means in said secondary chamber for controlling said valve, a liquid outlet from the primary chamber adapted to be connected to said delivery conduit, a liquid pump having an inlet connected to a source of uid supply and a discharge connection terminating in said primary separator, a Venturi passage formed in said discharge connection, said liquid drain line being connected to the throat of said venturi, whereby discharge of uid from said pump induces a ow of liquid from said secondary chamber into said primary chamber, and a by-pass connection between said primary chamber and the inlet of said pump, said by-pass being open upon the occurrence of predetermined pressure conditions in said discharge conduit to return liquid passing through said venturi and primary chamber.

2. Liquid and gas pumping and separating apparatus comprising a, pump having a liquid inlet and outlet, a primary separating chamber, a Venturi passage connecting said outlet and chamber, said Venturi passage terminating within said chamber at a high point therein and being tangential with respect to the wall thereof, a second separating chamber disposed above said primary chamber and divided therefrom by a wall, a baille depending from said wall, a uid passage between said chambers formed in said wall and within the confines of the baie, a drain line connecting said second chamber with the throat of the venturi, a iioat controlled valve in said second chamber for said drain line, a second valve in said second chamber for closing said uid passage, means operative upon the opening of the float controlled valve for closing said second valve, an air vent connected to said second chamber, a liquid discharge line connected to said primary chamber at a low point therein, a by-pass line connecting said liquid discharge line with the inlet of the pump, a normally closed valve disposed in said by-pass line, means for holding said last named valve in closed position, said means being movable to open said valve when liquid pressure in said discharge line reaches a predetermined value.

JOSEPH D. LEAR.

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