US2405734A - Pumping apparatus - Google Patents

Description

Au. is, w46. H. s. COE

PUMPING APPARATUS lNVg-:NTOR Har/'won .i Coe www YI ATTORNEY Au., n, ma

PUMPING APPARATUS Filed Aug. 19, 1944 2 Sheets-Sheet 2 lNyENToR /arr/son 5. Coe

ATTORNEY Patented Aug. 13, 1946 UNITED STATES PATENT OFFICE PUMPING APPARATUS Harrison S. Coe, Palo Alto, Calif.

Application August 19, 1944, Serial vNo. :550,240

(ci. s- 44) 14 Claims.

corrosion where abrasive or corrosive iluids arev being pumped.

To obtain eicient operation in a pinnp of this type, the .diaphragm must pulsate freely, or without undue strain, in its expansion and contraction .of the pumping compartment. Since, for like .positions of the piston in the cylinder, the degree of expansion or contraction 'of the pumping compartment depends entirely upon the volume of impelling liquid in the pump, it will be obvious that the free movement of the `diaphragm, throughout a stroke of the piston, can only be lmaintained if the impelling liquid remains constant within narrow limits.

While this class of pump has marked advantages over ordinary piston pumps where abrasive or corrosive liquids are to be handled and is used under some especially severe` conditions i-n the pumping of mud in drilling of oil wells and like services, its application, up to the present, has been very restricted, because of leakage of fluid past the piston that actuates the impelling liquid. This leakage is never completely avoidable and has kmade it necessary to stop the pump ai', intervals, dependent upon the rate of leakage, and adjust the volume of impelling liquid and displace any accumulated air in the impelling liquid compartment. Another factor tending to limit the application of the type of pump under consideration has been the deleterious effect on the apparatus and its operation produced by the overheating of the impelling liquid due to its friction in the pump.

Another factor which has heretofore presented difficulty in this type of pump arises from the tendency of solids and air, separating from the material rbeing pumped, to accumulate in parts of the pumping compartment .and interfere with eicient operation.

It is an object of the present invention to provide means to maintain the diaphragm in position to pulsate freely .and without strain.

It is a further object of the present invention to provide means to prevent air from accumulating in the impelling liquid compartment and to replace liquid escaping therefrom.

It is a further object of the present invention to provide means to introduce liquid into the impelling liquid compartmentl and to expel liquid therefrom and thereby .remove heat generated therein.

Other objects and advantages will appear from the following specification and drawings .in which:

Figure 1 is a side view, in cross-section, of a diaphragm'vpump incorporating the preferred embodiment of my invention.

Figure 2 is a cross-sectional detail taken along the line 2-2 of Figure 1.

Figure 3 is a cross-sectional'view taken along the line 3-'3 of Figure v1`.

Figure 4 is a modification of the invention illustrated in Figure 1 'in which a diierent type of diaphragm is used.

As shown in Figure 1 there is provided Va chamber lIU of oblong oval form, which is provided with annular flanges l! and I2 at its upper and lower ends. Mounted above chamber I is a suitable outlet valve body I3 which is secured thereto by suitable bolts 'through cooperating flanges I2 and Ill. An airtight and liquid-proof seal b'etween these members is obtained by the use of a' suitable gasket I 5. Mounted within valve body rI3 I have provided a poppet type valve I6 adapted to move longitudinally and to Vbe operated by differential pressure thereon. Valve I6 is normally maintained in the position shown in vFigure 1 b-y gravity. When the pressure in body I3 below valve I6 sufliciently exceeds the pressure in the larea above the valve, the same is opened. When .the pressure in body vI3 below valve I6 is less vthan the pressure in the area above the valve, the same maintains the position shown in Figure 1. vValvelbody I3 extends downwardly into chamber I0 forming a cylindrical projection Il,

the use of which will hereafter .be explained.

Secured to the lower end of chamber Il@ and projecting inwardly thereto I have provided a cylindrical member I8 provided with orifice I9.

pressures within body 26.

Also secured to the lower end of chamber IU by suitable bolts and gaskets, is a valve body 20 and its cooperating poppet valve 2I of the same type as vvalve I6 and likewise operated .by differential suitably connected .to a source of material to be pumped as "by means of flange 22.

Within chamber -I0 I have provided a -diaphragm .or tube 30 made .of ilexiblematerial such The entire device is 3 Y as natural or synthetic rubber, which is secured at its ends to members I1 and I8 respectively by any suitable means to provide a liquid-proof seal. As shown in Figure 1, diaphragm 30 may be secured to members I1 and I8 by clamps 3|. Extending downwardly from member I1 within tube 3l), I have provided an annular guard tube 32 to prevent the collapse of tube 30 into valve body I3.

Chamber Ill is provided with a cylindrical outlet 4Il'which is in communication with cylinder 4I. Within cylinder 4| there is a reciprocating piston or plunger (not shown) adapted to reciprocate longitudinally therein as indicated by the arrow. On that portion of diaphragm 30 opposite orice 40 I have provided a metal plate 42 which is adapted to act as a shield against the direct impact on diaphragm 3D cf'liquid entering chamber I through orifice 40 during the pressure stroke of the piston and to prevent diaphragm from being drawn unduly toward or into orice during the suction stroke of the piston. Diaphragm 30 is preferably iluted as shown in Figure 3 in order that the same may be expanded and contracted with the minimum of stretching As will hereinafter more fully be explained the space within chamber l0 and outside of diaphragm 30 is termed an impelling liquid compartment, and the same is lled with liquid hereinafter called impelling liquid. Upon reciprocaton of the piston within cylinder 4I a portion of the impelling liquid is alternately drawn into and out of the cylinder 4I thereby creating alternate suction and pressure pulsations within chamber I0. Alternate suction and pressure within chamber I0 expands and contracts the area within diaphragm 30, known vas the pumping or impelled liquid compartment thereby increasing or decreasing the pressure and volume within the same. As will be obvious to those skilled in the art, compression of tubular diaphragm 30 causes the impelled liquid ,therein to be forced through conduit I3'past'valve I8. Expansion of tubular diaphragm 30 creates differential pressure within the same and draws liquid into the same through valve 2|.

As has previously been pointed out, on suction strokes of the piston within cylinder 4I a small amount of air may be drawn into the impelling liquid compartment and ultimately this air seeks the highest point therein. To provide an escape for this air I have provided an orice connected by suitable piping 46 to a resistance means 41 vconsisting of cylinder 48 within which I have mounted a screw member 49.' Passage of liquid through orifice 45 is retarded thereby. Ballcheck valve 50 within liquid holding chamber 5I prevents the sucking of liquid into the impelling liquid compartment on the suction stroke. A suitable valve 52 is provided in the event it is found desirable to adjust or close the escape system. As will be pointed out hereinafter, at times it may be desirable to vent a portion of the impeiling liquid from chamber I0, and in that event baie41 and check valve 50 would operate in the same manner as with the escape 0f air. I contemplate that liquid chamber 5I may at times function as a heat exchange unit to supply cool liquid to the impelling liquid compartment.

To permit the introduction of liquid into the impelling liquid compartment surrounding diaphragm 30, I have provided a novel valve means designated generally at 60. Valvermeans 6I! consiste generally of a cylindrical housing or intermediate compartment BI which is in communication with the impelling liquidcompartment by means of circular orifice or passage 62. Valve means 60 is suitably secured to chamber III to insure a liquid and air-proof seal therewith. Coaxially mounted within housing 6I I have provided a cylindrical member 63. Extending into the impelling liquid compartment through orifice 62 I have provided a push rod 64 adapted to operate valve member 65, which cooperates with valve seat 66. Valve 65 is mounted adjacent one side of a piston 61 which is slidably mounted within cylindrical member 63. Valve 65 is Aadapted to close against seat E6, and when in engagement therewith prevents communication between housing 6I and chamber I. In order to maintain push rod 64 accurately aligned within orifice 62 to prevent jamming of the same, I have provided an axially aligneddnember 1I) adapted to cooperate with a cylindrical extension 1| upon piston 51. Spring 12 is adapted to urge piston 61 and valve 65 into closed position, that is, against valve seat 65. The interior of cylinder 63 is in communication with the space surrounding cylinder 63 by restricted orifice l13 in piston 61 and by orices 14 and 15 in cylindrical member 63. Orifices 14 are provided with closure members 16 of the pinched tube type which permit expulsion of liquid 4from Within the cylinder 63 through orifices 14 but do not permit return of liquid into said cylinder through said orifices. Orifices 13 and 15 are simple openings permitting inow and outflow therethrough. It is obvious therefore that liquid may be expelled from within cylinder 63 much more rapidly` than it may enter. Orices 68 are provided in cylindrical extension 1I to permit the entry of liquid therein and prevent creation of a vacuum. Housing 6I is also in communication with a source of liquid supply 5I through passage 11 and check valve 18. Check valve 1S permits the fiow of liquid from chamber 5I into housing 6I through passage 11 but prevents the expulsion of liquid from housing 6I through passage 11 into liquid chamber 5 I.

Operation of the device and method may vbriefly be described as follows: A quantity of `impelling liquid is placed in the pump sucient to establish pumping operation. The pump is attached to a source of material to be pumped by suitable connection to ange 22 on valve body 28. A quantity of impelling liquid is placed in liquid supply chamber 5I, and valve A52 is opened. Reciprocation of the piston within cylinder 4I as has previously been explained, draws a portion of the impelling liquid within the impelling liquid compartment into cylinder 4I causing expansion of tubular diaphragm 30 creating a differential pressure therein and drawing liquid into the pumping compartment through valve 2I. A pressure stroke of the impelling uid contracts diaphragm 3i] and expels liquid from the pumping compartment outwardly through valve I6.

Air entering the impelling liquid compartment would be trapped in chamber II! at its highest point and would cause the difculties previously enumerated. Air would tend to be` expelled upon a pressure stroke through orifice 45 and resistance means 41 into liquid chamber 5I. As a matter of fact, under some conditions, air and liquid or liquid would be expelled through orifice 46 to liquid chamber 5I. The flow through orice 45 may be controlled by resistance 41 and valve 52 as desired.

In the event liquid within the impelling liquid compartment escapesl through orifice 45 or around the piston within cylinder 4I', it is obvious-thattubular `diaphragm 36 will expand and will strike push rod 6d and urge valve 65 Vaway from its seat 66, thereby permitting communication between housing El and chamber l0, through orice 62. When valve E5 is forced away from its seat yESS, piston 61 is moved into cylinder .63, forcing liquid outwardly therefrom through oriiices 13 and M. When, upon the following pressure stroke, tubular diaphragm 3Q is contracted, it is no -longer in contact with push rod 64, and spring 'l2 urges valve E5 toward closed position. Valve `65 is prevented from closing rapidly by virtue vof the fact that the sole route by which liquid can reenter cylinder 63 is through metering orifice 'F3 in piston Si' and oriiices 15. Oriices 'l5 will be closed by piston Sl until valve 65 isfnearly closed. When piston S'Iwopens orifices 15, they will permit a substantial increase in the flow of liquid into cylinder t3 and allow spring 12 to accelerate the closure of valve S5. However, flow of liquid rcm'the impelling liquid compartment into housing 6l through orifice 62 upon the pressure stroke is prevented by check valve T8. Therefore upon a pressure stroke no liquid or pressure in chamber iii is lost by virtue of the opening of valve 65. However upon the start of the following suctionstroke, liquid is drawn from liquid chamber 5| through conduit 'Il into housing 6i and from there, through orice A62, into the impelling within-chamber l0.

If liquid drawn in during the period when valve 65 is open balances the liquid being lost from the impelling liquid compartment, the operation is in equilibrium and the position of the di.. aphragm at the end of the succeeding suction stroke remains Stabilized. If Valve closes too quickly to admit liquid to balance this loss the diaphragm 3i] expands and increases the range of movement of piston 67 thereby causing the period during which valve remains open to be extended and in turn causing more liquid to be drawn in through valve 18. This progressive expansion of diaphragm 30 will cease when the liquid drawn in balances the liquid loss. In rare cases liquid may enter through valve I8 during the period when valve 61 is open as diaphragm 30 approaches the end of the suction stroke. Under most conditions pressure exists in the impelling liquid compartment during this period and all passage of liquid through orice 52 will occur following the succeeding pressure stroke.

In the modication of my invention illustrated in Figure 4, the tubular diaphragm 39 of Figure 1 is replaced Iby a simple exible sheet-like diaphragm 8l. Impelling liquid compartment 82 is suitably connected to a reciprocating piston arrangement, not shown, by conduit 83. Operation of the impelling liquid within compartment 82 operates diaphragm 8l in much the same manner as the operation of diaphragm St as has heretofore been explained. Pulsation of diaphragm 8l creates alternate pressure and suction within impelled liquid or pumping compartment 84 thereby causing the entry of material through poppet valve 85 upon a suction stroke and expulsion of material through poppet valve 86 upon a pressure stroke. Escape .of air or liquid through orifice 6l and into liquid chamber 88 is identical to the escape of the same through oriiice 45 as pointed out .in connection with Figure l.

However the device permitting the introduction of compensating liquid to the impelling liquid 'in compartment 82 from liquid chamber liquid compartment n 6 88 is slightly different in the modification shown in Figure .2i than as shown in Figure 1. Upward movement of diaphragm t1 upon a suction stroke causes diaphragm 8l to strike push rod 90 and raise valve 9| from itsseat 92 thereby permitting communication between impelling iluid compartment 82 and valve chamber 93. Y Upward movement of valve 9! causes expulsion ci liquid above double piston arrangement 94 through the rubber nipples `95 as previously explained in connection with the operation of valve means '60.

in Figure 1. However the return of valve SI to its closed position issolely by gravity.l Reintroduction of liquid into the area above the dual valve 9i is permitted.

The cycle of operation and introduction of liquid into the impelling liquid compartment .is the same as has been previously explained in connection with Figure l.

I claim:

l. In a pump having a chamber and a diaphragm within said chamber and dividing the same into an impelling liquid compartment and a pumping compartment, inlet and outlet valves permitting the inflow and outow of liquid from said pumping compartment upon movement of` said diaphragm, a liquid holding chamber, valve means adapted to function in response to the action of the diaphragm to allow 0r prevent communication between said impelling liquid compartment and said liquid holding chamber, said valve means including means adapted to retard the closure of the valve through an interval of time dependent in duration on the volume of liquid in the impelling liquid compartment.

2. In a diaphragm pump wherein the diaphragm is adapted t0 move in response to the action of impelling liquid in contact therewith, a chamber adapted to act as a source of impelling liquid but spaced from the impelling liquid in contact with said diaphragm, a valve responsive to the position of said diaphragm to permit or preventV communication between said chamber and said impelling liquid in contact with said diaphragm, and means adapted to retard the closure of said valve through an interval of time dependent upon the position of the diaphragm at the conclusion of its suction stroke. f

3. In a diaphragm pump wherein a diaphragm dividing an enclosed space into a pumping compartment and an impelling liquid compartment is adapted to move in response to the action of impelling liquid in said impelling liquid compartment; a chamber adapted to act as a source ofY impelling liquid and spaced from the impelling liquid compartment, valve means responsive to the position of said diaphragm and adapted to open and close a passage between said chamber and said impelling liquid compartment, and means adapted to retard the closure of said passage through an interval of time dependent on the position of the diaphragm at the conclusion of its suction stroke.

4. 1n a diaphragm pump wherein a diaphragm dividing an `enclosed space into a pumping com-- partment and an impelling liquid compartment is pelling liquid in said impelling liquid-compari',

ment; a chamber adapted to act as an intermediate source of impelling liquid, a passage leading from said chamber to an exterior source of-supply of impelling liquid, a valve adapted to close said passage under the iniluence of pressure'in said chamber and to open said passage under the influence of suction therein, a passage communicating said chamber with said impelling liquid compartment, and means responsive to the position of said diaphragm adapted to open and close said passage.

5. In a diaphragm pump wherein a diaphragm dividing an enclosed space into a pumping compartment and an impelling liquid compartment is adapted to move in response to the action of impelling liquid in said impelling liquid compartment, a chamber adapted to act as an intermediate source of impelling liquid, a passage leading from said chamber to an exterior source of supply of impelling liquid, a valve adapted to close said passage under the influence of pressure in said chamber and to open it'under the influence of suction therein, a passage communicating said .chamber with said impelling liquid compartment,

valve means responsive to the position of said diaphragm and adapted to open and close said passage, said valve means including a cylinder enclosed at one end, a piston in said cylinder, means adapted to cause a movement of said piston in said cylinder in response to an action of the diaphragm, means adapted to establish a force against said piston in the opposite direction to said movement, a valve adapted to maintain a position in controlled relation to the position of said piston and to close said passage between said chamber and said impelling liquid compartment in response to movement of said piston under the influence of said force, and means adapted to control the movement of the piston due to said force including an orice adapted to admit liquid into said cylinder.

6. In` a diaphragm pump wherein the diaphragm is adapted to move in response to the action of impelling liquid in contact therewith, a chamber adapted to act as a source of impelling liquid and spaced from the impelling liquid in contact with said diaphragm, valve means responsive to the position of said diaphragm to permit communication between said chamber and the impelling liquid in contact with said diaphragm, whereby the opening of said valve is controlled by the movement of said diaphragm and the closure of said valve is controlled by the metering of liquid into a uid chamber associated with said valve means.

7. In a pump, a compartment, a tubular diaphragm adapted to be mounted in said compartment and to divide the same into an inside pumping compartment and an outside impelling liquid compartment, an auxiliary supply chamber, valve means adapted to permit or prevent the flow of liquid from said auxiliary chamber to said impelling liquid compartment and from said impelling liquid compartment tc 'said supply chamber, the opening of said valve means being controlled by the position of said diaphragm at the end of its suction stroke and closure of said valve means being controlled by metering of liquid into a fluid chamber associated with said valve means.

8. In a diaphragm pump wherein a diaphragm dividing an enclosed space into a pumping compartment and an impelling liquid Vcompartment is adapted to move in response to the action of the impelling liquid in said impelling liquid compartment, a chamber adapted to act as intermediate source of impelling liquid, apassage leading from said chamber to an exterior source of supply of impelling liquid, a valve adapted to close said passage under the influence of pressure in said chamber and to open it under the influence of suction therein, a second passage communicating said chamber with said impelling liquid compartment, valve means responsive to the position of said diaphragm andA adapted to open and close said second passage comprising a compartment of variable space, a member adapted to contract said space in response to an action of the diaphragm, means adapted to exert a force against said member tending to expand said space, a valve adapted'to maintain a controlled position in relation to the position of said member and to open said passage on the contraction of said space and to close it on the expansion, of said space, and

means adapted to control the rate of expansion of said space.

9. A diaphragm pump embracing an enclosed space divided by a diaphragm into a pumping compartment and an impelling liquid compartment, an intermediate compartment separatingY the impelling Yliquid compartment from a source of liquid supply, a passage leading from said source into said intermediate compartment, a valve in said passage adapted to admit liquid into and to close against the flow of liquid out of said compartment, a passage leading from said inter-l mediate compartment into said impelling liquid compartment, a valve adapted to open and close said passage, means adapted to open said valve in response to an action of the diaphragm, and means adapted to close said valve.

l0, A diaphragm pump embracing an enclosed space divided by a diaphragm into a pumping compartment and an impelling liquid compartment, an intermediate compartment separating the impelling liquid compartment from a source of liquid supply, a passage leading from said source into said intermediate compartment, a valve in said passage adapted to admit liquid into and to close against the flow of liquid out of said compartment, a passage leading from said inter mediate compartment into said impelling liquid compartment, a valve adapted to open and close said passage, means adapted to open said valve in response to an action of the diaphragm, means adapted to close said valve, and means adapted to retard the closure of said valve, said means including a. chamber, a passage communicating said chamber with a body of liquid in the pump and means adapted to vary the volume of the space enclosed in said chamber in response to an action of the diaphragm. Y

Vll. A diaphragm pump embracing an enclosed space divided by a diaphragm into a pumping compartment and an impelling liquid compart-V ment, a passage leading from said impelling liquid compartment to a point exterior to the pump andv adapted for the expulsion of fluid from the pump,v

passage adapted to admit liquid into and to closey against the flow of liquid out of said compartment, a passage leading from said intermediate compartment into said impelling liquid compartment, a valve adapted to open and close said pas-f. sage, meansV adapted to open said valve in response,v

to an action of the diaphragm, and means adapted to close said valve.

12. A diaphragm pump embracing an enclosed space divided by a diaphragm into a pumping compartment and an impelling liquid compartment, a passage leading from said impelling liquid compartment to a point exterior to the pump and adapted for the expulsion of fluid from the pump, an intermediate compartment separating the impelling liquid compartment from a source of liquid supply, a passage leading from said source into said intermediate compartment, a valve in said passage adapted to admit liquid into and to close against the flow of liquid out of said compartment, a passage leading from said intermediate compartment into said impelling liquid compartment, a valve adapted to open and close said passage, means adapted to open said valve in response to an action of the diaphragm, means adapted to close said valve, and means adapted to retard the closure of said valve, said means including a chamber, a passage .communicating said chamber With a body of liquid in the pump and means adapted to vary the volume of the space enclosed in said chamber in response to an action of the diaphragm.

13. In a pump characterized by a chamber and a diaphragm dividing said chamber into an impelling liquid compartment and a pumping compartment, said diaphragm being adapted to pulsate in response to a reciprocating movement of liquid in said impelling liquid compartment and to cause successive periods of change in the volume of said pumping compartment; means adapted to admit liquid into said impelling liquid compartment, means adapted to function in response to an action of the diaphragm and to cause said rst named means to admit said liquid, and means adapted to control the volume of liquid admitted by said first named means, said means being adapted to function in accordance with the position occupied by the diaphragm at the termination of a period of change in the volume of the pumping compartment.

14. In a diaphragm pump incorporating a pumping chamber, an impelling liquidr chamber, and a diaphragm forming a dividing Wall between said chambers, an intermediate chamber between the impelling liquid chamber and a source of liquid supply, and means adapted to operate in response to the action of the diaphragm and to cause the transfer of liquid from the intermediate chamber into the impelling liquid chamber and from the source of supply into the intermediate chamber.

HARRISON S. COE.

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