US3327635A

US3327635A - Pumps

Info

Publication number: US3327635A
Application number: US510765A
Authority: US
Inventors: Norman H Sachnik
Original assignee: Texsteam Inc
Current assignee: Texsteam Inc
Priority date: 1965-12-01
Filing date: 1965-12-01
Publication date: 1967-06-27
Anticipated expiration: 1984-06-27
Also published as: NL6615569A; NL155635B; DE1725007A1; GB1119278A; DE1476673C3; DE1476673B2; DE1476673A1

Description

June 27, 1967 s c m 3,327,635

PUMPS Filed Dec. 1, 1965 2 Sheets-Sheet 1 INVENTOR NORMAN His/AC a 1K ATTORNEYS June 27, 1967 Filed Dec.

2 Sheets-Sheet 2 INVENTOR NORMAN H SACH [K hm M ATTORNEYS United States Patent ()fitice Bernese l zitented June 227, 155'? 3,327,635 PUMPF? Norman H. Sachnih, El Borado, Tex., asslgnor to Texsteani Corporation, Houston, Tex, a corporation of Texas Filed Dec. 1, i965, Ser. No. 516L765 6 Claims. (Ql. Elli-d) AESTRAQT OF THE DESQLGSURE Positive displacement pump driven by a diaphragm motor controlled by a snap-over center device.

This invention relates in general to a pump, and more particularly to a positive displacement pump, and still more particularly to a single acting, positive displacement plunger-type pump having a novel ball check valve.

The pump of the present invention includes an injector unit capable of pumping high pressures and handling a wide range of volume output. Ball check valves are provided in the injector having novel valve seats capable of providing absolute leak-tightness and controlled reseating characteristics. Heretotore, such positive displacement plunger pumps or injectors have employed O-ring seals or similar seals in order to eliminate leakage, and it has been found that such is generally unsatisfactory due to the normal manufacturing tolerances in O-ring seals, and further because dilficulty is encountered in machining of the grooves or faces which retain the seals in order to precisely control the amount of compression applied to the seals.

It is therefore an object of the present invention to obviate the above named ditficulties and provide in a positive displacement plunger pump a leakproof, resilient seal plus controlled compression and solid seating of the ball into the metal seat.

It is a further object of the present invention to provide in a positive displacement plunger pump a ball check valve including a resilient seal and a metal seat capable of providing precise control of the resilient seal in order to maintain accurate displacement of the pump volume under varying stroke and pressure conditions.

The pump of the present invention is pneumatically operated and may be operated by natural gas or compressed air, and includes a diaphragm motor with spring return for operating a reciprocating piston of the pump. The piston is reciprocated by alternately charging and exhausting the diaphragm motor in response to piston movement. A snap-over center device is provided for controlling the operation of a three-way valve effects charging and exhausting of the diaphragm. The snap-over center device includes a flipper arm connected to the valve and in turn connected to a flipper spring that is connected to the pump plunger. Means is provided to give initial movement to the flipper arm and valve to position it between charge and exhaust positions. This means includes a bumper plate that is mounted so that it responds to movement of the pump plunger for overcoming the initial frictional forces in the valve caused primarily by pressure differential across valve parts.

Therefore, another object of the present invention is to provide a pump having a diaphragm motor and a control valve for charging and exhausting the diaphragm motor and which is operable by a snap-over center device responding to movement of the diaphragm motor, wherein means is provided to assure operation of the snap-over center device in overcoming frictional forces in the valve, whereby the problem of pump stalling is eliminated.

Other objects, features and advantages of the invention will be apparent from the following detailed disclosure, taken in conjunction with the accompanying sheets of drawings wherein like reference numerals refer to like parts, in which:

FIG. 1 is a top plan view of the pump according to the present invention, with the injector head removed;

FIG. 2 is an axial sectional view of the pump taken substantially along line 22 of FIG. 1 and also including the injector head;

FIG. 3 is a transverse sectional view taken substantially along line 33 of FIG. 1;

PEG. 4 is a front elevational view of the control valve, with some parts deleted and other parts shown in dotted lines for purposes of clarity;

FIG. 5 is an enlarged transverse sectional View of an insert seat for the ball check valves of the present invention; and

FIG. 6 is a transverse sectional view of an insert valve body having an insert seat therein, and being on a smaller scale than FIG. 5.

In the processing of petroleum products or in the production of transportation of oil and gas as Well as in similar processes, it is often necessary to inject relatively small amounts of chemicals or additives into flow lines of varying pressure. For example, such a problem exists in addition of emulsion breaking compounds into crude oil lines. In this example, the requirements for a chemical injecting device are very severe in that it is essential that the proper amount of chemical is injected into the flowing stream continually and accurately. In such a situation, the injecting device may well be open and exposed to the elements causing wide variation in ambient temperatures plus wind-blown rain, snow and dirt. An injector device may be required to continually inject as little as one pint of fluid per twenty-four hours but may on occasion be required to inject at the rate of thirty quarts per twentyfour hours for a short time to charge the system or to establish essential concentration of the additive. Such are the requirements of injecting corrosion inhibitors as well as many other ingredients, and the present invention is capable of satisfying these requirements.

Referring now to the drawings, and particularly to FIGS. 1 and 2, the pump of the present invention includes a body or casing 11) having an injector head 11 at one end and a diaphragm motor 12 at the other end. A control valve 13 is provided for controlling operation of the diaphragm motor 12.

The injector head 11 includes a body 14 having a plunger or piston boss 15 for slidably supporting a plunger or piston 16 operable to pump a fluid through a pumping chamber 17 from an inlet 17a thereof to an outlet 17b thereof. Suitable sealing means 18 is provided at the end of the plunger boss 15 to inhibit leakage of fluid from the pumping chamber 17 along the plunger. The injector 11 is mounted on the body ll? of the pump by providing threads on the plunger boss 15 engageable with a threaded bore 19 in the end of the body. A lockuut 20 is provided to lock the injector 11 in proper position on the pump body 10.

A ball check valve 21 is provided at the inlet end of the pumping chamber 17, while a ball check valve 22 is provided at the outlet end of the pumping chamber 17. The ball check valve 21 only permits fluid flow into the pumping chamber, While the ball check valve 22 only permits fluid flow out of the chamber. The ball check valve 21 includes a valve seat 21a and a ball 21b, while the ball check valve 22 includes a valve seat 22a and a ball 22b. The valve seat 21a is mounted in a fitting 23 that is in turn connected to a source of fluid, while the valve' seat 22a is mounted in the body 14 of the injector at the outlet end of the pumping chamber. While the ball 21b is seated by gravitational forces and pressure thereon during the pumping stroke of the plunger 16, the ball 2% is primarily seated by a spring 24 bottomed on a fitting '25 that is in turn connected to a line into which predetermined measured amounts of fluid are desired to be injected. A bleed valve 26 is provided for bleeding of the pumping chamber 17.

The valve seats of the

ball check valves

21 and 22 are identical and therefore only one will be described. Each valve seat includes a valve insert body 27 having a valve insert seat 28 secured therein. The insert seat 28 is secured or locked in place in the valve insert body 27 by ring staking the valve body at 27a, although any other suitable means of securing the insert seat may be employed. Further, any suitable sealing means may be provided between the insert seat 28 and the valve body to prevent leakage of fluids therealong. The valve insert body is provided with stepped bores 29 and 3t defining a shoulder 31 therebetween, wherein the insert seat is fitted tightly within the bore 29 and in abutment against the shoulder 31. Suitable means is provided to seal the engagement between the insert seat and the bore 29. As seen particularly in FIG. 5, the insert seat has a cylindrical outer surface 32 that is received in the bore 29, and internal stepped bores 33 and 34 defining therebetween a shoulder 35. Moreover, the upper end of the bore 34 is chamfered at 38 to define the seat for a ball. The main portion of the insert seat is metal, and an annular seal 37 of rubber or suitable resilient material is received within the bore 33 and against the shoulder 35. As a ball moves toward seated position against the seat 36, it first engages sealingly the annular rubber seal 37 providing a. leakproof valve plus control compression thereof before seating solidly onto the metal seat and against the edge 36. The annular rubber seal 37 is molded onto the metal seat to precisely control the relationship of the rubber dimensions relative to the rubber seat.

The plunger 1'6 is connected to a rod adapter 38 by means of a pin 39. The rod adapter is received in a bore 40 formed in one end of a thrust rod 41. A shoulder 42 is formed on the rod adapter against which the end of the thrust rod 41 abuts when driving the plunger 16 through the pumping stroke or to the right as seen in FIG. 2. A drip gland 42a is provided at the end of the rod adapter 38 to cause any leakages from the pumping chamber 17 along the plunger rod 16 to drop to the bottom of the casing and be expelled through a drain 4212. This precludes the fluids from the pumping chamber from entering into the main body of the pump which is filled with a lubricating oil and thereby contaminating the oil to cause damage to other parts of the pump. A slot 43 is formed along the diameter of the rod adapter 38 and coacts with an adjusting pin 44 that may be adjustably arranged in holes 45, 46 or 47 of the thrust rod 41. The return stroke of the plunger 16 is effected by the return stroke of the thrust rod 41 and engagement of the pin 44 against the end of the slot 43. Depending upon the position of the pin 44, the return stroke of the plunger 16 may be varied, and there may be a lost connection between the thrust rod 41 and the rod adapter 38.

The thrust rod 41 is slidably mounted within the body and particularly in bores provided in a housing divider 48 and a 'boss 49. The left end of the thrust rod 41 has mounted thereon a diaphragm plate 50 and a diaphragm 51 arranged in a bell-shaped chamber defined by a bellshaped portion 52 of the body 10 and a cover member 53. The diaphragm peripheral edge is secured between the portion 52 and the cover 53 which are secured together by suitable fasteners 54. A pressure chamber 55 is defined having an inlet 56 interconnected to a line 57. Powering of the diaphragm 51 and thrust rod 41 toward the right to effect the pumping stroke of the plunger 16 is accomplished by connecting the pressure chamber 55 to a source of pressurized fluid, while the return stroke of the diaphragm and thrust rod is accomplished by a spring 58 bottomed at one end on the diaphragm plate and at the other end on a housing surface 59.

The control valve 13 includes a valve body 60 mounted on the pump casing 10 and extending through an opening 61 in a side Wall of the casing as seen most clearly in FIG. 3. A valve disc 62 is rotatably mounted within a recessed portion of the body and open at one side to a pressurized fluid inlet 63 provided in a fitting 64. A suitable source of pressurized fluid, be it natural gas or compressed air, is supplied to the fitting 64. The valve disc 62 is resiliently held in position as shown in FIG. 3 by a spring 65. The control valve 13 is in effect a three-way rotary valve for charging and exhausting the pressure chamber of the diaphragm motor 12. The valve includes an exhaust port 66 and a pressure port 67 for connecting the pressure chamber 55 to a source of fluid pressure or exhaust to thereby operate the diaphragm motor 12. These ports are arranged in the valve disc 62 and adapted to be in communication therewith for the respective charging or exhausting of the diaphragm motor. To charge the motor, the valve disc 62 is rotated so that an aperture 67a is in line with a passageway 68 that leads to a fitting 69 and the line 57, and ultimately the pressure chamber 55. At the same time, an aperture 67b communicates with the pressure inlet 63. For exhausting the pressure from the pressure chamber 55, .an aperture 66a is aligned with the passage 68 so that the exhaust port 66 connects the pressure chamber to an exhaust valve 70.

through the aperture 66b of the exhaust port 66. The position of the valve disc for exhausting is shown in FIG. 4. The exhaust valve 70 may be adjusted to vary the exhausting of the pressure chamber to thereby control the speed of the pump.

Rotation of the valve disc 62 is accomplished by swinging of a flipper arm '71 that is rotatably mounted on the valve body and interconnected with the valve disc by means of a drive shaft 72. The flipper arm 71 has extending normally from its free end a pin 73 having pivotally mounted thereon one end of a flipper spring 74. The other end of the spring 74 is pivotally mounted on a pin 75 carried by a stirrup 76 secured on the thrust rod 41. As seen particularly in FIG. 3, the pins 73 and 75 extend so that they may engage a bumper plate 77 that is pivotally mounted on a shaft 78 carried on the back wall of the body 1%. As seen in FIG. 2, the bumper plate 77 is inverted, U-shaped and provided with upper abutting edges 77a and 77b for engagement by the pin 75 and lower abutting edges 77c and 77d for engagement by the pin 73. The flipper spring 74 together with the flipper arm '71 defines a snap-over center device.

In operation, the parts shown in FIG. 2 illustrate their position at the conclusion of the pumping stroke and with the flipper arm having been swung to the position shown in FIG. 2 so that the valve disc 62 attains the position shown in FIG. 4, whereby the pressure chamber 55 is connected through the valve disc exhaust port 66 to the exhaust valve for exhausting the pressurized fluid at a rate determined by the adjustment of the exhaust valve. When a sufiicient amount of pressure has been released from the pressure chamber 55 and against the diaphragm 51, the spring 58 will act against the diaphragm 51 and return the pump plunger 16 on its non-pumping stroke to the left position. As it moves to its left position as seen in FIG. 2, the pin carried by the stirrup V 76 engages the edge 77a of the bumper plate 77. With the pin 75 in this position, it has caused the center line of the flipper spring 74- to become coincident with the center line of the flipper arm 71. Upon further movement of the pin 75, it will swing the bumper plate 77 about its shaft toward the left as seen in FIG. 2 whereby the edge 77d strikes the pin 73 to give an initial momentum to the bottom end of the spring 74 to swing it to the left position. The bumper plate 77 thereby acts to provide useful work to the snap-over center device at the point Where it becomes unbalanced and further overcomes the initial frictional drag of the valve disc 62 caused primarily by pressure diflerential across the disc. As the flipper arm 71 continues, the torque available increases due to the greater moment arm upon which the spring 74 is acting. Further, as the center line of the flipper spring 74 progresses pass the center line of the flipper arm 71, a torque is created by the tension of the spring 74 causing the flipper arm to rapidly rotate or snap past the center with the assist of the striking action of the pumper plate.

It will be understood that modifications and variations may be eiiected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

The invention is hereby claimed as follows.

1. In a positive displacement pump having a pumping chamber and a piston reciprocating therein, an actuator for said piston comprising, a casing, a thrust rod reciprocally mounted in said casing, means for connecting said thrust rod to said piston, a diaphragm motor having a housing with a diaphragm therein, said thrust rod extending into said housing, means connecting said thrust rod to said diaphragm, a spring return for driving said diaphragm in one direction, and means responsive to the thrust rod for alternately charging with and exhausting from the diaphragm housing a pressurized fluid, said means including a rotary three-way valve having an actuator interconnected with atmosphere, the diaphragm housing, and a supply of pressurized fluid, a snap-over center device including a spring interconnecting the thrust rod and actuator for operating said valve between charge and exhaust positions, and means for giving initial movement to said snap-over center device, said means including a bumper plate actuated by said thrust rod.

2. In a positive displacement pump having a pumping chamber and a piston reciprocating therein, an actuator for said piston comprising, a casing, a thrust rod reciprocally mounted in said casing, means for connecting said thrust rod to said piston, a diphragm motor having a housing with a diaphragm therein, said thrust rod extending into said housing, means connecting said thrust rod to said diaphragm, a spring return for driving said diaphrgam in one direction, and means responsive to the thrust rod for alternately charging with and exhausting from the diaphragm housing a pressurized fluid, said means including a rotary three-way valve interconnected with atmosphere, the diaphragm housing, and a supply of pressurized fluid, a flipper arm for operating said valve between charge and exhaust positions, and a flipper spring connected at one end to said thrust rod and at the other end to said flipper arm arranged to drive said flipper arm between said charge and exhaust positions upon reciprocation of said thrust rod, and means for giving initial movement to said flipper arm as it is driven to charge and exhaust positions.

3. In a positive displacement pump having a pumping chamber and a piston reciprocating therein, an actuator for said piston comprising, a casing, a thrust rod reciprocally mounted in said casing, means for connecting said thrust rod to said piston, a diaphragm motor having a housing with a diaphragm therein, said thrust rod extending into said housing, means connecting said thrust rod to said diaphragm, a spring return for driving said diaphragm in one direction, and means responsive to the thrust rod for alternately charging with an exhausting from the diaphragm housing a pressurized fluid, said means including a rotary three-way valve interconnected with atmosphere, the diaphragm housing, and a supply of pressurized fluid, a flipper arm for operating said valve between charge and exhaust positions, a flipper spring connected at one end to said thrust rod and at the other end to said flipper arm arranged to drive said flipper arm between said charge and exhaust positions upon reciprocation of said thrust rod, and a bumper plate pivotally mounted on said casing and actuated by said thrust rod to give initial movement to said flipper arm as it is driven to charge and exhaust positions.

4. In a positive displacement pump having a pumping chamber and a piston reciprocating therein, an actuator for said piston comprising, a casing, a thrust rod reciprocally mounted in said casing, means for connecting said thrust rod to said piston, a diaphragm motor having a housing with a diaphragm therein, said thrust rod extending into said housing, means connecting said thrust rod to said diaphragm, a spring return for driving said diaphragm in one direction, and means responsive to the thrust rod for alternately charging with and exhausting from the diaphragm housing a pressurized fluid, said means including a rotary three-way valve interconnected with atmosphere, the diaphragm housing, and a supply of pressurized fluid, a flipper arm for operating said valve between charge and exhaust positions, a flipper spring connected at one end to said thrust rod and at the other end to said flipper arm arranged to drive said flipper arm between said charge and exhaust positions upon reciprocation of said thrust rod, a bumper plate pivotally mounted on said casing, and means extending from said thrust rod for engaging said bumper plate which in turn strikes said flipper arm to impart thereto an initial movement to charge and exhaust positions.

5. In a positive displacement pump having a pumping chamber and a piston reciprocating therein, an actuator for said piston comprising, a casing, a thrust rod reciprocally mounted in said casing, means for connecting said thrust rod to said piston, a diaphragm motor having a housing with a diaphragm therein, said thrust rod extending into said housing, means connecting said thrust rod to said diaphragm, a spring return for driving said diaphragm in one direction, and means responsive to the thrust rod for alternately charging with and exhausting from the diaphragm housing a pressurized fluid, said means including a rotary three-way valve interconnected with atmosphere, the diaphragm housing, and a supply of pressurized fluid, a flipper arm for operating said valve between charge and exhaust positions, a flipper spring connected at one end to said thrust rod and at the other end to said flipper arm arranged to drive said flipper arm between said charge and exhaust positions upon reciprocation of said thrust rod, a bumper plate pivotally mounted on said casing, means extending from said flipper arm engageable by said bumper plate, and means extending from said thrust rod for engaging said bumper plate which in turn strikes the means extending from the flipper arm to impart thereto an initial movement toward charge and exhaust positions.

6. In a ball check valve including a ball and a seat, the improvement in the seat which comprises an annular metal portion having first and second stepped bores defining a shoulder therebetween, the first bore being larger than said second bore, a chamfered portion at the end of the second bore adjacent the shoulder defining a ball seating portion, and a resilient annulus secured in said first bore against said shoulder for engaging the ball and being compressed thereby prior to seating the ball on said ball seating area to further define a seal and prevent leakage through the valve.

References Cited UNITED STATES PATENTS 2,630,102 3/1953 Osburn 230-52 X 2,790,460 4/1957 Radd 137-533.15 3,009,476 11/1961 Usab 137533.15 3,097,608 7/ 1963 Deibel et al 103-50 X 3,151,805 10/1964 Pribonic 230-52 ROBERT M. WALKER, Primary Examiner.

Claims

1. IN A POSITIVE DISPLACEMENT PUMP HAVING A PUMPING CHAMBER AND A PISTON RECIPROCATING THEREIN, AN ACTUATOR FOR SAID PISTON COMPRISING, A CASING, A THRUST ROD RECIPROCALLY MOUNTED IN SAID CASING, MEANS FOR CONNECTING SAID THRUST ROD TO SAID PISTON, A DIAPHRAGM MOTOR HAVING A HOUSING WITH A DIAPHRAGM THEREIN, SAID THRUST ROD EXTENDING INTO SAID HOUSING, MEANS CONNECTING SAID THRUST ROD TO SAID DIAPHRAGM, A SPRING RETURN FOR DRIVING SAID DIAPHRAGM IN ONE DIRECTION, AND MEANS RESPONSIVE TO THE THRUST ROD FOR ALTERNATELY CHARGING WITH AND EXHAUSTING FROM THE DIAPHRAGM HOUSING A PRESSURIZED FLUID, SAID MEANS INCLUDING A ROTARY THREE-WAY VALVE HAVING AN ACTUATOR INTERCONNECTED WITH PRESSURIZED FLUID, A SNAP-OVER CENTER DEVICE INCLUDING A SPRING INTERCONNECTING THE THRUST ROD AND ACTUATOR FOR OPERATING SAID VALVE BETWEEN CHARGE AND EXHAUST POSITIONS, AND MEANS FOR GIVING INITIAL MOVEMENT TO SAID SNAP-OVER CENTER DEVICE, SAID MEANS INCLUDING A BUMPER PLATE ACTUATED BY SAID THRUST ROD.