US2881709A

US2881709A - Abrasive fluid pump

Info

Publication number: US2881709A
Application number: US499918A
Authority: US
Inventors: Earl E Williams
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-04-07
Filing date: 1955-04-07
Publication date: 1959-04-14
Anticipated expiration: 1976-04-14

Description

April 14, 1959 E. E. WILLIAMS 'ABRASIVE FLUID PUMP 2 Sheets-Sheet 1 Filed April '7. 1955 WILLIAMS 0O EARL E I ATTORNEYS Aprifi 14, 1959 E. E. WILLIAMS 2,881,709.

ABRASIVE FLUID PUMP Filed April 7, 1955 2 Sheets-Sheet 2 INVENTOR EARL E. WILLIAMS 1 ATTORNEYS United States Patent O ABRASIVE FLUID PUMP Earl E. Williams, Augusta, Kans. Application April 7, 1955, Serial No. 499,918

7 Claims. (Cl. 103-150) The present invention relates to a pumping system, more particularly, to a plurality of hydraulic exchangers for pumping abrasive fluid wherein independent systems are provided for circulating the abrasive fluid and the clean pumping oil.

Considerable effort has been previously expended in order to devise eflicient and inexpensive methods for the drilling of oil. One method which has been used with some success involves employing a rotary bit and an abrasive fluid as the drilling agents. In this method an abrasive fluid under high pressure is forced into the proposed oil well. The action of this fluid is extremely effective in cutting the dirt and stone ordinarily encountered in drilling oil wells and removing the material loosened by the bit.

One common practice of forming an abrasive fluid is by adding clay compounds or the like to a drilling fluid. The drilling fluid primarily functions to cool the rotary bit bearing and to convey rock chips to the surface. In shallow wells clean water or oil may be employed as a drilling fluid.

The fluid is subsequently pumped from the depths of the well and recirculated through the abrasive fluid pumps for repeated use. If desired, the recirculated fluid may be passed through purifiers or filters in order to remove some of the larger pieces of debris which may be in the fluid.

While this method for oil drilling has considerable merit, a problem exists in devising pumps and pumping systems adequate to handle the tremendous volume of abrasive fluid at high pressures necessary for drilling extremely deep wells. As the practical limit of piston type pumps is soon reached, attention was directed toward the use of hydraulic exchangers to pump abrasive fluid. Consequently, hydraulic exchangers in the nature of flexible diaphragm pumps have been employed in oil drilling.

In order to achieve greater volume of abrasive fluid under higher pressure, conventional type pumps were compounded. In general, the compounding of conventional pumps for pressure proved to be diflicult and not particularly successful.

The use of conventional pumps resulted in the impart ing of certain undesirable characteristics to the pumped abrasive fluid. Pulsations due to the opening and closing of valves were transmitted to the abrasive fluid. These pulsations were undesirable as they combined to decrease the eificiency of the drilling process.

It has been found that a pumping system comprising a plurality of hydraulic exchangers could be successfully employed in the pumping of abrasive fluid. With this object in mind, a valving system was devised which as sured that only the pump pulsations appeared in the abrasive fluid flow. By employing a rotary type multiunit valve, pulsations due to the opening and closing of the various valves were eliminated.

Additional improvements to abrasive fluid pumping 2,831,709 Patented Apr. 14, 1959 'ice systems have been made in the structure by the hydraulic exchanger itself. The diaphragm of the hydraulic exchanger has been made of two flexible elements with a suitable detectable fluid contained therebetween. Detector means are installed in each of the outlets of the hydraulic exchanger. Consequently, rupture of the diaphragm would result in a portion of the detectable fluid escaping through one of the outlets. The presence of the detectable fluid accordingly actuates the detector means. Rather than cease operation of the system, means have been provided to enable a stand-by hydraulic exchanger to be substituted for the damaged hydraulic exchanger. This feature results in a continuous and uninterrupted abrasive fluid flow from the hydraulic exchanger system.

It is, therefore, the principal object of this invention to provide an improved hydraulic exchanger system adapted to the pumping of abrasive fluid.

It is another object of this invention to provide a valving system for a hydraulic exchanger system whereby only the pump pulsations are transmitted to the abrasive fluid.

It is a further object of this invention to provide a hydraulic exchanger system which will permit continuous uninterrupted service.

It is an additional object of this invention to provide improvements in flexible diaphragm pumps.

It is still another object of this invention to provide a rotary valve for transmitting pump characteristics to a pumped abrasive fluid.

It is a still further object of this invention to provide a hydraulic exchanger system which will impart certain desirable characteristics to pumped abrasive fluid under conditions of high volume and high pressure.

Other objects and advantages of this invention will become readily apparent upon reference to the accompanying description when taken in conjunction with the following drawings, wherein:

Figure 1 is a schematic view of the hydraulic exchanger system disclosed as this invention;

Figure 2 is a diametrical sectional view of a hydraulic exchanger employed in the system illustrated in Figure 1;

Figure 3 is an overall perspective view of the rotary multi-unit valve employed in the hydraulic exchanger system of this invention;

Figure 4 is a sectional View taken along the lines 44 of Figure 3;

Figure 5 is a sectional view taken along the lines 5-5 of Figure 3 and showing the suction and discharge grooves on the suction valve body portion;

Figure 6 is a plan view of the slotted rotary valve member employed in the rotary valve illustrated in Figures 3 and 5;

Figure 7 is a sectional view taken along thelines 77 of Figure 4;

Figure 8 is a schematic view showing the shifting system for substituting a stand-by hydraulic exchanger in the event of failure of a regular hydraulic exchanger;

Figure 9 is a longitudinal sectional view of the preloaded spring and housing connection employed in the system shown in Figure 8; and I Figure 10 is a schematic view of a modification of the shifting system for operatively connecting a stand-by hydraulic exchanger. t 1 i Proceeding now to the drawings, more particularly to Figure 1, it is pointed out that like reference symbols indicate the same parts throughout the various views. The clean oil pumping system illustrated in Figure 1 comprises a clean oil vacuum tank 10 having a vacuum pump 11A, and heating coils 11 and cooling coils 12 therein to maintain the oil at a constant temperature. Conduits 13 3 and 14 lead to and from the heating coils 11. A suitable coolant is conveyed into the cooling coil 12 by means of the inlet conduit 15 and the outlet conduit 16.

Located Within the tank 10 is a high-volume low pressure booster pump 17'. The booster pump 17 discharges oilinto a conduit 18: which is the suction line of a pump 19.. The pump 19. is of the radial type and has control means for shifting to neutral or to an inoperative position.

The pump 19 discharges the clean oil through a conduit 20to a rotary multi-unit valve indicated at 21. The valve 21 essentially comprises a discharge valve body portion'22' and a suction valve body portion 23. The specific structure of the rotary valve 21 is illustrated in Fig ures 3 through 7 and will be later describedin detail; The valve 21 regulates the flow of clean oil through the discharge'conduits 24A through D to a plurality of hydraulic exchangers 25A through D respectively. The valve 21 also controls the flow of fluid to and from a stand-by hydraulic exchanger indicated at 258 through a discharge conduit 24S and a suction conduit 265. The function of the stand-by hydraulic exchanger 258 will also be described later.

The clean oil is withdrawn from each of the hydraulic exchangers through suction conduits 26A through D which connect the respective hydraulic exchangers to the suction valve body suction portion 23. The clean oil is then passed through the conduit 27 and is returned to the vacuum tank 10 for recirculation.

Valves

28 and 29 are installed in the discharge and

suction conduits

20 and 27 respectively, in order to bypass the hydraulic exchanger system to enable the oil to be used atan'alternate location.

Each of the hydraulic exchangers 25 is connected between a suction line 30 and a discharge line 31. These connections are achieved by providing a plurality oflead suction conduits 32 between the exchangers 25 and thesuctionconduit 30. A valve 33 is inserted in each of the connecting conduits 32. Similarly a discharge connecting conduit 34 is used to connect each of the hydraulic exchangers 25 with the discharge line 31. Again, similarly,

a valve 35 is provided in each of the discharge connecting conduits 34.

Proceeding now to Figure 2, there is illustrated a diametrical sectional view of one ofthe hydraulic exchangers 25. Hydraulic exchanger 25 is essentially spherical in shape and comprises a clean oil half 36 and an abrasivefluid half 37. Each of the

halves

36 and 37 has an

external flange

38 and 39, respectively, thereon. The

flanges

38 and 39 are adapted to cooperate with each other and the

halves

36 and 37 are secured together through suitable means interconnecting the two external flanges.

A flexible diaphragm 40 has a periphery projecting between-the

flanges

38 and 39 and is secured in position by being clamped therebetween. The diaphragm 40' comprises

flexible elements

41 and 42. A suitable detectable fluid indicated at 43 is contained between flexible elements- 41 and 42. The fluid 43 may be rendered detectable by use of radioactive particles therein. The amount ofradioactivity is small and is only necessary to actuate detector instruments. Suitable detector means, such as a Geiger counter or the like, indicated at 44, are positioned in the discharge outlet 34 and the clean oil suction oil conduit 26 for each of the hydraulic exchangers 25.

A perforated steel plate 45 is positioned in the clean oil chamber to prevent over-extension of the diaphragm 40 or suction of the diaphragm into the clean oil suction line 26. Protection of the diaphragm 40 is achievedin the abrasive fluid discharge half of the hydraulic exchanger by connecting an emergency relief valve 46 thereto.

An additional safety feature is incorporated in. the. hydraulic exchanger 25. This feature comprises a springloaded semi-flexible mesh diaphragm 47 positioned. adjacent the flexible diaphragm 40 on the abrasiveside of the exchanger. This diaphragm assures the completion of the suction portion of the cycle when very viscous and heavy abrasive fluids are being handled.

Proceeding now to Figure 3, there is illustrated the rotary multi-unit valve 21. As described previously, the valve comprises a discharge valve body half 22 and a suction valve body half 23 which have opposed cooperating faces 48 and 49 respectively. The valve body halves may be secured together by suitably bolting

external flanges

50 and 51 which are respectively connected to the respective valve body halves 22 and 23.

Located in the discharge valve body half 22 is an anrrular discharge chamber 52. A passage 53 interconnects the discharge chamber 52 with the discharge conduit 20.

Inner faces 48 and 49 of the valve body portions have a plurality of arcuate grooves therein. The pattern of grooves on each face is reversed. Consequently, when the valve body halves are assembled the grooves will cooperate. Figure 5 indicates the pattern of the grooves in the suction valve body portion 23. These grooves comprise, discharge grooves 54 and suction grooves 55. There is a set of grooves comprising a discharge and suction groove for each of the units 25A through D serviced by the rotary valve. The opposed sets of grooves are located at varying distances from the center of the rotary valve.

Each of the discharge grooves 54 is connected to the discharge chamber 52 by means of the passages 56A through D. In addition, there are passages 57 which connect each of the suction grooves 55' in the discharge portion 22 with the suction conduits 26A through D.

The suction valve body 23 similarly has an annular space defining a suction chamber 58 therein. This chamber is connected by means of a passage 59 to the suction conduit 27. There are a plurality of axially extending passages 60 which connect the suction chamber 58 with each one of the suction grooves 55 located in the inner face of the suction valve body portion. Also formed. Within the suction valve body 23 are passages 61 which interconnect the discharge grooves 54 in the suction valve body portion with the discharge conduits 24A through D.

The valve structure enables the discharge oil to enter the chamber 52 of the discharge valve body portion 22 where it passes through the passages 56, discharge grooves 54, slotted openings in a valve plate to be presently described, through the passages 61 and discharged through the conduits 24, which project from the suction valve body portion 23, to the respective hydraulic exchangers.

The suction valve body portion 23 has an axial bore 62 therein which receives a shaft 63 upon the inner end of which is secured a disc-like rotary valve plate 64. The shaft 63 is driven by a suitable electric motor, as indicated at 65 in Figure l.

The valve plate 64 is illustrated in Figure 6 and comprises a plurality of arcuate slots 66 through 69. Each of the slots 66 through 69 is located a diflerent distance from the center of the valve plate. As the discharge and suction grooves 54 and 55A through D are also located at four equal distances from the center of the valve body, it can be seen that the slots in the valve plate readily cooperate with the grooves in the valve body. Consequently, continuous rotation of the valve plate 64 will continuously expose varying areas of the

grooves

54 and 55. As the

grooves

54 and 55 function as ports, it can be seen that the open port area will be regulated by the rotation of the rotary valve plate.

The spacing and length of both the grooves and the valve plate slots is of extreme importance. One of the objects of this invention is to achieve a hydraulic exchanger system wherein only' the pump pulsations are transmitted to the hydraulic exchanger. It has been found that by maintaining, a constant open area of the discharge orthe suction parts at any point of rotation of the valve. plate, a faithful transmission of pump characteristics:

will be achieved.

To clarify the various relationships between the various exposed port areas, reference is made to Table I.

TABLE I Part area table of clean oil Suction At Movement 45 Clockwise Discharge 1st Allof 4+%of 1+% of 3 All of 2. 2nd +A110f4 of 2+% of 1.

A of 2+A11 of 3+% of 4 All of 1.

+All of 3 i. of 1+% of 4. of 3| %fi ff1-1i-All of 2 g f 4y 4 a o 3 0 11 of1+% of 2+% of 4 A 1] of a. 2 All of 4+All of 1 l of 2+% of 3. Begin New Cycle Begin new cycle.

The figures 1, 2, 3 and 4 represent the port areas associated with the hydraulic exchangers A, B, C, and D respectively.

Table I shows the open port areas for both the discharge and suction ports at positions of the rotary valve plates spaced 45 apart. Regarding the valve body and the rotary valve plate in the initial or 0 positions, as depicted in Figures 5 and 6 respectively, reference to Table I will reveal that of the suction grooves all of D and one-half of A and one-half of C will be open. Of the discharge grooves all of groove B will be open. Rotation of the valve plate in increments of 45 in a clockwise direction will result in the open port areas as listed in Table 1.

Examination of Table I will reveal that at all times total area comprising a complete discharge port will be open. However, if desired, any other relationship of open suction and discharge ports may be readily attained by varying the positioning and lengths of the slots in the rotary valve plate.

Although the grooves in the valve body portions are of varying linear length, each of the grooves subtends the same angle. This angle is somewhat less than 90.

Therefore, use of the above defined relationships of the grooves and slots will result in the pump pulsations from the radial pump being faithfully duplicated in the abrasive fluid flow pumped by the hydraulic exchangers.

Proceeding now to Figure 8, there is illustrated therein a system for shifting a stand-by hydraulic exchanger into regular operation in order to achieve continuous uninterrupted service from the pumping system.

In this system a separate hydraulic valve 70 (AD) controls the flow of hydraulic fluid to each of the hydraulic exchangers. The hydraulic valve 70A is of the balanced type and is actuated by means of a rod 71 which is axially movable in order to expose either the discharge or suction ports of the hydraulic valve. The actuating rod 71 is connected to a pre-loaded spring and housing assembly indicated at 72 and illustrated in Figure 9. Extending from the other end of the pre-load and spring assembly is a cam shaft 73 which passes through a bearing 74 located in a valve stem guide plate 75. The lower end of the cam shaft 73 is engageable With a cam surface 76 located adjacent the periphery of a rotary cam plate 77. The cam plate 77 is secured to a drive shaft 78 which also passes through a suitable bearing located in the center of the valve stem guide plate 75. The drive shaft 78 is connected by means of suitable gearing indicated at 79 to a power source.

Each of the operating rods 71 has a stop collar or notch 80 thereon. The notch is adapted to be engaged by a trigger 81 operated by a solenoid 82. In normal position the trigger 81 is withdrawn into the solenoid 82 to cause the trigger 81 to be disengaged from the notch 80.

i It should be borne in mind that the valve stem guide plate 75 in Figure 8 is circular with the bearings 74 being equally spaced adjacent the periphery thereof.

Figure 8 is schematic to clarify the operation of the shifting system.

A balanced hydraulic valve 83 for the stand-by hydraulic exchanger is positioned on the other side of the cam 77. The hydraulic valve 83 is similarly operated by an operating rod 84 which engages the central portion of a plunger plate 85. Equally disposed about the periphery of the plunger plate 85 and aligned with the hydraulic valves 70 A-D is a like plurality of plungers 86, each of which is engageable with the plunger plate 85. Each of the plungers 86 has a pre-loaded spring assembly 87 connected thereto and has a cam shaft 88 extending from the other side of the assembly to be engageable with a cam surface 89'located on the cam 77 and aligned with the cam surface 76. The pre-loaded spring assembly 87 is similar to the spring assembly 72 depicted in Figure 9.

Each of the plungers 86 has a stop collar or notch 90 thereon which is engageable with a trigger 91 actuated by a solenoid 92. The normal position of the trigger 91 is in engagement with each of the notches 90 upon the plungers. Consequently, when the cam surface 89 depresses the cam shaft 88, as indicated at A in Figure 7, trigger 91 will restrain axial movement of the plunger 86 and, consequently, there will be no movement of the plunger plate 85.

The cam shafts 88 also pass through bearings 93 which are placed adjacent the periphery of a valve stem guide plate 94 which is similar to the valve stem guide plate 75. There is a thrust bearing 95 in the central portion of the valve stem guide plate 94 to accommodate the end of the cam drive shaft 78.

With the arrangement as illustrated in Figure 8, it can be seen that rotation of the cam plate 77 will result in sequential operation of each one of the hydraulic exchanger valves 70 A-D. Upon failure of any one of the hydraulic exchangers as will be indicated by the leakage of detectable fluid through one of the outlets, the respective detector means 44 will be energized to actuate the respective solenoid 82. This energization of the solenoid 82 will result in the trigger 81 being engaged with the stop collar 80. Consequently, that hydraulic valve would be rendered inoperable.

Simultaneously with the energization of the solenoid 82, the corresponding solenoid 92 will be energized to draw the trigger 91 from engagement in the notch 90. This would result in the plunger 86 being operatively engageable with the cam surface 89 on the cam plate 77. Depression of the plunger 86 would depress the plunger plate 85. This depression or tilting of the plunger plate 85 would depress the stand-by hydraulic exchanger valve 83. Consequently, the stand-by hydraulic exchanger valve 83 would be substituted for the operation of the hydraulic exchanger which had failed. This would result in continuous uninterrupted service of the hydraulic exchanger system.

During the operation of the stand-by hydraulic exchanger, the damaged hydraulic exchanger 25 may be repaired. Upon completion of the repairs both

solenoids

92 and 82 would be de-energized and stand-by hydraulic exchanger valve 83 would not be operated by the plunger plate 85. The repaired hydraulic exchanger would then resume operation in normal sequence with the remaining hydraulic exchangers.

In Figure 10 there is illustrated an alternate shifting system which is adapted for use with the rotary valve 21 previously described. Figure 10 illustrates diagrammatically the suction valve body portion 23 with the discharge conduits 24A through D extending therefrom. Connected in each one of the discharge conduits 24 is a solenoid operated two-way valve 96. There is a conduit 97 extending from each of the valves 96 to the stand-by hydraulic exchanger 25.

Upon failure of the hydraulic exchanger 25A, the solenoid operated valve 96A will be energized to divert 7 theflow of fluid through the conduit 97 to the stand-by hydraulic exchanger 25. This operation of the. solenoid operated valve 96A will occur in sequence to substitute the stand-by hydraulicexchanger 258 for theinoperative-hydraulic exchanger A.

A similar arrangement is connected to the suction conduits 26A through D. Consequently, the discharge and withdrawal of clean oil to the stand-by exchanger- 258 will. occur in sequence during that period of time that the hydraulic exchanger 25A is inoperative.

Consequently, either of the arrangements illustrated in Figures 8 and 10 will enable a hydraulic exchanger pumping. system to render continuous and uninterruptedservice in the event of failure of one of the hydraulic exchangers.

Thus it can be seen that a hydraulic exchanger system abrasive fluid under extremely high volume and pres sure conditions. By alternately injecting and withdrawing clean oil in a pre-determined sequence into each one of the hydraulic exchangers, it can be seen that the abrasive fluid is discharged from the lines of the hydraulic exchanger under an extremely high pressure. Furthermore, with the relationship of the exposed ports as disclosed in this invention, no pulsations due to the operation of the valve will be transmitted to the abrasive fluid. Only pump pulsations will be imparted to the abrasive fluid discharged in the hydraulic exchanger system. This will result in a smooth and an effective flow of abrasive fluid to accomplish the task of drilling.

Other than some hydraulic losses, there is virtually a perfect exchange to pumped abrasive fluid through the flexible membranes of each of the hydraulic exchangers.

In addition, this pumping system may be readily used for other specialized operations in drilling. One such operation would be in pumping a concrete mixture into a Well. Outside of the field of drilling, acids and many other fluids may be pumped within either inter or intra plant pipe-lines using the hydraulic exchanger system of this invention.

It will be understood that this invention is susceptible to modification in order to adapt it to diiferent usages and conditions, and, accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. In a pumping system, a plurality of hydraulic exchangers for normal operation and connected in parallel to a suction line and a discharge line, a stand-by hydraulic exchanger, a hydraulic valve to control actuated fluid flow into each of said hydraulic exchangers, said hydraulic exchanger valves being annularly arranged, pre-loaded spring means on each hydraulic valve for actuating each of said hydraulic exchanger valves, a rotary cam with one face thereof having a cam surface to sequentially engage said actuating means, the hydraulic valve for said stand-by hydraulic exchanger being positioned facing the opposite face of said rotary cam, a plurality of second spring-loaded actuating means aligned with said first actuating means and each being connected to operate said stand-by hydraulic exchanger valve, a second cam surface on the opposite face of said rotary cam and aligned with said first cam surface, means normally engaging said second actuating means for maintaining said second actuating means inoperative, means engageable with said pre-loaded spring means for selectively rendering one of said hydraulic exchanger valves inoperative,- and means engageable with said means for maintaining said second actuating means inoperative for rendering the corresponding second actuating means operative simultaneously with the rendering of a hydraulic exchange valve inoperative whereby said standby hydraulic exchanger is substituted for said one hy.-. draulic exchanger.

2; In a hydraulic exchanger pumping system, a hydraulic exchanger having a housing, a flexible diaphragm within saidthousing dividing the interior thereof into two chambers, the first of said chambers being provided'for a work fluid to be pumped and the second for clean oil. as an actuating fluid to actuate said flexible diaphragm to eft'ectpumping of said work fluid from said first chamber,

I a resiliently mounted semi-flexible mesh diaphragm posi tioned adjacent said flexible diaphragm in said first chamber for assuring the completion of the suction portion of the exchanger cycle when various viscous and heavy abrasivetfiuids are being handled, means in said housing providing an inlet and outlet for each of said chambers, means. connected to said first chamber for introducing a work fluid into said first chamber, means connected to. saidisecondl chamber for delivering clean oil under pres. sure, tov said second chamber to urge said flexible diaphragm. into said first chamber and thereby forcibly discharge the work fluid from said first chamber, and means. connected to said means for delivering clean oilandv operable independently of said housing and flexible diaphragmfon cycling the admission and discharge of; said clean oihintosaid second chamber.

3. In a hydraulic exchanger pumping system, a hy.-'

draulic exchanger having a housing, a flexible diaphragm within said housing dividing the interior thereof into two chambers, the said diaphragm comprising a pairof spaced flexible elements and a detectable fluid contained. between said elements whose presence in either the work fluid or clean oil will indicate a break in the diaphragm, the first. of said chambers being provided for a work fluid to be pumped and the second for a clean oil to actuate said flexible diapragm to effect pumping of said work fluid from said first chamber, means in said housing providing an inlet and outlet for each of said compartments, means connected to said first chamber for introducing work fluid into said first chamber, means. connected to said second chamber for delivering clean oil under pressure to said second chamber to force said. flexible diaphragm into said first chamber and thereby forcibly discharge the work fluid from said first char-n ber, and means connected to said means for delivering clean oil and operable independently of said housing and diaphragm for cycling the admission and dischargeof; said clean oil into said second chamber.

4. In a hydraulic pumping system as claimed in claim 3 with said detectable fluid comprising radioactive parti cles' therein whereby upon failure of the diaphragm the radioactive particles will become intermixed either with the clean oil or the work fluid or both and can be readily detected to reveal the presence of a break in the diaphragm.

5. In a hydraulic pumping system as claimed in claim 4 comprising means-at both outlets of both chambers for detecting the presence of radioactive particles in the clean oil and the work fluid whereby a leak in the diaphragm will be indicated.

6. In a hydraulic exchanger pumping system, a plurality of hydraulic exchangers operable in succession in a. predetermined sequence, each exchanger including a housing, a flexible diaphragm in said housing dividing the interior thereof into two chambers, the first of said chambers being provided for a work fluid to be pumped and the second for clean oil for actuating the flexible dia-vv phragm to effect pumping of said Work fluid from its associated first chamber, means in said housing providing an inlet and outlet for each of said chambers, means, connected to said first chamber for successively int roducing work fluid into the first chamber of the respective hydraulic exchangers, means connected to said second chamber for successively delivering clean oil under pressure to the second chamber of the respective exchangers to force the flexible diaphragm associated therewith into the first chamber and thereby forcibly discharge the work fluid from said first chamber, separate conduit means for said clean oil and said work fluid, and control means connected to said means for delivering clean oil and operable independently of said exchanger housing and the flexible diaphragm for so controlling the clean oil that it is successively introduced and exhausted from the second chambers of said hydraulicexchangers to provide a continuous pumping movement of the flexible diaphragms.

7. In a hydraulic exchanger pumping system, a plurality of hydraulic exchangers operable in succession in a predetermined sequence, each hydraulic exchanger including a housing, a flexible diaphragm in said housing dividing the interior thereof into two chambers, the first of said chambers being provided for a work fluid to be pumped and the second for a fluid under pressure for actuating said flexible diaphragm to effect pumping of said work fluid from its associated first chamber, means in said housing providing an inlet and outlet for each of said chambers, means connected to said first chamber for successively introducing work fluid into the first chamber of the respective hydraulic exchangers, means connected to said second chamber for successively delivering actuating fluid under pressure to the second chamher of the respective hydraulic exchangers to force the flexible diaphragms associated therewith into the first chamber and thereby forcibly discharge the work fluid from said first chamber, separate conduit means for said fluid under pressure and said work fluid, and control means connected to said means delivering fluid under pressure for cycling the admission and discharge of said fluid under pressure successively to said hydraulic exchangers comprising a rotary valve having a constant open area of the chamber inlet means and outlet means at any point of the rotation of the valve whereby the pulsations of the pump delivering the fluid under pressure will 'be faithfully duplicated in the work fluid flow pumped by the hydraulic exchangers.

References Cited in the file of this patent UNITED STATES PATENTS 1,256,127 Gould Feb. 12, 1918 1,627,257 Stevens May 3, 1927 2,566,873 Britton Sept. 4, 1951 2,578,160 Van Der Werfl Dec. 11, 1951 2,593,733 Davies Apr. 22, 1952 2,662,478 Surre Dec. 15, 1953 2,673,525 Lucas Mar. 30, 1954 2,691,943 Wilson Oct. 19, 1954 FOREIGN PATENTS 147,826 Sweden Nov. 23, 1954 888,626 Germany Nov. 26, 1953