US3583834A

US3583834A - Pressure pumping system utilizing pilot fluid

Info

Publication number: US3583834A
Application number: US829641A
Authority: US
Inventors: Jack Isreeli; Aaron Kassel
Original assignee: Technicon Corp
Current assignee: Technicon Corp
Priority date: 1969-06-02
Filing date: 1969-06-02
Publication date: 1971-06-08
Anticipated expiration: 1988-06-08
Also published as: DE2026294A1; CH524066A; BE751256A; GB1297862A; DE2026294C3; NL7007939A; FR2049713A5; DE2026294B2

Abstract

New and improved pressure pumping system utilizing a pilot fluid is provided and comprises means to pressurize a pilot fluid for flow at substantially constant flow rate to fluid pressure exchange means which are operable, in response thereto, to flow the fluid to be pumped therefrom at substantially constant flow rate. Means which take the form of additional fluid pressure exchange means, multicondition fluid flow directing means, and pilot fluid return means, respectively, are provided to enable substantially continuous system pumping operation from alternate ones of said fluid pressure exchange means, with substantially continuous recirculation of said pilot fluid and substantially continuous replenishment of said fluid to be pumped in said fluid pressure exchange means from a nonpressurized source of said fluid.

Description

United States Patent [72] inventors Jack lsreell Mamaroneek; Aaron Kassel, Brooklyn, both of,'N.Y. [21] Appl. No. 829,641 [22] Filed June 2, 1969 {45] Patented June 8, 1971 [73] Assignee Technicon Corporation Tarrytown, N.Y.

s41 PRESSURE PUMPlNG SYSTEM uTILi'ZiNoPiLoT FLUID 17 Claims, 2 Drawing Figs.

[52] US. Cl 417/347, 417/372, 417/390, 417/394 [51] Int. Cl ..F04b 17/00, F04b 9/08, F04b 43/06 [50] Field of Search 103/44 D,

Primary Examiner-Carlton R. Croyle Assistant Examiner-John J. Vrablik Attorney-S. P. Tedesco ABSTRACT: New and improved pressure pumping system utilizing a pilot fluid is provided and comprises means to pressurize a pilot fluid for flow at substantially constant flow rate to fluid pressure exchange means which are operable, in response thereto, to flow the fluid to be pumped therefrom at substantially constant flow rate. Means which take the form of additional fluid pressure exchange means, multicondition fluid flow directing means, and pilot fluid return means, respectively, are provided to enable substantially continuous system pumping operation from alternate ones of said fluid pressure exchange means, with substantially continuous recirculation of said pilot fluid and substantially continuous replenishment of said fluid to be pumped in said fluid pressure exchange means from a nonpressurized source of said fluid.

PATEN [H1 .nm 8 IU'II 02674 TIA 6 4/64/75 INVENTORS JACK ISREELI AARON. KASSEL ATTORNEY PRESSURE PUMPING SYSTEM UTILIZING PILOT FLUID BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a new and improved pressure pumping system utilizing a pilot fluid and, more specifically, to such system as is particularly adaptable for use in automatic, sequentially operable blood sample analysis means.

2. Background of the Invention Although pressure pumping systems are known as described in greater detail hereinbelow for the supply of liquids in the nature of suitable color-producing reagents to automatic, sequentially operable, constant flow rate blood sample analysis systems in the nature, for example, of those disclosed in US. Pat. No. 3,241,432 issued Mar. 22, 1966 to Leonard T. Skeggs, ct al., it may be understood that certain problems do arise in such use of the prior art pressure pumping systems and that, as currently foreseen, these problems will become particularly acute when it is attempted to apply said prior art pressure pumping systems to such use in advanced versions of said blood sample analysis systems as are currently under development and which operate, to significant advantage, through the use of substantially reduced, constant blood sample and reagent flow rates, respectively. More specifically, it may be understood that the prior art pressure pumping systems would require extremely long and unwieldy components in the nature of high flow resistance coils for reagent flow to provide the said substantially reduced constant reagent flow rates, and will require extremely long periods of time to enable the suitable cleaning of such coils to prevent reagent deposition therewithin with attendant intolerable change in the reagent flow rate therethrough, all at considerable expense in additional coil fabrication and calibration costs and system downtime, as should be obvious.

Further, it may be understood that the viscosity, and accordingly the flow rates of such reagents through such coils, are acutely affected by reagent temperature change whereby may be understood that substantially precise temperature control is required to prevent intolerable change in reagent flow rate. Too, the said prior art systems may be understood to rely upon external sources of pressurization, and the use of pressurized reagent containers of somewhat limited capacity which require relatively frequent replenishment, each of which constitute a potential source of difficulty as should be obvious.

OBJECTS OF THE INVENTION It is, accordingly, an object of this invention to provide a new and improved pressure pumping system utilizing a substantially stable, inert, and nondepositive pilot fluid of relatively high viscosity which is substantially unaffected by moderate temperature changes to provide for substantially constant system discharge flow rate over long periods of time without requiring the use of extremely expensive or unwieldy system components.

Another object of this invention is the provision of a pressure pumping system as above which does not require extended periods of system downtime for the cleaning thereof.

A further object of this invention is the provision of a pressure pumping system as above which is complete within itself and does not require an external source of pressurization, or the pressurized containment, of the liquid to be pumped thereby, to thus eliminate major sources of potential system disability.

Another object of this invention is the provision of a pressure pumping system as above which embodies a large storage capacity for the liquid to be pumped to thus eliminate the need for frequent replenishment of the latter.

A further object of this invention is the provision of a pressure pumping system as above which requires the use of only readily available components of proven dependability in the fabrication thereof and will accordingly provide for long periods of satisfactory, maintenance free system operation.

A still further object of this invention is the provision of a pressure pumping system as above which is particularly, though not exclusively, adapted for use in the supply of liquids in the nature of suitable color-producing reagents at very low, constant flow rates to improved versions of automatic, sequentially operable blood sample analysis systems.

SUMMARY OF THE INVENTION As currently preferred, the new and improved pressure pumping system of the invention comprises means to pressurize a pilot fluid and flow the same at substantially constant flow rate to fluid pressure exchange means which are operative, in response thereto, to flow the fluid to be pumped, from a nonpressurized container thereof, for discharge from the system at a substantially constant flow rate. More specifically, the means to pressurize the pilot fluid comprise a pressurized chamber and pump means which are operable to pump said pilot fluid thereinto at substantially constant pressure, and pilot fluid outlet means, including a high flow resistance coil means disposed within said chamber, which are operative to provide for the flow of the pilot fluid from the pressurized chamber at a substantially constant flow rate. The fluid pressure exchange means comprise containers for the pilot fluid and fluid to be pumped, respectively, and at least one of said containers is of variable volume and so related to the other of said containers that when the volume of the former increases the volume of the latter decreases and vice versa. Through the provision of two of said fluid pressure exchange means, of pilot fluid return means, and of multiposition valve means, it is made possible to pump from one of said exchange means while refilling the other from said nonpressurized source, and vice versa, with said pilot fluid return means providing for continual pilot fluid recirculation through the system.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects and advantages of this invention are believed made clear by the following detailed description thereof taken in conjunction with the accompanying drawings wherein;

FIG. I is a schematic or flow diagram of a pressure pumping system constructed in accordance with the principles of the prior art; and

FIG. 2 is a schematic or flow diagram of a new and improved pressure pumping system utilizing a pilot fluid and constructed and operative in accordance with the teachings of this invention.

BRIEF DESCRIPTION OF THE PRIOR ART A pressure pumping system constructed and operative in accordance with the principles of the prior art for use in fluid analysis systems is indicated generally at 10 and may, for example, take the form of that shown and described in the copending application Ser. No. 712,431 of Edward B. M. De- .Iong filed Mar. 12, 1968 and assigned to the assignee hereof.

More specifically, the pressure pumping system 10 comprises a tank 12 of a suitably inert gas at suitable pressure, as for example nitrogen at 2,200 p.s.i., connected as shown through suitable pressure regulator means 14 to a branched conduit or manifold 16 to maintain the latter at a substantially constant pressure in the order, for example, of 66.8 cm. Hg.

Flasks l8 and 20, including screw-

on covers

22 and 24, respectively, are provided and may be understood to respectively contain liquids in the nature, for example, of colorproducing reagents for use in the fluid analysis system in the event the latter is constituted by a blood sample analysis system as discussed hereinabove, and the respective interiors of the said flasks are connected as shown by relatively short inlet conduits 26 and 28 to the branched conduit 16.

An outlet conduit 30 connects the interior of flask 18 to the inlet of a high flow resistance coil 32, and a conduit 34 connects the outlet of the coil as indicated to the fluid analysis system. In like manner, an outlet conduit 36 connects the interior of flask to the inlet of a high flow resistance coil 38, and a conduit 40 connects the outlet of the coil as Indicated to the fluid analysis system For use in a representative blood sample analysis system, the respective internal diameters of the high

flow resistance coils

32 and 38 are made relatively small on the order, for example, of 0.010 inch or 0.25 mm., while the respective lengths thereof are made relatively long on the order, for example, of 210 inches for liquids, to provide the desired high flow impedance and attendant, relatively low flow rates. In addition, the respective high

flow resistance coils

32 and 38 would be disposed in a temperature control bath as indicated in dashed lines at 42 which operates at a suitable temperature as, for example, 37 C. to maintain the liquids passing through the said coils at substantially constant pressure and viscosity. If desired, the respective flasks l8 and 20, and the respective entireties of the

outlet conduits

30 and 36 may also be disposed in the said temperature control baths.

In operation, the gas from container 12 will pressurize the respective interiors of flasks l8 and 20 to force the liquids therefrom through the respective high

flow resistance coils

32 and 38 and therefrom, through

conduits

34 and 40 at predetermined, substantially constant flow rates.

The flow rates of the liquids through the respective high

flow resistance coils

32 and 38 are determined by the Hagen/Poiseuille equation:

wherein:

Q is the flow rate;

AP is the pressure drop across the coil;

D is the internal coil diameter;

u is the viscosity of liquid; and

L is the effective length of the coil.

In view of this flow determinative equation, and despite the fact that pressure pumping systems in the nature of that described are believed generally satisfactory for use in blood sample analysis apparatus, it may be understood that problems do arise in the fabrication and manner of operation thereof, and that these problems become particularly acute when viewed in light of the more advanced blood sample analysis systems currently under development which make use of extremely low blood sample and reagent flow rates. More specifically, and in accordance with the said equation, it may be seen that internal coil diameter and effective coil length are of particular consequence in establishing the flow rate. This is to say that in order to establish a very low flow rate, the coil diameter must be made very small and the effective coil length very large which gives rise to the problem of unduly high cost of coil fabrication, and especially since the internal coil diameter must be maintained substantially constant throughout with the attendant requirement of extremely precise manufacturing tolerances. Too, it may be understood that the use of very long high flow resistance coils, and the attendant use of very extensive temperature control baths, will, of course, render the same decidedly unwieldy for practical utilization in relatively compact, blood sample analysis systems as discussed hereinabove. A further disadvantage of the use of particularly long high flow resistance coils resides in the fact that, for use in systems requiring extremely low flow rates, the liquid flow times therethrough would, of course, be inordinately long to thus materially decrease the operational rate of the system.

In addition, and even though the internal coil diameters are closely controlled during coil fabrication, it may be understood that liquids in the nature of the reagents discussed hereinabove will have a tendency to plate or deposit therewithin during periods of extended system utilization to ultimately reduce the internal coil diameters to the extent, if unchecked, that the resultant change in the liquid flow rates therethrough cannot be tolerated by the system. Accordingly, it may be understood that periodic, or in fact daily, cleaning of such coils would be required, as by the flow of water therethrough by the pressure pumping system, and the very substantial period of time required for such coil cleaning of course constitutes nonproductive system downtime.

Too, it may be understood that since the respective flasks l8 and 20 are, of necessity, of somewhat limited capacity, the same must be periodically replenished during system operation. Accordingly, and in view of the fact that the said flasks function as pressure vessels, as is believed obvious, it may further be understood that any failure to properly retighten the respective covers thereof following such replenishment, as has been observed to occur during system utilization, will, of course, render the system substantially inoperative. The requisite periodic replacement of the pressurized fluid supply means 12 also gives rise to a potential source of system disability as should be obvious.

DETAILED DESCRIPTION OF THE INVENTION Referring now to FIG. 2, a new and improved pressure pumping system utilizing a pilot fluid and constructed and operative in accordance with the teachings of this invention is indicated generally at 46 and may be seen to comprise a substantially fluidtight container 48 which is suitably constructed for function as a pressure vessel and is internally divided, as by

walls

50 and 52, into respective, substantially fluidtight chambers 54, 56 and 58. Temperature control means which may, for example, take the forms of the temperature control bath as indicated by the dashed lines at 60, are operatively associated with the container 48 to maintain the temperature thereof, and of the liquids contained therein at a substantially constant, predetermined level with attendant maintenance of the respective viscosities of the liquids contained therein at substantially constant, predetermined values, and it be un-- derstood that such temperature control means are preferably thermostatically controlled.

Two-position, exchange valve means are indicated sche matically at 62 and may be understood to take any form suitable to the disclosed function thereof as described in detail hereinbelow. Accordingly, said exchange valve means may, for example, take the form of relatively movable upper and

lower valve plates

63 and 65, each of which contains appropriate valve passages formed therein in a manner believed clear to those skilled in this art.

An open, nonpressurized liquid supply container is indicated at 64, and a liquid supply conduit 68 extends as shown from the lower portion of the interior of the liquid supply container 64 into communication with the exchange valve means A pilot fluid supply conduit 70, including a high flow resistance coil 72 connected as shown at the inlet endthereof, extends from the interior of chamber 58 into communication with the exchange valve means 62, while a pilot fluid return conduit 74 extends as shown from communication with the said exchange valve means to the chamber 56.

A fluid pressure exchange bottle is indicated generally at 76 and is disposed as shown in chamber 54. The said exchange bottle comprises a substantially fluidtight, fixed volume outer container 78, and a substantially fluidtight, variable volume inner container 80 in the nature, for example, of a bellows, disposed as shown therewithin. A liquid supply conduit 82 extends as shown from communication with the fixed volume container 78 into a communication with the exchange valve means 62, while a pilot fluid supply and return conduit 84 extends as shown from communication with the variable volume container 80 into communication with the fluid exchange valve means 62.

A fluid pressure exchange bottle of substantially the same construction as just described is indicated generally at 86 and comprises a fixed volume outer container 88 and a variable volume inner container 90. A liquid supply conduit 92 extends as shown from communication with the fixed volume outer container 88 into communication with the fluid exchange valve means 62, and a pilot fluid supply and return conduit 94 similarly extends as shown from the inner variable volume container 90.

Pump means 96 which may take any suitable form are disposed as shown with the pump inlet 98 in communication with chamber 56 and the pump outlet 100 in communication with chamber 58 to pump fluid from the former to the latter. Bleed means 102, which preferably include nonillustrated air filter means, are formed as shown in the upper wall of chamber 56 to enable the pumping of fluid therefrom by the said pump means.

Pressure balanced relief valve means, which may take any suitable form, are indicated schematically at 104 and are disposed as shown in the upper wall of chamber 58 so as to be effective to prevent the fluid pressure in the said chamber from exceeding a predetermined maximum.

A system discharge conduit is indicated at 106 and may be understood to extend as shown from the fluid exchange valve means 62 to the point of utilization of the liquid pumped by the system of the invention.

Fluid agitation means are indicated schematically at 107 and 108, respectively, and are disposed as shown in the respective lower portions of the chambers 54 and 58 for obvious purpose. The said fluid agitation means may, of course, take any suitable form and be driven in any convenient manner as, for example, from the nonillustrated pump drive means.

Optional pilot fluid supply conduits are indicated at 109 and 112, and may be seen to respectively include high flow resistance coils 114 and 116 connected to the inlet ends thereof. These optional pilot fluid supply conduits are disposed as shown in the chamber 58 and would, if utilized, extend therefrom as indicated to the fluid exchange valve means 62, or fluid exchange valve means of similar nature, to increase the capacity of, or the number of liquids which can be pumped by, the system of the invention as described in greater detail hereinbelow.

Prior to a detailed description of the operation of the system of the invention, it is to be understood that the exchange valve means 62 are shiftable, either manually or under the control of suitably timed, automatic valve means operating means as indicated schematically at 110, between first and second positions thereof.

in said first position thereof, the exchange valve means 62 may be understood to be operative to connect pilot fluid supply conduit 70 to pilot fluid supply and return conduit 84; to connect liquid supply conduit 68 to liquid supply conduit 92; to connect pilot fluid supply and return conduit 94 to pilot fluid return conduit 74; and to connect liquid supply conduit 82 to system discharge conduit 106.

la said second position thereof, the fluid exchange valve means may be understood to be operative to connect pilot fluid supply conduit 70 to pilot fluid supply and return conduit 94; to connect liquid supply conduit 68 to liquid supply conduit 82; to connect pilot fluid supply and return conduit 84 to pilot fluid return conduit 74; and to connect liquid supply conduit 92 to system discharge conduit 106.

OPERATION In operation, for representative use of the system of the invention, as for example in the supply of a color-producing reagent to an improved, substantially lower constant flow rate version of the blood sample analysis system disclosed in said U.S. Pat. No. 3,241,432 which will operate, for example, at a blood sample flow rate of 0.05 ml. per minute and a reagent flow rate of 0.50 ml. per minute, it may be understood that liquid container 64 would be substantially filled with such reagent, while the respective chambers 54, 56 and 58 would contain therein to the indicated levels a suitable pilot fluid in the nature, for example, of a silicone oil which provides the advantages of substantial chemical inertness and nondepositiveness, long term stability, and a relatively high viscosity which is relatively insensitive to moderate temperature changes.

As a result of this relatively high oil viscosity, and referring again to the Hagen/Poiseuille equation as described hereinabove, it may be understood that the provision of the desired low flow rate may be accomplished substantially without requiring the use of a high flow resistance coil 72 of extreme and/or unwieldy length. This is to say that the said coil may be made quite short.

For such representative use, it may further be understood that the temperature control means 60 might be set to maintain the temperature within the container 48 at a substantially constant 37 C., and the volume of chamber 48 made sufficiently large to insure that the pilot fluid silicone oil returned thereto at substantially ambient temperature through return conduit 70 would have negligible, if any, overall effect on the temperature, and thus viscosity, of the silicone oil contained within the said chamber.

In addition, the pump means 96 would be suitably sized to rapidly transfer the silicone oil pilot fluid and thereafter pumping air from chamber 56 to chamber 58 while developing, for example, approximately 3 to 5 p.s.i. suction in chamber 56 by virtue of restriction 102 and establishing an air pressure above the oil level within chamber 58 of approximately l5 p.s.i. at the total reagent flow rates. Under such conditions, the pressure balanced relief valve 104 would, of course, be set to open at 15 p.s.i.

Also, the respective fluid pressure exchange bottles 76 and 86 would preferably be sized, as determined by the total reagent flow rate from the system, to provide for an hour's supply of reagent to thus enable system operation for a full hour without operation of the exchange valve means 62. Too, although for convenience of illustration, the respective container 48, liquid container 64 and exchange valve means 62 are depicted as somewhat spaced, it may be understood that in.

actual practice the same would be disposed as closely together as practical to maintain the respective connecting conduits short and minimize the effect thereof upon consistent system pumping operation.

if it considered that system operation has assumed steady state conditions and is at the point wherein

outer containers

78 and 88 are filled with reagent, inner containers 80 and are filled with the silicone oil and are respectively fully contracted and fully expanded, and the exchange valve means 62 have just been shifted from the second position thereof to the first position thereof, the new and improved pressure pumping system of the invention may be understood to operate as follows.

Silicone oil from chamber 58 will be forced, by the positive pressure created therein through operation of the pump means 96, to flow into and through the high flow resistance coil 72 at substantially constant, predetermined flow rate, and to flow from the latter, through conduit 70, to the exchange valve means 62. The thusly pressurized oil will be directed by the said exchange valve means to flow, through conduit 84, into the variable volume inner container 80 to commence the expansion thereof with concomitant reduction in the available volume of fixed volume outer container 78 and attendant forced flow of the reagent therefrom through conduit 82 to the exchange valve means 62 for direction by the latter for discharge from the system through system discharge conduit 106.

Concomitantly, it may be understood that operation of the pump means 96 will create a suction in chamber 56 to draw oil from variable volume inner container 90, through conduit 94, exchange valve means 62 and conduit 74, respectively, into the said chamber and commence the contraction of the said variable volume inner container. The latter will of course result in increase in the available volume of fixed volume container 88 and the creation of a suction therein, whereby reagent will commence to be drawn thereinto from reagent container 64 through conduit 68, exchange valve means 62, and conduit 92, respectively.

Operation will, of course, continue in this manner until the usable volume of reagent within fixed volume outer container 78 has been forced therefrom for discharge from the system by the expansion of variable volume inner container 80, at which time the exchange valve 62 will be manually or automatically, as the case may be, shifted to the second position thereof, it being understood that variable volume inner container 90 will, at this point, have been contracted to the maximum practicable extent to provide for the storage of the maximum practicable amount of reagent from reagent container 64 in the now maximum available volume of the fixed volume outer container 88.

As this shifting of the exchange valve means 62 occurs, it may be understood that the pressurized oil from chamber 58 will commence to flow therefrom, through high flow resistance coil 72, conduit 70, exchange valve means 62 and conduit 94, respectively, to the variable volume inner container 90 to commence the reexpansion thereof with attendant forced flow of reagent from fixed volume outer container 88 through conduit 92 and exchange valve means 62, respectively, for discharge from the system through system discharge conduit 106.

Concomitantly, the drawing of oil from variable volume inner container 80, through conduit 84, exchange valve means 62 and return conduit 74, respectively, into the chamber 56 will, of course, commence the recontraction of the said container with the result that reagent will commence to be drawn from the reagent container 64 into the fixed volume outer container 78 through conduit 82, exchange valve means 62, and conduit 68, respectively.

Operation as described will, of course, continue for so long as the pump means 96 are maintained energized, the exchange valve means 62 appropriately shifted between the respective first and second positions thereof, and a suitable supply of reagent maintained in reagent container 64.

Referring now to the optional pilot fluid supply conduits .109 and 112, and the respective high flow resistance coils 114 and 116 connected thereto, it may be understood that the same may be provided for operative connection, through exchange valve means in the nature of exchange valve means 62 having additional valve passages, to suitably operate additional pairs of fluid pressure exchange bottles which may, in turn, be supplied with second and third reagents from second and third reagent containers to thus enable the concomitant pumping, at substantially constant and predetermined flow rate or rates, from the system of the invention. Alternatively, the said second and third containers may contain liquids in the nature of water of clinical purity for use in the formation of recipient streams, and/or for use as diluents, in the blood sample analysis system.

With regard to high flow resistance coil 72, it may be understood that a single coil size may be used to provide the same flow rate for substantially all reagents since the silicone oil, rather than the reagent, is being pumped therethrough, and since the flow resistance of the coil is so much greater than the combined flow resistances of the remainder of the system. Of further interest, and advantage, with regard to high flow resistance coil 72 and silicone oil chamber 58 is the fact that, since the silicone oil in the latter is automatically at the proper temperature before the same enters the said coil, there is no need for a carefully temperature controlled, coil inlet conduit of substantial length as there would be in the prior art system of FIG. 1.

With regard to the respective times required for the refilling with reagent of the respective fixed volume

outer containers

78 and 88, it may be understood that the same will be quite short because there is no high flow resistance coil in the silicone oil return line 74. Accordingly, it is believed clear that there will be absolutely no loss of analysis time for reagent replenishment.

Since reagent container 64 is an open, nonpressurized container, it is believed clear that the same may be handled easily and casually without concern for whether or not the said container is properly sealed as discussed hereinabove with regard to sealed

reagent containers

18 and 20 of the prior art pressure pumping system ofFlG. 1.

While we have shown and described the preferred embodiment of our invention, it will be understood that the invention may be embodied otherwise than as herein specifically illustrated or described, and that certain changes in the form and arrangement of parts and in the specific manner of practicing the invention may be made without departing from the underlying idea or principles of this invention within the scope of the appended claims.

lclaim:

1. In an automated sample analysis system, utilization conduit means, respective sources of first and second fluids, means to pressurize said first fluid source at a substantially constant level, fluid pressure exchange means including a container for said first fluid and a container for said second fluid, at least one of said containers being of variable volume and said containers being operatively related in such manner that when the volume of said variable volume container increases the volume of the other of said containers decreases substantially in proportion thereto and vice versa, means for connecting said first fluid source to said first fluid container and including resistance means, extending into said first fluid source, having a much higher flow resistance than said utilization conduit means, and temperature control means operatively associated with said first source and said resistance means, to maintain the respective temperatures thereof, and the fluids contained therein, substantially at a constant level, so that a substantially constant first fluid flow rate is established, whereby said pressurized first fluid will flow into said first fluid container at a substantially constant flow rate to concomitantly flow said second fluid from said second fluid container into said utilization conduit means at a substantially constant flow rate.

2. ln a system as in claim 1 further comprising, fluid return means for connecting said first fluid container to said pressurization means in such manner that said first fluid will be drawn from said first fluid container to said first fluid source upon operation of said pressurization means, connecting means for connecting said source of said second fluid to said second fluid container means, and flow directing means which are operable to connect said first fluid container and said pressurization means through said fluid return means, and are operable to concomitantly connect said source of said second fluid to said second fluid container means whereby, said first fluid will be drawn from said first fluid container for return to said first fluid source and said second fluid will be concomitantly drawn from said second fluid source to said second fluid container.

3. in a system as in claim 1 further comprising, additional fluid pressure exchange means including, in the manner of said fluid pressure exchange means, containers for said first and second fluids, respectively, means including said high flow resistance means for connecting said first fluid source to said first fluid container of said additional fluid pressure exchange means, fluid return means for connecting the respective first fluid containers of said fluid exchange means and said additional fluid exchange means to said pressurization means in such manner that said first fluid will be drawn from said first fluid containers to said first fluid source upon operation of said pressurization means, means for connecting the respective second fluid containers of said fluid exchange means and said additional fluid exchange means to said second fluid source, means for connecting the respective second fluid containers of said fluid exchange means and said additional fluid exchange means to said utilization conduit means, and flow directing means operable in a first condition thereof to connect said first fluid source with said first fluid container of said fluid pressure exchange means, to connect said first fluid container of said additional fluid pressure exchange means with said pressurization means through said first fluid return means, to connect said second fluid container of said fluid pressure exchange means with said utilization conduit means, and to connect said second fluid container of said additional fluid pressure exchange means with said second fluid pressure source, said flow directing means being operable in a second condition thereof to connect said first fluid source with said first fluid container of said additional fluid pressure exchange means, to connect said first fluid container of said fluid pressure exchange means with said pressurization means through said first fluid return means, to connect said second fluid container of said additional fluid pressure exchange means with said utilization conduit means, and to connect said second container of said fluid pressure exchange means with said second fluid pressure source whereby, with said flow directing means in said first condition thereof, said second fluid will be flowed at substantially constant flow rate from said second fluid container of said fluid exchange means to said utilization conduit means and concomitantly flowed from said second fluid source to said second fluid container of said additional fluid pressure exchange means and, with said flow directing means in said second condition thereof, said second fluid will be flowed at substantially constant flow rate from said second fluid container of said additional fluid pressure exchange means to said utilization conduit means and concomitantly flowed from said second fluid source into said second fluid container of said fluid pressure exchange means.

4. In a system as in claim 1 wherein, said first fluid source comprises a pressurized fluid chamber, and said pressurization means comprise pump means which are operable to pump said first fluid into said chamber at substantially constant pressure.

5. In a system as in claim 4 wherein, said high flow resistance means comprise a high flow resistance coil, the inlet of which is substantially immersed in said first fluid in said chamber.

6. in a system as in claim 2 wherein, said first fluid source comprises a pressurized fluid chamber, and said pressurization means comprise pump means which are operable to pump said first fluid into said chamber at substantially constant pressure.

7. In a system as in claim 6 wherein, said high flow resistance means comprise a high flow resistance coil, the inlet of which is substantially immersed in said first fluid in said chamber.

8. In a system as in claim 2 wherein, said first fluid source comprises a vacuum chamber and a pressurized chamber, respectively, said fluid return means are connected to said vacuum chamber, and said pressurization means comprise pump means which are effective to pump said first fluid from said vacuum chamber to said pressurized chamber at substantially constant pressure.

9. In a system as in claim 8 wherein, said high flow resistance means comprise a high flow resistance coil which is substantially immersed in said first fluid in said pressurized chamber.

10. ln a system as in claim 3 wherein, said first fluid source comprises a vacuum chamber and a pressurized chamber, respectively, said fluid return means are connected to said vacuum chamber, and said pressurization means comprise pump means which are effective to pump said first fluid from said vacuum chamber to said pressurized chamber at substantially constant pressure.

11. In a system as in claim 10 wherein, said high flow resistance means comprise a high flow resistance coil which is substantially immersed in said first fluid in said pressurized chamber.

12. In a system as in claim 4 wherein, said second fluid source is constituted by a nonpressurized container thereof.

13. In a system as in claim 7 wherein, said second fluid source is constituted by a nonpressurized container thereof.

14. In a system as in claim 10 wherein, said second fluid source is constituted by a nonpressurized container thereof.

15. In a system as in claim 11 wherein, said second fluid source is constituted by a nonpressurized container thereof.

16. In a system as in claim 9 further comprising, a chamber for the containment of said fluid ressure exchan e means, said chamber containing said first md to a level su ficient to substantially immerse said fluid pressure exchange means, said temperature control means being operatively associated with said chamber and said vacuum chamber and operable to maintain the respective temperatures thereof, and of the fluids contained therein, substantially at a constant level.

17. in a system as in claim 11 wherein, said pressurized chamber is disposed adjacent said vacuum chamber, said system further comprises a chamber for the containment of said fluid pressure exchange means and said additional fluid pressure exchange means, respectively, said containment chamber also being disposed adjacent said vacuum chamber and containing said first fluid to a level sufficient to substantially immerse said fluid pressure exchange means and said additional fluid pressure exchange means, said temperature control means being operatively associated with said chamber and said vacuum chamber and operable to maintain the respective temperatures thereof, and of the fluids contained therein, substantially at a constant level.

Claims

2. In a system as in claim 1 further comprising, fluid return means for connecting said first fluid container to said pressurization means in such manner that said first fluid will be drawn from said First fluid container to said first fluid source upon operation of said pressurization means, connecting means for connecting said source of said second fluid to said second fluid container means, and flow directing means which are operable to connect said first fluid container and said pressurization means through said fluid return means, and are operable to concomitantly connect said source of said second fluid to said second fluid container means whereby, said first fluid will be drawn from said first fluid container for return to said first fluid source and said second fluid will be concomitantly drawn from said second fluid source to said second fluid container.

5. In a system as in claim 4 wherein, said high flow resistance means comprise a high flow resistance coil, the inlet of which is substantially immersed in said first fluid in said chamber. 6. In a system as in claim 2 wherein, said first fluid source comprises a pressurized fluid chamber, and said pressurization means comprise pump means which are operable to pump said first fluid into said chamber at substantially constant pressure.

10. In a system as in claim 3 wherein, said first fluid source comprises a vacuum chamber and a pressurized chamber, respectively, said fluid return means are connected to said vacuum chamber, and said pressurization means comprise pump means which are effective to pump said first fluid from said vacuum chamber to said pressurized chamber at substantially constant pressure.

16. In a system as in claim 9 further comprising, a chamber for the containment of said fluid pressure exchange means, said chamber containing said first fluid to a level sufficient to substantially immerse said fluid pressure exchange means, said temperature control means being operatively associated with said chamber and said vacuum chamber and operable to maintain the respective temperatures thereof, and of the fluids contained therein, substantially at a constant level.