Abstract:
A fluid pump for moving fluid from a first reservoir to a second reservoir is described. The fluid pump comprises a first reservoir containing a fluid, a second reservoir for receiving the fluid, at least one chamber subject to alternating high and low pressure, and an inlet valving device modulating or switching pressures to which the at least one chamber is exposed, causing the fluid to flow into the at least one chamber from the first reservoir when the at least one chamber is exposed to low pressure and causing the fluid to flow out of the at least one chamber into the second reservoir when the chamber is exposed to high pressure.

Description:
[0001]    This application claims benefit of U.S. Provisional application Ser. No. 62/231,755, filed on Jul. 15, 2015, and herein incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This application relates to the general field of fluid pumps, and more particularly, to pumps specialized for moving aggressive, delicate, unstable, flammable, particulate-laden, ultrapure, dense, or viscous fluids. 
       BACKGROUND 
       [0003]    State of the art pumps or fluid moving devices largely fall into two large categories: dynamic or centrifugal, and displacement. The former type uses some form of a fast moving impeller, while the latter uses a displacement device such as a piston, diaphragm, or flexible tube. Either of these types can be driven by motors, air, exhaust gases from an engine, or other suitable form of energy. 
         [0004]    In virtually all of the above cases, there are moving parts and seals in contact with the fluid being pumped. Seals deteriorate, generate contaminants and particles, and have to be replaced periodically. Shafts wear out and have to be sealed from the power device (i.e. motor) and often are exposed to the fluid, thus contaminating it and contributing particles to it. Impellers are quite susceptible to attack by the fluid, even in cases of rather inert substances by cavitation. Impellers also exert considerable shear forces onto the fluid, sometimes deteriorating it. Diaphragms are flexed continuously and often fatigue and rupture—failing and exposing sensitive parts of the pump to the fluid. Pistons have to seal against the piston wall and can bind and their seals wear, thus constantly contaminating the fluid with their wear by-products. In the absence of seals, they leak or bind against the piston sleeve or wall. 
         [0005]    Even pumps that magnetically levitate their impellers suffer from serious limitations. Designs constraints make them hard to prime and their impellers wear and have to be replaced periodically. They also shear the fluids and make use of seals which also deteriorate. 
       SUMMARY 
       [0006]    It is a primary object of the present disclosure to provide a method and apparatus to move fluids from one reservoir to another. 
         [0007]    It is another object of the present disclosure to provide an apparatus that can apply pressure to a fluid in such manner as to move it to a place that is higher or at a distance from the container of origin. 
         [0008]    A further object of the present disclosure is to provide an apparatus and method to move fluids from one reservoir to another requiring no moving parts, or very few moving parts, such as pistons, impellers, diaphragms, lobed structures, shafts, among many others. 
         [0009]    Yet another object is to provide an apparatus and method to move fluids from one reservoir to another requiring no shaft seals or other seals that are frequently wetted by the fluids being moved, thus preventing contamination and extending the life of the apparatus. 
         [0010]    Yet another object is to provide a device and method that can be very used in moving aggressive, delicate, unstable, flammable, particulate-laden, ultrapure, dense, or viscous fluids that may be otherwise difficult, potentially hazardous, or less practical to move with a more conventional pump. 
         [0011]    In accordance with the objectives of the present disclosure, a fluid pump for moving fluid from a first reservoir to a second reservoir is achieved. The fluid pump comprises a first reservoir containing a fluid, a second reservoir for receiving the fluid, at least one chamber subject to alternating high and low pressure, and an inlet valving device modulating or switching pressures to which the at least one chamber is exposed, causing the fluid to flow into the at least one chamber from the first reservoir when the at least one chamber is exposed to low pressure and causing the fluid to flow out of the at least one chamber into the second reservoir when the chamber is exposed to high pressure. 
         [0012]    Also in accordance with the objects of the present disclosure, a method of pumping fluid from a first reservoir to a second reservoir is achieved. First and second reservoirs are provided. At least one chamber is connected by an inlet valving device to a high pressure source and to a low pressure source. The at least one chamber is connected by an outlet valving device to the first and second reservoirs. Pressures are modulated or switched, through the inlet valving device, into the at least one chamber, causing fluid to flow into the at least one chamber from the first reservoir when the at least one chamber is exposed to low pressure and causing fluid to flow out of the at least one chamber into the second reservoir when the chamber is exposed to high pressure. 
         [0013]    Further and also in accordance with the objects of the present disclosure, a method of moving fluid from one reservoir to a point of use of said fluid, or in general for moving fluid from one place to another. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    In the accompanying drawings forming a material part of this description, there is shown: 
           [0015]      FIG. 1  illustrates a side view of a first preferred embodiment of the present disclosure. 
           [0016]      FIG. 2  illustrates a side view of a second preferred embodiment of the present disclosure. 
           [0017]      FIG. 3  illustrates a side view of a third preferred embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The present disclosure relates to a method and apparatus to move fluids from one reservoir to another. This apparatus can apply pressure to the fluid in such manner as to move it to a place that is higher or at a distance from the container of origin. In contrast with conventional pumps, the apparatus and method of this disclosure requires no moving parts, or very few moving parts, such as pistons, impellers, diaphragms, lobed structures, shafts, among many others. Also, the apparatus and method described herein requires no shaft seals or other seals that are frequently wetted by the fluids being moved, thus preventing contamination and extending the life of the apparatus. The device and method subject of the present disclosure can be very useful in moving aggressive, delicate, unstable, flammable, particulate-laden, ultrapure, dense, or viscous fluids that may be otherwise difficult, potentially hazardous, or less practical to move with a more conventional pump. Industries such as biomedical, medical, chemical, semiconductor, analytical, petroleum, among many others, may benefit from such a fluid moving device and method. 
         [0019]    Referring now more particularly to  FIG. 1 , a first preferred embodiment will be described. A reservoir  10 , which can be filled with fluid  20  is shown. The interior of reservoir  10  is alternatingly subject to high and low pressures. In a typical embodiment, an inlet valving device  30  (which can be comprised of a plurality of pneumatic valves, electric valves, electro-pneumatic valves, flapper valves, ball valves, floats, or combinations thereof, among others) can modulate or switch the pressure to which the inside of the chamber  10  is exposed, such that fluid  20  can be made to flow into or out of the chamber  10 . One or more of the valving devices  30  can be proportional, multi-way, or the on/off type, either passive or actuated. 
         [0020]    The chamber  10  can have one or more openings  40 , typically on top and bottom, to allow for the fluid and pressure to move in and out of the chamber. The openings can also be on the same side, opposite sides, rotated, or connected with tubes or other types of channels in such a way that the above functions, or combinations thereof, are accomplished. 
         [0021]    In a typical embodiment, the chamber would have a source of low pressure  50  (i.e. vacuum) and a source of high pressure  60  (i.e. a suitable compressed gas or other suitable fluid). The relative value of these high and low pressures is referenced to atmospheric values, the values present at the destination reservoir, or other suitable pressure reference. In a typical embodiment, a 3-way valving device  30  would alternatively select the low pressure source  50  to draw fluid into the chamber and the high pressure source  60  to eject it from the chamber. This valving device can be 3-way, on/off, or proportional, among other types. In a typical embodiment, a suitable valving device  70 , chosen from the same categories as the inlet valving device  30 , would allow the fluid to alternatingly enter the chamber  10  and leave the chamber. In a typical embodiment, the two aforementioned valving devices would work in a suitable coordinated or uncoordinated fashion to achieve the desired fluid transport or motion. 
         [0022]    In a typical embodiment, the inlet valving device  30  would expose the interior of the chamber to the low pressure source  50  at the same time as the outlet valving device  70  exposes its interior to a fluid reservoir  90 . This action would cause the fluid to flow from the fluid reservoir  90  into the chamber  10 . After a suitable time interval the inlet valving device  30  would switch to expose the chamber to the source of high pressure  60  while in a suitable coordinated or uncoordinated fashion, the outlet valving device  70  switches to expose the chamber interior to an outlet path  100 . The execution of one or more of the cycles described herein, or modifications thereof, would cause a fluid to be moved from a source  90  to a destination  110  in which these source and destination reservoirs can be at the same or different pressures or heights. 
         [0023]    In a preferred embodiment, the fluid level is sensed at one or more appropriate locations by sensors capable of producing a detectable change of state in the presence of fluid within their sensing range. The level reached by the fluid during any part of the cycle described above can also be sensed in a variety of other ways, such as by a time interval (fixed or variable), floats, magnetic switches, capacitive devices, and optical devices, among other types. The fluid level can be controlled in conjunction with the pressure fluctuations in the chamber, with passive valving systems, such as floats, flap valves, ball valves, or combinations thereof, among others. In a preferred embodiment, the level sensing switches are of the optical type and produce a detectable electrical state change on their output when liquid is present within their sensing range. These can be located in a variety of suitable positions, such as near or at the bottom  120  of the chamber  10 , and/or at or near the top  130  of the chamber  10 . In a preferred embodiment optical switches  120 ,  130  control a pair of 3-way valves  30 ,  70  working in tandem to periodically fill and empty the fluid in the chamber thus producing the desired fluid motion or pumping action. In another embodiment, there may be only one optical switch located at or near either end of the chamber in combination with a delay-on or delay-off mechanism, thus fixing the time that either the low pressure or the high pressure are acting upon the chamber, and thus taking fluid in or ejecting it. One or more of these cycles can be repeated to produce the desired pumping action. The above operating mode can be achieved with simple components and made to operate in an autonomous fashion upon power up, without the need for external program control. The term 3-way valve is intended to describe a general type of valving device that routes the fluids in accordance to the purposes of this disclosure. Other types of valving devices may be used instead and are also subjects of the present invention. It may be noted that use of switches as described above provides a timing and synchronization function akin to that provided in conventional pumping systems by mechanical or other more conventional means (e.g. crankshafts, connecting rods, and pistons; or equivalent). 
         [0024]    Alternatively, all or some of the switches and valves can be controlled by a control device that takes inputs from these devices and affects the state of valves or switches in such manner as to achieve the desired fluid moving action. 
         [0025]    Such control device is particularly useful if more than one chamber is connected in parallel, as illustrated in  FIG. 2 . In this second preferred embodiment, with more than one chamber  10  in parallel, the throughput of the whole apparatus increases and the flow becomes proportionally smoother. In this embodiment, the chambers can be timed such that some of the chambers are being filled while others are ejecting the fluid, thus accomplishing a more continuous flow. When connected in this manner, the flow from one chamber can be prevented from flowing into another by appropriate use of directional valves  140 . As many chambers as practical can be connected in the above described fashion. With a larger number of chambers and an appropriate fill/eject sequence, the device and method described herein would achieve a substantially fluctuation-free flow without the aid of dampening devices. 
         [0026]    In addition, the device and method of the present disclosure times its flow into and out of the chamber or multiplicity of chambers in the absence of a hardware link, crankshaft, connecting rod, piston or other similar device. The timing of one chamber and the synchrony of a multi-chamber device can be controlled by timing of the valving devices or by a combination of switches  120 ,  130  and a controlling device. 
         [0027]    In a preferred embodiment, the switches  120 ,  130  are optical and the controlling device is a microcontroller running suitable software. It is evident to anyone versed in the art that many implementations and variations of these schemes are possible without departing from the scope and sequence of the present disclosure. 
         [0028]    The flow out of the chamber  10  can be placed on hold, pulsed or modulated by using an additional valving device  150  in the output path in a third preferred embodiment, as illustrated in  FIG. 3 . It should be obvious that many other embodiments are possible and are also subject of this disclosure. It should also be evident that many other arrangements of valving devices, chamber arrangements, chamber geometries and layouts, low pressure sources and low pressure generating devices, high pressure sources and high pressure generating devices are possible and are also subject of this disclosure. 
         [0029]    It should be noted in the present disclosure, the absence or near absence of shaft seals, piston seals, or other seals, and other components frequently wetted by the fluids being moved, thus preventing contamination and extending the life of the apparatus. There is also a substantial lack of moving parts, such as shafts, pistons, diaphragms, impellers, cams, pushrods, among others. The lack of moving parts and wetted seals make the device and method subject of this disclosure particularly rugged and suitable for a great variety of applications where chemical resistance, high purity, low particle generation, component longevity, among other desirable properties, are desired. 
         [0030]    An additional feature of the device subject of this disclosure is its delicate handling of the fluid and the near absence of shearing forces being exerted onto the fluid being moved thus making it particularly suited for delicate fluid that may be affected by said shearing forces. 
         [0031]    Further, unlike many other fluid moving devices, the device and method subject of this disclosure is self-priming and does not require any additional steps or aids to initiate its function. 
         [0032]    The chamber or chambers of the device and method subject of this disclosure can range in volume from a fraction of a milliliter to hundreds, even thousands of gallons. Some materials that are suitable for said chamber are steel, PTFE, acrylic, polycarbonate, other plastics and composites, rigid or elastic materials, among many others. 
         [0033]    Further, the chamber, valving devices, channels and other features of the device and method described herein, can be made either by conventional fabrication techniques, as well as by microfabrication techniques (i.e. MEMS, LIGA, among others), as well as any other technique that can produce structures that can perform the functions of the device and method described herein. As such it is contemplated that the device and method subject of this disclosure can be incorporated in micro- or nano-fluidic components. The structure and method of this disclosure is also suitable for planar applications where all or most of the devices are built into a substantially flat fashion. Such applications are contemplated and subject of this disclosure. 
         [0034]    Applications 
         [0035]    Multiple industries and applications would benefit from the device and method subject of this disclosure. The pharmaceutical and medical industries would benefit from a gentle, non-shearing, non-heating, ultra-clean, no particulate-generating, pumping device. The chemical industry and other chemical applications would benefit from an extremely inert, self-priming, no-seals, no-moving parts, high throughput pumping device. 
         [0036]    Other applications that require the movement of fluids with particulates, or are too viscous or dense for conventional pumping devices would benefit from the device and method subject of this disclosure. 
         [0037]    In particular, the delivery of highly corrosive chemicals from their containers of origin (i.e. vendor bottles, carboys or drums) is a challenging application for a pumping device. A suitable device has to be easily primed, it has to be corrosion resistant throughout (including its control and motor device), it has to be susceptible to metering (i.e. deliver a controllable amount of fluid that can be dosed by a suitable device to achieve a desired volume), it has to move fluid at a reasonable rate, it has to be able to handle bubbles which often form in chemical lines (i.e. hydrogen peroxide) without disruption or loss of prime, and it has to be scalable (from cc/min to multi-liter/min). In all these accounts the fluid moving device subject of this disclosure is superior to the state of the art. Also, the reduced or absent use of spark sources (e.g. motors) as well as friction between surfaces (e.g. pistons), make the method and apparatus subject of this invention also suitable for handling flammable or unstable liquids. 
       EXAMPLES 
       [0038]    Example 1. Extracting corrosive chemicals from their bottles and delivering them to a mixing container in a specified ratio. In a preferred embodiment, there is a single chamber as described above per chemical channel and a flow or mass metering device in the delivery line. There is also a valve controlled by the metering device closing and opening as needed to achieve the desired volume per channel. The entire system can be driven by compressed air and the chambers are 250 ml in internal volume 
         [0039]    Example 2. Two or more chambers as described above are linked in parallel and sequenced such that at any given time one or more are delivering fluid and one or more are filling up. In such mode of operation the flow is substantially smooth (i.e. continuous and with small or no pressure fluctuations) while enjoying all the above enumerated advantages. 
         [0040]    Alternatives and Variations 
         [0041]    Although many embodiments, variations and combinations are conceivable, and also subjects of this disclosure; some such relevant embodiments and variations are listed below: 
         [0042]    The apparatus and method of the disclosure can be used for any fluid. The chamber or chambers can be of any geometry and any material. Any other valving devices or devices may be used in any arrangement, geometry, or positioning. Any sources of low and high pressure, such as pumps, venturis, or others may be used. Any suitable gas or any suitable fluid conveying low and high pressure to the chamber and any of its components may be used. 
         [0043]    Any fluid sensing device or devices may be placed in any location or geometry. Any method of timing the fluid intake or expulsion or any other method of timing or sequencing multiple chambers may be used. Any other processes, configurations, or form of energy source may be used. 
         [0044]    The parts of the apparatus may be inverted, rotated or mirrored about any of its axes. Any number of chambers and any chamber shape or size may be used. Different process structures or fluid channels, internal or external, may be used. Any material, medium, or structure inside or outside the fluid cavity or part of the fluid cavity may be used. Any different type of fluid interaction element, any different type or number of fluid or exhaust channels, different arrangements, variations, or geometries of fluid and exhaust channels or different combinations of fluid channels and valving devices, such as top access valving devices suctioning or delivering fluids via tubes or channels incorporated into or around the chamber or its components, or any other combinations or permutations thereof may be used. 
         [0045]    Different combinations or sequences or graduated or modulated variation or sequences of low pressure and high pressure applications to the fluid chamber channels and valving devices may be used. Additional components that perform any other function, including, but not limited to, components that perform heating, scrubbing, agitating, stirring, cleaning, ultrasonic cleaning or excitation, laser exposure or exposure to any form of radiation or energy, among others, may be present. The apparatus may be used or may have any number of its components in an inverted fashion (i.e. upside down) or at an angle from the horizontal. 
         [0046]    The removal of fluid or fluids may be accomplished via other means or arrangements in addition to those described above, such as, but not limited to, suction, gravity, chemical reaction, moving gas or fluid, displacement, mechanical, or electromagnetic. The delivery of fluid or fluids may be accomplished via different means or arrangements in addition to those described above, such as suction, or any other means 
         [0047]    Although the preferred embodiment of the present disclosure has been illustrated, and that form has been described in detail, it will be readily understood by those skilled in the art that various modifications may be made therein without departing from the spirit of the disclosure or from the scope of the appended claims.