CA2961914A1 - A valveless hydraulic pressure intensifier incorporating energy recovery and self-optimizing energy use means - Google Patents

Description

The following represents a detailed description of an invention by Gerald J.
Vowles of Vankleek Hill, ON Canada KOB 1RO. The purpose of this document is to establish a priority date with regard to a yet to be completed patent application for the present invention. The balance of the documents and materials required to complete the application process including the Claims and Summary will be provided in due course in accordance with the instructions and time limits provided by the Canadian Intellectual Property Office (CIPO).
Title A Valveless Hydraulic Pressure Intensifier Incorporating Energy Recovery and Self-Optimizing Energy Use Means Abstract A hydraulic pressure intensifier incorporating energy recovery and self-optimizing energy use means for use with, but not limited to, semipermeable membrane based fluid filtration and separation systems; these capabilities being provided for by a valveless, positive displacement rotary pump based apparatus characterized by separate pumps or pump sets moving an unequal volume of fluid at a stable ratio within a shared circuit. The apparatus functions without the need for valves, cams, sliding fluid control parts, switches, timers, regulators, sensors, electrical or electronic circuitry or any other similarly acting flow control, restricting and/or distribution means. It can be driven by a variety of prime movers such as rotary or ratcheting cranks, wind turbines, water wheels, wave followers and motors, as well as by a relatively low pressure fluid in-feed provided by either incorporated or external feed pumps or any other suitable low pressure fluid in-feed means.
Flushing, backwashing or purging may be accomplished by simply reversing the pumps rotation.
Technical field This invention relates generally to hydraulic pressure intensifiers typically designed for use with but not limited to crossf low type semipermeable membrane based fluid filtration and separation systems. More particularly, it refers to devices of this type which incorporate pressure intensification, energy recovery and self-optimizing energy use means. Immediate applications include seawater and brackish water desalination, freshwater purification and reclamation, the processing of harmful industrial effluents that Page 1 of 43 could otherwise pollute the environment or cause illness and death and a growing range of commercial, industrial, institutional, scientific, and military applications.
Background The growing, global crisis in the need for lower cost, more widely available potable water for drinking, food preparation, basic sanitation and, by extension, disease control is well known and documented by organizations such as the United Nations and World Health Organization who have labelled it the single greatest challenge of the twenty-first century. In response, the desalination of seawater and brackish water by reverse osmosis has become the primary means of addressing this global crisis for those coastal regions and states having access to the significant finances and other resources required to implement it. In addition, reverse osmosis and other semipermeable membrane based processes such as nano-filtration, ultra-filtration and micro-filtration are increasingly being used to process groundwater, industrial, commercial and institutional waste waters and effluents, bottled and residential water and for the filtration and separation of a growing number of commercial, industrial, institutional, scientific, and military applications.
Fortunately, ongoing progress in the design, engineering and production methods of semi-permeable membranes continues to result in significant improvements in their efficiency and range of use as well as in cost reduction.
Unfortunately, driven by such factors as lack of innovation, high production costs due to complexity, the need for demanding manufacturing tolerances requiring high cost production machinery and a primary focus on utility scale systems, the same cannot be said for the devices, systems and processes of which these membranes are the heart.
The primary goal of the present invention is to provide a solution to these issues.
Prior Art The following review of patent applications and grants focuses mainly on prior art that incorporates notable similarities of design and/or function to the present invention.
Numerous, less similar examples were also reviewed but are not included because major differences exist. In all these cases, no example of prior art teaches an apparatus of such simplicity, while still providing pressure intensification, energy recovery and self-optimizing energy use means and prime mover flexibility.
Page 2 of 43 As shall become apparent in the discussion that follows, the use of valves and other hydraulic flow control means provides the most useful way of comparing the advantages of apparatus of the present invention over the prior art. Specifically, all of the prior art apparatus studied depend for their operation on some combination of valves and/or flow control means, whether these be primary control valves, directional control valves such as check (non-return), spool, poppet or sliding valves or valve designs that are unique to the inventors. In some cases, externally controlled solenoid valves, pressure control, relief, and reducing valves and flow (volume) control valves as well as electro hydraulic, servo, and proportional valves are used. Other non-valve flow control and/or restricting means were also encountered.
By way of comparison, the apparatus of the present invention does not require the use of any of these components which, besides adding unnecessary complexity, introduce varying degrees of flow resistance, whether from turbulence, disruption or restriction, thereby leading to a loss of efficiency. Their inclusion also increases the potential for fouling related blockages, component failure due to fatigue or corrosion and leakage due to uneven wear of precision machined or polished sliding and mating surfaces. Any of these can lead to reduced life cycle, premature failure and/or more frequent maintenance and, in combination, this potential only increases. Complexity also invariably adds to manufacturing and quality assurance costs and increases supply chain requirements.
As shall become apparent, these significant disadvantages are addressed and overcome by the simplicity and the unique and novel aspects of the present invention.
US 8,449,771 Philip David Giles:
This rotary type device incorporates one or more oscillating partitions that sweep back and forth around an axis, that being a centre shaft. These serve the same purpose as do impellers in rotating pumps or pistons in reciprocating pumps, however, the sweep alternates back and forth rather than being continuous as with the present invention. The device also incorporates low pressure and high pressure pumps and a spool valve in addition to the two oscillating pumps. While the device does provide for energy recovery, it is not an energy intensifier.
Page 3 of 43 US 8,025,157 Shigeo Takita:
Like that of US 8,449,771 Giles discussed above, this rotary type device incorporates energy recovery means but does not function as an energy intensifier. It also incorporates an electric motor driven high pressure pump, which the apparatus of the present invention does not require. While its power recovery module is a rotary device with two pumps mounted on a common shaft, it uses a turbine rather than a positive displacement pump like the apparatus of the present invention. In a second embodiment an additional positive displacement piston pump and a control valve are incorporated, adding further to the complexity of the system. In several other variations a plurality of other valves and controllers are employed adding further to its complexity.
US 2006/0,037,895; Appl. No. 10/922,284 Scott Shumway:
This rotary type device is comprised of three main sections, those being a high pressure boost pump, a pressure exchanger and a low pressure boost pump, all mounted on a common shaft running coaxially through the three sections and attached to a prime mover such as a motor. The apparatus of the present invention is comprised of only two sections.
The high pressure boost pump uses one or more spinning impellers to further boost an already high pressure fluid stream whereas the present invention is capable of drawing in unpressurized fluid and converting it to high pressure. The pressure exchanger incorporates another two spinning rotors and the low pressure boost pump incorporates what is defined as "a series of impellers". This amounts to a minimum of six spinning members versus as little as one but typically two or four in the apparatus of the present invention with it being noted that the present invention's impellers may be rotated at low speed. The operating principles are also different, this made more evident by the fact that a fully functioning filtration system incorporating this pressure exchange device requires an additional reservoir pump, that being a low pressure feed pump as well as a high pressure pump. The apparatus of the present invention, when incorporated into an equivalent fully functioning filtration system requires neither of these additional pumps. This significantly more complex device only boosts what is already a high pressure fluid stream by about 20 psi according to the inventor.
Page 4 of 43 US 4,632,754 Robert S. Wood:
A reversing cycle device wherein a first embodiment incorporates a reservoir employing a reciprocating piston and three valves cooperating with mechanical linkages. In a second embodiment of thd device, the three valves used in the first embodiment are replaced with a rotary plate valve, the reciprocating piston based reservoir is replaced with a flexible membrane based reservoir and a second pump is added to provide liquid recirculation through the filtering means. Variations of this embodiment additionally incorporate either a vane type reciprocating pump or a gear box driven cam. Unlike the continuous rotation of the apparatus of the present invention the various embodiments of this device operate on reversing cycles and they incorporate valves and other flow control means.
US 3,369,667 George B. Clark:
Similar to the apparatus of the present invention in physical design, this rotary type device incorporates a set of two rotating positive displacement impellers located in separated casings, both of which are fixedly attached to a common shaft such that they rotate in unison. However the operating principles and fluid flow within the two apparatus are very dissimilar. Rather than acting as a pressure intensifier, this apparatus is designed to continuously recirculate the flow of high pressure fluid across the filtering element in order to increase the ratio of permeate to waste fluid. On the other hand, the apparatus of the present invention functions primarily as an pressure intensifier and energy recovery device, rather than primarily as a fluid recirculator. This difference can be seen in terms of the fluid flow paths and pressure differences between the two devices with the most obvious difference being that the feed fluid flows freely and at the same pressure between the two casings of the device while neither of these conditions is true for the apparatus of the present invention. It is also noted that the device requires both a feed pump and a pressure valve in order to operate within a fully functioning filtration system whereas the apparatus of the present invention requires neither to accomplish the same.
US 7,828,972 B2 Young-Bog Ham:
This reciprocating piston, dual cylinder based apparatus incorporates an assembly wherein a primary valve, called a concentrated water control valve block, includes a concentrated water chamber cover functioning as a hydrostatic bearing using the pressure of supplied Page 5 of 43 water, a concentrated water inlet/outlet cover and a fluctuating plate-like concentrated water valve, the latter part being required to rotate between the covers. In order for the valve to rotate a plurality of pinion gear teeth are located on its outer peripheral surface.
These teeth are enmeshed with teeth on two rack gears located in separate, opposite spools which in turn interact with a plurality of pilot valves. A plurality of check valves are also incorporated into the apparatus.
US 7,297,268 B2 Rodney E. Herrington:
This dual head, single acting, reciprocating diaphragm pump incorporates a primary valve called a differential pressure activated (DPA) valve, which requires the presence of additional check valves to function. The pump's cycle involves a suction stroke that requires work and time but during which production does not occur, unlike the continuous flow and production from the rotary cycle of the present invention. As with the apparatus of the present invention, the device provides for energy recovery.
US 2009/0194471 Al Antonio Pares Criville:
This double-acting,reciprocating piston based apparatus incorporates two primary valves comprised of sliding members, clips and springs with protective sheaths. The clips connect the sliding pieces to thicker sections of two piston rods which, in turn, drag the sliding pieces with them as they approach the end of their stroke, causing the shift in the position of the two primary valves needed to reverse the pistons. It is based upon an earlier, single pressure intensifier design (US 6,604,914 B2 Criville) discussed below. This apparatus incorporates two pressure intensifier units operating in opposition, rather than just one as with the apparatus of the present invention.
US 6,604,914 B2 Antonio Pares Criville:
This design teaches a double acting, self-reversing piston design. It utilizes both a primary valve, called a directional valve and a separate pilot valve. The directional valve incorporates two sliding blocks with flat, polished sliding surfaces that mate with adjacent sliding surfaces to seal against passage of pressurized fluid. The separate pilot valve also incorporates these mating, flat, polished sliding surfaces. These valves then interact cooperatively in order to accomplish the cyclical reversing of the double acting piston.
Unlike the present invention, an additional chamber is also needed. As stated in the Page 6 of 43 discussion of US 2009/0194471 Al Criville, this design was the basis for certain marine water maker models sold but later withdrawn from the market by companies called HRO
and Sea Recovery Corp. Based on unconfirmed end-user comments, this was apparently due to unusually high, valve related premature failure and maintenance issues.
US 6,491,813 B2 Riccardo Verde:
This double acting, reciprocating piston design teaches several embodiments.
In the first embodiment, the primary valve, called an exchange valve, works in cooperation with four check valves and also requires micro switches to initiate piston reversal. A
variation of this first embodiment uses a pilot valve cooperating with a primary valve called a "power valve,"
as well as still requiring the plurality of check valves. In a second, similar embodiment a high pressure feed pump is added to the system, while continuing to use the low pressure feed pump. Variations of this embodiment utilize either bypass, throttle or exhaust valves.
A final embodiment introduces machined grooves into the piston rod, thus allowing for a change in fluid flow at certain piston positions as means for shifting the position of the power valve and in a variation, the pilot valve is replaced with a ducted plate that interacts with the shaft grooves with all in turn interacting in a cooperative manner with the power valve. In all of the above configurations, the large number of valves, whatever the type, adds significant complexity to the apparatus.
US 6,203,696 B1 Colin Pearson:
This double acting, reciprocating piston design does not rely on a single, primary valve.
Rather, it incorporates eight valves, all working cooperatively within the apparatus.
According to the description these are a unique poppet valve design incorporating an integrated, secondary bleed valve and springs. Four of these serve as control valves that are mechanically actuated by the pistons.
US 6,017,200 Willard D. Childs:
This double acting, reciprocating piston design incorporates a minimum of eight separate check valves and a non-hydraulic control unit to control the feed pump as well as solenoid actuated water pilot and air pilot valves.
Page 7 of 43 US 5,628,198 Clark Permar & US 5,462,414 Clark Permar:
The two described apparatus, each being a double acting, reciprocating piston design incorporate a primary valve called a re-track valve, that being a two way spool valve, as well as four check valves and two pilot valves with the latter interacting mechanically with dual, opposed piston heads at each stroke end triggering a shift in the re-track valves position that in turn causes the piston to reverse.
US 4,929,347 Masaaki 'mai:
In a first embodiment a single acting, reciprocating piston is powered by a rod extending out of the pumping cylinder to a reciprocal drive pump. A spool type primary valve called a selector valve interacts cooperatively with check valves, unlike the apparatus of the present invention which eliminates the need for valves. In a second embodiment, a third partition is added to the selector valve due to a variation in the routing of the fluid flow. In a third embodiment, a second single acting, reciprocating pump is arranged in parallel with the first pump with their pistons reciprocating in opposite directions. In fourth and fifth embodiments, which are also reciprocating single and dual pump variations of the above, most of the check valves are eliminated by incorporating second pistons into each of the pumping cnambers and adding sub-selector valves.
US 4,913,809 A lwao Sawada:
A double acting, reciprocating piston design where, in a first embodiment, a pilot valve is used to control one or more selector valves that cooperate with two check valves to cause reversal of the double acting piston. In a second embodiment two additional check valves are needed. In both cases, non-pumping pistons are incorporated into either one or both of the pilot and control valves, adding further complexity to the design.
US 4,534,713 & US RE 33,135 William F. Wanner:
The apparatus is comprised of an electro-mechanical or hand driven single acting, reciprocating piston pump utilizing a spool type primary valve working in cooperation with inlet and outlet valve assemblies comprised of seats, poppets, springs and spring retainers. The spool valve shuttle is reversed directly by a mechanical linkage to an external prime mover. The apparatus is designed specifically for use as a seawater desalinator and is similar in design and function to US 4,187,173 Keefer and US 3,558,242 Page 8 of 43 Jenkyn-Thomas. A commercial version of the apparatus was embodied in both the manual and electric powered PUR brand portable desalinators.
US 4,367,140 A Leslie P. S. Wilson:
This double acting, reciprocating piston design incorporates a valve controller (whether electrical, mechanical or hydraulic) in communication with four non-return valves. These are in addition to four more non-return valves for a total of eight. A second embodiment utilizes a spring loaded pulse pump that responds to pressure pulses by operating a semi-rotary reversing switch which, in turn, cooperates with a discrete pressure intensifier. A
plurality of flow control valves such as check valves are also a requirement of this embodiment. A third embodiment replaces the pressure intensifier assembly of the second embodiment with an pump assembly comprised of a piston within a cylinder with rods extending through seals in the cylinder chambers walls on each side of the piston to connected ball valves with it being stated by the inventor that two such control devices would be required. Otherwise, the complexity of the second embodiment remains.
A fourth embodiment incorporates a solenoid switch interacting with a set of opposing ball valves.
Finally, a fifth embodiment describes a construction wherein the spools of the spool valve are located on a rod that serves as an armature for a solenoid switch cooperating with a timer or a proximity sensor on the main piston.
US 4,187,173 & US RE 32,144 Bowie G. Keefer &
US 4,288,326 Bowie G. Keefer (continuation in part of US 4,187,173):
In each case, the apparatus incorporates reciprocating, single acting pumping piston. In order to maintain a flow of pressurized fluid to an incorporated, semi-permeable membrane for the extended time needed to complete the return suction stroke, an accumulator like feed surge absorber chamber comprised of a spring driven piston in an expansion chamber is employed. The apparatus primary valve is a two position, centre-closed, three-way spool valve with a closed intermediate position, this valve working cooperatively with two check valves. Both the spool valve and a pumping piston work cooperatively via linkages connected to a common drive such as a manual lever or a cam shaft. As with the apparatus of the present invention, the device provides for energy recovery.
Page 9 of 43 US 3,855,794 Kenneth H. Mayer:
While there are similarities to some circuits taught in other prior art examples described in this document, the objective of this apparatus is to synchronize the movement of at least two reciprocating, hydraulic cylinders rather than to provide an energy recovering pressure intensifier. The design incorporates a combination of check valves, relief valves and a fluid power control source to accomplish its synchronization objectives.
US 3,558,242 William Dixon Jenkyn-Thomas:
This single acting, reciprocating piston design is similar to US 4,187,173 Keefer but does not incorporate any accumulator/surge absorption capability. There are two embodiments, each employing a spool valve as the primary valve. The first incorporates two check valves working in cooperation with a manually operated and controlled 2-port spool valve while the second incorporates a manually operated and controlled 3-port spool valve.
In both embodiments, the spool valve and pumping piston work in fixed cooperation through a mechanically connected lever arm and linkage assembly.
US 3,234,746 Lewis T. Cope:
In this case, an apparatus and method for transferring liquid carbon dioxide from a supply container to a cylinder under pressure is described. A double acting, reciprocating piston with a shared rod operating in two collinear cylinders is employed with the driven piston being smaller than the driving piston. A cam located at the centre of the piston rod mechanically engages control followers at each end of the reciprocating stroke in order to activate the primary valve called a reversing valve. The design also incorporates a large number of check valves.
In conclusion and by way of comparison to the prior art, the present invention teaches a highly simplified apparatus that is, nonetheless, capable of providing hydraulic energy intensification, energy recovery and self-optimizing energy use means, while overcoming the complexity related costs and disadvantages of the aforementioned prior art and does so in accordance with the following objectives.
Page 10 of 43 Objectives of the Invention The objectives of the present invention are to: greatly reduce the build complexity typical of the prior art; reduce the servicing requirements and servicing complexity typically associated with the prior art; provide at least one embodiment which does not require the tight manufacturing tolerances typical of the prior art designs, thereby reducing the need for sophisticated production capability and/or supply chain; provide a design which, not including the outsourced membranes, could be produced at a low enough cost to be considered expendable and preferably also recyclable; provide a design which is better suited than the prior art to production by emerging additive manufacturing means, often referred to as 3D printing; provide a design which can be powered by a wide range of prime movers and in different ways in order to maximize its fitness for use in differing situations; provide an apparatus which, when used to produce potable water, better addresses local supply chain, knowledge and financial limitations in less developed regions where safe, potable water is often scarce; provide an apparatus which is suitable for rapid deployment and simple operation during times of natural disaster.
As shall become apparent in the following description of the present invention, these objectives, as well as the significant disadvantages or limitations of the prior art, are addressed and overcome by the simplicity, flexibility and novelty of the present invention.
Summary of the Invention The Summary and Claims will be provided in due course in accordance with the instructions and time limits provided by the Canadian Intellectual Property Office (CIP0).
Brief Description of the Drawings Figure 1 provides a schematic side view of a first embodiment of the present invention wherein a prime mover, that being a manually operated rotary crank handle in this particular case, is employed to rotate two positive displacement pumps of different volumetric displacement mounted onto a common shaft. An optional belt and pulley assembly is employed to provide a mechanical advantage.
Figure 2 provides a schematic side view of the first embodiment of the present invention wherein the rotation of the apparatus is reversed as a means of flushing, backwashing or Page 11 of 43 purging those semi-permeable membranes and pre-filters typically associated with the systems within which the apparatus of the present invention is intended to operate.
Figure 3 provides a schematic side view of a variation of Fig's 1 and 2 wherein the individual pumps are replaced with same acting pump sets such that the pumps within each set are connected in either series or parallel.
Figure 4 provides a schematic side view of an embodiment of the invention equivalent to those above except that the prime mover employed to rotate the pumps is an external source of pressurized fluid acting directly upon the first pump's impeller(s).
Certain non-essential features are removed in this more basic embodiment.
Figure 5 provides a schematic side view of a typical single shaft, gerotor type positive displacement pump, it being an example of a pump type capable of producing the high pressure required for the application taught in the detailed description of Fig. 18.
Figure 6 provides a schematic side view of a flexible impeller, vane type positive displacement pump which, in this case, incorporates certain unique features designed to increase the pump's pressure handling capability, particularly with regard to the apparatus of the present invention.
Figure 7 provides a schematic side view of a typical external gear type positive displacement pump design commonly used in high pressure applications and which could be incorporated into the apparatus of the present invention.
Figure 8 provides a schematic side view of a typical vane type positive displacement pump design. Conventional units are available with both spring and hydraulically actuated vanes and either could be incorporated into the apparatus of the present invention.
Figure 9 provides a schematic side view of a typical peristaltic type positive displacement pump design that might be incorporated into the apparatus of the present invention for low pressure applications.
Page 12 of 43 Figure 10 provides a schematic side view of a peristaltic type positive displacement pump similar to that of Fig. 9 but with attention drawn to the option of mounting two peristaltic hoses into a shared cavity.
Figure 11 provides a schematic side view of a rotating wind turbine type prime mover that could be employed to rotate the apparatus pumps, whether by direct attachment or through a speed changing means.
Figure 12 provides a schematic side view representative of a rotating water wheel or water turbine type prime mover that could be employed to rotate the apparatus pumps, whether by direct attachment or through a speed changing means.
Figure 13 provides a schematic side view of a ratchet handle type prime mover that could be employed to rotate the apparatus pumps whether continuously or in incremental steps and whether by direct attachment or through a speed changing means.
Figure 14 Removed - to be filed under a separate application.
Figure 15 provides a schematic side view representative of any motor type prime mover, whether it be electric, hydraulic, pneumatic, fuel powered or otherwise, that could be employed to rotate the apparatus pumps, whether by direct attachment or through a speed changing means.
Figure 16 provides a schematic side view representative of any pressurized fluid bearing conduit such as a pipe or hose that could be employed to provide external, prime mover capability to the apparatus through direct interaction with an pump's impeller(s) rather than via a rotating drive shaft.
Figure 17 provides a schematic side view of an optional flywheel with over-riding clutch assembly. Such an arrangement would typically be incorporated between the apparatus drive shaft and the prime mover as an input smoothing and sustaining means and employed when irregular input prime movers such as the wave follower Fig. 14 are employed. It could also be employed as a higher capacity input energy storage means.
Page 13 of 43 Figure 18 provides a schematic side view of the apparatus of the present invention integrated into a semi-permeable membrane based fluid filtering system, in this case being an integrated, portable, manually powered reverse osmosis type water purification system.
Figure 19 provides a schematic side view of a simple setup used to facilitate flushing, backwashing and/or purging of the system shown in Fig. 18.
Figure 20 provides a schematic side view of an optional manifold assembly representative of how various accessories deemed by the user to be useful or adding convenience may be attached to the apparatus, whether permanently or only as needed.
Figure 21 provides a schematic side view of a highly simplified embodiment of the present invention wherein the two separate positive displacement pumps of previous embodiments are replaced with a single, positive displacement impeller module incorporating circumferential fluid sealing means that divide a single, shared cavity into separate pumping chambers of different volumetric displacement.
Figure 22 provides a partially rotated three dimensional (3D) view of the impeller module incorporated into the apparatus described in Fig. 21.
Figure 23 provides a schematic end view of the apparatus taught in Fig's 1 and

2 with attention focused on the pumps that are incorporated into this preferred embodiment of the present invention.
Figure 24 provides a partially rotated three dimensional (3D) view of the impeller module incorporated into the apparatus described in Fig. 23.
Figure 25 provides a schematic end view of a rigid but otherwise same acting impeller for use in the apparatus seen and described in Fig. 23.
Detailed Description Referring to the figures in general, all of the fluid conduit means incorporated into the apparatus of the present invention, whether they be channels, pipes, tubes or other equivalent means and including their inflow and outflow ports, are unrestricted. That is to say that they do not incorporate or require the direct or indirect use of any flow restricting Page 14 of 43 means such as valves, regulators or other flow control means.
In practice, these fluid conduit means are sized and laid out in a fashion that minimizes resistance to flow and unevenness of flow due such factors as friction, directional turns or conduit size. In fact, as shall be seen, the apparatus of the present invention provides the means by which a complete fluid filtration or separation system including all necessary connectors and couplings may be assembled wherein the only significant restrictions to fluid flow are the pump's impellers and the unavoidable resistance associated with fluids passing through the filtration media.
While discrete fluid sealing components are incorporated into the apparatus described herein, other embodiments may be produced with tight enough clearances and tolerances that these or similarly acting sealing components are either minimally or not at all required, particularly for those intended to be expendable and/or recyclable in nature.
Because the positive displacement pumps incorporated into the apparatus of the present invention variably function as pumps, hydraulic motors, circulators and flow resistors depending on their rotation direction, position within the fluid circuit, prime mover means and because a variety of pump types and designs may be incorporated into different embodiments of the apparatus, the following description uses the term pump interchangeably when referring to these components. In similar fashion, the term cavity is understood to have the same meaning as the term chamber, which is also commonly used in describing different pumps types and features.
A key operating principle of the apparatus of the present invention, is the existence of a stable, volumetric difference in the amount of fluid displaced by each of two positive displacement pumps or pump sets operating within the same closed circuit such that the greater flow volume from the upstream pump encounters a back pressure from the downstream pump, resulting in a rise in pressure in that part of the closed circuit incorporating a cross-flow, semipermeable membrane means located between the two pumps. This can be implemented in at least three ways. The first, being the preferred implementation, employs two pumps or pump sets with different internal displacement rotating at the same speed such that their output volumes differ at a stable ratio or ratio range. The second employs two pumps or pump sets with the same internal displacement rotating at different speeds such that their output volumes differ at a stable ratio or ratio Page 15 of 43 range. The third employs two pumps or pump sets with different internal displacement rotating at different speeds such that their output volumes differ but still at a stable ratio or ratio range. In any of these cases it is understood that the ratio could be adjusted but that would require adding complexity. Other variations may also be possible but regardless of which approach is taken, the operating principle remains essentially the same.
However, for the benefit of greater clarity and ease of understanding, only the first of these implementations forms the basis for the preferred embodiment and its variants presented herein, with the understanding that with the addition of varying degrees of complexity and cost, typically involving at least the use of external control means and/or more complex prime mover requirements, those other implementations mentioned above could be employed to achieve the same outcome employing essentially the same core operating principles. Therefore, it is understood that while the description of the embodiments taught herein refers specifically to pumps or pump sets of different internal displacement due to the opportunity for least complexity, this is not meant to limit this inventor's claims to only that particular means or arrangement of parts for providing a displacement volume differential between two positive displacement pumps or pump sets.
Referring now to Fig. 1, a first preferred embodiment of the present invention, hereafter referred to as the core module 1, a rotational speed changing means, hereafter referred to as the pulley assembly 2 and one of numerous prime mover possibilities, a crank handle 3 are shown. The crank handle 3 is telescopic in nature in order to provide the user with an adjustable mechanical advantage means and, in this embodiment, is used to drive the core module 1 in a generally continuous rotation. The crank handle 3 is fixedly attached by means of a female spline bore 4 to a freely rotating, splined shaft 5 that is rotatably attached to a main body 6 of the core module 1. A first pulley 7 is fixedly mounted to the freely rotating splined shaft 5. A second pulley 8 is fixedly mounted to a second splined shaft, hereafter referred to as the common shaft 9, running horizontally through the main body 6. A drive belt 10 connects the two pulleys 7 and 8 in typical fashion such that rotating the crank handle 3 causes the common shaft 9 to rotate. The pulley assembly 2 incorporates an adjustable, belt tensioning idler sub-assembly hereafter called the idler pulley 11, shown here being mountable to the core module 1 with a mounting plate 12.
It is noted at this time that the use of the pulley assembly 2 and associated freely Page 16 of 43 rotating spline shaft 5 or of any similarly acting rotational speed changing means such as a gearbox is not required in all cases for the operation of the apparatus and so is deemed to be optional. For example, the crank handle 3 may be mounted directly to the common shaft 9. Also, as shall be seen, the crank handle 3 is only one of many prime mover means that may be employed to power the apparatus. It is also noted that the pulley and belt system could be replaced with such similarly acting means as a gearbox, or a gearbox and flywheel combination.
Focus is now directed specifically to the non-optional, core aspects of the embodiment of the present invention shown here in Fig. 1 but, which are understood to also apply to those other embodiments taught herein. With that in mind, the major components of the core module 1 include the main body 6, which incorporates first and second circular shaped access ports with fluid sealed covers, hereafter referred to as a front port and cover 13 and a rear port and cover 14; the previously mentioned common shaft 9; a first positive displacement pump with a displacement of 1.0 volumetric units (VU), hereafter referred to as the 1.0 VU pump 15; a second positive displacement pump with a displacement of 0.9 volumetric units (VU), hereafter referred to as the 0.9 VU
pump 16;
four essential fluid conduits, these being an in-feed conduit 17 and an output conduit 18, communicating with the 1.0 VU pump 15; an in-feed conduit 19 and output conduit 20, communicating with the 0.9 VU pump 16; and a non-essential but recommended flushing conduit 21 and associated port 39 that become involved only if and when the apparatus is driven in reverse rotation for the purpose of flushing, backwashing or purging feed fluid from various components of those systems which the apparatus may be integrated into ¨
otherwise this normally blocked flushing conduit 21 could be eliminated. It is noted that all of these conduits will be referred to by the term conduit and its associated number.
Other components of the core module 1 include suitable, fluid pressure sealed bearings or bushings into which the common shaft 9 is rotatably mounted, these hereafter being referred to as shaft bearings 22 and 23; spring-lock washers 24 and 25 fitted into grooves in the common shaft 9 in order to hold it in place; a suitable fluid seal, in this case being an 0-ring 26 mounted into a groove 27 in that portion of the main body 6 separating the chambers of the 1.0 VU pump 15 and 0.9 VU pump 16; any suitable fluid seals, in this case being an 0-ring 28 inserted into a groove 29 in the front port and cover 13 and an 0-Page 17 of 43 ring 30 inserted into a groove 31 in the rear port and cover 14. Fastening means suitable for holding the port and covers 13 and 14 affixed to the main body 6 such that they are sealed against the loss of pressurized fluid as well as suitable for the chosen in-situ environment are employed in whatever quantities needed for the purpose. In this case these fastening means are comprised of a suitable number of non-corroding machine screws, but are hereafter more generally referred to as port fasteners 32 while recognizing that other suitable means such as cam lock mechanisms could also be employed for the purpose. The freely rotating, splined shaft 5 incorporated into the main body 6 is rotatably mounted into a bore hole 33 in the main body 6 and held in place by an appropriate retaining means 34.
While conduits 17, 18, 19 and 20 are open ported at their intake and output ends such that they do not incorporate any flow-restricting elements or components, it is understood that suitably mated connectors may be employed outside the apparatus of the present invention in order to integrate the core module 1 into various processing systems such as that taught in the description of Fig. 17. They too should be of the non-flow-restricting type whenever those systems allow. In the case of the apparatus taught herein, these external connectors are understood to compatible with the ports 35, 36, 37, 38 and 39, even though their type and design would be dependant on the associated system's design.
Except for their differing volumetric displacement, the 1.0 VU pump 15 and 0.9 VU
pump 16 are otherwise typically identical. Preferably, this also includes the radial alignment of their impellers whether they be gears, vanes, rollers or other fluid moving parts, this in order to maintain the best possible pressure and flow matching between the two pumps as their impellers rotate in unison.
As shall also be seen with other embodiments of the apparatus the chambers of the 1.0 VU pump 15 and the 0.9 VU pump 16 in which the impellers move fluid are actually cavities within the main body 6. In that regard, it is seen here that the section of the main body 6 located between the two pump cavities serves as a pressure and fluid sealed divider wherein the 0-ring 26 serves to prevent the passage of pressurized fluid along the bore 40 through which the common shaft 9 passes. It is noted however, that other embodiments of the present invention could employ discrete pumps incorporating their own housings.
Page 18 of 43 While specific design and structural details of the 1.0 VU pump 15 and the 0.9 VU pump 16 are not shown in Fig's 1 to 4 because a variety of positive displacement pump designs may be used depending on their suitability for the intended application, several examples of are provided in Fig's 5 to 10, including a more detailed description of one type understood to be employed in the preferred embodiments of the apparatus.
While the direction of rotation is ultimately tied to any given pump's design, the flows and pressures associated with the normal production cycle of any of the apparatus taught herein are, for convenience, assumed to be based on the clockwise rotation of the 1.0 VU
pump 15 and the 0.9 VU pump 16. With that in mind and with the aid of flow direction arrows, it is seen here that feed fluid first enters the apparatus through the port 35 into the conduit 17 which opens into the 1.0 VU pump 15. It is noted that in this embodiment, the 1.0 VU pump 15 also serves as the feed pump for the apparatus by virtue of it's ability to draw in feed fluid by creating a partial vacuum when rotated, thereby having the advantage of eliminating the need for an external feed pump in most cases.
Having been drawn into and propelled through the 1.0 VU pump 15, the fluid flows into the open ended conduit 18 and on out of the core module 1 through the port 36 from where it continues on via any suitably connected, fluid sealed and preferably unrestricted conduit into whatever system the core module 1 has been integrated into, that typically being a cross-flow, semi-permeable membrane based filtration or separation system.
Noting that because the focus here is on Fig. 1 and to facilitate understanding, a detailed tracking of the flow path within those circuits and aspects of the filtration or separation system beyond the core module 1 is provided later in the description associated with Fig's 18 to 20. However, a key aspect in understanding the functionality of the apparatus of the present invention seen here in Fig.1 relates to how fluid pressure intensification occurs and how the energy stored in the resultant, more highly pressurized fluid is then used by the apparatus to greatly reduce its own energy requirements, rather than being wasted as is often the case. Therefore, rather than looking ahead at this time to the description of Fig. 18, it is noted now for the benefit of clarity that after passing through the connected filtration or separation system (a) 0.9VU of the fluid that was propelled out of the core module 1 by the 1.0 VU pump 15 through the port 36 returns via any suitably connected, fluid sealed and preferably unrestricted conduit, there re-entering Page 19 of 43 the core module 1 through a port 37 into a conduit 19 that in turn opens into the smaller displacement 0.9 VU pump 16 and (b) the fluid within that part of the circuit located between the pumps 15 and 16 is now under high pressure for reasons that shall become apparent in the description of Fig. 18.
Finally, upon passing through the 0.9 VU pump 16 where the energy stored in the high pressure fluid is recovered and transmitted via the common shaft 9 to the 1.0 VU pump 15, the now depressurized fluid is expelled from the core module 1 through the output conduit 20 and the port 38, in most cases without any significant pressure but in somewhat more concentrated form. That then defines the path of the fluid from the time it initially enters the the core module 1 as raw feed fluid until, after having passed through and returning from the connected filtration or separation system, it finally exits the core module 1 for the second time, now in moderately more concentrated form due to 0.1 VU having been processed and drawn off outside the apparatus of the present invention in a manner that too shall become apparent in the description of Fig. 18.
However, it is noted that the port 39 and conduit 21 remain unaccounted for in this flow.
This is due to the fact that they are not involved in the normal production phase that takes place during the just described clockwise rotation of the apparatus and so, are addressed later on in the description. In that regard, it is also understood that while the port 39 and conduit 21 are non-essential for the basic operation of the apparatus, they have been incorporated into the apparatus described herein as an innovative means of facilitating system cleaning and servicing and a convenient means by which optional components such as monitoring devices may be attached, all without adding complexity.
Reference is now made to Fig. 2, which focuses on the effect on fluid flows and pressures within the core module 1 when rotation of the pumps 15 and 16 is reversed by rotating the common shaft 9 counterclockwise. This is done for the purpose of flushing and backwashing those semi-permeable membranes and pre-filters typically associated with the systems within which the apparatus of the present invention is intended to operate, as well as for purging these same systems of unprocessed feed fluids and replacing them either with purified permeate that the system has already produced, whether with or without added constituents, or with some other suitable fluid for the purpose of maintaining the system in good condition during periods of non-use including storage.
Page 20 of 43 Recalling that in Fig.1 the flows and pressures were based on the clockwise rotation of the impellers or similarly acting fluid moving elements of 1.0 VU pump 15, the 0.9 VU
pump 16 and the common shaft 9 to which they were fixedly attached, it is shown here in Fig. 2 with the aid of directional arrows that upon reversing the rotation of these elements to counter-clockwise, a reversal of the fluid flow occurs. Fluid is now first drawn through port 38 and conduit 20 into the smaller displacement 0.9 VU pump 16 from whence it is propelled back out of the core module 1 through the conduit 19 and the port 37. Following the same circuit as before but in reverse, the fluid then flows on into the connected filtration or separation system and from there back into the core module 1 through port 36 and conduit 18 into the larger displacement 1.0 VU pump 15 from where it is expelled through the conduit 17 and port 35 as waste, having taken on accumulated residue from the outer surface of the semi-permeable membrane. Assuming the likely presence of one or more intake pre-filters being connected in some way to the port 35, as shall be seen later in Fig.
17, the reverse flow of fluid may also be utilized to backwash these, thereby extending their useful life and mitigating the gradual loss of efficiency that would occur as a result of residue buildup on the surface of the intake pre-filters. It is understood that these residues are the materials whose passage has been blocked by the semi-permeable membranes and pre-filters during the clockwise rotation based production phase.
In effect, this represents a simple reversal of flow along the same path as that taken in clockwise rotation mode. However, in practice, this is not practical for two reasons. Firstly, in the case of clockwise rotation, fluid is moved from the larger displacement 1.0 VU pump 15, through the connected filtration or separation system and on back to the smaller displacement 0.9 VU pump 16, giving up within the filtration or separation module a portion of the fluid equal to the difference in volumetric displacement of the pumps 15 and 16. It is noted that being an enclosed circuit and due to the resistance imparted by the semi-permeable membrane through which the given-up portion of fluid must pass, this results in a steep fluid pressure increase in the portion of the circuit between the pumps 15 and 16, the details and understanding of which shall become apparent in the description of Fig. 18.
However, in counter-clockwise mode, the flow now moves from the smaller displacement 0.9 VU pump 16 to the larger displacement 1.0 VU pump 15. Being that these fixedly linked pumps 15 and 16 are of the positive displacement type moving an Page 21 of 43 essentially incompressible/non-expandable fluid within an enclosed circuit, this means that makeup fluid must be found to fulfil the greater demand of the larger displacement 1.0 VU
pump 15 in order to address such potential issues as cavitation, pressure lock, stressing or damaging of connected semi-permeable membranes, increased resistance to the prime mover or any other possible issues that could be associated with starving the larger displacement pump 15. By providing the apparatus with the optional access port 39 and conduit 21, shown here feeding into the conduit 19, the required makeup fluid can be drawn in, as needed, by the larger displacement 1.0 VU pump 15, thereby setting up a self-adjusted fluid volume condition between the pumps 15 and 16 and, in so doing, eliminating the potential issues indicated above. This also eliminates the need to draw permeate in reverse through the semi-permeable membrane as the means of addressing this volumetric difference. This also removes the question of suitability that would arise when using standard, off-the-shelf semi-permeable membrane cartridges that are not designed for reversed permeate flow but, nonetheless, still require downtime related flushing and/or purging. As resistance from fluid needing to pass through the membrane is no longer a factor, there is the added benefit that rotation is easier, thereby offering the opportunity to increase the reverse flow volume and velocity, with the same amount of effort resulting in better flushing.
In consideration of its simplicity and of the opportunity to eliminate the added complexity otherwise required to build this capability elsewhere into such complete filtration or separation systems as the apparatus may be integrated into, this becomes a highly desirable, albeit optional feature. Nonetheless, if reversing is not desirable, whether due to pump type limitations or otherwise, a one-way clutch, brake or other such mechanism may be incorporated into the apparatus as needed to prevent counter-clockwise rotation.
Referring now to Fig. 3, the core module 1 of an embodiment of the present invention similar to that taught in Fig's 1 and 2 is shown wherein the single 1.0 VU
pump 15, is replaced with a series connected 1.0 VU pump set 15A and 15B and the single 0.9 VU
pump 16 is replaced with a series connected 0.9 VU pump set 16A and 16B.
However, it is noted that the number of pumps within the sets need not be limited to two as shown here.
The 15A and 15B pumps are separated by a fluid sealed divider 41 and the 16A
and 16B
pumps are separated by a fluid sealed divider 42 such that while they act cooperatively Page 22 of 43 and in unison, they are still independent. It is noted, however, that in other embodiments, depending on operating requirements and design advantages for specific applications, the pumps within each of these independent sets may also be connected in parallel.
Inflows and outflows are routed and linked either through conduits within the main body 6 as shown here within manifolding zones 43 and 44 but may alternatively be connected in like fashion through other equivalent means. This is arranged such that the combined flows of pumps 15A and 158 move into and out of the conduits 17 and 18 in the same way as was taught for the apparatus described in Fig's 1 and 2 and likewise, the combined flows of pumps 16A and 16B move into and out of the conduits 19, 20 and 21.
While the combined volumetric displacement of the pump sets 15A/15B and may or may not be the same as that of the single pumps they replaced depending on needs, it is understood that there remains a differential between the larger combined volumetric displacement of the pump set 15A/156 and the smaller combined volumetric displacement of the pump set 16A/166, in the same way as was taught with the apparatus previously described in Fig's 1 to 3.
Other than for the use of pump sets rather than single pumps, the operating principles and general design of this embodiment is the same as that incorporating single pumps as taught in the descriptions of Fig's 1 and 2.
Referring now to Fig. 4, the core module 1 of an embodiment of the present invention similar to that taught in Fig. 1 is shown wherein the prime mover function is provided by the relatively low pressure inflow of the feed fluid 45, as signified here by the symbol "P"
into the port 35, rather than by a force rotating the common shaft 9 as shown in Fig. 1.
In this case the 1.0 VU pump 15, and the 0.9 VU pump 16 are fixedly attached to a freely rotating, common shaft 46 shown here without the need for a splined extension as seen on the common shaft 9 in Fig. 1 but otherwise mounted in the same fashion.
Attention is also drawn to the fact that while they would generally be incorporated into the apparatus, the conduit 21 and port 39 as seen in Fig's 1 and 2 have not been incorporated into this embodiment in order to signify a design choice that could be taken if and when an integrated flushing, backwashing and purging means is not required. By extension, if it is determined that having this capability is not required in certain implementations, then it follows that the apparatus as shown here in Fig. 4 may optionally Page 23 of 43 replace the reversible pumps 15 and 16 with non-reversing but otherwise equivalent positive displacement pumps 15N and 16N . Otherwise, the apparatus general design, function and operating principle are the same as that taught in Fig. 1.
Referring first to Fig.'s 5 to 10 in general terms, a variety of positive displacement pump types are shown for the purpose of highlighting that any number of pump types may be incorporated into the apparatus of the present invention, whether aspects of their structure, such as the housing, are incorporated into the core module, or they are connected or attached as fully discrete devices. All of these pump types are well known and commercially available in both standard and custom configurations. With the exception of certain added features of the flexible impeller vane pump described in Fig. 6, and the peristaltic pump described in Fig. 10, these pump types are not in themselves claimed as new and inventive aspects of the present invention and thus need not all be fully taught here. However, a more detailed description will be provided with regard to the added, unique features of the otherwise typical flexible impeller pump shown in Fig.
6 and the otherwise typical peristaltic pump shown in Fig. 10.
Referring more specifically now to Fig. 5, it is noted that while other pump types may be used, the design, capabilities and characteristics of the Gerotor type positive displacement pump, including its Geroler variant, make it particularly well suited for use with the apparatus of the present invention. They provide a constant, even discharge, have the ability to handle the higher pressures required for applications such as seawater reverse osmosis filtration, are bidirectional, provide for prime mover flexibility, are simple in design with few moving parts and offer the opportunity for comparatively easy servicing. They also offers flexibility of design, are relatively low in cost and are widely available in either standard or custom configurations if outsourced as a discrete components. In cases where higher circuit pressure is involved, the use of pump sets in series configuration is anticipated as a means of reducing the the amount of leakage (also known as slip or slippage) past the fluid seals within the the pumps, particularly for low rpm apparatus such as those manually operated.
A gear-toothed inner rotor 47 and a gear-toothed outer rotor 48 are assembled in a gear-within-a-gear arrangement mounted into a shared, fluid cavity 49 within a housing 50 such that the round, outer circumference of the outer rotor 48 forms a close but sliding fit Page 24 of 43 with the inner circumference of the fluid cavity 49. The housing 50 incorporates an unrestricted intake port 51 and an unrestricted discharge port 52 leading into and out of the fluid cavity 49. The inner rotor 47 is fixedly mounted to a rotating shaft 53 and, due to the meshing of their respective teeth, draws the outer rotor 48 around with it such that both rotate in the same direction. A close tolerance exists between the two rotors teeth, which are most fully messed at location 54, thereby providing a fluid seal there.
As is standard with gerotor type pumps, the smaller diameter inner rotor 47 has one less tooth than the larger diameter outer rotor 48 with the centre line of the inner rotor 47 being located at a fixed eccentricity from the centre line of the outer rotor 48 such that an increasing large gap is formed within that part of the fluid cavity 49 between the rotors with the gap being widest at location 55 opposite location 54, where the rotors most fully mesh, the latter being equidistant between the intake port 51 and discharge port 52.
As the rotors turn in unison, their teeth begin to diverge near the intake port 51, thereby creating an expanding gap or volume between them. This results in a partial vacuum being formed at the intake port 51, thus drawing fluid in from its source and subsequently trapping it in the expanding gaps that continuously form between the teeth as the rotors 47 and 48 rotate. At that location 55 where the gap between the rotors reaches it's maximum, volume expansion shifts to volume contraction as the teeth now begin to converge, this resulting in the progressive reduction or shrinking of the spacing and corresponding volume between the teeth. Because the pump is sealed against fluid leakage, also know as slip or slippage, between the rotors respective teeth where they most fully mesh at location 54, this then results in the fluid being forced out of the discharge port 52.
As was seen in Fig's 1 to 4 which, it may be assumed, teach the use of same acting but more fully integrated gerotor pumps, it is understood that in this figure, the shaft 53 upon which the inner rotor 47 is fixedly attached is rotatably mounted into suitable, fluid sealed bearings located in the housing 50 on each side of the cavity 49 and, by the same reference, it is also understood that one or more fluid sealed access ports are typically located within the housing 50 for the purpose of accessing and servicing the rotors.
In certain embodiments of the apparatus of the present invention, the housing 50, fluid cavity 49, intake port 51 and discharge port 52 that are shown here as separate elements Page 25 of 43 may all be comprised of a single cavity formed within a main body, whether that body be machined, moulded, 3D printed or otherwise produced.
Referring now to Fig. 6, an example of a flexible impeller type vane pump is shown wherein a flexible impeller 56 is fixedly mounted to a shaft 57 understood to be rotated by means of an external prime mover. As is standard with this type of pump, the flexible impeller 56 rotates within a fluid cavity 58 located within a housing 59 with fluid entering the cavity 58 via an intake port 60 and exiting via a discharge port 61. As is also standard with this type of pump, the flexible vanes being jointly represented here by the vane 62 are all in continuous contact with both the circumferential and the side walls of the cavity 58 such that a continuous fluid seal is formed by each so that as the impeller 56 rotates, fluid is driven ahead of each of the vanes 62.
Because these are positive displacement pumps, they create the partial vacuum needed to draw fluid into the pump through the intake port 60. This is accomplished by creating a narrowing of the gap between the impeller's hub 63 and a region of the circumferential inner wall of the cavity 58 located between the intake port 60 and discharge port 61 as the impeller rotates. This is done by adding thickness to that region, hereafter being referred to as the cam 64, by a suitable means such as, but not limited to forming the otherwise circular cavity 58 so that the cam 64 is more oval or elliptical in shape.
As a result, the volume within the gaps between the vanes 62 becomes progressively larger as the vanes 62 rotate away from the cam 64, thereby creating the partial vacuum needed to draw fluid into the cavity 58 through the intake port 60. As the impeller 56 continues to rotate, the vanes re-encounter the cam 64 where it is now increasing rather than diminishing in thickness. This results in a progressive reduction in the gap between the impeller hub 63 and the cam 64, thereby producing a corresponding reduction of volume between the vanes, which causes fluid to be forced out of the discharge port 61.
It is noted that with exception of a unique combination of design aspects described below, the general features and operating principles of this type of pump are not aspects of the inventiveness to be claimed herein. However, with regard to the unique aspects, it is seen that the thickness of the vanes tips 65, whatever their shapes may be, is such that when passing through the narrowest part of the gap between the impeller hub 63 and the cam 64 as seen at locations 66 and 67, the vanes tips 65 are in full contact with the Page 26 of 43 surfaces of both the impeller hub 63 at location 66 and the cam at location 67 such that a snug, sliding fit fluid seal is formed and noted that the durometer and/or reinforcing of the vanes tips 65 is such that the ability of this unique combination of design features enhances the pressure handling capability of any apparatus of this type incorporating flexible vane type pumps.
Referring now to Fig's 7 to 9, a further selection of pump types is shown only for the purpose of reinforcing the fact that various other types and designs of positive displacement pumps may also be integrated into any number of embodiments of the present invention. To that end, it is sufficient to say that the generic drawings of the external gear pump shown in Fig. 7, the vane pump shown in Fig. 8 and the peristaltic pump shown in Fig. 9, all represent well known pump types that, depending upon requirements, could be incorporated into those various semi-permeable membrane based filtration or separation systems that the apparatus of the present invention may be connected to or an integral part of.
Referring now to Fig. 10, a peristaltic pump similar to that of Fig. 9 is seen wherein two peristaltic hoses 15D and 16D, these being functionally equivalent to the pumps 15 and 16 seen in Fig.1, may optionally be mounted into a single, common cavity as long as their inside diameters and, therefore, their volumetric displacements differ in like fashion to those previously discussed, pressure within the 16D hose does not cause diameter expansion to negate the volumetric differential between the two hoses and proper occlusion is maintained for both.
Referring now to Fig's 11 to 16, a selection of prime movers is shown only for the purpose of reinforcing the fact that various types of prime movers may be used to drive the apparatus of the present invention. To that end, it is sufficient to say that the generic drawings of the wind turbine shown in Fig. 11, the water wheel shown in Fig.
12, and the telescopic ratcheting handle shown in Fig. 13 all shown with generic couplings, (Fig.14 has been removed for filing under a separate application), as well as the motor shown in Fig. 15, whether it be electric, hydraulic, pneumatic or otherwise, are all representative examples of prime movers that could be used to drive the apparatus of the present invention. In the case of Fig. 16, the drawing relates to prime movers that act directly upon Page 27 of 43 the pump's impellers as opposed to acting upon the rotating shafts to which the impellers are attached. In this example, an externally sourced flow of low pressure fluid is delivered to the apparatus of the present invention by a conduit such as but not limited to a hose or pipeline. Particular attention is drawn to the fact that the fluid stream driving the apparatus is often the same fluid stream being processed by the various filtration or separation systems into which the apparatus of the present invention may be incorporated.
Referring now to Fig. 17, a representative drawing of an optional flywheel 68 with over-riding clutch 69 assembly is shown for the purpose of highlighting that various prime movers, or the apparatus of the present invention itself, could incorporate this or other similarly acting means by which the driving force is smoothed, stored in reserve, or both.
One example of where this would be beneficial is with the wave follower shown in Fig. 14 wherein the intermittent force of the slowly reciprocating wave follower, which is assumed to be one-way acting in this example, is transmitted to a flywheel via an overriding clutch.
The overriding clutch, or any similarly acting device allows the wave follower to descend into the incoming wave troughs without imparting a resistance or braking force to the one-way motion of the flywheel, while the flywheel's stored energy continues to drive the apparatus during those continuously repeating periods in the wave follower's reciprocating cycle when no driving force is being applied to cause rotation. Depending on the application, this approach may be more practical and cost effective than other alternatives such as installing hydraulic accumulators, with or without pulsation dampening capability.
Referring now to Fig. 18, a detailed description of how the apparatus of the present invention such as that taught in the descriptions of Fig's 1 to 4, 21 and 23 may be incorporated into a complete, semi-permeable membrane based filtration or separation system designed for the conversion of raw seawater to potable freshwater by reverse osmosis is described in the text that follows. However, it is understood that by simply selecting the correct, semi-permeable membrane cartridge from the wide range of standard cartridges now available, this same system is also suitable for other fluid filtration or separation processes.
As was seen and previously taught in Fig. 1, a core module 1, an optional speed changing pulley assembly 2, a crank handle 3 prime mover and their associated, freely rotating, splined shaft 5 are shown here with their numbering carried over.
Also seen with Page 28 of 43 their numbering carried over are the intake and output conduits 17, 18, 19, 20 and 21 and their associated port2 35, 36, 37, 38 and 39, all with the understanding that for reasons of continuity and improved clarity, the positioning of some has been adjusted and the depth of the core body 1 has been extended ¨ all of these adjustments being made with the understanding that there is no change to or effect on the fluid routing, function or operating principles of the apparatus as it was initially taught in Fig. 1. Also, the 1.0 VU pump 15 and 0.9 VU pump 16, shown in Fig.1 and subsequently taught in the detailed description of Fig. 5 are the same pumps as those incorporated into the system taught here in Fig. 18 and hence, the same numbering is applied.
For improved clarity, the balance of the system as a whole is first broken down into logical sub-assemblies, these being a main systems module 70 that is a depth extended version of the core body 1 of Fig's 1 to 4, a lower body module 71, a pre-filter module 72, first, second, third and fourth quick-connect hose assemblies 73, 74, 75 and 76 and a standard, commercially available cross-flow type, semi-permeable membrane based reverse osmosis cartridge 77 chosen to best suit the location of use conditions.
As was the case with those earlier descriptions of the apparatus and of the pumps incorporated therein, the portable, seawater to potable freshwater reverse osmosis filtration system seen here, whether it be land, platform or marine vessel based, is best described and understood by following the flow of fluid through it. With that in mind, the fluid being raw seawater in this case, is first drawn into the pre-filter module 72 through a replaceable strainer 78 that removes sand and other course materials. It then passes through a site suitable, pre-filter cartridge 79 located within a filter housing 80 where finer particulate matter is removed as is common practice for these types of systems. In this setup the pre-filter module 72 is attached via outlet port 81 to a quick-connect fitted hose assembly 73 of suitable length and diameter such that the fluid passes unrestricted through it and then, via inlet port 35 into the main systems module 70, the main components of which are the apparatus of the present invention and a standard, commercially available, semi-permeable membrane based reverse osmosis cartridge 77.
Upon entering the port 35 the fluid continues on through the conduit 17 that opens unrestricted into the 1.0 VU pump 15 which, as was taught in the description of Fig. 1, also serves as its own feed pump by virtue of it's ability to draw in fluid by creating a partial Page 29 of 43 vacuum when rotated. The fluid is then propelled out of the 1.0 VU pump 15 into the open ended conduit 18 and exits through port 36, which is designed to form a suitable fluid seal with the intake fitting 82 built into the reverse osmosis cartridge 77, the latter being removably installed into a cavity 83 within the main systems module 70.
At this point, description of the fluid flow path is temporarily interrupted in order to remind the reader that the volumetric displacement (VU) of the downstream 0.9 VU pump 16 is approximately 11 percent less than that of the 1.0 VU pump 15, which the fluid is now being propelled forward by. The reader is also reminded that the two pumps 15 and 16 are of the positive displacement type, meaning that they are effectively sealed against the forward or backward flow of fluid past their impellers and finally, that those impellers are fixedly attached to a shared, common shaft. In other words, the downstream 0.9 VU pump 16 can not rotate faster than the 1.0 VU pump 15 in order to match their volumetric output.
As has been well established by commercially available devices of this type, such as the Spectra Watermaker as taught in the US 5,628,198 (Clark Permar) patent and the Schenker Watermaker as taught in US 6,491,813 B2 (Riccardo Verde) patent, this results in a rapid and continuing pressure rise within the closed hydraulic circuit between the pumps 15 and 16 until either (a) the incoming excess fluid from the 1.0 VU
pump 15 can find a path of escape (b) the 1.0 VU pump 15 stalls because the back pressure upon it overcomes the capability of the prime mover, or (c) there is a rupture or similar failure within the circuit. As with the above commercially available devices, the apparatus of the present invention relies upon (a) where the incoming excess fluid finds a path of escape, in all these cases as a means of accomplishing the intended outcome.
Returning now to the description of the fluid flow path from the point where it entered the intake fitting 82 built into the reverse osmosis cartridge 77, it can be seen with the help of the larger arrows that the fluid flows freely across and around the surface 84 of the cylindrically shaped cartridge 77, the latter typically being comprised of layers of semi-permeable membranes 85 and then exits through the cartridge's built-in discharge fitting 86 into the a compatible port 87 located in a fixedly attached but removable lower body module 71 from where it continues on through the conduit 88, the fitting 89 where it re-enters the main systems module 70, flows on through the port 37, the conduit 90 and the port 19 that opens into the smaller displacement 0.9 VU pump 16, whereupon it Page 30 of 43 encounters the fluid sealed impeller (inner rotor 47/Fig. 5) that prevents any further, unrestricted flow.
In the same manner as with the Spectra and Schenker devices referred to above, this results in a rapid and continuing pressure rise within the circuit between the pumps 15 and 16 until the excess volume of incoming fluid can find a path of escape.
Recalling that the reverse osmosis cartridge is located within the closed circuit between the 1.0 VU pump 15 and the 0.9 VU pump 16, this path of escape occurs the moment that the fluid pressure within the cartridge 77 reaches the point where osmotic pressure is overcome and the process of reverse osmosis commences with a volume of fluid equal to the approximately 11 percent displacement differential between the 1.0 VU pump 15 and the 0.9 VU
pump 16, now passing through the semi-permeable membranes 85 within the cartridge 77 as filtered "permeate," as shown here by the series of smaller arrows. The permeate then flows into a channel 91 within the core of the cartridge 77 and on out through the cartridge's built-in discharge fitting 92 into a compatible, fluid sealed port 93 located in the fixedly attached but removable lower body module 71, from where it continues on through the conduit 94 and out through a port 95 ,thus completing its flow within the apparatus. A
suitable, fitted hose assembly 75 is then employed to carry the typically non-pressurized potable freshwater permeate away for collection in a reservoir or other suitable means.
It is noted that the pressure point at which reverse osmosis self-initiates is dependent on a number of factors including but not limited to salinity level in the case of desalination, fluid temperature and semi-permeable membrane type and characteristics.
Nonetheless, it is brought to the readers attention that the process is self-initiating meaning that the apparatus of the present invention.
Recalling that taught in the description of Fig 1, the (0.9VU) balance of the fluid that was not forced by high pressure through the semi-permeable membranes 85 is returned to the 0.9 VU pump 16, such that it provides an energy recovery means, beyond which it is expelled through the output conduit 20 and the port 38 to be returned to its source, typically no longer under any significant pressure and in somewhat more concentrated form via fitted hose assembly 74 or similar other means. This waste fluid is commonly known as concentrate or, in the case of seawater desalination, as brine.
With the path of the fluid now described from the time it first enters the system as 1.0 Page 31 of 43 volumetric unit (VU) of raw seawater until it leaves the system in two streams, one being 0.1VU of potable freshwater and the other being 0.9VU of pre-filtered but otherwise unprocessed seawater, attention is now drawn to the remaining features seen in Fig. 18.
While not necessary for the operation of the apparatus, a set of extendable feet 96 and 97 are provided for the benefit of stability. These are seen here as a pair but may be installed in any suitable number. Also, the port 39 and the conduit 21 are not involved in the production phase that takes place during the clockwise rotation of the apparatus and, therefore, the reader is referred back to the detailed description of Fig. 2, which describes their function as well as to their involvement with the items described in Fig's 19 and 20. In that regard, the fitted hose assembly 76 is shown here only for the purpose of highlighting that the accessories taught in the descriptions of Fig's 19 and 20 are intended to be connected to the apparatus seen here in Fig. 18 via the port 39.
Referring now to Fig. 19, we are reminded that when the pumps 15 and 16 in Fig. 2 are rotated counter-clockwise, there is a need to provide the larger displacement 1.0 VU pump 15 with makeup fluid, this being drawn into the apparatus through the conduit 21 via the port 39 that is otherwise blocked off during normal, clockwise operation. As was seen in Fig. 18, the conduit 21 feeds unrestricted into the conduit 88, thereby allowing the makeup fluid to be drawn in as needed such that when combined within the conduit 88 with the fluid discharged by the smaller displacement 0.9 VU pump 16, the volumetric need of the larger displacement 1.0 VU pump 15 is met with the flow then continuing on in reverse beyond the 1.0 VU pump 15, as was taught in the detailed description of Fig. 2.
An important factor however, is to ensure that the fluid being used is suitable for the purpose and so it follows that the ideal fluid is that which has been captured from the apparatus as permeate. There is shown here a simple means by which to provide this. As previously stated, the filtration system used in this example is employed for converting raw seawater to potable freshwater so it is reasonable to assume that the resulting permeate, here being potable freshwater 98 is being stored, as in a reservoir 99 from which it can be drawn off as needed. This is accomplished by first immersing the open end of the unrestricted fitted hose assembly 74 into the permeate 98 stored in the reservoir 99, while ensuring that its other end is connected to the port 38 as was seen in Fig.
18. In this way, the fluid needs of the smaller displacement 0.9 VU pump 16 are provided for.
Next, the Page 32 of 43 open end of the fitted hose assembly 76 is also immersed into the permeate 98 stored in the reservoir 99 while ensuring that its fitted end is connected for unrestricted flow to the otherwise blocked port 39, as was also discussed in the description of Fig.
18, thus providing the makeup fluid needs of the larger displacement 1.0 VU pump 15.
In this way, the apparatus of the present invention provides a simple, convenient and dependable means for addressing the flushing, backwashing and purging needs typically required for maintaining and extending the life of semi-permeable membranes and pre-filters used in this fashion, while removing the potential for such possible issues as pump cavitation, pressure lock or the stressing of membranes that could be associated with starving the larger pump 15 of adequate fluid or by drawing the necessary makeup fluid through the semi-permeable membranes in reverse; these benefits all being accomplished without adding any appreciable complexity, costs or equipment requirements.
Referring now to Fig. 20, it is anticipated that some users may want the option of adding further capabilities to their systems, whether for convenience, the ability to monitor certain operating parameters, inject cleaning and storage agents or to serve some other useful purpose. In that regard, providing access to the otherwise closed fluid circuit within the apparatus via the normally blocked port 39 and conduit 21 shown in Fig's 1, 2, 3 and 18 offers a simple and convenient way of attaching a range of such means to the apparatus. One example, as seen here in Fig. 20, would be a manifold 100 that incorporates a fitting 101 compatible with the port 39 so that it can be readily and directly attached to the apparatus, whether only as needed or permanently. In this example, the manifold 100 has three branches, one with a pressure gauge 102 mounted to an unrestricted port 103, one with a sensor (S) 104 capable of detecting some other aspect of the fluid during the normal processing cycle mounted to an unrestricted port 105 and one, incorporating a one-way check valve 106 and which is compatible with the fitted hose assembly 76 used to provide fluid from the permeate reservoir 99, as was seen in Fig. 19.
However, it is understood that any number of devices, whether gauges, sensors, injectors or other beneficial devices could be attached to the apparatus, whether in this fashion or individually to the port 39.
Referring generally to Fig's 21 to 25, two embodiments of the apparatus of the present invention that incorporate a hybrid type of positive displacement, single impeller vane Page 33 of 43 pump are described. The term hybrid is used in the sense that while the pump is a positive displacement type, it does not incorporate the usual expansion type fluid moving chambers that provide vacuum generating/suction capability and, therefore, it depends for its feed upon an external source of positive head/lower pressure fluid to keep it primed, as with centrifugal type pumps.
This allows for certain novel features that provide significant advantages over prior art vane pumps when incorporated into the apparatus of the present invention.
Depending on whether the prior art is a sliding vane pump or flexible vane pump, these advantages can include any combination of (a) greater design simplicity and thus, the opportunity to produce lower cost, more dependable apparatus (b) two-way pumping capability (c) increased pressure handling capability (d) greater ease of servicing.
However, while not shown in the embodiments described in Fig's 21 and 23, it is well understood that a suction-type positive displacement feed pump could simply be added onto or incorporated into the apparatus and mounted to the shared, common shaft or equivalent rotating means such that it rotates in unison with the 1.0 VU pump 15 and the 0.9 VU pump 16, thereby providing the necessary flow of positive head/lower pressure fluid to the apparatus existing non-suction pumps.
Besides the use of non-suction, positive displacement pumps of unequal displacement in this type of apparatus, these novel aspects may also include: Firstly, the use of unique, flared vane tips 119 designed to cause an increase in fluid sealing capability as fluid pressure builds against the vanes 118, this due to the fluid pressure acting upwardly against the flared vane tips 119 in addition to the normally occurring perpendicular fluid pressure acting upon the lower stalk portion of the vanes 118 (See arrows 124 in Fig. 23).
In this way, the greater the pressure acting upon the vanes 118, the more the flared vane tips 119 are forced against the surface of the cavity 109/Fig. 21 and 126/Fig.
23, rather than away from it, as is typically the case with conventional vane pump designs. Secondly, the relatively high rigidity of the vanes 118 compared to those typically found in conventional flexible vane pumps prevents excessive bending of the vanes 118 that might otherwise offset or overcome the upward acting force on the flared vane tips 119.
With regard to where the surfaces of the vane tips 119 come into snug, sliding contact with the circumferential surface 127 of the pump cavity 126, it is noted that in all of the Page 34 of 43 Fig's 21 to 24, this surface is understood to be some form of tough, resilient, essentially smooth faced material suited to the application and further, that the impeller modules 108 and 125 including their vanes 118 might, depending on needs and design be a single, fully homogenous unit formed of such a material.
Otherwise the operating principles, circuits, unrestricted fluid flow capability and general structure of these embodiments remain the same as those taught in the previously described embodiments that do incorporate vacuum generating/suction capable pumps. In similar fashion also, the impeller is rotated by means of any number of connected prime movers such as those described previously. For these reasons, a fully detailed repetition of those same aspects is not deemed to be necessary here.
In descriptions that follow, depending on such factors as manufacturing tolerances and capabilities, materials of construction, rigidity of the impeller modules and vanes, the working pressures involved and whether the impeller incorporates fluid sealing means or is a seal-less design, the use of the descriptor "snug, sliding fit" and its variants is understood to mean either actual physical contact between the impeller and the cavity walls or a clearance or gap of such small dimensions between the surfaces of the impeller(s) and the cavity(s) that significant leakage/slip/slippage and corresponding loss of pressure are prevented to the degree necessary for the intended application. In either case, the novel aspects and operating principles of the apparatus of the present invention do not differ.
Fig. 21, being a side view of the first of the two embodiments and Fig. 22, being a partially rotated 3D view of it's impeller are best viewed together and, in like manner, Fig.
23 being an end view of the second of the two embodiments and Fig. 24 being a partially rotated 3D view of it's impeller are best viewed together. It is noted that the design concept and operating principle of both impellers is essentially the same with the primary difference being that the one shown in Fig's 21 and 22 relates to an implementation where the two pumps continue to function separately but are unified into a single impeller module rotating within a single cavity whereas the one shown in Fig's 23 and 24 relates to an implementation where the two pumps are comprised of separate rotors operating within separate cavities but still in like manner as those described in previous embodiments.
Referring to Fig's 21 and 22 together, a core module 107 incorporates a single impeller module 108 centrally located within a single, cylindrical cavity 109 located within a main Page 35 of 43 body 110. The core module 107 differs from the core module 1 of previous embodiments in that it has only one access port and cover 13, rather than the two seen previously.
The impeller module 108 incorporates two circumferential fluid seals 111 and 112, one at each end of the impeller module 108 and a third circumferential fluid seal 113 located between them, offset rather than centred such that the impeller module 108 is partitioned into two separately acting impellers of unequal width, these being a wider impeller 114 and a narrower impeller 115. As the circumferential faces of the fluid seals 111, 112 and 113 are in a snug, sliding, full contact type fit with the circumferential wall of the cavity 109, this effectively partitions the cavity 109 into two separately acting sub-cavities that correspond with the widths of the wider impeller 114 and a narrower impeller 115.
This effectively results in the existence of a larger displacement 1.0 VU pump 15 and a smaller displacement 0.9 VU pump 16 whose function, interoperability, fluid circuit positioning and operating principles in general are the same as those of the previously described embodiments. For example, the 0.9 VU displacement pump 15 limits the higher fluid flow of the 1.0 VU displacement pump 16 to 0.9 VU and, just as with the previously described embodiments, the resultant back pressure induces a pressure rise in that portion of the enclosed fluid circuit located between them, that being an external filtration or separation system circuit connected between outlet port 36 and return intake port 37.
How the fluid is either propelled forward or held back, as the case may be, within this particular pump design occurs in the same fashion as with previously described embodiments, meaning it is accomplished by rotation the impellers 114 and 115 or, more specifically, by a variable number of horizontally aligned vanes 118 that protrude from a hub 120 (see Fig. 22) of the impeller module 108. There are four vanes 118 in this case, all being numerically represented by the vane 118. The vanes 118 and hub 120 are a single moulded component here but it is understood that other same acting implementations such as fully rigid hub and vanes are also anticipated, especially where high pressures are involved. For clarity, the areas of the vanes 118 and circumferential fluid seals 111, 112 and 113 that come in snug, sliding contact with the circumferential wall of the cavity 109 are marked here with hatching.
A shaft means is integrated into the impeller module 108 such that it is self-centring when installed into cavity 109 within the main body 110; this as a way of further reducing Page 36 of 43 complexity, while also facilitating removal and installation during servicing.
This self-centring capability is achieved through the use of a centrally located, tapered male extension 121 of the impeller module 108 being rotatably mounted into a precisely mated, tapered female cavity 122 centrally located in the rear side wall of the cavity 116 on the one side of the core module 107 and, on the other side, with an extension of the impeller module 108 in the form of a shaft 123 extending through a fluid sealed shaft bearing 22 that is centrally located in the front port cover 13. This results in the impeller module 108 being mounted, enclosed and sealed within the core module 107 such that it is centred within the cavity 109. and in snug, sliding contact in all those locations where fluid sealing under pressure is required.
The intake and output conduits 17 and 18 enter and exit the cavity 116 between the circumferential fluid seals 111 and 113 and the intake and exit conduits 19 and 20 enter and exit the cavity 117 between the circumferential fluid seals 112 and 113.
By way of comparison, it is now seen that the fluid flow within this embodiment matches that of previously described embodiments such as that in Fig. 1 as further highlighted by the directional arrows associated with the same acting conduits 17, 18, 19, 20 and 21 and their corresponding intake and outlet ports 35, 36, 37, 38 and 39. Also, in similar fashion as with previously described embodiments, the impellers 114 and 115 seen here are rotated via a splined shaft 123 powered by any number of previously described external prime movers.
It is now seen that while this non-suction type, positive displacement pump based embodiment depends on a flow of positive head/low pressure feed fluid 45 to keep it primed, which in most of the previously described embodiments is not required, it's core operating principles do not differ from those previously described embodiments.
Referring now to Fig's 23 and 24 together, attention is focused on the pumps that are incorporated into a preferred embodiment of the present invention, noting that all aspects of the apparatus taught in the descriptions of Fig's 1 to 4 apply here so do not need to be restated. For example, a first positive displacement pump or pump set with a displacement of 1.0 volumetric units (VU) and a second positive displacement pump or pump set with a displacement of 0.9 volumetric units are likewise employed here and the two impeller modules 125 seen here are mounted to a common shaft 9 such that they rotate in unison, as was also the case with Fig's 1 to 4.
Page 37 of 43 In this case, a version of the impeller described in Fig.s 21 and 22 but without the circumferential seals 111, 112 and 113 is employed in each of two separate pumps and hereafter referred to as the impeller module(s) 125. This difference is best seen by comparing Fig's 22 and 24. As with the impeller module 108 described in Fig's 21 and 22, the two impeller modules 125 are mounted such that each forms a snug, sliding fit within its own cavity. However, in the absence of the circumferential seals 111 and 112 there remains a need to ensure against leakage down and along the ends of the impeller module 125. While this might be accomplished by ensuring that very exacting smoothness and flatness tolerances exist between the end walls of the impeller module 125 and the end walls of the cavity 126, the amount of friction would be high and wear related servicing of the impeller impractical. This problem is addressed by mounting one or more 0-rings 127 into suitable grooves in each end of the impeller module 125, thereby providing a solution that allows for extending the useable life of the impeller by simply replacing the 0-rings if and when wear occurs. While it is noted that other, same acting resilient/compressible seals could be used in place of the 0-rings 127, the overall benefit would be questionable.
The impeller seen in Fig. 24 incorporates three additional albeit optiona/features that provide the opportunity to (a) reduce sliding friction (b) reduce leakage (c) reduce tight manufacturing tolerance requirements, and (d) increase serviceability. The first of these features is the use of 0-rings 128, as discussed above, or other similarly acting means.
The second involves the use of replaceable, linear fluid seals 129, typically being resilient but not limited in that respect, mounted into grooves cut or formed into the circumferential faces of the vanes 118 such that they, rather than the faces of the vanes themselves form the snug, sliding fit with the circumferential surfaces 127 of the cavity 126 and, if required and as seen here, extend outward from the sides of the impeller module 108 as far as the 0-rings 128 to eliminate leakage paths there. The third involves the use of grooves 130 cut or formed linearly into the circumferential faces of the vanes 118 such that they increase the resistance to fluid leakage past the vanes 118. This feature is described in greater detail in the description that follows, however, before proceeding, it is noted that any or all of these added, optional features may also be applied to the impeller module 108 seen in Fig's 21 and 22 as well to other pumps used in the apparatus of the present invention.
As was taught in the description above, the snug, sliding fit between the impeller Page 38 of 43 module 108 and the cavity 109 minimizes the amount of leakage past the vanes.
As indicated above, this type of leakage can optionally be further reduced, if required, by the use of axial grooves 130, whether occurring singly or in groove sets, cut or otherwise formed into the faces of the vanes 118 such that they create a turbulence induced increase in the amount of pressure drop between the vanes 118 and the walls of the cavity 126, thus resulting in a reduction in leakage/slip/slippage and corresponding pressure loss.
These single grooves or groove sets 130 are cut or formed such that the size, shape or other relevant features of the individual grooves as well as the number of grooves and the spacing between the individual grooves within a set may vary, this for the purpose of still further increasing their effectiveness. Such grooves or groove sets may (a) extend out from the side surfaces of the impeller module 125 as seen in Fig. 24, or (b) may also be applied separately to the side surfaces of the impeller module 125, whether in radial, circular or some other fashion, or (c) may even be cut or formed into the surface of the cavity 126 if deemed to be beneficial.
Referring now to Fig. 25, a fully rigid but otherwise same acting impeller 131 for use in the embodiment taught in Fig. 23 is seen wherein the impeller 131 is comprised of a variable number of vanes, all represented by the vane 132 extending outward from a central hub 133 in perpendicular fashion. Outer tips 134 of the vanes 132 may be either (a) in very close proximity to but not in physical contact with the pump cavity's walls such that the minimal clearance/gap 135 between the vane's tips 134 and the cavity's circumferential wall 136 and between the vane's sides 137 and the cavity's side walls (hidden) minimizes possible leakage/slip/slippage between a series of fluid moving chambers 138 located between the vanes 118 such that adequate fluid pressure can be both built and maintained, or (b) incorporate a compressible/resilient fluid sealing means that is in snug, sliding, full contact with the cavity's circumferential walls 136 and side walls (hidden) and extending across the width of the circumferential faces of the vane tips 134, down the vane sides 137 and around the outer perimeter 139 of the impeller hub 133 side walls, again minimizing possible leakage/slip/slippage opportunities.
It is noted at this time that while the embodiments taught in the descriptions of Fig's 21 to 25 are capable of functioning without the need for discrete sealing parts as aspects of Page 39 of 43 their impellers, other embodiments incorporating a variety of other fluid sealing means with the same effect are anticipated, whether these other means relate to the impeller vanes or to/as circumferential seals and whether or not they are fully integrated or discrete aspects, two examples being conventional piston ring style means or other resilient/compressible materials of suitable thickness and durometer, whether attached, applied or as a formed aspect of the impeller.
Finally, the readers attention is drawn to several aspects of the apparatus of the present invention that relate to multiple figures or are general in nature. These include:
- In cases where higher circuit pressure is involved, the use of pump sets in series configuration is anticipated as a preferred means of reducing the the amount of leakage, also known as slip or slippage, past the fluid seals within the the pumps, particularly for low rpm apparatus such as those that are manually operated.
- In those embodiments where pump sets configured in series are employed, the pumps within each set are typically matched in terms of their displacement. However, in applications where any significant degree of uneven leakage between the pumps within the set is anticipated, the displacement of one or more of the pumps, depending on how many are in the set, may need to be adjusted to reduce the potential for such issues as cavitation or excessive pressure buildup. Otherwise, in the case of excessive pressure buildup and if the leakage volumes were unable to self-regulate enough to bring about balanced flow volume between the pump in the set, a pressure relief means could be required.
- In the case of most of the embodiments described herein, the pumps are two-way acting, although this is not a core requirement for the basic functionality of the apparatus of the present invention.
- The flow of fluid within the various circuits of the apparatus of the present invention is described in the embodiments herein as being unrestricted with the exception of where the fluid encounters or is acted upon by the impellers of the positive displacement pumps.
However, it is understood that this is a preferred condition - not a requirement. In other words, while being able to function without the use of flow restricting components such as valves and/or other flow control means is a novel aspect of the present invention, its core design and operating principles remain the same, even if a user would choose to incorporate such components.
Page 40 of 43 - While the volumetric displacement of the two pumps was defined as being 0.9 VU and 1.0 VU with an effective differential of 11 percent for the purpose of this description, it is understood that the differential will vary depending upon the design, requirements and capabilities of the semi-permeable membranes and systems which they are a part of.
- The design, function, operating principles and operating conditions associated with the reverse osmosis process as it relates to cross-flow type semi-permeable membranes and cartridges is well established and well documented and so, being that these are not themselves aspects the apparatus of the present invention and for the sake of maintaining focus, further detail regarding these is not deemed to be necessary within this description.
- Where two-way embodiments are involved, the smaller displacement 0.9 VU
pump also serves as a feed pump for the apparatus during counter-clockwise rotation by virtue of it's ability to draw in feed fluid by creating a partial vacuum, as was the case during the clockwise rotation of the 1.0 VU pump.
- Complete filtration or separation systems, whether or not described herein, need not be limited to the commercially available cartridge based setups employed with the preferred embodiments described herein. In that regard, it is understood that other semi-permeable membrane means serving the same purpose, whether custom designed or not and including those intended to render a system disposable, may be employed instead.
- For reasons of clarity, ease of viewing and because a variety of pump types and designs can be employed by the apparatus of the present invention, the sizing and placement of the ports and circuits seen in the various figures within this description are understood to be representative only. For example, in some cases such as the gerotor type pump, the ports may typically be found in the cavity side walls whereas, in the case of peristaltic types, the ports functions may be made redundant in some cases by the hoses.
- Certain embodiments of the apparatus of the present invention may be powered either by applying force to a rotating drive shaft to which the pump's impellers are fixedly attached or by a flow of pressurized fluid acting directly upon the the impellers themselves with little or no modification. In the latter case it is further understood that this same fluid is typically also the feed fluid to be processed.
- While not a part of the apparatus of the present invention itself or essential for it's operation but because positive displacement pumps are employed, it is noted that for Page 41 of 43 reasons of safety, some means of pressure relief be integrated into any connected system circuits downstream from any point where the apparatus is generating high pressure.
- While not essential to the functioning of the apparatus of the present invention, pulsation dampening means, whether with or without accumulator capacity, may either be incorporated into the apparatus itself or installed upstream, depending upon fluid in-feed characteristics and in-reserve flow requirements.
- For greater understanding of how fluid pressure is intensified within the portion of the circuit located between the two positive displacement pumps/pump sets of differing volumetric displacement, attention is drawn to the fact that during the apparatus production related rotation, the smaller of the pumps/pump sets is employed primarily to provide a resistance based back pressure, rather than only for propelling the fluid forward, which it also does. In that regard, as was stated at the outset of the detailed description, it is noted that a key operating principle of the apparatus of the present invention, is the existence of a stable, volumetric difference in the amount of fluid displaced by each of two positive displacement pumps or pump sets operating within the same closed circuit such that the greater flow volume from the upstream pump encounters a back pressure from the downstream pump, resulting in a rise in pressure in that part of the closed circuit incorporating a cross-flow, semipermeable membrane means located between the two pumps. This can be implemented in at least three ways: The first, being the preferred implementation, employs two pumps or pump sets with different internal displacement rotating at the same speed such that their output volumes differ at a set ratio or ratio range.
The second employs two pumps or pump sets with the same internal displacement but rotating at different speeds such that their output volumes differ at a controlled ratio or ratio range. The third employs two pumps or pump sets with different internal displacement rotating at different speeds such that their output volumes differ but still at a controlled ratio or ratio range. Other variations may also be possible but regardless of which approach is taken, the operating principle remains essentially the same.
However, for the benefit of greater clarity and ease of understanding, only the first of these implementations forms the basis for the preferred embodiment and its variants presented herein, with the understanding that with the addition of varying degrees of complexity and cost, typically involving at least the use of external control means and/or more complex prime mover Page 42 of 43 requirements, those other implementations mentioned above could be employed to achieve the same outcome employing essentially the same core operating principles.
Therefore, it is understood that while the description of the embodiments taught herein refer specifically to pumps or pump sets of different internal displacement rotating at the same speed due to the opportunity for least complexity, this is not meant to limit the inventor's claims to only that particular means or arrangement of parts for providing a displacement volume differential between two positive displacement pumps or pump sets.
- VOWLES, Gerald J., sole inventor The preceding represents a detailed description of an invention by Gerald J.
Vow/es of Vankleek Hill, ON Canada KOB 1 RO. The purpose of this document is to establish a priority date with regard to a yet to be completed patent application for the present invention. The balance of the documents and materials required to complete the application process including the Claims and Summary will be provided in due course in accordance with the instructions and time limits provided by the Canadian Intellectual Property Office (CIP0).
VOWLES, Gerald J., sole inventor 128 Barton Street Vankleek Hill, Champlain Township Ontario Tel. 613-678-3253 Cell. 613-847-5687 Canada March 24, 2017 Page 43 of 43