AU2005266144B2

AU2005266144B2 - Jet pump

Info

Publication number: AU2005266144B2
Application number: AU2005266144A
Authority: AU
Inventors: Marcus Brian Mayhall Fenton; Alexander Guy Wallis
Original assignee: Pursuit Dynamics PLC
Current assignee: Pursuit Dynamics PLC
Priority date: 2004-07-29
Filing date: 2005-07-29
Publication date: 2012-06-07
Anticipated expiration: 2025-07-29
Also published as: JP5188180B2; CA2573712A1; CA2573712C; BRPI0513918A; JP2008508462A; AU2005266144A1; EP1789684B1; WO2006010949A1; EP1789684A1

Abstract

A fluid mover (1) includes a hollow body (2) provided with a straight-through passage (3) of substantially constant cross section with an inlet end (4) an outlet end (5) for the entry and discharge respectively of a working fluid. A nozzle (16) substantially circumscribes and opens into the passage (3) intermediate the inlet (4) and outlet (5) ends. An inlet (10) communicates with the nozzle (16) for the introduction of a transport fluid and a mixing chamber (3A) is formed within the passage (3) downstream of the nozzle (16). The nozzle internal geometry and the bore profile immediately upstream of the nozzle exit are disposed and configured to optimise the energy transfer between the transport fluid and working fluid. In use, through the introduction of transport fluid, the working fluid or fluids are atomised to form a dispersed vapour/droplet flow regime with locally supersonic flow conditions within a pseudo-vena contracta, resulting in the creation of a supersonic condensation shock wave (17) within the downstream mixing chamber (3A) by the condensation of the transport fluid. Methods of moving and processing fluids using the fluid mover are also disclosed.

Description

WO 2006/010949 PCT/GB2005/002999 JET PUMP 1 This invention relates to a method and apparatus for 2 moving a fluid. 3 4 The present invention has reference to improvements 5 to a fluid mover having a number of practical 6 applications of diverse nature ranging from marine 7 propulsion systems to pumping applications for 8 moving and/or mixing fluids and/or solids of the 9 same or different characteristics. The present 10 invention also has relevance in the fields inter 11 alia of heating, cooking, cleaning, aeration, gas 12 fluidisation, and agitation of fluids and 13 fluids/solids mixtures, particle separation, 14 classification, disintegration, mixing, 15 emulsification, homogenisation, dispersion, 16 maceration, hydration, atomisation, droplet 17 production, viscosity reduction, dilution, shear 18 thinning, transport of thixotropic fluids and 19 pasteurisation.

-2 More particularly the invention is concerned with the provision of an improved fluid mover having essentially no moving parts. Any discussion of the prior art throughout the 5 specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. Ejectors are well known in the art for moving working or process fluids by the use of either a central or an annular 10 jet which emits steam into a duct in order to move the fluids through or out of appropriate ducting or into or through another body of fluid. The ejector principally operates on the basis of inducing flow by creating negative pressure, generally by the use of the venturi principle. 15 The majority of these systems utilise a central steam nozzle where the induced fluid generally enters the duct orthogonally to the axis of the jet, although there are exceptions where the reverse arrangement is provided. The steam jet is accelerated through an expansion nozzle into a 20 mixing chamber where it impinges on and is mixed with working fluid. The mixture of working fluid and steam is accelerated to higher velocities within a downstream convergent section prior to a divergent section, e.g. a venturi. The pressure gradient generated in the venturi 25 induces new working fluid to enter the mixing chamber. The energy transfer mechanism in most steam ejector systems is a combination of momentum, heat and mass transfer but by varying proportions. Many of these systems employ the momentum transfer associated with a converging flow, while 30 others involve the generation of a shock wave in the divergent section. One of WO 2006/010949 PCT/GB2005/002999 3 1 the major limitations of the conventional 2 convergent/divergent systems is that their 3 performance is very sensitive to the position of the 4 shock wave which tends to be unstable, easily moving 5 away from its optimum position. It is known that if 6 the shock wave develops in the wrong place within 7 the convergent/divergent sections, the relevant unit 8 may well stall. Such systems can also only achieve 9 a shock wave across a restricted section. 10 11 Furthermore, for systems which employ a central 12 steam nozzle, the throat dimension restriction and 13 the sharp change of direction affecting the working 14 fluid presents a serious limitation on the size of 15 any particulate throughput and certainly any rogue 16 material that might enter the system could cause 17 blockage. 18 19 An improved fluid mover is described in our 20 International Patent Application No 21 PCT/GB2003/004400 in which the interaction of a 22 working fluid or fluids and a transport fluid 23 projected from a nozzle arrangement provides 24 pumping, entrainment, mixing, heating, 25 emulsification, and homogenization etc. of the 26 working fluid or fluids. The fluid mover introduces 27 an annular supersonic jet of transport fluid, 28 typically steam, into a relatively large diameter 29 straight through hollow passage. Through a 30 combination of momentum transfer, high shear, and 31 the generation of a condensation shock wave, the 32 high velocity steam induces and acts upon the WO 2006/010949 PCT/GB2005/002999 4 1 working fluid passing through the centre of the 2 hollow body. 3 4 PCT/GB2003/004400 describes that the transport fluid 5 is preferably a condensable fluid and may be a gas 6 or vapour, for example steam, which may be 7 introduced in either a continuous or discontinuous 8 manner. At or near the point of introduction of the 9 transport fluid, for example immediately downstream 10 thereof, a pseudo-vena contracta or pseudo 11 convergent/divergent section is generated, akin to 12 the convergent/divergent section of conventional 13 steam ejectors but without the physical constraints 14 associated therewith since the relevant section is 15 formed by the effect of the steam impacting upon the 16 working or process fluid. Accordingly the fluid 17 mover is more versatile than conventional ejectors 18 by virtue of a flexible fluidic internal boundary 19 described by the pseudo-vena contracta. The 20 flexible boundary lies between the working fluid at 21 the centre and the solid wall of the unit, and 22 allows disturbances or pressure fluctuations in the 23 multi phase flow to be accommodated better than for 24 a solid wall. This advantageously reduces the 25 supersonic velocity within the multi phase flow, 26 resulting in better droplet dispersion, increasing 27 the momentum transfer zone length, thus producing a 28 more intense condensation shock wave. 29 30 PCT/GB2003/004400 further discloses that the 31 positioning and intensity of the shock wave is 32 variable and controllable depending upon the WO 2006/010949 PCT/GB2005/002999 5 1 specific requirements of the system in which the 2 fluid mover is disposed. The mechanism relies on a 3 combination of effects in order to achieve its high 4 versatility and performance, notably heat, momentum 5 and mass transfer which gives rise to the generation 6 of the shock wave and also provides for shearing of 7 the working fluid flow on a continuous basis by 8 shear dispersion and/or dissociation. Preferably 9 the nozzle is located as close as possible to the 10 projected surface of the working fluid in practice 11 and in this respect a knife edge separation between 12 the transport fluid or steam and the working fluid 13 stream is of advantage in order to achieve the 14 requisite degree of interaction. The angular 15 orientation of the nozzle with respect to the 16 working fluid stream is of importance and may be 17 shallow. 18 19 Further, PCT/GB2003/004400 discloses that the or 20 each transport fluid nozzle may be of a convergent 21 divergent geometry internally thereof, and in 22 practice the nozzle is configured to give the 23 supersonic flow of transport fluid within the 24 passage. For a given steam condition, i.e. dryness, 25 pressure and temperature, the nozzle is preferably 26 configured to provide the highest velocity steam 27 jet, the lowest total pressure drop and the highest 28 static enthalpy between the steam chamber and the 29 nozzle exit. The nozzle is preferably configured to 30 avoid any shock in the nozzle itself. For example 31 only, and not by way of limitation, an optimum area 32 ratio for the nozzle, namely exit area: throat area, WO 2006/010949 PCT/GB2005/002999 6 1 lies in the range 1.75 and 7.5, with an included 2 angle of less than 9'. 3 4 The or each nozzle is conveniently angled towards 5 the working fluid flow and also faces generally 6 towards the outlet of the fluid mover. This helps 7 penetration of the working fluid by the transport 8 fluid, which may help shear or thermal dispersion of 9 the working fluid. This may also prevent both 10 kinetic energy dissipation on the wall of the 11 passage and premature condensation of the steam at 12 the wall of the passage, where an adverse 13 temperature differential prevails. The angular 14 orientation of the nozzles is selected for optimum 15 performance which is dependent inter alia on the 16 nozzle orientation and the internal geometry of the 17 mixing chamber. Further the angular orientation of 18 the or each nozzle is selected to control the 19 pseudo-convergent/divergent profile, the pressure 20 profile within the mixing chamber, the enthalpy 21 addition and the condensation shock wave intensity 22 or position in accordance with the pressure and flow 23 rates required from the fluid mover. Moreover, the 24 creation of turbulence, governed inter alia by the 25 angular orientation of the nozzle, is important to 26 achieve optimum performance by dispersal of the 27 working fluid to a vapour-droplet phase in order to 28 increase acceleration by momentum transfer. This 29 aspect is of particular importance when the fluid 30 mover is employed as a pump. For example, and not 31 by way of limitation, in the present invention it 32 has been found that an angular orientation for the -7 or each nozzle may lie in the range 0 to 30 with respect to the flow direction of the working fluid. A series of nozzles with respective mixing chamber sections associated therewith may be provided longitudinally of the 5 passage and in this instance the nozzles may have different angular orientations, for example decreasing from the first nozzle in a downstream direction. Each nozzle may have a different function from the other or others, for example pumping, mixing, disintegrating, and may be selectively 10 brought into operation in practice. Each nozzle may be configured to give the desired effects upon the working fluid. Further, in a multi-nozzle system by the introduction of the transport fluid, for example steam, phased heating may be achieved. This approach may be 15 desirable to provide a gradual heating of the working fluid. It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. 20 Advantageously, the present invention in at least one preferred embodiment improves the performance of the fluid mover by enhancing the energy transfer mechanism between the high velocity transport fluid and the working fluid. This advantageously improves the performance of the fluid 25 mover having essentially no moving parts having an improved performance than fluid movers currently available in the absence of any constriction such as is exemplified in the prior art recited in the aforementioned patent. Unless the context clearly requires otherwise, throughout 30 the description and the claims, the words "comprise", -8 "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". 5 According to a first aspect of the present invention a fluid mover includes a hollow body provided with a straight-through passage of substantially constant cross section with an inlet at one end of the passage and an outlet at the other end of the passage for the entry and 10 discharge respectively of a working fluid, a nozzle substantially circumscribing and opening into said passage intermediate the inlet and outlet ends thereof, an inlet communicating with the nozzle for the introduction of a transport fluid, a controllable transport fluid source in 15 fluid communication with the transport fluid inlet, wherein the transport fluid source is adapted to control the pressure of the transport fluid at the inlet such that a momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70, a mixing 20 chamber being formed within the passage downstream of the nozzle, the nozzle internal geometry and the bore profile immediately upstream of the nozzle exit being so disposed and configured to optimise the energy transfer between the transport fluid and working fluid that in use through the 25 introduction of transport fluid the working fluid or fluids are atomised to form a dispersed vapour/droplet flow regime with locally supersonic flow conditions within a pseudo vena contracta, resulting in the creation of a supersonic condensation shock wave within the downstream mixing 30 chamber by the condensation of the transport fluid, and a microprocessor coupled to the transport fluid source and to at least one sensor that monitors one or more properties of the mixed fluids within the downstream mixing chamber which -9 relate to the resulting supersonic condensation shock wave, the microprocessor being adapted to allow the transport fluid source to control the pressure of the transport fluid based on information measured through said at least one 5 sensor. The transport fluid is preferably a condensable fluid and may be a gas or vapour, for example steam, which may be introduced in either a continuous or discontinuous manner. Preferably, an internal wall of the passage upstream of the 10 mixing chamber is provided with at least one groove that creates turbulence in the working fluid flow prior to any interaction between the working fluid and the transport fluid. According to a second aspect of the present invention a 15 fluid mover includes a hollow body provided with a straight-through passage of substantially constant cross section with an inlet at one end of the passage and an outlet at the other end of the passage for the entry and discharge respectively of a working fluid, a nozzle 20 substantially circumscribing and opening into said passage intermediate the inlet and outlet ends thereof, an inlet communicating with the nozzle for the introduction of a transport fluid, a controllable transport fluid source in fluid communication with the transport fluid inlet, wherein 25 the transport fluid source is adapted to control the pressure of the transport fluid at the inlet such that a momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70, and a mixing chamber being formed within the passage downstream of the 30 nozzle, wherein the nozzle internal geometry and the bore profile of the passage immediately upstream of the nozzle -10 exit are so disposed and configured to optimise the energy transfer between the transport fluid and working fluid that in use through the introduction of transport fluid the working fluid or fluids are atomised to form a dispersed 5 vapour/droplet flow regime with locally supersonic flow conditions within a pseudo-vena contracta, resulting in the creation of a supersonic condensation shock wave within the downstream mixing chamber by the condensation of the transport fluid, and wherein the position of the supersonic 10 condensation shock wave is controlled by varying the pressure of the transport fluid through the controllable transport fluid source, and varying a parameter selected from the group consisting of an inlet temperature of the transport fluid, an inlet pressure of the transport fluid, 15 and a flow rate of the transport fluid, as well as varying a parameter selected from the group consisting of an inlet temperature of the working fluid, a flow rate of the working fluid, an inlet pressure of the working fluid, an outlet pressure of the working fluid, properties of the 20 working fluid resulting from the inclusion of an additive liquid, gas or solid, a flow rate of a fluid additive added to the working fluid, an inlet pressure of a fluid additive added to the working fluid, an outlet pressure of a fluid additive added to the working fluid, and a temperature of a 25 fluid additive added to the working fluid. The nozzle may be of a form to correspond with the shape of the passage and thus for example a circular passage would advantageously be provided with an annular nozzle circumscribing it. The term 'annular' as used herein is 30 deemed to embrace any configuration of nozzle or nozzles that circumscribes the passage of the fluid mover, and encompasses circular, irregular, polygonal and rectilinear shapes of nozzle. The term "circumscribing" or "circumscribes" as used herein is deemed to embrace not only a continuous nozzle surrounding the passage, but also a discontinuous nozzle having two or more nozzle outlets partially or entirely surrounding the passage. 5 The or each nozzle may be of a convergent-divergent geometry internally thereof, and in practice the nozzle is configured to give the supersonic flow of transport fluid within the passage. For a given steam condition, i.e. dryness, pressure and temperature, the nozzle is preferably 10 configured to provide the highest velocity steam jet, the lowest total pressure drop and the highest enthalpy between the steam chamber and nozzle exit. The condensation profile in the mixing chamber determines the expansion ratio profile across the nozzle. With 15 relatively low working fluid temperatures condensation is dominant, and the exit pressure of the transport fluid nozzle is low. The exit pressure of the transport fluid nozzle is higher when the bulk temperature of the working fluid is higher. 20 According to another invention a method of moving a working fluid includes presenting a fluid mover to the working fluid, the mover having a straight-through passage of substantially constant cross section, 25 applying a substantially circumscribing stream of a transport fluid to the passage through an annular nozzle, controlling the pressure of the transport fluid through a controllable transport fluid source such that a momentum flux ratio (M) between the transport fluid and 30 working fluid lies in the range 2 M 70, -12 atomising the working fluid to form a dispersed vapour and droplet flow regime with locally supersonic flow conditions, generating a supersonic condensation shock wave within 5 the passage downstream of the nozzle by condensation of the transport fluid, inducing flow of the working fluid through the passage from an inlet to an outlet thereof, modulating the condensation shock wave to vary the 10 working fluid discharge from the outlet, and controlling the position of the condensation shock wave within the passage by varying the pressure of the transport fluid through the controllable transport fluid source and varying a parameter selected from the group 15 consisting of an inlet temperature of the transport fluid, an inlet pressure of the transport fluid, and a flow rate of the transport fluid, as well as varying a parameter selected from the group consisting of an inlet temperature of the working fluid, a flow rate of the working fluid, an 20 inlet pressure of the working fluid, an outlet pressure of the working fluid, properties of the working fluid resulting from the inclusion of an additive liquid, gas or solid, a flow rate of a fluid additive added to the working fluid, an inlet pressure of a fluid additive added to the 25 working fluid, an outlet pressure of a fluid additive added to the working fluid, and a temperature of a fluid additive added to the working fluid. Preferably the modulating step includes modulating the intensity of the condensation shock wave. Alternatively or 30 additionally the modulating step includes modulating the position of the condensation shock wave.

- 13 The bore profile immediately upstream of the nozzle is preferably configured to encourage working fluid atomisation. Preferably an instability in working fluid flow is introduced immediately upstream of the nozzle. 5 The or each nozzle is preferably optimally configured to operate with a particular working fluid, upstream wall contour profile and mixing chamber geometry. The nozzles, upstream wall contour profile and mixing chamber combination are configured to encourage working fluid 10 atomisation creating a vapour/droplet mixed flow with local supersonic flow conditions. This encourages the formation of the downstream condensation shock wave, by enhancing local turbulence, pressure gradient and the momentum and heat transfer rate between the transport and working fluids 15 by maximising surface contact between the fluids. The or each nozzle is preferably configured to operate with a particular working fluid, upstream wall contour profile and mixing chamber to provide an optimum nozzle exit pressure. Initial pressure recovery due to transport fluid 20 deceleration, coupled with the downstream pressure drop due to condensation, is used to ensure the nozzle expansion ratio is adjusted to enhance atomisation of the working fluid and momentum transfer.

- 14 The exit velocity from the or each nozzle may be controlled by varying the transport fluid supply pressure, the expansion ratio of the nozzle and the condensation profile in the immediate region of the mixing chamber. The nozzle 5 exit velocities may be controlled to enhance Momentum Flux Ratios M in the immediate region of the mixing chamber, where M is defined by the equation _ (px U") (pr X Uf) Where p = Fluid density U = Fluid velocity 10 Subscript s represents transport fluid Subscript f represents working fluid In the present invention it has been found that an optimum Momentum Flux Ratio M for the or each nozzle lies in the range 2 M 70. For example, when using steam as the 15 transport fluid, with a working fluid with a high water content, M for the or each nozzle lies in the range 5 M 40. The or each nozzle is configured to provide the desired combination of axial, radial and tangential velocity 20 components. It is a combination of axial, radial and tangential components which influence the primary turbulent break-up (atomisation) of the working fluid flow and the pressure gradient. The interaction between the transport fluid and the working 25 fluid, leading to the atomisation of the working fluid, is enhanced by flow instability. Instability enhances the droplet stripping from the contact surface of the core flow of the working fluid. A turbulent dissipation layer between - 15 the transport and working fluids is both fluidically and mechanically (geometry) encouraged ensuring rapid fluid core dissipation. The pseudo-vena contracta is a resultant aspect of this droplet atomisation region. 5 The internal walls of the flow passage upstream of the or each nozzle may be contoured to provide a combination of axial, radial and tangential velocity components of the outer surface of the working fluid core when it comes into contact with the transport fluid. It is a combination of 10 these velocity components which inter alia influence the primary turbulent break-up (atomisation) of the working fluid and the pressure gradient when it comes into contact with the transport fluid. Under optimum operating conditions the disintegration or 15 atomisation of the working fluid core is extremely rapid. The disintegration across the whole bore will typically take place in the mixing chamber within, but not limited to, a distance approximately equivalent to 0.66D downstream of the nozzle exit. Under different non- optimised 20 operating conditions disintegration across the whole bore of the mixing chamber, may still occur within, but not limited to, a distance equivalent to 1.5D downstream of the nozzle exit, where D is the nominal diameter of the bore through the centre of the fluid mover. 25 Recirculation occurs in the flow. The recirculation is particularly dominant where tangential velocity components of the transport fluid are present. The radial pressure gradients created within the mixing chamber are responsible for this flow phenomenon which encourages complete and 30 rapid flow dispersion characteristics across the bore.

-16 This effect is also created when the pseudo-vena contracta is partially established, i.e. vapour- droplet flow is dominant along the mixing chamber boundary. The localised pressure gradient draws flow outwards, causing a region 5 downstream of the transport fluid nozzle exit, typically between 1 diameter and 2 diameters downstream, where the axial flow component of the working fluid stagnates and may even reverse briefly on the centre-line, i.e. the centre of the flow region. 10 Recirculation has particular benefits in some applications such as emulsification. A series of nozzles with respective mixing chamber sections associated therewith may be provided longitudinally of the passage and in this instance the nozzles may have different 15 angular orientations, for example decreasing from the first nozzle in a downstream direction. Each nozzle may have a different function from the other or others, for example pumping, mixing, disintegrating or emulsifying, and may be selectively brought into operation in practice. Each nozzle 20 may be configured to give the desired effects upon the working fluid. Further, in a multi-nozzle system by the introduction of the transport fluid, for example steam, phased heating may be achieved. This approach may be desirable to provide a gradual heating of the working 25 fluid, enhanced atomisation, pressure gradient profiling or a combinatory effect, such as enhanced emulsification. In addition the internal walls of the flow passage immediately upstream of the or each nozzle exit may be contoured to provide different degrees of turbulence to the 30 working fluid prior to its interaction with the transport fluid issuing from the or each nozzle.

-17 The mixing chamber geometry is determined by the desired and projected output performance and to match the designed transport fluid conditions and nozzle geometry. In this respect it will be appreciated that there is a combinatory 5 effect as between the various geometric features and their effect on performance, namely there is interaction between the various design and performance parameters having due regard to the defined function of the fluid mover. According to a fourth aspect of the present invention a 10 method of processing a working fluid includes presenting a fluid mover to the working fluid, the fluid mover having a straight-through passage of substantially constant cross section, applying a substantially circumscribing stream of a 15 transport fluid to the passage through an annular nozzle, the fluid mover further comprising a mixing chamber being formed within the passage downstream of the nozzle, wherein an internal wall of the passage upstream of the mixing chamber is provided with at least one groove that creates 20 turbulence in the working fluid flow prior to any interaction between the working fluid and the transport fluid, atomising the working fluid to form a dispersed vapour and droplet flow regime with locally supersonic flow 25 conditions, generating a supersonic condensation shock wave within the passage downstream of the nozzle by condensation of the transport fluid, wherein the nozzle internal geometry and the internal wall of the passage are so disposed and 30 configured to optimise energy transfer between the transport fluid and working fluid, the position of the condensation shock wave remaining substantially constant under equilibrium flow, -18 inducing flow of the working fluid through the passage from an inlet to an outlet thereof, and changing the position of the condensation shock wave to vary the working fluid discharge from the outlet. 5 Changing the position of the condensation shock wave is preferably achieved by varying at least one of a group of parameters, the group of parameters including the inlet temperature of the working fluid, the flow rate of the working fluid, the inlet pressure of the working fluid, the 10 outlet pressure of the working fluid, the flow rate of a fluid additive added to the working fluid, the inlet pressure of a fluid additive added to the working fluid, the outlet pressure of a fluid additive added to the working fluid, the temperature of a fluid additive added to 15 the working fluid, the angle of entry of the transport fluid to the passage, the inlet temperature of the transport fluid, the flow rate of the transport fluid, the inlet pressure of the transport fluid, the internal dimensions of the passage downstream of the nozzle, and the 20 internal dimensions of the passage upstream of the nozzle. The term straight-through when used to describe a passage encompasses any passage having a clear flow path therethrough, including curved passages. The fluid additive may be gaseous or liquid. The fluid 25 additive is not an essential element of the invention, but in certain circumstances may be beneficial. The fluid additive may comprise a powder in dry form or suspended in a fluid.

- 18a The parameter varying step may include switching between a plurality of transport fluids or between a plurality of fluid additives. According to a fifth aspect of the present invention a 5 method of moving a working fluid comprises the steps of: presenting a fluid mover to the working fluid, the mover having a straight-through passage of substantially constant cross section; applying a substantially circumscribing stream of a 10 transport fluid to the passage through an annular nozzle; controlling the pressure of the transport fluid through a controllable transport fluid source such that a momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70; 15 atomising the working fluid to form a dispersed vapour and droplet flow regime with locally supersonic flow conditions; generating a supersonic condensation shock wave within the passage downstream of the nozzle by condensation of the 20 transport fluid; inducing flow of the working fluid through the passage from an inlet to an outlet thereof; monitoring through a microprocessor coupled to at least one sensor one or more properties of the mixed fluids 25 within the passage downstream of the nozzle which relate to the resulting supersonic condensation shock wave; allowing the transport fluid source to control the pressure of the transport fluid based on information measured through said at least one sensor; and 30 modulating the condensation shock wave to vary the working fluid discharge from the outlet.

- 18b The improvements of the present invention may be employed to the fluid mover of the aforementioned patent, and enhance its use in a variety of applications as disclosed in the aforementioned patent. These applications range from 5 use as a fluid processor, including pumping, mixing, heating, homogenising etc, to marine propulsion, where the mover is submersed within a body of fluid, namely the sea or lake or other body of water. In its application to fluid processing a variety of working fluids may be processed and 10 may include liquids, liquids with solids in suspension, slurries, sludges and the like. It is an advantage of the straight- through passage of the mover that it can accommodate material that might find its way into the passage. 15 The fluid mover of the present invention may also be used for enhanced mixing, dispersion or hydration and again the combination of the shearing mechanism, droplet formation and presence of the condensation shock wave provides the mechanism for achieving the desired result. In this 20 connection the fluid mover may be used for mixing one or more fluids, one or more fluids and solids in particulate form, for example powders. The fluids may be in liquid or WO 2006/010949 PCT/GB2005/002999 19 1 gaseous form. It has been found that the use of the 2 present invention when mixing liquid with a powder 3 of particulate form results in a homogeneous 4 mixture, even when the powder is of material which 5 is difficult to wet, for example Gum Tragacanth 6 which is a thickening agent. 7 8 The treatment of the working fluid, for example 9 heating, dosing, mixing, dispersing, emulsifying etc 10 may occur in batch mode using at least one fluid 11 mover or by way in an in-line or continuous 12 configuration using one or more fluid movers as 13 required. 14 15 A further use to which the present invention may be 16 put is that of emulsification which is the formation 17 of a suspension by mixing two or more liquids which 18 are not soluble in each other, namely small droplets 19 of one liquid (inner phase) are suspended in the 20 other liquid(s) (outer phase) . Emulsification may 21 be achieved in the absence of surfactant blends, 22 although they may be used if so desired. In 23 addition, due to the straight through nature of the 24 invention, there is no limitation on the particle 25 size that can be handled, allowing particle sizes up 26 to the bore size of the unit to pass through whilst 27 emulsification is taking place. 28 29 The fluid mover may also be employed for 30 disintegration, for example in the paper industry 31 for disintegration of paper pulp. A typical example 32 would be in paper recycling, where waste paper or WO 2006/010949 PCT/GB2005/002999 20 1 broken pieces are mixed with water and passed 2 through the fluid mover. A combination of the heat 3 addition, the high intensity shearing mechanism, the 4 low pressure region in the vapour-droplet flow and 5 the condensation shock wave both rapidly hydrates 6 the paper fibres, and macerates and disintegrates 7 the paper pieces into smaller sizes. Disintegration 8 down to individual fibres has been achieved in 9 tests. Similarly, the fluid mover could be used in 10 de-inking processes, where the heating and shearing 11 assist in the removal of ink from paper pulp as it 12 passes through the fluid mover. 13 14 The straight through aspect of the invention has the 15 additional benefit of offering very little flow 16 restriction and therefore a negligible pressure 17 drop, when a fluid is moved through it. This is of 18 particular importance in applications where the 19 fluid mover is located in a process pipe work and 20 fluid is pumped through it, such as the case, for 21 example, when the fluid mover of the present 22 invention is turned 'off' by the reduction or 23 stopping of the supply of transport fluid. In 24 addition, the straight through passage and clear 25 bore offers no impedance to cleaning 'pigs' or other 26 similardevices which may be employed to clean the 27 pipe work. 28 29 A detailed description of the energy transfer 30 mechanism, focussing on the momentum transfer 31 between the transport fluid and working fluid by an 32 enhanced shearing mechanism is best described with WO 2006/010949 PCT/GB2005/002999 21 1 reference to the accompanying drawings. By way of 2 example, eight embodiments of geometrical features 3 that may be employed to enhance this energy transfer 4 mechanism in accordance with the present invention 5 are described below with reference to the 6 accompanying drawings in which: 7 8 Figure 1 is a cross sectional elevation of a fluid 9 mover according to the present invention; 10 Figure 2 is a magnified view of the shearing 11 mechanism shown in Figure 1; 12 Figure 3 is a cross sectional elevation of a first 13 embodiment; 14 Figure 4 is a cross sectional elevation of a second 15 embodiment; 16 Figure 5 is a cross sectional elevation of a third 17 embodiment; 18 Figure 6 is a cross sectional elevation of a fourth 19 embodiment; 20 Figure 7 is a cross sectional elevation of a fifth 21 embodiment; 22 Figure 8 is a cross sectional elevation of a sixth 23 embodiment; 24 Figure 9 is a cross sectional elevation of a seventh 25 embodiment; 26 Figure 10 is a schematic section through the fluid 27 regime of the fluid mover of the present invention; 28 Figure 11 is a schematic drawing of the fluid mover 29 of the present invention in use; 30 Figure 12 is a schematic drawing showing pressure in 31 the fluid mover of the present invention under three 32 different operating conditions; WO 2006/010949 PCT/GB2005/002999 22 1 Figure 13 is a schematic drawing showing a section 2 through the fluid mover of the present invention and 3 the pressure distribution in the fluid mover under 4 two different condensation shock wave positions; and 5 Figures 14a and 14b are partial cross sectional 6 views through an eighth embodiment of the fluid 7 mover of the present invention. 8 9 Like numerals of reference have been used for like 10 parts throughout the specification. 11 12 Referring to Figure 1 there is shown a fluid mover 13 1, comprising a housing 2 defining a passage 3 14 providing an inlet 4 and an outlet 5, the passage 3 15 being of substantially constant circular cross 16 section. 17 18 The housing 2 contains a plenum 8 for the 19 introduction of a transport fluid, the plenum 8 20 being provided with an inlet 10. The distal end of 21 the plenum is tapered on and defines an annular 22 nozzle 16. The nozzle 16 being in flow communication 23 with the plenum 8. The nozzle 16 is so shaped as in 24 use to give supersonic flow. 25 26 In operation the inlet 4 is connected to a source of 27 a process or working fluid. Introduction of the 28 steam into the fluid mover 1 through the inlet 10 29 and plenum 8 causes a jet of steam to issue forth 30 through the nozzle 16. Steam issuing from the 31 nozzle 16 interacts with the working fluid in a 32 section of the passage operating as a mixing chamber WO 2006/010949 PCT/GB2005/002999 23 1 (3A). In operation the condensation shock wave 17 2 is created in the mixing chamber (3A). 3 4 In operation the steam jet issuing from the nozzle 5 occasions induction of the working fluid through the 6 passage 3 which because of its straight through 7 axial path and lack of any constrictions provides a 8 substantially constant dimension bore which presents 9 no obstacle to the flow. At some point determined 10 by the steam and geometric conditions, and the rate 11 of heat and mass transfer, the steam condenses 12 causing a reduction in pressure. The steam 13 condensation begins shortly before the condensation 14 shock wave and increases exponentially, ultimately 15 forming the condensation shock wave 17 itself. 16 17 The low pressure created shortly before and within 18 the initial phase of the condensation shock wave 19 results in a strong fluid induction through the 20 passage 3. The pressure rises rapidly within and 21 after the condensation shock wave. The condensation 22 shock wave therefore represents a distinct pressure 23 boundary/gradient. 24 25 The parametric characteristics of the steam coupled 26 with the geometric features of the nozzle, upstream 27 wall profile and mixing chamber are selected for 28 optimum energy transfer from the steam to the 29 working fluid. The first energy transfer mechanism 30 is momentum and mass transfer which results in 31 atomisation of the working fluid. This energy 32 transfer mechanism is enhanced through turbulence.

WO 2006/010949 PCT/GB2005/002999 24 1 Figure 1 shows diagrammatically the break-up, or 2 atomisation sequence 18 of the working fluid core. 3 4 Figure 2 shows a magnified and exaggerated schematic 5 of the shearing and atomisation mechanism 18 of the 6 working fluid by the transport fluid. It is 7 believed that this mechanism can be broken down into 8 three distinct regions, each governed by established 9 turbulence mechanisms. The first region 20 10 experiences the first interaction between the 11 transport and working fluid. It is in this region 12 that Kelvin-Helmholtz instabilities in the surface 13 contact layer of the working fluid may start to 14 develop. These instabilities grow due to the shear 15 conditions, pressure gradients and velocity 16 fluctuations, leading to Rayleigh-Taylor ligament 17 break-up 24. Second order eddies within the fluid 18 surface waves may reduce in size to the scale of 19 Kolmogorov eddies 22. It is believed that the 20 formation of these eddies, in association with the 21 Rayleigh-Taylor ligament break-up, result in the 22 formation of small droplets 28 of the working fluid. 23 24 The droplet formation phases may also result in a 25 localised recirculation zone 26 immediately 26 following the ligament break-up region. This 27 recirculation zone may enhance the fluid atomisation 28 further by re-circulating the larger droplets back 29 into the high shear region. This recirculation, a 30 feature of the localised pressure gradient, is 31 controllable via the transport fluid's axial, 32 tangential and radial velocity and pressure WO 2006/010949 PCT/GB2005/002999 25 1 components. It is believed that this mechanism 2 enhances inter alia the mixing, emulsifying and 3 pumping capabilities of the fluid mover. 4 5 The primary break-up mechanism of the working fluid 6 core may therefore be enhanced by creating initial 7 instabilities in the working fluid flow. 8 Deliberately created instabilities in the transport 9 fluid/working fluid interaction layer encourage 10 fluid surface turbulent dissipation resulting in the 11 working fluid core dispersing into a liquid-ligament 12 region, followed by a ligament-droplet region where 13 the ligaments and droplets are still subject to 14 disintegration due to aerodynamic characteristics. 15 16 Referring now to Figure 3 the fluid mover of Figure 17 1 and 2 is provided with a contoured internal wall 18 in the region 19 immediately upstream of the exit of 19 the steam nozzle 16. The internal wall of the flow 20 passage 3 immediately upstream of the nozzle 16 is 21 provided with a tapering wall 30 to provide a 22 diverging profile leading up to the exit of the 23 steam nozzle 16. The diverging wall geometry 24 provides a deceleration of the localised flow, 25 providing disruption to the boundary layer flow, in 26 addition to an adverse pressure gradient, which in 27 turn leads to the generation and propagation of 28 turbulence in this part of the working fluid flow. 29 As this turbulence is created immediately prior to 30 the interaction between the working fluid and the 31 transport fluid, the instabilities initiated in 32 these regions enhance the Kelvin-Helmholtz WO 2006/010949 PCT/GB2005/002999 26 1 instabilities and hence ligament and droplet 2 formation as foreshadowed in the foregoing 3 description occurs more rapidly. 4 5 An alternative embodiment is shown in Figure 4. 6 Again, the fluid mover of Figure 1 and 2 is provided 7 with a contoured internal wall 19 of the flow 8 passage 3 immediately upstream of the nozzle 16. 9 The contoured surface in this embodiment is provided 10 by a diverging wall 30 on the bore surface leading 11 up to the exit of the steam nozzle 16, but the taper 12 is preceded with a step 32. In use, the step 13 results in a sudden increase in the bore diameter 14 prior to the tapered section. The step 'trips' the 15 flow, leading to eddies and turbulent flow in the 16 working fluid within the diverging section, 17 immediately prior to its interaction with the steam 18 issuing from the steam nozzle 16. These eddies 19 enhance the initial wave instabilities which lead to 20 ligament formation and rapid fluid cone dispersion. 21 22 The tapered diverging section 30 could be tapered 23 over a range of angles and may be parallel with the 24 walls of the bore. It is even envisaged that the 25 tapered section 30 may be tapered to provide a 26 converging geometry, with the taper reducing to a 27 diameter at its intersection with the steam nozzle 28 16 which is preferably not less than the bore 29 diameter. 30 31 The embodiment shown in Figure 4 is illustrated with 32 the initial step 32 angled at 90' to the axis of the WO 2006/010949 PCT/GB2005/002999 27 1 bore 3. As an alternative to this configuration, 2 the angle of the step 32 may display a shallower or 3 greater angle suitable to provide a 'trip' to the 4 flow. Again, the diverging section 30 could be 5 tapered at different angles and may even be parallel 6 to the walls of the bore 3. Alternatively, the 7 tapered section 30 may be tapered to provide a 8 converging geometry, with the taper reducing to a 9 diameter at its intersection with the steam nozzle 10 16 which is preferably not less than the bore 11 diameter. 12 13 Figures 5 to 8 illustrate examples of alternative 14 contoured profiles. All of these are intended to 15 create turbulence in the working fluid flow 16 immediately prior to the interaction with the 17 transport fluid issuing from the nozzle 16. 18 19 The embodiments illustrated in Figures 5 and 6 20 incorporate single or multiple triangular cross 21 section grooves 34, 36 immediately prior to a 22 tapered or parallel section 30, which is in turn 23 immediately prior to the exit of the steam nozzle 24 16. 25 26 The embodiments illustrated in Figures 7 and 8 27 incorporate single or multiple triangular 38 and/or 28 square 40 cross section grooves a short distance 29 upstream of the exit of the steam nozzle 16. These 30 embodiments are illustrated without a tapering 31 diverging section after the grooves. 32 WO 2006/010949 PCT/GB2005/002999 28 1 Although Figures 1 to 8 illustrate several 2 combinations of grooves and tapering sections, it is 3 envisaged that any combination of these features, or 4 any other groove cross-sectional shape may be 5 employed. 6 7 The tapered section 30 and/or the step 32 and/or the 8 grooves 34, 36, 38, 40 may be continuous or 9 discontinuous in nature around the bore. For 10 example, a series of tapers and/or grooves and/or 11 steps may be arranged around the circumference of 12 the bore in a segmented or 'saw tooth' arrangement. 13 14 The nature of the flow regime in the fluid mover of 15 the present invention is described in more detail 16 below, with reference to Figure 10. 17 18 The transport fluid, usually steam 80, enters 19 through nozzle 16 at supersonic velocity. Wherever 20 the term steam is used, it is to be understood that 21 the term can also be applied to other transport 22 fluids. The working fluid, usually liquid 82, flows 23 at a subsonic velocity into the inlet 4. At the 24 nozzle 16 there is a subsonic liquid core 84 which 25 is bounded by a generally rough or turbulent conical 26 interface with the steam 80 and the region of 27 dispersion 88. As the steam 80 exits the nozzle 16 28 it exhibits local shock and expansion waves 86 and 29 forms a pseudo vena contracta 90. The accelerated 30 region of dispersion 88 (or dissociation) of the 31 liquid core flows at a locally supersonic velocity 32 into the vapour-droplet region 92, in which the WO 2006/010949 PCT/GB2005/002999 29 1 vapour is steam and the droplets are the working 2 fluid. Condensation takes place in the supersonic 3 condensation zone 94 and the subsonic condensation 4 zone 96. The condensation shock wave 17 is produced 5 when the condensation, which initiates in the 6 locally supersonic low density region 94, reaches an 7 exponential rate. The zone 96 immediately after the 8 condensation shock wave 17 has a considerably higher 9 density and is hence subsonic. The condensation 10 shock wave 17 thus defines the interface between 11 these two densities. 12 13 In the liquid phase 98 beyond the condensation zone 14 96 there are small vapour bubbles. The position of 15 the condensation shock wave is controllable over a 16 distance L by adjustment of one of the plurality of 17 parameters described herein. 18 19 The break-up and dispersion of the primary liquid 20 core produces a droplet vapour region. Any liquid 21 instabilities on the primary liquid cone surface 18 22 are amplified to form 'waves'. These waves are 23 further elongated to form ligaments that undergo 24 Rayleigh-Taylor break-up, resulting in the formation 25 of small droplets 28, separated ligaments 24 and 26 larger droplets. 27 28 The secondary region 24 is thus characterised by the 29 rapid increase in the effective fluid surface area. 30 These droplets 28, of varying size, are then subject 31 to several aerodynamic and thermal effects which 32 ultimately result in their break up to sizes WO 2006/010949 PCT/GB2005/002999 30 1 characteristic with the turbulence levels in this 2 region. This results in the vapour-droplet region 3 which defines the flow regime within the fluid 4 mover. 5 6 The thickness of the viscous sub layer, comprising 7 the high speed vapour/gas and the locally entrained 8 liquid in droplet or ligament form, increases 9 downstream to ultimately extend across the entire 10 bore. The turbulence within this region arises from 11 shear (velocity gradient) and eddies (large scale to 12 Kolmogorov scale), as the flow is essentially of a 13 vapour-droplet consistency. High levels of shear 14 exist in the gas/liquid interface. 15 16 A large amount of energy is transferred in this 17 secondary region 24 as a result of further particle 18 break-up. Mass transfer takes place as the shear 19 forces and thermal discontinuities result in the 20 droplets becoming ever smaller. The pressure 21 reduces and droplets are evaporated in order to 22 maintain equilibrium in the flow. Heat transfer 23 takes place as equilibrium conditions are reached, 24 ensuring that liquid vapour phase transitions and 25 the inverse transitions all occur within the mixing 26 section of the passage 3. In the secondary region 27 there is a very rapid increase in the void fraction 28 ag ATot 29 30 where a = void fraction 31 Ag area of gas phase (dispersion cone) 32 ATot = total area of pump flow WO 2006/010949 PCT/GB2005/002999 31 1 2 Thus the rapid increase in specific volume as the 3 liquid droplets/ligaments are further dispersed, 4 will obviously result in a larger void fraction. 5 Subsequently as the flow conditions begin to 6 approach a state of equilibrium, and due to the 7 geometry within the mixing chamber, the vapour flow 8 is encouraged to follow a condensation profile 9 towards an aerodynamic and condensation shock wave, 10 which is a region of non-equilibrium and entropy 11 production. 12 13 The condensation shock wave arises from the rapid 14 change from a two-phase fluid mixture to a 15 substantially single phase fluid with complete 16 condensation of the vapour phase. Since there is no 17 unique sonic speed in vapour droplet mixtures, non 18 equilibrium and equilibrium exchanges of momentum, 19 mass and energy can occur. In order to achieve a 20 normal condensation shock wave, the velocity of the 21 vapour mixture within the mixing chamber has to be 22 maintained above a certain value defined as the 23 equilibrium sonic speed. For conditions where the 24 vapour velocity is greater than the frozen sonic 25 speed, or where the velocity of the vapour mixture 26 is between the equilibrium and frozen sonic speed, 27 this results in a dispersed or partially dispersed 28 condensation shock wave. These two asymptotic sonic 29 speeds are: 30 WO 2006/010949 PCT/GB2005/002999 32 1 ae = equilibrium shock speed. This is the speed at 2 which every fluid is in its correct equilibrium 3 condition, i.e. vapour is vapour, liquid is liquid 4 5 af = frozen shock speed. This occurs primarily due 6 to a 'lag' effect, so that some fluids are not in 7 their correct phase, for example the local 8 temperature and pressure dictate that a vapour 9 should be turning to liquid, but the phase change 10 has not happened. 11 12 af and ae are defined as: 13 14 a,= yRv,-T 15 16 a, - T R -T c-T h,, hf 17 18 where 19 20 c=Cp, + CPf 21 y = Ratio of specific heats (the vapour and the 22 fluid) 23 Rv = Gas constant for vapour phase (steam) 24 T, = Saturation temperature of mixture (vapour and 25 fluid) 26 Cp = Specific heat 27 Hfs = Latent heat of vapourisation 28 X = Initial vapour quality 29 s = Vapour fraction (gas/liquid) 30 WO 2006/010949 PCT/GB2005/002999 33 1 Subscript v, represents vapour (steam) 2 Subscript f, represents fluid (e.g. liquid) 3 4 Frozen flow arises when the interface transport of 5 mass, momentum and energy between the vapour phase 6 and liquid droplets is frozen completely, i.e. the 7 liquid droplets do not take part in the fluid 8 mechanical processes. 9 10 Equilibrium flow arises when the velocity and 11 temperature of the vapour and liquid are in 12 equilibrium, and the partial pressure due to the 13 vapour is equal to the saturation pressure 14 corresponding to the temperature of the flow. 15 16 The secondary flow regime can better be understood 17 by further subdivision into three sub-regions. 18 19 The first sub-region of the secondary flow regime is 20 the droplet break-up sub-region. Just as in the 21 primary zone, where the liquid core is stripped to 22 form the droplet-vapour zone, with the stripping of 23 the ligaments and droplets on the surface, so in the 24 secondary region there is further break-up or 25 dispersion of these separated ligaments, and also 26 the break-up of droplets whose characteristics are 27 unstable in the turbulent flow regime. The dominant 28 mechanism responsible for the break-up in the 29 secondary region is the acceleration of droplets or 30 momentum transfer due to the slip velocity between 31 vapour and liquid. The injection velocity of the 32 vapour in the present invention is important to this WO 2006/010949 PCT/GB2005/002999 34 1 functional aspect of the flow regime. If required, 2 multiple nozzles staggered downstream may be used to 3 encourage this aspect. Other parameters such as 4 nozzle angle and mixing chamber geometry can be 5 selected to establish favourable flow conditions. 6 7 Typical break-up mechanisms in this region are 8 dependant on the local velocity slip conditions and 9 the respective working fluid properties. These are 10 gathered into a dimensionless number referred to as 11 the aerodynamic Weber number defined as: 12 13 We= .(Uf-U .Df 0-f 14 15 where 16 pv = Density of vapour 17 U Velocity 18 D= Hydraulic diameter of fluid 19 f= Surface tension of fluid 20 21 Typical break-up mechanisms found in the fluid mover 22 of the present invention are vibrational break-up, 23 which can be found with ligaments and droplets whose 24 characteristic length is greater than the stable 25 length; catastrophic break-up, which is especially 26 dominant in the liquid-vapour shear layer where We 27 350; wave crest stripping, which occurs where 28 droplets, due to their size, experience large 29 aerodynamic forces causing ellipsoidal shapes, 30 typically where We 300; and short stripping, which 31 is the dominant break-up mechanism where daughter WO 2006/010949 PCT/GB2005/002999 35 1 and sattelite droplets have been formed following 2 the ligament stripping and dispersion, typically 3 where We100. 4 5 The turbulent motion of the surrounding gas, 6 especially where the Reynold numbers are large (Re > 7 104), as is usually the case in the present 8 invention, results in large amounts in local energy 9 dissipation and accompanying droplet break-up. The 10 fluctuating dynamic pressures resulting from these 11 turbulent fluctuations are dominant in droplet 12 break-up but very importantly it is this energy that 13 ensures extremely effective dispersion and mixing of 14 the fluids in the flow. 15 16 Turbulent pressure fluctuations result in shear 17 forces capable of rupturing fibres or filaments and 18 dissipating powder lumps or similar solid or semi 19 solid matter. In the primary region energy, mass 20 and momentum transfer takes place through a more 21 distinct boundary, associated with the liquid cone 22 dispersion. In the secondary break-up region this 23 transfer is directly related to the turbulence 24 intensity, closely associated with the turbulent 25 dissipation region in the flow. 26 27 The thermal boundary layer, although similar in 28 characteristic to the turbulent dissipation 29 sublayer, represents the effective boundary where 30 evaporation/condensation and energy transfer occur 31 in either an equilibrium state or 'frozen' state. 32 WO 2006/010949 PCT/GB2005/002999 36 1 Interfacial transport, which begins within the 2 primary cone dissipation, continues into the 3 secondary vapour-droplet region and is characterised 4 by distinct mechanisms enhanced within the fluid 5 mover of the invention through vapour introduction 6 conditions, dependent on pressure and velocity, the 7 physical geometry of the steam nozzles and the 8 mixing chamber geometry. This results in a 9 continuous surface renewal process, which together 10 with the turbulence results in a series of renewed 11 eddies of various scales. These eddies create 12 bursts arising from the interface of the liquid 13 vapour and the waves formed on ligaments and 14 droplets which are undergoing further break-up. 15 These bursts have a period which is a function of 16 the interfacial shear velocity. These bursts 17 greatly encourage mixing, heat transport and 18 emulsification (droplet size reduction). 19 20 The second sub-region of the secondary flow regime 21 is the subcooled vapour-droplet region. As the 22 vapour mixture flows through the fluid mover of the 23 invention its velocity profile is adjusted through 24 fluidic interaction as well as the static pressure 25 gradient which gradually rises due to general 26 deceleration of the flow. This controlled diffusion 27 of the supersonic flow, balance of natural fluidic 28 and thermodynamic interactions coupled with discrete 29 geometry results in a vapour-droplet state where 30 sub-cooled droplets exist within a vapour dominant 31 phase. The sub-cooled state of this frozen mixture 32 increases until droplet nucleation, and hence WO 2006/010949 PCT/GB2005/002999 37 1 condensation, begins to occur very rapidly. The 2 point of maximum sub-cooling (Wilson point) 3 determines the point at which the nucleation rate, 4 which is closely dependent on sub-cooling because of 5 the available surface area for condensation, begins 6 to occur very rapidly, and reaches near exponential 7 rates. The vapour-droplet region within the fluid 8 mover of the invention thus is able to attain near 9 thermodynamic equilibrium within a very short zone. 10 11 The fluid mover of the invention makes special use 12 of geometric conditions created through both 13 geometry and pseudo geometric conditions to ensure 14 the flow conditions upstream of the critical 15 subcooled state deviate from the thermodynamic 16 equilibrium. This ensures maintenance of the 17 desired vapour-droplet region with its desirable 18 droplet break-up, particle dispersion and heat 19 transfer effects. 20 21 The rapid acceleration of the fluid from the primary 22 fluid cone into the vapour region results in an 23 expansion wave, which similarly represents a 24 thermodynamic discontinuity and allows the vapour 25 droplet region to deviate markedly from equilibrium 26 and enter a 'frozen' flow condition. 27 28 Figure 9 shows an embodiment of the fluid mover of 29 the invention in which the geometry of the passage 3 30 has a mixing chamber 3A with a divergent region 50, 31 a constant diameter region 52 and a re-convergence 32 profile region 54. The constant through bore is WO 2006/010949 PCT/GB2005/002999 38 1 maintained, but the embodiment of Fig 9 promotes 2 this expansion and non-equilibrium. This offers 3 excellent particle dispersion, and good flow, 4 pressure head and suction conditions. 5 6 The third sub-region of the secondary flow regime is 7 the condensation shock region. As a result of the 8 sub-cooled vapour-droplet flow regime within the 9 fluid mover, the point at which exponential 10 condensation begins to occur defines the 11 condensation shock wave boundary. The mixture 12 conditions upstream of the condensation shock wave 13 determine the nature of the pressure and temperature 14 recovery experienced within the fluid mover. 15 16 The phase change across the condensation shock wave 17 obviously results in heat removal from the vapour 18 phase, although there will be an entropy increase 19 across the condensation shock wave. The ideal 20 operating conditions in the fluid mover of the 21 invention coincide with the formation of a normal 22 condensation shock wave, referred to as being 23 discrete, due to its relatively rapid and hence 24 negligible size measured along the X-axis. 25 26 The nature of the fluid flow in the fluid mover of 27 the present invention may better be understood by 28 reference to Figure 12, which shows the distribution 29 of pressure p in the fluid mover over length x along 30 the axis. Reference is made to the two shock 31 speeds, a, and af, defined earlier. 32 WO 2006/010949 PCT/GB2005/002999 39 1 Fig. 12a shows condition A and represents the 2 situation where Umixture > a., where Umixture is the 3 velocity of the vapour/droplet mixture. 4 5 This results in a normal condensation shock wave, 6 with a fairly rapid rise in pressure across the 7 condensation shock wave. The resulting exit 8 pressure is higher than the local pressure at the 9 steam inlet into the bore of the fluid mover. 10 11 Fig. 12b shows condition B and represents the 12 situation where af > Umixture > ae. In this case the 13 mixture velocity is higher than the equilibrium 14 shock speed but less than the frozen shock speed. 15 In this condition the condensation shock wave is 16 fully dispersed resulting in a much more gradual 17 pressure rise across the condensation shock wave. 18 19 Fig. 12c shows condition C and represents the 20 situation where Umixture > af. In this condition an 21 'unstable' condition arises, with the steam not 22 fully condensing. This is referred to as a 23 partially dispersed condensation shock wave. This 24 results in the start of the formation of a 25 condensation shock wave (with a reasonably steep 26 pressure gradient), the condensation shock wave 27 formation 'stalling', and then restarting again. 28 However, it has been found that the final resulting 29 exit pressure is often higher than for either 30 Condition A or Condition B. 31 WO 2006/010949 PCT/GB2005/002999 40 1 There are several mechanisms for determining the 2 state of the flow regime in the fluid mover, and 3 using this information in a control system to 4 provide the flow regime that best meets the demands 5 of the application. For example one can measure the 6 temperature at a particular point along the length 7 of the mixing chamber, to determine the existence of 8 a vapour-droplet region. Such a method is non 9 intrusive since the mixer wall can be of thin 10 section allowing a rapid response to the change in 11 conditions. Multiple temperature probes spaced 12 downstream of one another can be used to monitor the 13 position of the condensation shock wave, as well as 14 to determine the state of the condensation shock 15 wave profile. 16 17 As a further example the use of pressure sensors 18 allows the condensation shock wave position to be 19 determined. 20 21 With reference to Figures 13 and 14 there is shown a 22 method of using a series of pressure sensors to 23 detect the position of the condensation shock wave 24 in the mixing chamber. When the condensation shock 25 wave 17 is in the position 17A indicated by Case 1, 26 i.e. in the convergent profile portion 3C of the 27 passage 3, the pressure profile is shown with the 28 reference numeral 101. When the condensation shock 29 wave 17 is in the position 17B indicated by Case 2, 30 i.e. in the uniform profile portion 3B of the 31 passage 3, the pressure profile is shown with the 32 reference numeral 102. Pressure sensors P1, P2 and WO 2006/010949 PCT/GB2005/002999 41 1 P3 in the passage 3 can be used to measure the 2 pressure at three points 103, 104, 105 along the 3 passage. The pressure measurements at these points 4 can be used to determine the position of the 5 condensation shock wave 17. Depending on the flow 6 profile required, one or more parameters, as 7 described hereinbefore, can be changed to alter the 8 flow profile and the position of the condensation 9 shock wave 17. 10 11 Figure 14a shows a typical pressure sensor, although 12 it is to be understood that this is not limiting, 13 and any suitable pressure sensor or measuring device 14 may be used. This method of measuring pressures in 15 the mixing chamber is especially suited for 16 condensation shock wave detection, since the 17 measurement technique only needs to measure a change 18 in pressure rather than being calibrated to measure 19 accurate values. 20 21 The mixing chamber 3A is sleeved with a thin walled 22 inner sleeve 107 of suitable material, such as 23 stainless steel. A thin layer of oil 108 fills the 24 gap between the sleeve 107 and the inner wall 106 of 25 the mixing chamber 3A. The pressure sensor P1 is 26 located through the wall 106 of the mixing chamber 27 and is in contact with the oil 108. When the 28 pressure inside the mixing chamber 3A changes, the 29 sleeve 107 expands or contracts a small amount, 30 thereby increasing or decreasing the pressure in the 31 oil 108, which is then detected by the pressure 32 sensor Pl.

WO 2006/010949 PCT/GB2005/002999 42 1 2 In the embodiment of Figure 14b the sleeve 107 is 3 segmented so that the oil is separated by walls 109 4 fixed to the sleeve. This results in separate 5 individual chambers of oil 108A, 108B, each with 6 their own pressure sensor P1, P2. A number of 7 separate chambers and pressure sensors may be 8 arranged along the wall 106 of the mixing chamber 9 3A. 10 11 The advantage of this instrumentation method is that 12 the sleeve 107 provides a clean inner bore, free of 13 any crevices or other features in which working '14 fluid or other transported material can become 15 trapped. This is of particular relevance for use in 16 the food industry. In addition, the pressure sensor 17 P1 is free from contamination, suffers no wear or 18 abrasion, and does not become blocked. 19 20 A further possible way of monitoring the 21 condensation shock wave is by the use of acoustic 22 signatures. Due to the density variation in the 23 mixer, even during powder addition, it is possible 24 to determine the 'state' of flow which is an 25 indication of vapour flow, and hence the condition 26 of having a condensation shock wave. The mechanisms 27 for determining the state of the flow regime in the 28 fluid mover may of course be combined. 29 30 Figure 11 shows an embodiment of the fluid mover 1 31 with various control means for controlling the 32 parameters of the flow. The inlet 4 is in fluid WO 2006/010949 PCT/GB2005/002999 43 1 communication with a working fluid valve 66 which 2 can be used to control the flow rate and/or inlet 3 pressure of the working fluid. A heating means or 4 cooling means (not shown) may be provided upstream 5 or downstream of the valve 66 to control the inlet 6 temperature of the working fluid. The outlet 5 is 7 in fluid communication with an optional working 8 fluid outlet valve 68 which can be used to control 9 the outlet pressure of the working fluid. 10 11 A transport fluid source 62, such as a steam 12 generator, is controllable to provide transport 13 fluid through the transport passage 64 to the plenum 14 8. The source 62 can be used to control the inlet 15 temperature and/or the flow rate and/or the inlet 16 pressure of the transport fluid. 17 18 The nozzle or nozzles 16 may be mounted for 19 adjustable movement such that a nozzle angle control 20 means (not shown) can be used to control the angle 21 of entry of the transport fluid to the passage. 22 23 The internal dimensions of the passage downstream of 24 the nozzle 16 can be adjusted by means of moveable 25 wall sections 60, which can alter the mixing chamber 26 wall profile between convergent, parallel and 27 divergent at a plurality of sections along the 28 mixing chamber 3A. 29 30 An additive fluid source 70 may be provided to add 31 one or more fluids to the working fluid. An 32 additive fluid valve 72 can be used to control the WO 2006/010949 PCT/GB2005/002999 44 1 flow rate of the additive fluid, including to switch 2 the flow on or off as appropriate. Separate heating 3 means may be provided for the additive fluid, which 4 may be a heated liquid, a gas such as steam or a 5 mixture. The additive may be a powder, and may be 6 introduced through a valve means from a secondary 7 hopper. 8 9 Control means such as a microprocessor may be 10 provided to control some or all of the parameters 11 described above as appropriate. The control means 12 can be linked to the condensation monitoring 13 devices, such as the pressure sensors P1, P2, P3 14 which monitor the condensation shock wave, or any 15 other sensor means eg temperature or acoustic 16 sensors. 17 18 The versatility of the fluid mover of the present 19 invention allows it to be applied in many different 20 applications over a wide range of operating 21 conditions. Two of these applications will now be 22 described, by way of example, to illustrate the 23 industrial applicability of the fluid mover of the 24 present invention. 25 26 The first of the applications is a method of 27 activating starch. The nature of the energy 28 transfer between the transport fluid and the working 29 fluid affords significant advantages for use in 30 starch activation. Due to the intimate mixing 31 between the hot transport fluid and the working 32 fluid, very high heat transfer rates between the WO 2006/010949 PCT/GB2005/002999 45 1 fluids are achieved resulting in rapid heating of 2 the working fluid. In addition, the high energy 3 intensity within the unit, especially the high 4 momentum transfer rates between the steam and 5 working fluid result in high shear forces on the 6 working fluid. It is therefore this combination of 7 heat and shear that result in enhanced starch 8 activation. 9 10 The fluid mover may be incorporated in either a 11 batch or a single pass fluid processing 12 configuration. One or more fluid movers may be used, 13 possibly mounted in series in a single pipeline 14 configuration. A single fluid mover may pump, heat, 15 mix, and activate the starch, or a separate pump may 16 be used to pass the working fluid through the fluid 17 mover. Alternatively, two or more fluid movers may 18 be used in series, each fluid mover may be 19 configured and optimized to carry out different 20 roles. For example, one fluid mover may be 21 configured to pump and mix (and do some initial 22 heating) and a second fluid mover mounted in series 23 down stream of the first, optimized to heat. 24 25 The energy intensity within the fluid mover is 26 controllable. By controlling the flow rates of the 27 steam and/or the working fluid, the intensity can be 28 reduced to allow slow heating of the working fluid, 29 and provide a much lower shear intensity. This could 30 be used, for example, to provide gentle heating of 31 the working fluid to maintain a batch of working WO 2006/010949 PCT/GB2005/002999 46 1 fluid at a constant temperature without causing any 2 shear thinning. 3 4 This method may also be employed for entraining, 5 mixing in, dispersing and dissolving other hard-to 6 wet powders commonly employed in the food industry, 7 such as pectins. Pectins are typically used to 8 thicken foods or form gells, and are activated by 9 heat. Some pectins form thermoreversible gels in the 10 presence of calcium ions whereas others rapidly form 11 thermally irreversible gels in the presence of 12 sufficient sugars. The intense mixing, agitation, 13 shear and heating afforded by the Fluid Mover 14 enhances these gelling processes. 15 16 By way of example only, a fluid mover has been used 17 to pump, mix, homogenise, heat (cook) and activate 18 the starch in the manufacture of a 65kg batch of 19 tomato based sauce. Conventional processing required 20 the sauce to be heated to 85 0 C to activate the 21 starch. It was found, using the fluid mover to mix, 22 heat and process the sauce, that the starch was 23 activated at the much lower batch temperature of 24 70 0 C. Combining this saving in heating requirement 25 with the highly efficient mixing and heating 26 afforded by the fluid mover, the overall process 27 time was reduced by up to 95% over the conventional 28 tank heating and stirring method. 29 30 It has also been found that the Fluid Mover 31 activates a higher percentage of the starch present 32 in the mix than conventional methods. It is not WO 2006/010949 PCT/GB2005/002999 47 1 uncommon with food mixes containing highly modified 2 starches for a large percentage (greater than 50%) 3 of the starch to sometimes remain inactivated. 4 Activating a higher percentage of the starch 5 provides an obvious commercial advantage of reducing 6 the amount of starch that has to be added to a mix 7 to achieve a target viscosity. A similar effect has 8 been observed with the (relatively) expensive 9 pectin. Reducing the amount of pectin that has to be 10 added to a mix provides a significant cost saving to 11 the process. 12 13 This method may alternatively be employed in the 14 brewing industry. The brewing process requires the 15 rapid mixing, heating and hydration of ground malt, 16 known as grist, and activation of the starch. It has 17 been found that this can be achieved using the 18 method described in this invention, with the 19 additional advantages of maintaining the integrity 20 of both the enzymes and the husks of the grist. 21 Maintaining integrity of the enzymes in the mix is 22 important as they are required to convert the starch 23 to sugar in a later process, and similarly, the 24 husks are required to be of a particular size to 25 form an effective filter cake in a later Lauter 26 filtration process. 27 28 The second application offered by way of example is 29 a method of enhancing bioethanol (biofuel) 30 production using the fluid mover of the present 31 invention. The nature of the energy transfer 32 between the steam and the working fluid affords WO 2006/010949 PCT/GB2005/002999 48 1 significant advantages for use in bioethanol 2 production. Due to the intimate mixing between the 3 hot transport fluid (steam) and the working fluid, 4 very high heat transfer rates between the fluids are 5 achieved resulting in rapid heating of the working 6 fluid. In addition, the high energy intensity within 7 the unit, especially the high momentum transfer 8 rates between the steam and working fluid result in 9 high shear forces on the working fluid. 10 11 Two or more fluid movers may be used in series, each 12 fluid mover may be configured and optimized to carry 13 out different roles. For example, one fluid mover 14 may be configured to pump and mix (and do some 15 initial heating) and a second fluid mover mounted in 16 series down stream of the first, optimized to heat 17 and macerate. 18 19 Utilising the method described in this invention, 20 the process of mixing, heating, hydrating and 21 macerating the carbohydrate polymers in the biomass 22 can be achieved more rapidly and efficiently than 23 conventional methods. Utilising the high shear and 24 the presence of shockwave allows the active chemical 25 or biological components to be intimately mixed with 26 the carbohydrate polymers more efficiently, 27 enhancing the contact through pulping of the plant 28 matter as it begins to breakdown. Although the 29 method described in this invention utilizes high 30 temperature and high shear, it is still suitable for 31 use in an Enzymatic Hydrolysis process without 32 damage to the enzymes.

WO 2006/010949 PCT/GB2005/002999 49 1 2 The shape of the fluid mover of the present 3 invention may be of any convenient form suitable for 4 the particular application. Thus the fluid mover of 5 the present invention may be circular, curvilinear 6 or rectilinear, to facilitate matching of the fluid 7 mover to the specific application or size scaling. 8 The enhancements of the present invention may be 9 applied to the fluid mover in any of these forms. 10 11 The fluid mover of the present invention thus has 12 wide applicability in industries of diverse 13 character ranging from the food industry at one end 14 of the chain to waste disposal at the other end. 15 16 The present invention when applied to the fluid 17 mover of the aforementioned patent affords 18 particularly enhanced emulsification and 19 homogenisation capability. Emulsification is also 20 possible with the deployment of the fluid mover of 21 the present invention on a once-through basis thus 22 obviating the need for multi-stage processing. In 23 this context also the mixing of different liquids 24 and/or solids is enhanced by virtue of the improved 25 shearing mechanism which affects the necessary 26 intimacy between the components being brought 27 together as exemplified heretofore. 28 29 The localised turbulence within the working fluid 30 dispersion region provides rapid mixing, dispersion 31 and homogenisation of a range of different fluids 32 and materials, for example powders and oils.

WO 2006/010949 PCT/GB2005/002999 50 1 2 The heating of fluids and/or solids can be effected 3 by the use of the present invention with the fluid 4 mover by virtue of the use of steam as the transport 5 fluid and of course in this respect the invention 6 has multi-capability in terms of being able to pump, 7 heat, mix and disintegrate etc. 8 9 The fluid mover of the present invention may be 10 utilised, for example, in the essence extraction 11 process such as decaffeination. In this example the 12 fluid mover may be utilised to pump, heat, entrain, 13 hydrate and intimately mix a wide range of aromatic 14 materials with a liquid, usually water. 15 16 The vapour-droplet flow region of the present 17 invention provides a particular advantage for the 18 hydration of powders. Even extremely hard-to-wet 19 hydrophilic powders, for example Guar gum, may be 20 entrained and dispersed into a fluid medium within 21 this vapour-droplet region. 22 23 As has been disclosed above, the fluid mover of the 24 present invention possesses a number of advantages 25 in its operational mode and in the various 26 applications to which it is relevant. For example 27 the 'straight-through' nature of the fluid mover 28 having a substantially constant cross section, with 29 the bore diameter never reducing to less than the 30 bore inlet, means that not only will fluids 31 containing solids be easily handled but also any 32 rogue material will be swept through the mover WO 2006/010949 PCT/GB2005/002999 51 1 without impedance. The fluid mover of the present 2 invention is tolerant of a wide range of particulate 3 sizes and is thus not limited as are conventional 4 ejectors by the restrictive nature of their physical 5 convergent sections. 6 7 Modifications and improvements may be incorporated 8 without departing from the scope of the invention as 9 defined in the appended claims.

Claims

1. A fluid mover comprising: a hollow body provided with a straight-through passage of substantially constant cross section with an inlet at 5 one end of the passage and an outlet at the other end of the passage for the entry and discharge respectively of a working fluid; a nozzle substantially circumscribing and opening into said passage intermediate the inlet and outlet ends 10 thereof; an inlet communicating with the nozzle for the introduction of a transport fluid; a controllable transport fluid source in fluid communication with the transport fluid inlet, wherein the 15 transport fluid source is adapted to control the pressure of the transport fluid at the inlet such that a momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70; a mixing chamber being formed within the passage 20 downstream of the nozzle; wherein the nozzle internal geometry and the bore profile of the passage immediately upstream of the nozzle exit are so disposed and configured to optimise the energy transfer between the transport fluid and working fluid that 25 in use through the introduction of transport fluid the working fluid or fluids are atomised to form a dispersed vapour/droplet flow regime with locally supersonic flow conditions within a pseudo-vena contracta, resulting in the creation of a supersonic condensation shock wave within the 30 downstream mixing chamber by the condensation of the transport fluid; and a microprocessor coupled to the transport fluid source and to at least one sensor that monitors one or more -53 properties of the mixed fluids within the downstream mixing chamber which relate to the resulting supersonic condensation shock wave, the microprocessor being adapted to allow the transport fluid source to control the pressure 5 of the transport fluid based on information measured through said at least one sensor.

2. A fluid mover according to claim 1, wherein the passage is a substantially circular passage and the nozzle is an annular nozzle substantially circumscribing the 10 passage.

3. A fluid mover according to either preceding claim, wherein the nozzle is of a convergent-divergent geometry internally thereof.

4. A fluid mover according to claim 1, wherein the nozzle 15 is configured to give the supersonic flow of transport fluid within the passage.

5. A fluid mover according to any one of the preceding claims, wherein an internal wall of the passage upstream of the mixing chamber is provided with at least one groove 20 that creates turbulence in the working fluid flow prior to any interaction between the working fluid and the transport fluid.

6. A method of moving a working fluid, the method comprising the steps of: 25 presenting a fluid mover to the working fluid, the mover having a straight-through passage of substantially constant cross section; applying a substantially circumscribing stream of a transport fluid to the passage through an annular nozzle; 30 controlling the pressure of the transport fluid through a controllable transport fluid source such that a -54 momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70; atomising the working fluid to form a dispersed vapour and droplet flow regime with locally supersonic flow 5 conditions; generating a supersonic condensation shock wave within the passage downstream of the nozzle by condensation of the transport fluid; inducing flow of the working fluid through the passage 10 from an inlet to an outlet thereof; modulating the condensation shock wave to vary the working fluid discharge from the outlet; and controlling the position of the condensation shock wave within the passage by varying the pressure of the 15 transport fluid through the controllable transport fluid source and varying a parameter selected from the group consisting of an inlet temperature of the transport fluid, an inlet pressure of the transport fluid, and a flow rate of the transport fluid, as well as varying a parameter 20 selected from the group consisting of an inlet temperature of the working fluid, a flow rate of the working fluid, an inlet pressure of the working fluid, an outlet pressure of the working fluid, properties of the working fluid resulting from the inclusion of an additive liquid, gas or 25 solid, a flow rate of a fluid additive added to the working fluid, an inlet pressure of a fluid additive added to the working fluid, an outlet pressure of a fluid additive added to the working fluid, and a temperature of a fluid additive added to the working fluid. 30

7. A method of claim 6, wherein the modulating step includes modulating the intensity of the condensation shock wave. -55

8. A method of claim 6 or claim 7, further comprising the step of introducing an instability in working fluid flow immediately upstream of the nozzle.

9. A method according to any of claims 6 to 8, wherein 5 the transport fluid is steam.

10. A method according to claim 9, wherein the momentum flux ratio (M) lies in the range 5 M 40.

11. A method of moving a working fluid, the method comprising the steps of: 10 presenting a fluid mover to the working fluid, the mover having a straight-through passage of substantially constant cross section; applying a substantially circumscribing stream of a transport fluid to the passage through an annular nozzle; 15 controlling the pressure of the transport fluid through a controllable transport fluid source such that a momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70; atomising the working fluid to form a dispersed vapour 20 and droplet flow regime with locally supersonic flow conditions; generating a supersonic condensation shock wave within the passage downstream of the nozzle by condensation of the transport fluid; 25 inducing flow of the working fluid through the passage from an inlet to an outlet thereof; monitoring through a microprocessor coupled to at least one sensor one or more properties of the mixed fluids within the passage downstream of the nozzle which relate to 30 the resulting supersonic condensation shock wave; -56 allowing the transport fluid source to control the pressure of the transport fluid based on information measured through said at least one sensor; and modulating the condensation shock wave to vary the 5 working fluid discharge from the outlet.

12. A fluid mover comprising: a hollow body provided with a straight-through passage of substantially constant cross section with an inlet at one end of the passage and an outlet at the other end of 10 the passage for the entry and discharge respectively of a working fluid; a nozzle substantially circumscribing and opening into said passage intermediate the inlet and outlet ends thereof; 15 an inlet communicating with the nozzle for the introduction of a transport fluid; a controllable transport fluid source in fluid communication with the transport fluid inlet, wherein the transport fluid source is adapted to control the pressure 20 of the transport fluid at the inlet such that a momentum flux ratio (M) between the transport fluid and working fluid lies in the range 2 M 70; and a mixing chamber being formed within the passage downstream of the nozzle; 25 wherein the nozzle internal geometry and the bore profile of the passage immediately upstream of the nozzle exit are so disposed and configured to optimise the energy transfer between the transport fluid and working fluid that in use through the introduction of transport fluid the 30 working fluid or fluids are atomised to form a dispersed vapour/droplet flow regime with locally supersonic flow conditions within a pseudo-vena contracta, resulting in the creation of a supersonic condensation shock wave within the -57 downstream mixing chamber by the condensation of the transport fluid; and wherein the position of the supersonic condensation shock wave is controlled by varying the pressure of the 5 transport fluid through the controllable transport fluid source, and varying a parameter selected from the group consisting of an inlet temperature of the transport fluid, an inlet pressure of the transport fluid, and a flow rate of the transport fluid, as well as varying a parameter 10 selected from the group consisting of an inlet temperature of the working fluid, a flow rate of the working fluid, an inlet pressure of the working fluid, an outlet pressure of the working fluid, properties of the working fluid resulting from the inclusion of an additive liquid, gas or 15 solid, a flow rate of a fluid additive added to the working fluid, an inlet pressure of a fluid additive added to the working fluid, an outlet pressure of a fluid additive added to the working fluid, and a temperature of a fluid additive added to the working fluid. 20

13. A fluid mover substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

14. A method of moving a working fluid, the method being substantially as herein described with reference to any one 25 of the embodiments of the invention illustrated in the accompanying drawings and/or examples.