Fluid flow transducer with support structure - Patents.com

Abstract

An apparatus (1) for converting rotation into a fluid flow and / or a fluid flow into rotation, the apparatus (1) comprising a coiled fluid conduit (3) having an inlet (11) and an outlet (13), a support structure (5) for holding the coiled fluid conduit (3) such that the inlet (11) is higher / lower than the outlet (13), a first fluid separator (15) configured to receive batches of a first fluid and batches of a second fluid output from the outlet (13) of the coiled fluid conduit (3) and separate the first and second fluids, and an intra-stage flow path (17) connecting the first fluid separator (15) to the inlet (11) of the coiled fluid conduit (3) such that the second fluid separated by the first fluid separator (15) is transported towards the inlet (11) of the coiled fluid conduit (3).

Description

[Technical field]

[0001] The present invention relates to a device for converting rotation into a fluid flow, and to a device for converting a fluid flow into rotation. [Background technology]

[0002] It has long been known to pump water or compress air using devices that alternate between air and water in a coiled pipe and rotate it around a rotating shaft. Such devices have few moving parts and are considered relatively simple and reliable.

[0003] For example, U.S. Patent No. 5,399,633 discloses a device for pumping a fluid, the device comprising a tube of constant cross section wound multiple times around a cylindrical structure to form a cylindrical coil. One end of the coiled tube is connected to a hollow shaft of the device, and the other end of the coiled tube terminates at the outer periphery of the cylindrical structure and is open to the atmosphere. When the cylindrical structure is rotated, water and air alternately enter the open end of the tube and are conveyed up the hollow shaft.

[0004] Patent document 2 discloses a more energy efficient device, in which, according to an embodiment, one coiled fluid conduit (a pressure increase fluid conduit) is used to achieve a gradual increase in pressure of the first and second fluids, and one coiled fluid conduit (a pressure decrease fluid conduit) is used to return the first and second fluids while achieving a gradual decrease in pressure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] UK Patent Application Publication No. 1427723 [Patent Document 2] International Publication No. 2016 / 080902

[0006] There still appears to be room for improvement. In particular, it would be desirable to provide more compact and / or energy efficient devices for converting rotation into fluid flow and / or converting fluid flow into rotation. Summary of the Invention [Problem to be solved by the invention]

[0007] In view of the above, it is an object of the present invention to provide improved conversion of rotation to fluid flow and / or improved conversion of fluid flow to rotation. [Means for solving the problem]

[0008] Thus, according to a first aspect of the present invention, there is provided an apparatus for converting rotation into fluid flow, comprising at least a first stage, the first stage including a coiled fluid conduit having an inlet for receiving a first fluid having a first density and a second fluid in liquid form having a second density higher than said first density, and an outlet, the coiled fluid conduit arranged to transport batches of said first fluid and batches of said second fluid towards said outlet of said coiled fluid conduit when said coiled fluid conduit is rotated about an axis of rotation, the first stage being arranged to pressurize said first fluid and said second fluid to provide a pressure differential between said outlet and said inlet; and a support structure for holding said coiled fluid conduit of said first stage, the support structure being held such that a vertical level of a centre of a circle formed by said inlets when said coiled fluid conduit is rotated about said axis of rotation is higher than a vertical level of a centre of a circle formed by said outlets when said coiled fluid conduit is rotated about said axis of rotation, the vertical offset distance being such that a vertical offset distance between said vertical outgoing and incoming fluids is greater than a vertical offset distance between said vertical outgoing and incoming fluids. and at least a first fluid separator configured to receive batches of the first fluid and batches of the second fluid from the outlet of the coiled fluid conduit of the first stage and separate the first and second fluids, the first stage further comprising an intra-stage flow path connecting the first fluid separator of the first stage and the inlet of the coiled fluid conduit of the first stage, the intra-stage flow path enabling the second fluid separated by the first fluid separator of the first stage to be transported towards the inlet of the coiled fluid conduit of the first stage by the pressure differential between the outlet and the inlet of the coiled fluid conduit of the first stage.

[0009] A fluid is any substance that flows. Fluids therefore include, for example, gases, liquids, and solid particles suspended in a liquid to form, for example, a particle suspension that exhibits fluid behavior. The first and second fluids may be mutually immiscible. For example, the first fluid is preferably a gas, such as air, and the second fluid is preferably a liquid, such as water.

[0010] The coiled fluid conduit does not necessarily have to be a coiled tube, but can be configured in many other ways, so long as the fluid path is coiled.

[0011] It should be noted that the inlet and / or outlet of the coiled fluid conduit may be located near or on the axis of rotation, such that the inlet / outlet of the coiled fluid conduit will rotate about a point that constitutes the center of a circle formed by the inlet / outlet of the coiled fluid conduit as the coiled fluid conduit rotates about the axis of rotation.

[0012] As the coiled fluid conduit is rotated about its axis of rotation against a pressure head, the combined center of mass of the first and second batches of fluid shifts along the coiled fluid conduit in response to the gradually increasing pressure in the coiled fluid conduit. The shifted combined center of mass in the coiled fluid conduit imparts a torque to the coiled fluid conduit. To maintain rotation, a torque of opposite sign must be applied to the coiled fluid conduit that is greater than or equal to the torque induced by the shift in center of mass.

[0013] In order to transport the first fluid from the inlet to the outlet of the coiled fluid conduit of the first stage while maintaining a closed circuit operation with respect to the second fluid, the inventors have realized that it is desirable to arrange the coiled fluid conduit such that there is a vertical offset distance between the inlet level and the outlet level. This allows the second fluid to flow back towards the inlet with substantially no resistance, converting the energy of the pressure difference between the outlet and the inlet into potential energy of the second fluid returned to the inlet. This improves energy efficiency. Furthermore, less tubing is required since the intrastage flow path can be made using significantly shorter fluid conduits compared to the device of US Pat. No. 5,999,336. In an embodiment, the intrastage flow path may be straight. By using less tubing for the return of the second fluid from the outlet to the inlet, the device can also be made significantly more compact for a given output, at least during transport to the installation site. The intrastage flow path of the first stage can directly or indirectly connect the first stage first fluid separator to the inlet of the coiled fluid conduit of the first stage, as long as the inlet is also configured to receive the first fluid. To receive the first fluid, the inlet of the coiled fluid conduit of the first stage may be arranged in direct contact with a source of the first fluid. In an example where the first fluid is air, the inlet of the coiled fluid conduit of the first stage may be in direct contact with the atmosphere during at least a first portion of the rotation of the coiled fluid conduit of the first stage about the axis of rotation of the device. The second fluid may be provided to the inlet of the coiled fluid conduit of the first stage substantially continuously or batchwise through the intra-stage flow passage of the first stage during a second portion different from the first portion of the rotation of the coiled fluid conduit of the first stage about the axis of rotation of the device. In another example, the inlet of the coiled fluid conduit of the first stage may receive the first and second fluids through a second fluid separator, which may be in fluid communication with the inlet of the coiled fluid conduit of the first stage, may be in fluid communication with the intra-stage flow passage, and may be in fluid communication with the device inlet for receiving the first fluid from the source of the first fluid.

[0014] For an optimum tradeoff between energy efficiency and device design considerations, it has been found to be beneficial to configure the support structure to hold the first stage coiled fluid conduit such that the axis of rotation is inclined at an angle in the range of 35° to 65° relative to the horizontal. In theory, a larger angle would provide greater energy efficiency, but the inventors have found that it is difficult to reliably form and maintain the batches of first and second fluids required to build up pressure along the coiled fluid conduit at angles greater than about 65°.

[0015] It should be noted that embodiments of the apparatus according to aspects of the invention provide selective return of the second fluid from the outlet of the coiled fluid conduit of an apparatus stage (first stage, second stage, etc.) towards the inlet of the coiled fluid conduit of the apparatus stage. In other words, substantially only the second fluid is returned from the outlet to the inlet of the coiled fluid conduit of the first stage. Selective return should be understood to mean that the return of the second fluid is prioritized over the return of the first fluid. For example, at least 80% of the total return volume may be made up of the second fluid. Advantageously, the volumetric proportion may be greater than 90%.

[0016] According to various embodiments of the first aspect of the invention, an apparatus includes a second stage, a coiled fluid conduit having an inlet for receiving a first fluid and a second fluid and an outlet, the coiled fluid conduit being arranged to pressurize the first fluid and the second fluid to transport batches of the first fluid and batches of the second fluid toward the outlet of the coiled fluid conduit of the second stage as the coiled fluid conduit of the second stage rotates about the axis of rotation; a first fluid separator of the second stage configured to receive batches of the first fluid and batches of the second fluid from the outlet of the coiled fluid conduit of the second stage and separate the first fluid and the second fluid; an intra-stage flow path of the second stage, the first fluid separator configured to receive batches of the first fluid and batches of the second fluid from the outlet of the coiled fluid conduit of the second stage and separate the first fluid and the second fluid; and an intra-stage flow path of the second stage connecting the first fluid separator of the first stage to the inlet of the coiled fluid conduit of the second stage and allowing the second fluid separated by the first fluid separator of the second stage to be transported towards the inlet of the coiled fluid conduit of the second stage by a pressure differential between the outlet and the inlet of the coiled fluid conduit of the second stage; and a first inter-stage flow path connecting the first fluid separator of the first stage to the inlet of the coiled fluid conduit of the second stage for selectively supplying a first fluid from the outlet of the coiled fluid conduit of the first stage to the inlet of the coiled fluid conduit of the second stage and allowing the first fluid to be brought to a higher pressure by the second stage of the apparatus.

[0017] According to a second aspect of the present invention, there is provided an apparatus for converting a fluid flow into rotation about an axis of rotation, the apparatus comprising: an apparatus inlet for receiving a pressurized first fluid in gaseous form having a first density; an apparatus outlet for discharging a depressurized first fluid from said apparatus; at least a first stage, the coiled fluid conduit adapted to depressurize said first and second fluids as said coiled fluid conduit rotates about said axis of rotation to transport alternately batches of said first fluid and batches of a second fluid in liquid form having a second density higher than the first density from said inlet in fluid communication with said apparatus inlet to an outlet while providing a pressure differential between said outlet and said inlet of said coiled fluid conduit of said first stage; and a support structure for holding said coiled fluid conduit of said first stage, the support structure being adapted to hold said coiled fluid conduit of said first stage such that a vertical level of a centre of a circle formed by said inlets when said coiled fluid conduit is rotated about said axis of rotation is greater than or equal to a vertical level of a centre of a circle formed by said inlets when said coiled fluid conduit is rotated about said axis of rotation. and a support structure, the support structure being maintained such that a vertical level of a center of a circle formed by the outlets when the support structure is rotated about an axis of rotation of the coiled fluid conduit in such a way that a vertical offset distance is selected such that a pressure exerted by a fluid column of the second fluid having a height equal to the vertical offset distance substantially matches a pressure difference between the outlet and the inlet of the coiled fluid conduit of the first stage; and at least a first fluid separator of the first stage configured to receive batches of the first fluid and batches of the second fluid output from the outlet of the coiled fluid conduit of the first stage and to separate the first fluid and the second fluid, the first stage comprising an intra-stage flow path connecting the first fluid separator of the first stage and the inlet of the coiled fluid conduit of the first stage, the intra-stage flow path enabling the second fluid separated by the first fluid separator of the first stage to be transported towards the inlet of the coiled fluid conduit of the first stage.

[0018] According to various embodiments of the second aspect of the invention, the apparatus may further comprise: a second stage including a second stage coiled fluid conduit for reducing pressure of the first and second fluids to accommodate alternate transport of batches of the first fluid and batches of the second fluid from the inlet to the outlet as the coiled fluid conduit rotates about the axis of rotation; and a first inter-stage flow path connecting the first fluid separator and the inlet of the coiled fluid conduit (7) of the second stage for supplying the first fluid to the inlet (31) of the coiled fluid conduit (7) of the second stage.

[0019] It should be noted that the device for converting rotation to fluid flow according to the first aspect of the invention and the device for converting fluid flow to rotation can be realized using the same structure. For example, the device may have two modes of operation: converting rotation to fluid flow and converting fluid flow to rotation. In this case, the direction of rotation in the second mode will be opposite to the direction of rotation in the first mode, the outlet in the first mode will be the inlet in the second mode, etc. Furthermore, in a multi-stage device, the first stage in the first mode will be the last stage in the second mode, the second stage in the first mode will be the penultimate stage in the second mode, etc.

[0020] In summary, according to various embodiments, the present invention relates to an apparatus for converting rotation into fluid flow and / or fluid flow into rotation, the apparatus comprising a coiled fluid conduit having an inlet and an outlet, a support structure for holding the coiled fluid conduit such that the inlet is higher than the outlet, a first fluid separator configured to receive a batch of a first fluid and a batch of a second fluid output from the outlet of the coiled fluid conduit and separate the first and second fluids, and an intra-stage flow path connecting the first fluid separator to the inlet of the coiled fluid conduit such that the second fluid separated by the first fluid separator is transported towards the inlet of the coiled fluid conduit.

[0021] These and other aspects of the invention will now be described in more detail with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a schematic perspective view of an apparatus according to an exemplary embodiment of the invention in the form of a multi-stage apparatus having two modes of operation, namely, a mode in which the apparatus converts rotation into fluid flow, and a mode in which the apparatus converts fluid flow into rotation. [Diagram 2] FIG. 2 is a simplified, partially disclosed schematic diagram of the apparatus of FIG. 1 when in operation to convert rotation into fluid flow. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS In this detailed description, various embodiments of the apparatus and methods according to the present invention will be described primarily with reference to apparatus for converting rotation to fluid flow and / or fluid flow to rotation using air as a first fluid and water as a second fluid.

[0024] It should be noted that this is not intended to limit the scope of the invention, which similarly includes devices that operate using other combinations of first and second fluids, for example having different densities, and operation with more than two different fluids is also envisaged.

[0025] Further, an example of a multi-stage device is described herein, it being understood that the appended claims also cover a single stage device having an intra-stage flow path that allows a second fluid output through an outlet of the coiled fluid conduit to be returned to an inlet of the coiled fluid conduit.

[0026] 1 illustrates generally an apparatus according to an exemplary embodiment of the present invention in the form of a compressor / air motor 1. Compressor / air motor 1 is a device capable of operating in two modes of operation: a first mode in which rotation is converted into fluid (air) flow, and a second mode in which pressurized fluid (air) flow is converted into rotation.

[0027] The first operating mode mentioned above is described in detail herein. The second operating mode mentioned above involves operating the device "in reverse" compared to the first operating mode, i.e. the "inlet" in the first mode becomes the "outlet" in the second mode and vice versa. This also means that an electric motor (not shown in FIG. 1 ) arranged to rotate the device 2 in the first operating mode may act as a generator in the second operating mode, converting the rotation into electrical power.

[0028] The compressor / air motor 1 comprises at least a first stage including a coiled fluid conduit 3 of the first stage, and a support structure 5 that holds the coiled fluid conduit 3 of the first stage (in a first mode of operation "compressor mode") such that the inlet of the coiled fluid conduit 3 of the first stage is higher than the outlet of the coiled fluid conduit 3 of the first stage. As noted above, the compressor / air motor 1 of Figure 1 is a multi-stage device and is shown diagrammatically as further having a second stage including a coiled fluid conduit 7 of the second stage, and a third stage including a coiled fluid conduit 9 of the third stage. In the second mode of operation ("air motor mode"), the first stage includes the coiled fluid conduit 9 that was in the third stage in the first mode of operation, the second stage includes the coiled fluid conduit 7 that was in the second stage in the first mode of operation, and the third stage includes the coiled fluid conduit 3 that was in the first stage in the first mode of operation. As shown diagrammatically in Figure 1, each stage may in embodiments actually comprise a plurality of coiled fluid conduits each having an inlet and an outlet that are angularly spaced from one another. This configuration provides a more uniform flow of the first and second fluids in time.

[0029] FIG. 2 is a simplified, partially disclosed schematic diagram of the device 1 of FIG. 1 in operation to convert rotation into a fluid flow, in this example used as a compressor.

[0030] As discussed above in relation to Figure 1, the first stage of the apparatus 1, when operating in a first mode of operation, comprises a first stage coiled fluid conduit 3 (only one first stage coiled fluid conduit 3 is shown in Figure 2). The first stage coiled fluid conduit 3 has an inlet 11 and an outlet 13, and the apparatus 1 comprises a first stage first fluid separator 15 in fluid communication with the outlet 13, and an intra-stage flow passage 17 connecting the first fluid separator 15 with the inlet 11 of the first stage coiled fluid conduit 3. In the exemplary configuration of Figure 2, the intra-stage flow passage 17 extends within the first coil formed by the first stage coiled fluid conduit 3, thereby making the apparatus 1 compact.

[0031] 2, the apparatus further includes a first stage second fluid separator 19 in fluid communication with the inlet 11 of the first stage coiled fluid conduit 3, in fluid communication with the outlet of the first stage intra-stage flow passage 17, and in fluid communication with an apparatus inlet 21 for receiving air from the atmosphere. The inclusion of the second fluid separator 19 may be beneficial in certain applications and may facilitate the design of a relatively compact apparatus 1. However, it should be noted that it is also possible to design the apparatus 1 to function without the second fluid separator 19. As an alternative to the second fluid separator 19, the intra-stage flow passage 17 may be directly connected to the first stage coiled fluid conduit 3 at its inlet 11 or through a dedicated opening in the first stage coiled fluid conduit 3 downstream of the inlet 11.

[0032] Furthermore, the device inlet 21 does not necessarily have to be a separate dedicated inlet, but may be constituted by the inlet 11 of the first stage coiled fluid conduit 3 .

[0033] As can be easily understood, each turn / coil of the first stage fluid conduit 3 (as well as the second stage fluid conduit 7 and the third stage fluid conduit 9) is partially filled with a first fluid (air) in gaseous form and partially filled with a second fluid (water) in liquid form. In particular, the lower portion of each turn / coil is filled with the second fluid (water). When the device 1 is in operation, a batch of the first fluid (air) and a batch of the second fluid (water) are transported towards the outlet 13 of the first stage coiled fluid conduit 3, pressurizing the first fluid (air) and the second fluid (water), providing a pressure difference ΔP between the outlet 13 and the inlet 11 of the first stage coiled fluid conduit 3. As described in detail in WO2016 / 080902, the entirety of which is incorporated herein by reference, rotation of the first stage coiled fluid conduit 3 about the axis of rotation 23 offsets the vertical position of the second fluid (water) at each turn / coil due to pressure build-up in the first stage fluid conduit 3.

[0034] The support structure 5 (omitted in FIG. 2 for clarity) holds the first stage coiled fluid conduit 3 such that a first vertical level h1 of a center 25 of a circle formed by the inlets 11 when the coiled fluid conduit 3 is rotated about the axis of rotation 23 is higher than a second vertical level h2 of a center 27 of a circle formed by the outlets 13 when the coiled fluid conduit 3 is rotated about the axis of rotation 23. The difference between the first vertical level h1 and the second vertical level h2 (the vertical offset distance Δh) is selected to be of a magnitude such that a pressure exerted by a fluid column of a second fluid (water in the exemplary case of FIG. 2) having a height equal to the vertical offset distance Δh substantially matches a pressure difference ΔP between the outlets 13 and the inlets 11 of the first stage coiled fluid conduit 3. It should be noted that the height of the fluid column of the second fluid actually present in the intra-stage flow passage 17 need not be equal to the vertical offset distance Δh, but may deviate somewhat from the vertical offset distance Δh, depending on the exact configuration of the apparatus 1 and / or the properties (e.g., density) of the first and second fluids used in the apparatus 1. For example, in the exemplary configuration of the apparatus 1 of FIG. 2, it can be seen that the level of the second fluid in the first fluid separator 15 does not exactly coincide with the aforementioned center 27 of the circle formed by the outlets 13 when the coiled fluid conduit 3 is rotated about the axis of rotation 23. It can also be seen that the level of the second fluid in the second fluid separator 19 of the first stage does not exactly coincide with the aforementioned center 25 of the circle formed by the inlets 11 when the coiled fluid conduit 3 is rotated about the axis of rotation 23. In the exemplary configuration of the apparatus 1 of Figure 2, the height of the fluid column of the second fluid actually present in the intra-stage flow passage 17 is determined by the difference in height between the level of the second fluid in the second fluid separator 19 and the level of the second fluid in the first fluid separator 15, which will differ somewhat from the vertical offset distance Δh mentioned above. The difference between the actual fluid column height and the vertical offset distance Δh depends on a variety of factors, including the ratio of the first and second fluids that are set to be fed in batches to the inlet 11 of the coiled fluid conduit 3 of the first stage, and the inclination of the axis of rotation 23. This difference is expected to be on the order of ±10% at most.It is therefore believed that the vertical offset distance Δh is selected so that the pressure exerted by a fluid column of the second fluid having a height equal to the vertical offset distance Δh substantially matches the pressure difference between the outlet 13 and inlet 11 of the first stage coiled fluid conduit 3, i.e. has a magnitude within ±10%.

[0035] The pressure difference ΔP transports the second fluid (in this case water) separated by the first fluid separator 15 of the first stage through the intra-stage passage 17 of the first stage towards the inlet 11 of the coiled fluid conduit 3 of the first stage with almost no flow resistance. During passage through the intra-stage passage 17, the second fluid (water) is decompressed and the energy of the pressure difference ΔP is converted into an increase in potential energy substantially proportional to the vertical offset distance Δh (e.g., within ±10% as explained above). This configuration improves the energy efficiency of the closed-loop return of the second fluid (water) within the first stage of the apparatus 1. Although the closed-loop return of the second fluid (water) has been described in detail only for the first stage of the apparatus 1, it will be apparent to one skilled in the art that the same principles also apply to the closed-loop return of the second fluid (water) in additional stages (in the case of a multi-stage apparatus) of the apparatus 1.

[0036] In this context, it should be mentioned that the fluid column and the pressure difference ΔP of the second fluid in the device 1 do not need to be precisely adjusted to each other to achieve improved energy efficiency with respect to prior art solutions. For example, the pressure difference ΔP may exceed the counter pressure of the fluid column in the intra-stage flow passage 17, so that a residual overpressure exists at the outlet of the intra-stage flow passage 17 (e.g., where the intra-stage flow passage 17 enters the second fluid separator 19). Alternatively, the pressure difference ΔP may be insufficient to independently transport the second fluid (water) from the first fluid separator 15 to the inlet 11 of the coiled fluid conduit 3 of the first stage. In that case, the device 1 may be provided with an auxiliary flow passage device, such as a small impeller.

[0037] 2, the rotating shaft 23 is shown inside the first stage coiled fluid conduit 3, with the first stage coiled fluid conduit 3 coiled around the rotating shaft 23. This may make the device 1 simpler and more compact, although it should be noted that the device 1 will also work if the rotating shaft 23 is outside the coiled fluid conduit 3.

[0038] In an embodiment of a multi-stage apparatus, such as apparatus 1 of Figure 2, the apparatus may advantageously comprise a second stage including the above-mentioned coiled fluid conduit 7 of the second stage (only one coiled fluid conduit 7 of the second stage is shown in Figure 2). With reference to Figure 2, this coiled fluid conduit 7 of the second stage has an inlet 29 for receiving a first fluid (air) and a second fluid (water), and an outlet 31. As described above with reference to the coiled fluid conduit 3 of the first stage, the coiled fluid conduit 7 of the second stage is arranged to transport batches of the first fluid (air) and batches of the second fluid (water) towards the outlet 31 while pressurizing the first fluid (air) and the second fluid (water).

[0039] As seen in FIG. 2, the multi-stage apparatus 1 further includes a second stage first fluid separator 28, a second stage intra-stage flow path 30, and a first inter-stage flow path 33 connecting the first stage first fluid separator 15 with the inlet 29 of the second stage coiled fluid conduit 7 to supply pressurized first fluid (air) to the inlet 29 of the second stage coiled fluid conduit 7. In the example configuration of FIG. 2, as described above for the first stage, the apparatus may further include a second stage second fluid separator 32 in fluid communication with the inlet 29 of the second stage coiled fluid conduit 7, the outlet of the second stage intra-stage flow path 30, and the outlet of the first inter-stage flow path 33. As described above in connection with the description of the first stage, the inclusion of the second stage second fluid separator 32 may be beneficial in certain applications and may facilitate the design of a relatively compact apparatus 1. However, it should be noted that it is also possible to design the apparatus 1 to function without the second stage second fluid separator 32.

[0040] When the device 1 operates in the first operating mode, the first interstage flow path 33 selectively supplies pressurized first fluid (air) from the outlet 13 of the first stage coiled fluid conduit 3 to the inlet 29 of the second stage coiled fluid conduit 7 without further pressure increase.

[0041] In the exemplary arrangement shown in Figure 2, the apparatus 1 comprises a third stage including a third stage coiled fluid conduit 9 as described above (only one third stage coiled fluid conduit 9 is shown in Figure 2). With reference to Figure 2, the third stage coiled fluid conduit 9 has an inlet 35 for receiving a first fluid (air) and a second fluid (water), and an outlet 37. As described above with reference to the first stage coiled fluid conduit 3, the third stage coiled fluid conduit 9 is arranged to transport batches of the first fluid (air) and batches of the second fluid (water) towards the outlet 37 whilst pressurising the first fluid (air) and the second fluid (water).

[0042] As seen in FIG. 2, the multi-stage apparatus 1 further comprises a third stage first fluid separator 39 for supplying pressurized first fluid (air) to the inlet 35 of the third stage coiled fluid conduit 9, a third stage intra-stage flow path 41, and a second inter-stage flow path 43 connecting the second stage first fluid separator 28 to the third stage coiled fluid conduit 9 inlet 35. In the example configuration of FIG. 2, as described above for the first stage, the apparatus may further comprise a third stage second fluid separator 45 in fluid communication with the inlet 35 of the third stage coiled fluid conduit 9, the outlet of the third stage intra-stage flow path 41, and the outlet of the second inter-stage flow path 43. As described above in connection with the description of the first stage, the provision of the third stage second fluid separator 45 may be beneficial in certain applications and may facilitate the design of a relatively compact apparatus 1. However, it should be noted that it is possible to design an apparatus that functions without the third stage second fluid separator 45.

[0043] When the apparatus 1 operates in the first operating mode, the second interstage flow path 43 selectively supplies pressurized first fluid (air) from the outlet 31 of the coiled fluid conduit 7 of the second stage to the inlet 35 of the coiled fluid conduit 9 of the third stage without any further pressure increase.

[0044] Following the pressure increase provided by the third stage coiled fluid conduit 9, as described above for the first stage coiled fluid conduit 3, the pressurized first fluid becomes available at the device outlet 47 via the fluid flow in conduit 49 connecting the third stage first fluid separator 39 and the device outlet 47.

[0045] Thus, through the provision of interstage flow paths, by selectively supplying a pressurized first fluid (air) from the outlet of the coiled fluid conduit of one stage to the inlet of the coiled fluid conduit of the next stage without further pressure increase, the coiled fluid conduits of different stages of the device can be substantially completely overlapped, as shown diagrammatically in Figures 1 and 2. This allows a more compact multi-stage device to be achieved than that described in US Patent No. 5,999,336.

[0046] In FIG. 2, the intrastage and interstage flow paths are illustrated as straight pipes extending parallel to the axis of rotation 23 of the device 1 along substantially the entire length of the intrastage and interstage flow paths inside the first coil formed by the coiled fluid conduits 3 of the first stage. It should be noted that the intrastage and interstage flow paths may be provided in different configurations. For example, all or a portion of the intrastage and interstage flow paths may extend partly inside and partly outside the first coil, such as inside the first coil for a first portion of the entire distance along the intrastage or interstage flow path and outside the first coil for a second portion of the entire distance. For example, the first interstage flow path may extend at least partly inside and partly outside the first coil. This configuration may facilitate the manufacture and maintenance of the device 1 according to some configurations. Additionally, at least a portion of the intrastage and / or interstage flow paths may be coaxial with the axis of rotation 23 along at least a portion of the total length of the intrastage or interstage flow path. This configuration makes it possible to provide a more compact device 1, especially with regard to the dimensions perpendicular to the axis of rotation 23.

[0047] In the case of a multi-stage device, as shown diagrammatically for the device illustrated in Figures 1 and 2, the coiled fluid conduit 7 of the second stage may be radially inward of the coiled fluid conduit 3 of the first stage, the coiled fluid conduit 9 of the third stage may be radially inward of the coiled fluid conduit 7 of the second stage, and so on. This may facilitate easier manufacture of the device since the large volume of air in the first stage will benefit from the coiled fluid conduit 3 having a larger internal cross section.

[0048] As also shown diagrammatically in Figures 1 and 2, the distance along axis of rotation 23 between inlet 11 and outlet 13 of coiled fluid conduit 3 of the first stage may be less than the distance along axis of rotation 23 between inlet 29 and outlet 31 of coiled fluid conduit 7 of the second stage, which may be less than the distance along axis of rotation 23 between inlet 35 and outlet 37 of coiled fluid conduit 9 of the third stage, and so on. This is particularly advantageous in embodiments where the first fluid is a compressible gas, such as air in the apparatus 1 of Figures 1 and 2.

[0049] As another approach to optimizing the apparatus of Figures 1 and 2 for use with a compressible gas, such as air, as the first fluid, the fluid separator(s) associated with the first stage may have a larger volume than the fluid separator(s) associated with the second stage, which may have a larger volume than the fluid separator(s) associated with the third stage, and similarly for the other stages.

[0050] When operating in the second operating mode ("air motor" mode), pressurized air (or other suitable gas) is supplied to the device inlet of device 1. As explained at the beginning of this detailed description, the device operates "in reverse", so that the device inlet in the second mode corresponds to the device outlet 47 in the first mode, and so on.

[0051] Those skilled in the art will appreciate that the present invention is not limited to the preferred embodiments described above, but rather many modifications and variations are possible within the scope of the appended claims.

[0052] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope.

Claims

1. A device (1) for converting rotation into fluid flow, The first stage includes at least a first stage, which comprises a coiled fluid conduit (3) having an inlet (11) and an outlet (13) for receiving a first fluid in gaseous form having a first density and a second fluid in liquid form having a second density higher than the first density, wherein the coiled fluid conduit (3) is arranged to transport batches of the first fluid and batches of the second fluid toward the outlet (13) of the coiled fluid conduit (3) when the coiled fluid conduit (3) is rotated about a pivot axis (23), and is arranged to pressurize the first and second fluids to create a pressure difference between the outlet (13) and the inlet (11); A support structure (5) for holding the first stage coiled fluid conduit (3), wherein the coiled fluid conduit (3) is held such that the vertical level (h1) of the center (25) of the circle formed by the inlet (11) when the coiled fluid conduit (3) is rotated about the rotation axis (23) is higher than the vertical level (h2) of the center (27) of the circle formed by the outlet (13) when the coiled fluid conduit (3) is rotated about the rotation axis (23), and the vertical offset distance (Δh) is selected such that the pressure exerted by the fluid column of the second fluid having a height equal to the vertical offset distance (Δh) substantially matches the pressure difference between the outlet (13) and the inlet (11) of the first stage coiled fluid conduit (3); The first stage first fluid separator (15) is configured to receive a batch of the first fluid and a batch of the second fluid from the outlet (13) of the coiled fluid conduit (3) of the first stage, and to separate the first fluid and the second fluid, The first stage further comprises an internal stage channel (17) connecting the first fluid separator (15) of the first stage and the inlet (11) of the coiled fluid conduit (3) of the first stage, which enables the second fluid separated by the first fluid separator (15) of the first stage to be transported toward the inlet (11) of the coiled fluid conduit (3) of the first stage by the pressure difference between the outlet (13) and the inlet (11) of the coiled fluid conduit (3) of the first stage. Device (1).

2. The apparatus (1) according to claim 1, wherein the first stage coiled fluid conduit (3) is wound around the rotating shaft (23).

3. The apparatus (1) according to claim 1 or 2, wherein the internal flow path (17) of the first stage extends within the first coil formed by the coil-shaped fluid conduit (3) of the first stage.

4. This is the second stage, A coiled fluid conduit (7) having an inlet (29) and an outlet (31) for receiving a first fluid and a second fluid, wherein the coiled fluid conduit (7) is arranged to pressurize the first fluid and the second fluid and transport batches of the first fluid and batches of the second fluid toward the outlet (31) of the coiled fluid conduit (7) when it rotates about the rotation axis (23); The second stage first fluid separator is configured to receive batches of the first fluid and batches of the second fluid from the outlet (31) of the second stage coiled fluid conduit (7) and to separate the first fluid and the second fluid; The second stage internal flow path connects the second stage first fluid separator and the second stage coiled fluid conduit (7) inlet (29), and allows the second fluid separated by the second stage first fluid separator to be transported toward the inlet (29) of the second stage coiled fluid conduit (7) by the pressure difference between the outlet (31) and the inlet (29) of the second stage coiled fluid conduit (7); The second paragraph includes; The first interstage flow path (33) further comprises a first interstage flow path (33) that connects the first fluid separator (15) of the first stage and the inlet (29) of the second stage coiled fluid conduit (7) in order to supply the first fluid to the inlet (29) of the second stage coiled fluid conduit (7). The apparatus (1) according to claim 1 or 2.

5. The apparatus (1) according to claim 4, wherein the first interstage flow path (33) is configured to supply the first fluid to the inlet (29) of the second stage coiled fluid conduit (7) without pressurizing the first fluid.

6. The apparatus (1) according to claim 4, wherein the interstage flow path (33) and the in-stage flow path (17) of the first stage are coaxial with respect to the rotation axis (23) along at least a portion of the total length of the in-stage flow path (17) of the first stage.

7. The apparatus (1) according to claim 4, wherein the second stage coiled fluid conduit (7) is located radially inward of the first coil formed by the first stage coiled fluid conduit (3) with respect to the rotating shaft (23).

8. The third section, A coiled fluid conduit (9) having an inlet (35) and an outlet (37) for receiving a first fluid and a second fluid, wherein the coiled fluid conduit (9) is arranged to pressurize the first fluid and the second fluid and transport batches of the first fluid and batches of the second fluid toward the outlet (37) of the coiled fluid conduit (9) when the coiled fluid conduit (9) rotates about the rotation axis (23); The third stage first fluid separator (39) is configured to receive batches of the first fluid and batches of the second fluid from the outlet (37) of the second stage coiled fluid conduit (9) and to separate the first fluid and the second fluid; A third stage internal flow path, which connects the first fluid separator (39) of the third stage to the inlet (35) of the coiled fluid conduit (9) of the third stage, and which allows the second fluid separated by the first fluid separator of the third stage to be transported toward the inlet (35) of the coiled fluid conduit (9) of the third stage by the pressure difference between the outlet (37) and the inlet (35) of the coiled fluid conduit (9) of the third stage; The third paragraph includes; The second interstage flow path (43) further comprises a second interstage flow path (43) that connects the first fluid separator (28) of the second stage and the inlet (35) of the coiled fluid conduit (9) of the third stage in order to supply the first fluid to the inlet (35) of the coiled fluid conduit (9) of the third stage, Each of the first stage coiled fluid conduit (3), the second stage coiled fluid conduit (7), and the third stage coiled fluid conduit (9) is wound around the rotating shaft (23); The second interstage flow path (43) extends, at least partially, into the first coil formed by the first stage coil-shaped fluid conduit (3). The apparatus (1) according to claim 4.

9. The apparatus (1) according to claim 1 or 2, wherein the support structure (5) holds the first stage coiled fluid conduit (3) such that the rotation axis (23) is inclined with respect to the horizontal plane by an angle within the range of 35° to 65°.

10. It has multiple shelves ranging from 4 to 7 tiers, Each section is A coiled fluid conduit having an inlet and an outlet for receiving a first fluid and a second fluid, wherein the coiled fluid conduit is arranged to pressurize the first fluid and the second fluid as it rotates around a rotation axis, and to transport batches of the first fluid and batches of the second fluid toward the outlet of the coiled fluid conduit; A first fluid separator configured to receive batches of the first fluid and batches of the second fluid from the outlet of the coiled fluid conduit, and to separate the first fluid and the second fluid; A stepped fluid channel, which connects the first fluid separator and the inlet of the coiled fluid conduit, and which allows the second fluid separated by the first fluid separator to be transported toward the inlet of the coiled fluid conduit by the pressure difference between the outlet and the inlet of the coiled fluid conduit; Includes, The interstage flow path connects the first fluid separator of each stage, which has a subsequent stage for compressing the first fluid to a higher pressure, to the inlet of the coiled fluid conduit of the subsequent stage for supplying the first fluid to the inlet of the coiled fluid conduit of the second stage; Each of the coiled fluid conduits in each stage is wound around the rotating shaft; The axis of rotation is tilted with respect to the horizontal plane by an angle within the range of 35° to 65°. The apparatus (1) according to claim 1 or 2.

11. A device (1) for converting a fluid flow into rotation around a rotation axis (23), An inlet for receiving a pressurized first fluid in gaseous form having a first density; A device outlet (21) for discharging the first fluid, which has been depressurized from the device (1); At least a first stage, comprising a coiled fluid conduit (9) adapted for alternately transporting a batch of a first fluid and a batch of a liquid second fluid having a second density, from the inlet of the coiled fluid conduit (9) of the first stage, which is in fluid communication with the inlet of the device, toward the outlet of the coiled fluid conduit (9) of the first stage, while depressurizing the first and second fluids and creating a pressure difference between the outlet and inlet of the coiled fluid conduit (9) of the first stage; A support structure (5) for holding the first stage coiled fluid conduit (9), wherein the coiled fluid conduit (9) is held such that the vertical level of the center of the circle formed by the inlet when the coiled fluid conduit (9) is rotated around the rotation axis (23) is lower than the vertical level of the center of the circle formed by the outlet when the coiled fluid conduit (9) is rotated around the rotation axis (23), and the vertical offset distance is selected such that the pressure exerted by the fluid column of the second fluid having a height equal to the vertical offset distance substantially matches the pressure difference between the outlet and the inlet of the first stage coiled fluid conduit (9). Support structure (5) and; The first stage first fluid separator is configured to receive a batch of the first fluid and a batch of the second fluid from the outlet of the coiled fluid conduit (9) of the first stage, and to separate the first fluid and the second fluid, The first stage further comprises an internal stage channel of the first stage connecting the first fluid separator of the first stage to the inlet of the coiled fluid conduit of the first stage, the internal stage channel enabling the second fluid separated by the first fluid separator of the first stage to be transported toward the inlet of the coiled fluid conduit (9) of the first stage. Device (1).

12. The apparatus (1) according to claim 11, wherein the first stage coiled fluid conduit is wound around the rotating shaft (23).

13. The apparatus (1) according to claim 11 or 12, wherein the internal flow path of the first stage extends into the first coil formed by the coil-shaped fluid conduit (9) of the first stage.

14. A second stage, comprising a coiled fluid conduit (7) adapted to alternately transport batches of the first fluid and batches of the second fluid from the inlet to the outlet of the coiled fluid conduit (7) of the second stage, by depressurizing the first and second fluids as the coiled fluid conduit (7) of the second stage rotates about the rotation axis (23); The first fluid separator of the second stage is configured to receive batches of the first fluid and batches of the second fluid from the outlet (29) of the coiled fluid conduit (7) of the second stage, and to separate the first fluid and the second fluid; The second stage internal flow path, which connects the first fluid separator of the second stage to the inlet (31) of the coiled fluid conduit (7) of the second stage, and which allows the second fluid separated by the first fluid separator of the second stage to be transported toward the inlet (31) of the coiled fluid conduit (7) of the second stage; A first interstage flow path further comprising a first interstage flow path that connects the first fluid separator of the first stage and the inlet of the coiled fluid conduit (7) of the second stage in order to supply a first fluid to the inlet (31) of the coiled fluid conduit (7) of the second stage, The apparatus (1) according to claim 11 or 12.

15. Each of the first stage coiled fluid conduit (9) and the second stage coiled fluid conduit (7) is wound around the rotating shaft (23); The first interstage flow path extends into the first coil formed by the coil-shaped fluid conduit (9) of the first stage and into the second coil formed by the coil-shaped fluid conduit (7) of the second stage. The apparatus (1) according to claim 14.

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