The present invention covers an arrangement for Acoustical Phase conversion.
It is known that a powerful sound wave shows a pressure swing and because a sound wave is always adiabatic, i.e. no heat is added or removed, there is always a temperature variation, which follows the pressure swing. This means that a high pressure gives a high temperature and that a low pressure gives a low temperature. The relation between temperature and pressure can be shown in other ways. One example is when one goes up a mountain, the temperature and pressure drop in approximately the same way and with a similar order of magnitude.
It is also known that rain clouds are created when warm air is forced upwards on a mountain and is cooled. In the same way a rain cloud can form in an acoustic sound wave. One difference is that the passage up a mountain takes a long time while a sound wave can offer 200 roundtrips per second up and down an equivalent 300 meter high mountain, all within a tube of small dimensions. Hence, different gases and vapors can condense within a tube under these conditions. Primarily, we are concerned with the extraction of water from air, but methane and carbon dioxide may be condensed using this technology, for example.
The density of air is approximately 1.33 kg/cubic meter at atmospheric pressure and this amount of air according to the diagram in
Today, water is manufactured on a large scale by desalination of sea water using distillation or osmosis. The actual industrial manufacturing requires 5 to 30 times more energy than the theoretical value.
Natural gas from the oil fields consists of approximately 87% methane. Because methane is a very light gas it is hard to transport by boat or train. Where there is a pipeline the natural gas can be used, otherwise it will be burned off and wasted. If methane can be converted to a liquid form in an inexpensive way it would mean that far more methane from the oil fields can be used. Farmers have a large opportunity to manufacture methane from manure or other biological waste. A simple conversion to liquid form should mean that a single farm could increase its profits and produce carbon dioxide neutral fuel. Such an activity reduces the Greenhouse Effect in a powerful way, because methane leakage to the atmosphere is avoided.
In 1997, the first thermo-acoustic unit in the world was used to produce liquefied natural gas (LNG). This known thermo-acoustic unit contains a thermo-acoustic stack with a cold heat exchanger and a warm heat exchanger at either end of the stack. This thermo-acoustic unit is several storeys high and has a cooling effect of 2 kilowatts. It also uses helium as its cooling medium and 35% of the natural gas is used to drive the unit in a large burner at the top. Hence, only 65% of the gas is condensed to LNG.
In stack based thermo-acoustic systems the resonator tube contains a thermal stack composed of several small parallel channels or plates where pressure and speed variations through the stack are such that the heat is supplied to the oscillating gas at high pressure and removed at low pressure. Furthermore, the stack has a cold heat exchanger at one end, that is a heat exchanger from which the working gas absorbs heat and in the other end a warm heat exchanger, that is a heat exchanger to which the working gas delivers heat.
A disadvantage of stack based thermo-acoustic devices is that the stack must have a large surface area and be made from thin heat exchanging materials. The technology has been developed over decades without reaching reliability, especially where high temperatures and large pressure swings are involved. A further disadvantage with stack-based systems is that they often use hydrogen or helium as working media and it is a known problem that these gases have a tendency to dissipate even from apparently hermetically sealed systems. A third disadvantage is that the stack dampens the wave.
The present invention comprises an arrangement and a method for phase change, where for example a liquid substance can be extracted from a gas. One such proposed arrangement according to the invention contains a volume which in turn contains a working gas and is arranged to contain a generated standing or traveling wave, where said wave is generated when the sum of the added useful and wasted energy is greater than or equal to zero. Furthermore, the arrangement is composed of a valve mechanism to add or take away an amount of a compound substance. The generated sound wave exposes the working gas and compound substance to a pressure and temperature change where a gas compression creates an elevated temperature and where a gas decompression creates a reduced temperature, and thereby the externally added amount of the compound substance in the form of particles, drops or gases, into the working gas will undergo a phase change. As an example a part of the added amount of gas can condense.
In some cases this compound substance can consist of a multiple compound or a simple element. The said compound substance can be in a gaseous, solid or liquid form. In certain cases said compound substance can comprise water vapor that can be phase condensed to water droplets. Said compound substance can be gaseous such as air, methane, carbon dioxide, butane or propane. Said compound substance can comprise water drops that can be phase converted to snow. Said compound substance can comprise a solid form such as snow that can be phase converted to water vapor.
In another embodiment of the invention the arrangement comprises a device to supply energy or a device to consume energy, arranged to add or consume acoustic wave energy in such a way that the overall sum of the added and consumed energy is greater or equal to zero.
In another embodiment the device to supply energy is a membrane, a piston device, an engine, a salt or a volume reduction.
In the embodiments a condensation or chemical reaction takes place in the volume whereby acoustical wave energy is added or consumed so that the overall sum of the added and consumed energy is greater or equal to zero.
The valve mechanism can be arranged to open a valve opening at a minimum pressure of the sound wave, whereby an amount of gas is introduced to the volume. Furthermore, the valve mechanism can be arranged to remove an amount of working gas and an amount of the introduced compound substance from the volume, when said first valve is opened.
In the embodiments the arrangement comprises an external chamber connected to the volume so that said valve mechanism is arranged to open a second valve at a maximum pressure of the sound wave, whereby a gas exchange will take place between the volume and the chamber and whereby the chamber reaches the same pressure as the volume, when the second valve is open and whereby a part of said introduced amount of the compound substance which is introduced into the chamber will condense or undergo a phase change in the chamber. In the case of condensation, the chamber may contain a catalyst, for example a salt, to speed up the condensation.
The valve mechanism can possess a stationary disc having a number of holes and a rotating disc also having a number of holes, whereby the valve mechanism is arranged to open when the holes of the rotating disc are co-incident with the holes of the stationary disc.
In the embodiments at least one of the holes in the rotating disc is an asymmetric hole. Furthermore, in the embodiments at least one of the holes in the stationary disc is an asymmetric hole.
It shall of course be understood that the valve mechanism can be a moveable flap over one of the said holes or other type of valve that is capable of regulating the inflow or outflow to or from the volume. The valve mechanism can be controlled mechanically, hydraulically or electrically. It shall however be understood that the valve mechanism can be opened without active control, for instance by a pressure difference. One example of such a valve mechanism is a flap valve. The valve mechanism can further consist of two valve parts that can be controlled in an independent or dependent manner to each other. The valve mechanism can possess a symmetrical or asymmetrical opening.
The embodiments further comprise a drive device and a drive rod arranged to rotate said rotating disc in relation to said stationary disc and said volume.
In the embodiments a second container is arranged in connection with the chamber via a vertical tube, so that the second container and the vertical tube and the chamber contain a condensate up to a level in the chamber. A distance D1 between the level in the chamber and the upper surface of the second container can be of the size one to 100 meters, preferably around 5 meters.
In the embodiments the resonator for the sound wave is of cylindrical form, funnel shaped, or has a spherical or toroidal shape. The resonator can have a variable diameter along its axis. In the embodiments the resonator has a separating plane whereby the resonator along its axis is divided in two parts, with the purpose of controlling and improving the compound substance and working gas flow.
Embodiments comprise the working fluid air and the compound substance introduced to the volume such as air, methane, carbon dioxide, butane or propane.
The present invention will be described more in detail with reference to the attached figures, in which;
In
The present invention intends a method and an arrangement for acoustic phase conversion. As is schematically shown in
In the embodiments the resonator device 30 is arranged so that the X-displacement of the molecules S has an anti-node and two nodes, preferably a node at each end of the resonator device. It shall be understood that the resonator device can be dimensioned such that the soundwave in the resonator device has several entire wavelengths or half wavelengths so that the number of nodes and anti-nodes can vary.
It shall be understood that the resonator device 30 can have different shapes, for example spherical or cylindrical, but it can also be shaped as a toroid, that is, formed as an inflated tire. The resonator device 30 can have a diameter that varies along the X direction of the resonator device 30, that is, the resonator device 30 can for example be funnel shaped or conical.
The embodiments of the arrangement 100 according to the invention have in addition an energy adding device 32, also called an energy adding unit 32, arranged to generate an acoustical wave in the space 30. These are shown for example FIGS. 7,9,11,13,15. The energy adding unit 32 can be shaped as a back and forth movable membrane 32 to create a standing wave with a resonance frequency within the space 30. The energy adding unit 32 can for example also be a piston arrangement, an engine, a salt or a volume reduction, which will cause a wave to be generated and which will be described below.
The embodiments of the arrangement according to the invention contain further a control device 35, as shown in
Reflections at the ends of the resonator device 30 can take place via a closed or open end, for example a wall or in a open end, an opening through a diameter change.
In the embodiments the valve mechanism 10,20 is placed where the pressure variations are at a maximum, that is, by a closed or open end of the resonator device 30. Valve mechanism 10,20 can be arranged axially, as shown for example in
The valve mechanism 10,20 can be attached to a first end 31, a second end 31 or to both ends 31,31 of the resonator device 30, depending on the function or goal. Preferably the valve mechanism 10, 20 is attached to one end of the resonator device 30, in the embodiments where an energy adding unit, for example a piston or a membrane, is placed at the other end. The valve mechanism 10,20,10′,20′ may be arranged at both ends of the resonator device 30 in the embodiments, where for example an engine functionality is desired at one end and a condensation of liquid at the other end, that is consumption of energy from the wave in the other end. The driving rod 42 that is assembled straight through the resonator device 30 will not interfere with the standing wave, as the rod is aligned in the same axis as the wave.
In the embodiments the resonator device 30 has a stationary disc 10 and a rotating disc 20 in a first end 31 and a reflecting wall 31′ in the other end, as for example in
In
As is schematically shown in
For example a supply pipe 36 to the resonator device 30 and a drain pipe from the resonator device 30 open up when the holes 21,23 of the rotating disc 20 are situated in a vertical position and correspond to the holes 11,13 of the static disc 10, whereby the valve mechanism 10,20 through the holes 11,13,21,23 is open. Further the connections 38,39 from the resonator device 30 to and from the container 50 are open when the holes 21,23 of the rotating disc 20 are situated in a horizontal position and correspond to the holes 12,14 of the static disc 10.
The number of holes 21,23 of the rotating disc 20 can be for example two and be round or pie shaped (triangular). It shall be understood that the number of holes can vary and that the holes can have other shapes. One or several of the holes can have an irregular shape. In
The static disc 10 has preferably a reflecting surface, mounted in such a way that it cannot rotate and in such a way that the rotating disc 20 is positioned between the static disc 10 and the one end 30 of the resonator device.
The static disc 10 has a number of holes 11,12,13,14, for example four holes. The holes may be round or pie shaped (triangular). In the embodiments the holes have a shape corresponding to the holes in the rotating disc. For example the holes can have an irregular asymmetric shape corresponding to a hole 70 in the rotating disc. It shall be understood that the number of holes can very depending on for example the number of desired supply pipes and drain pipes and that the holes can have other shapes, even asymmetric shapes. Furthermore a different pattern having a large number of holes can constitute an alternative valve mechanism, whereby the disc can rotate with considerably lower RPM.
Between the rotating disc 20 and the reflecting surface of the static disc 10 there is a friction reducing agent to reduce friction. Examples of a friction reducing agent are an oil, for example a thin oil film, or a very small and frictionless air gap. The size of the air gap can be constant and preferably the size of some micrometers. In the embodiments the rotating disc 20 is arranged to rest upon or hover on an air “cushion” or magnetic “cushion” with active or passive control to achieve the least possible air gap and thus a good seal between the static disc 10 and the rotating disc 20.
In the embodiments where the rotating valve disc 20 rests on an oil film, the rotation speed is preferably under or of the order of 10 m/s. In the embodiments where the rotation speed is higher than 10 m/s it may be to preferable to allow the valve disc 20 to hover on a magnetic “cushion” or air “cushion” (not shown) to minimize friction and to reduce friction down to almost zero.
In the embodiments with a short resonator device 30, that is where the length of the resonator along its X axis is shorter than for example 10 to 20 cm, the RPM become extremely high. As an example, it can be mentioned that a resonator device 30 with a length of 11 cm will have a valve disc 20 that rotates with approximately 44,000 RPM (rotations per minute), while a resonator arrangement with a length of 1 m requires a rotation of approximately 4800 RPM of the valve disc 20. Furthermore a resonator device 30 with a length of 4 m requires approximately 1200 RPM of the valve disc 20.
In
If a phase change from water vapor to water takes place in the resonator device during a pressure minimum, then the phase change in the container 50 equally takes place, that is a phase change from water vapor to water also takes place in the container 50.
An advantage of arranging a container 50 with the resonator device 30 is that the process has a longer time in which to occur. That means for example that a phase change becomes more complete, such that a larger portion of the liquid substance can be extracted from the gas compared with embodiments where the container 50 is not a part of the arrangement. In the resonator device 30 a phase change has only a few milliseconds in which to occur and it is easy to understand that the vapor cloud that appears at the minimum pressure may not have time enough to change to liquid droplets. With the container 50, the process has plenty of time to occur and it can be supported further by the influence of a catalyst. The catalyst's function is to facilitate the extraction of liquid substances and it can be salt crystals, a high-voltage, ultrasound, organic fibers or other measures. Organic fibers can be plant fibers such as those found in nature like cactus fiber or pine tree fiber. A catalyst is especially convenient in embodiments where a low temperature differential is desirable, as the catalyst can speed up extraction of the liquid substance despite a lower temperature differential.
A soundwave in the resonator device 30 has several properties like pressure, molecular movement, temperature and so on. By affecting some of these properties at the right moment the sound wave can be weakened or enhanced.
In embodiments of the invention a mixture of gases and vapors, liquid droplets and chemical substances and/or salts in powder form can be used. Usable energies exist bound in phase changes and the bonds between molecules and an acoustic resonator device 30 can interact with these energies in different ways.
In
As shown in sequence S1 gas is transported through a source pipe 36. It also can be created through suitably mounted gas adding device 75, for example fans or turbo unit, or through asymmetric shapes of the valves (not shown). In
In the sequence S2 the amount of gas 60 approaches the valve mechanism 10,20 and in sequence S3 the said amount of gas 60 is situated in the resonator device 30. When the said amount of gas 60 is situated in the resonator device 30 the valve mechanism 10,20 is closed and the said amount of gas 60 is subject to pressure and volume changes through the influence of a soundwave, preferably a standing or traveling soundwave. In sequence S4, the valve mechanism 10, 20 to the container 50 is opened and in sequence S5 said amount of gas 60 moves in a pipe 38 towards the container 50, under a different pressure, temperature and volume compared with the conditions in sequence S1 and S2.
In sequence S6 and S7, when a reaction or a phase change has taken place in the container 50, said amount of gas 60 moves from the container 50 via a pipe 39 towards the valve mechanism 10,20. This can be done with a flow controlling device 40, for example a pump device or by creating a pressure differential as for example has been described above, by means of asymmetric openings. The control device 35 can further be arranged to control the flow controlling device 40, whereby the control device 35 can control the flow of gas between the resonator device 30 and the container 50.
In sequence S8, said amount of gas 60: is again situated in the resonator device 30 and the valve mechanism 10, 20 is closed. Everything repeats from the beginning. Under these circumstances, the sound wave and the original pressure from the beginning of sequence S1 is restored. In sequence S9 said amount of gas 60 exits the resonator device 30 via a drain pipe 37.
In
The fact that the rotating disc 20 has one or more asymmetric holes 70, means that if for example a gas at atmospheric pressure (atm) that has been placed in the space 30 is exposed to a standing wave, the injected gas volume will be exposed to an increase in pressure and after a certain time of exposure in this space 30 the gas volume would have a pressure of for example 5 atm. This final pressure corresponds to the pressure in the container 50 (not shown in
In an arrangement in accordance with the invention with a thermo-acoustic resonator device, it is possible for vapor, liquid drops, salt in powder form or salt in liquid drops to interact to achieve different results. Salt in powder form and water vapor can for example be seen as a fuel for a thermo-acoustic engine. Salt in powder form can also be a fuel for a condensation process.
In embodiments of the invention the resonator device 30 has an energy adding device 32, as shown in
Hence it should be understood that the energy adding device can be a physical device, but it can also be a salt added to the space to speed up the process. The energy adding device can also be a spontaneous reaction like a spontaneous volume decrease in the space 30 when a large volume of water vapor collapses into small liquid drops, for example small water drops.
It shall further be understood that the energy adding device is only schematically shown in the figures.
In embodiments of the invention the resonator device 30 shows a energy consuming device 34 that consumes energy from the wave, as shown in
In embodiments of the invention the resonator device 30 can have an energy adding device 32 and an energy consuming device 34, as shown in
Furthermore, one single unit may contain both an energy adding and an energy consuming device 32,34 at the same time. One example is condensation of water vapor, carried by air. Due to the fact that the partial vapor volume collapses when the pressure is minimal, the wave is strengthened. Due to the fact that the slowest molecules create the first drops, the remaining air thus becomes warmer when the wave is at its coldest, which weakens the wave. If the first effect dominates the acoustical wave in the resonator device will swing spontaneously. In another case an energy adding device 32 is arranged at the resonator device 30, whereby the energy adding device 32 provides the acoustic wave with the missing energy.
An advantage of extracting water directly from air is, that the sun has already done the energy demanding phase change from water vapor and separated the water from the salt of the ocean.
In
In
In embodiments of the invention the resonator arrangement 30 and the container 50 are arranged at a the distance M from the ground with a pipe 81, whereby for example liquid substance 84 from the container 50 can be transported down towards the ground M. As is schematically illustrated in
Furthermore, embodiments of the arrangement 100 according of the invention can have a second container 82 arranged at pipe 81 and for example placed on the ground M. The second container 82 can have a tap 83 with which the volume of the extracted liquid substance 84 can be tapped from the container 82 under positive pressure, while maintaining the lower pressure in container 50.
It should be understood the a tap or tap arrangement can be attached at the pipe or tube 81 in an embodiment that for example is missing the second container 82 or as a complement to the tap device 83 attached to the second container 82.
The pipe or tube 81 has such dimensions that it creates atmospheric pressure or higher at the lowest end of the tube. Thus, the liquid substance can be tapped without affecting the lower pressure in the container 50.
To maintain the standing wave for example, an energy adding unit 32 can be placed at one end of the resonator device 30, as shown in
It shall be understood that according to the description above, natural gas can be transformed to liquid natural gas. With this invention a number of other gases including air, can be condensed, for instance CO2, butane and propane.
With reference to
In other embodiments the temperature can be taken down several steps, whereby different gases may condense. When processing natural gas, one may extract water in a first step, butane in the second step, methane in the third step and CO2 in a fourth step.
The injected gas can be mixed with a cooling agent, for instance air, nitrogen, etc. that condense at an even lower temperature than minus 160 C. If the cooling agent does not condense at a lower temperature it is useless as agent. At the point of condensation there is no relation anymore between pressure and temperature and the cooling effect disappears. To maintain the standing wave, an energy adding unit 34 can by placed at one and of the resonator device 30. The energy adding unit 34 is preferably placed at the end of the resonator device 30 that is at the opposite end to the inlets C and D.
Suppose that water saturated air is injected into the resonator device 30 via inlet C and out through outlet D when the soundwave has a maximum pressure, see
Suppose that air, saturated with water vapor is injected into the resonator device 30 via inlet C and out via outlet D when the sound wave has a maximum pressure, see
The generated energy can be taken out through an energy consuming unit 34 in the resonator device 30, see
In
The present invention has been described referring to exemplified embodiments, but it should be understood that the invention is not limited by these embodiments. They are only intended to illustrate the invention. For example, embodiments can be combined and it shall also be understood that embodiments of the arrangement 100 can include one or several resonator devices 30, arranged in several steps for example to obtain a bigger pressure swing and a better phase conversion. The invention has been described with reference to embodiments where an injected composition, for example a gas is condensed, but it shall also be understood that the injected composition can be in the state of a liquid or a solid and that other phase conversions than condensation can take place. The present invention is only limited by the enclosed claims.
Number | Date | Country | Kind |
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0850105-8 | Nov 2008 | SE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/SE2009/051342 | 11/26/2009 | WO | 00 | 5/24/2011 |