Patent Description:
Vortex chambers are used in various technical domains wherein a gas vortex flow within a cavity is required, such as for example in the domain of plasma reactors or in the domain of combustion devices.

An example of a plasma reactor making use of a vortex chamber is a gliding arc discharge reactor, as disclosed for example by <NPL>.

A vortex chamber comprises a swirl generator having one or more swirl channels configured for injecting the gas into the cavity of the vortex chamber. These swirl channels are generally tangential with respect to a cylindrical cavity. As a result, when gas is injected in the cavity through the swirl channels, the gas is swirling and follows a vortex gas flow path.

Depending on the geometry of the vortex chamber, the swirling path can result in a forward vortex or a reverse vortex flow path.

The vortex flow aims at stabilizing a central zone within the cavity. Due to the vortex flow mass flow takes place from the outer side of the cavity to the inner side. The vortex chambers are effective at for example stabilizing a swirling flame or a plasma discharge.

However, one of the problems with the vortex chambers is that to generate successfully a vortex flow, a specific velocity and pressure in the swirl inlets is required. As a result, the vortex chambers work in a limited range of flow rates. For instance, a flow rate that is too low might not form a vortex flow pattern, while a flow rate that is too high will cause too much pressure strain on the tangential inlets and potentially damage the vortex chamber.

For example, in a plasma reactor, if the flow rate is too low, a vortex flow might not be generated and the temperature of the plasma can increase and overheat the reactor.

A further problem is that the vortex flow pattern can change significantly over usable flow rates, influencing the combustion or plasma characteristics.

Hence there is room for improving vortex chambers for generating a vortex flow in a cavity. <CIT> discloses a prior art vortex chamber with a swirl generator having a plurality of swirl channels and a blocking wall to regulate the total gas flow into the swirl channels.

It is an object of the present disclosure to provide a robust vortex chamber with improved vortex flow controlling capacities when compared to the prior art vortex chambers. More specifically, it is an object to control the vortex flow pattern for different gas flow rates.

According to a first aspect of the invention a vortex chamber comprising a cavity elongating along a central axis and a swirl generator is provided. The swirl generator comprises a plurality of swirl channels configured for introducing a gas flow into the cavity as a vortex flow about the central axis and each swirl channel comprising a channel entrance and a channel exit. The vortex chamber is characterized in that the swirl generator further comprises a gas redistribution chamber comprising i) one or more main gas supply inlets for receiving a gas, ii) a distribution channel configured for distributing the gas received from the one or more main gas supply inlets to the channel entrances of the swirl channels, and iii) one or more blocking walls configured for blocking and unblocking one or more entrances of the plurality of swirl channels. The vortex chamber is further configured for relatively rotating the channel entrances with respect to the one or more blocking walls from a first angular position to at least a second angular position and vice versa, and wherein when in the second angular position the one or more blocking walls block a larger number of channel entrances than when in the first angular position.

Advantageously, by providing a one or more blocking walls for blocking and unblocking one or more entrances of the plurality of swirl channels, when increasing for example a gas flow rate at the main gas supply inlet, the velocity of the gas in the swirl channels can be kept constant by opening more entrance channels. In this way, the flow rate of the gas can be increased without causing pressure strain in the swirl channels.

Advantageously, with the one or more blocking walls, the vortex chamber can operate in a broader range of gas flow rates while controlling the gas velocity and hence the vortex flow pattern.

Advantageously, a combustion or plasma reactor that utilizes a vortex chamber according to the present disclosure becomes capable of sustaining wider ranges of power, flow rate, pressure and gas mixtures.

In embodiments, the swirl generator is configured for generating a forward vortex flow while in other embodiments, the swirl generator is configured for generating a reversed vortex flow.

In embodiments, each of the swirl channels is traversing a cavity peripheral wall from the channel entrance at an outer side of the cavity peripheral wall to the channel exit at an inner side of the cavity peripheral wall. The cavity peripheral wall is elongating along the central axis and radially delimits the cavity.

Preferably, in embodiments with swirl channels traversing the cavity peripheral wall, the vortex chamber is configured for relatively rotating the cavity peripheral wall or for relatively rotating at least a portion of the cavity peripheral wall comprising the plurality of swirl channels with respect to the one or more blocking walls for performing the rotation from the first to the second angular position and vice versa.

In embodiments, the blocking walls are formed by wall portions of a circumferential side of the gas redistribution chamber.

In further embodiments, each of the swirl channels is traversing a cavity axial wall from the channel entrance at an outer side of the cavity axial wall to the channel exit at an inner side of the cavity axial wall. The cavity axial wall is axially delimiting the cavity.

Preferably, in embodiments with swirl channels traversing the cavity axial wall, the vortex chamber is configured for relatively rotating the cavity axial wall, or at least a portion of the cavity axial wall comprising the swirl channels, with respect to the one or more blocking walls for performing the rotation from the first to the second angular position and vice versa.

In embodiments, the blocking walls are formed by wall portions of an axial side of the gas redistribution chamber.

According to a further aspect of the disclosure a plasma reactor or a combustion device comprising a vortex chamber as presently disclosed is provided.

These and further aspects of the present disclosure will be explained in greater detail by way of example and with reference to the accompanying drawings in which:.

The drawings of the figures are neither drawn to scale nor proportioned. Generally, identical components are denoted by the same reference numerals in the figures.

The present disclosure will be described in terms of specific embodiments, which are illustrative of the disclosure and not to be construed as limiting. It will be appreciated by persons skilled in the art that the present disclosure is not limited by what has been particularly shown and/or described and that alternatives or modified embodiments could be developed in the light of the overall teaching of this disclosure.

Use of the verb "to comprise", as well as the respective conjugations, does not exclude the presence of elements other than those stated. Use of the article "a", "an" or "the" preceding an element does not exclude the presence of a plurality of such elements.

It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the disclosure described herein are capable of operation in other sequences than described or illustrated herein.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiments is included in one or more embodiment of the present disclosure. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one ordinary skill in the art from this disclosure, in one or more embodiments.

A gas vortex flow has to be construed as a gas flow swirling around an axis line. In a vortex chamber, the gas injected through swirl channels swirls around a central axis of the cavity. In <FIG>, an example of a known vortex chamber is shown wherein gas is injected in a cavity <NUM> through swirl channels <NUM> resulting in a vortex flow around the central axis Z of the cavity. The gas exits the cavity through the gas outlet <NUM>. Is this example the vortex flow is a reversed vortex flow. The present disclosure is however not limited to any specific vortex flow generated in the vortex chamber. Depending on the geometry of the vortex chamber, in some embodiments a forward vortex is generated in the cavity while in other embodiments a reversed vortex flow is generated in the cavity. The vortex chamber according to the present disclosure is also not limited to a specific gas to be used. The gas, or the gas mixture to be used, depends on the application the vortex chamber is used for, as will be further discussed below.

The vortex chamber according to the present disclosure is a vortex chamber having an adjustable swirl generator, i.e. a swirl generator that allows to adjust the number of operational swirl channels.

An isometric view of an embodiment of a vortex chamber <NUM> according to the present disclosure is shown in <FIG>. To better illustrate this embodiment, <FIG> shows a cut-out view of the vortex chamber shown in <FIG>. The vortex chamber <NUM> comprises a cavity <NUM> elongating along a central axis Z and a swirl generator. The swirl generator comprises a plurality of swirl channels <NUM> configured for introducing a gas flow into the cavity <NUM> as a vortex flow about the central axis Z. Each swirl channel comprising a channel entrance for receiving gas and a channel exit for injecting the gas into the cavity.

A swirl channel is to be construed as a channel configured for introducing the gas into the cavity in a given direction and that results in the formation of a vortex gas flow within the cavity.

A cross-sectional view of the vortex chamber of <FIG> taken through a plane perpendicular with the central axis is shown in <FIG> illustrating the location of the swirl channels <NUM>. In this embodiment, the swirl generator comprises twelve swirl channels <NUM>. The number of swirl channels can vary from embodiment to embodiment and is typically comprised between two and two hundred swirl channels.

The vortex chamber according to the present disclosure is characterized in that the swirl generator comprises a gas redistribution chamber <NUM>. In <FIG>, an example of a gas redistribution chamber <NUM> is shown, without any other components of the vortex chamber. The gas redistribution chamber <NUM> comprises one or more main gas supply inlets <NUM> for receiving a gas, a distribution channel <NUM> configured for distributing the gas received from the one or more main gas supply inlets to the channel entrances of the swirl channels, and one or more blocking walls 32a, 32b, 32c, 32d configured for blocking and unblocking one or more entrances of the plurality of swirl channels.

Blocking and unblocking of an entrance channel of a swirl channel has to be construed as respectively enabling and disabling a gas flow through the swirl channel.

In the embodiment shown in <FIG>, the gas redistribution chamber <NUM> comprises four blocking walls 32a, 32b, 32c, 32d. The number of blocking walls can vary depending on the geometry of the gas redistribution chamber and depending on the number of swirl channels. Generally, there is at least one blocking wall, but the number of blocking walls can also be as large as one hundred.

With reference to <FIG> and <FIG>, the gas flow in the gas redistribution chamber is explained. <FIG> is an enlarged view of <FIG>, showing a quarter of the cross-sectional view of <FIG>. The subsequent arrows indicate the path of the gas flow. The gas enters the gas distribution chamber via the main gas supply inlet <NUM> and then the gas is distributed through the distribution channel <NUM> to the channel entrances of the swirl channels <NUM>. Generally openings are provided in a wall portion of the gas redistribution chamber to fluidly connect the distribution channel <NUM> with entrances of swirl channels. The gas further flows through the swirl channels <NUM> and enters the cavity <NUM> as a vortex gas flow.

The vortex chamber according to the present disclosure is further characterized in that the vortex chamber is configured for relatively rotating the entrances of the swirl channels with respect to the one or more blocking walls 32a, 32b, 32c, 32d. The rotation can be performed from a first angular position to at least a second angular position and vice versa, and wherein when in the second angular position the one or more blocking walls blocks a larger number of channel entrances than when in the first angular position. In this way, the number of operational swirl channels for injecting gas in the cavity can be adjusted.

As a result of the relative rotation of the swirl entrances with respect to the blocking walls, the vortex chamber according to the present disclosure comprises a stationary part and a rotatable part. What part is stationary and what part is rotatable can vary and different embodiments are discussed below.

In embodiments the first angular position is a position wherein no channel entrances of the plurality of swirl channels are blocked and the second angular position is position wherein a portion of the channel entrances of the plurality of swirl channels are blocked.

In embodiments, the vortex chamber is configured for relatively rotating the channel entrances with respect to the blocking walls to a plurality of angular positions. In other embodiments, the rotation can be performed continuously over a given angular range and hence the channel entrances can be positioned with respect to the blocking walls in an infinite number of rotational positions. In embodiments, the rotation can be performed continuously from <NUM>° to <NUM>°.

The present disclosure is not limited to a specific number of swirl channels or specific number of blocking walls. Generally, #C ≥ <NUM> x #B, with #C and #B being respectively the number of swirl channels and the number of blocking walls, preferably <NUM> ≤ #C ≤<NUM> and <NUM> ≤ #B ≤<NUM>, more preferably <NUM> ≤ #C ≤<NUM> and <NUM> ≤ #B ≤<NUM>.

In embodiments, the plurality of swirl channels are grouped into groups of swirl channels wherein #B = #G, with #B and #G being respectively the number of blocking walls and the number of groups. Each group comprises two or more swirl channels. For example the embodiment shown on <FIG> comprises four groups of swirl channels and four blocking walls. In this example each group of swirl channels comprises three swirl channels.

In some embodiments wherein the swirl channels are grouped into groups, each blocking wall is associated to one of the groups and each blocking wall is configured for blocking and unblocking entrances of swirl channels of the group of swirl channels the blocking wall is associated with. For the embodiment shown on <FIG> and <FIG>, for each blocking wall, a group of three swirl channels is associated. When in the first rotational position, shown in <FIG>, each of the four blocking walls is blocking one channel entrance. When in the rotational second position shown in <FIG>, in this example after a <NUM>° rotation, each of the four blocking walls is blocking two channel entrances.

In embodiments, for example in embodiments wherein the vortex chamber is part of a plasma reactor, the vortex chamber further comprises electrodes or the peripheral wall or part of the peripheral wall forms an electrode.

In embodiments, as illustrated on <FIG>, the cavity <NUM> is radially delimited by a cavity peripheral wall and each swirl channel is traversing the cavity peripheral wall from the channel entrance at an outer side of the cavity peripheral wall to the channel exit at an inner side of the cavity peripheral wall.

In other words, in these embodiments, the channel exits of the swirl channels are radially distributed on an inner radial side of the cavity. This is further illustrated on <FIG>, which is a cross-section of the embodiment of <FIG>, where twelve swirl channels <NUM> are shown having, in this example, both channel entrances and channel exits that are radially distributed.

In the embodiment shown on <FIG>, the vortex chamber is configured for relatively rotating the cavity peripheral wall or relatively rotating at least a portion of the cavity peripheral wall comprising the plurality of swirl channels with respect to the one or more blocking walls for performing the rotation from the first to the second angular position and vice versa. The arrow on <FIG> and the two larger arrows on <FIG> illustrate the rotational direction of the cavity peripheral wall <NUM> for rotating for example from the first to the second position.

The dashed circle on <FIG> and the dashed line on <FIG> schematically show the interface between a rotatable and a stationary part, in this example the rotatable part being the cavity peripheral wall or at least a portion of the cavity peripheral wall comprising the swirl channels and the stationary part being the gas redistribution chamber comprising the blocking walls. Hence the rotatable part and the stationary part can differ from one embodiment to the other.

In embodiments, between the rotatable part and the stationary part a mechanical seal is placed in order to obtain an airtight rotational interface. In other embodiments, a lubricating fluid is located between the rotatable part and the stationary part. In further embodiments an airtight bearing can be used as an interface element between the rotating and the stationary part. In some embodiments, a low leakage can be acceptable if the amount of leakage is much lower when compared to the overall gas flow rate through the swirl channels.

In <FIG>, the cavity peripheral wall comprising the swirl channels is rotated by <NUM>° with respect to the blocking walls 32a, 32b, 32c, 32d when compared to <FIG>. By rotating from the first angular position, shown in <FIG>, to the second angular position, shown in <FIG>, in this example following a rotation of <NUM>°, the number of operational channels, i.e. the number of channels that inject gas into the cavity <NUM> is reduced from eight to four open channels.

The reduction of the number of operational channels has an impact on the vortex pattern and especially on the velocity of the gas flow. For example when comparing the velocity of the gas flow inside the swirl channels when in the position shown in <FIG> with the position shown in <FIG>, for the same gas flow rate, the velocity increases in this example from <NUM>/s to <NUM>/s. This has the advantage that the gas flow rate can be adjusted over time while keeping the same or a similar gas flow velocity. A vortex flow can for example initially be created with a lower gas flow rate and then increased afterwards.

In some embodiments, as illustrated on <FIG> and <FIG>, the channel exits of all the swirl channels are axially, i.e. with respect to the central axis Z, located in the same axial position. In other embodiments, as illustrated on <FIG>, a first portion 20a of the swirl channels have radially distributed channel exits that are located at a first axial position and a second portion 20b of the swirl channels have radially distributed channel exits that are located at a second axial position. In these embodiments, the blocking walls are configured for blocking the channel entrances of both the first and second portion of swirl channels.

In embodiments, the cavity peripheral wall is made of or partly made of a metal, such as for example stainless steel. Examples of embodiments wherein the cavity peripheral wall comprises different parts made of different materials will be discussed below.

In some embodiments, a portion of the cavity is cylindrical and the swirl channels are tangential with respect to the cylindrical portion. In other embodiments, the swirl channels are not tangential.

In the embodiment shown on <FIG> and <FIG>, the blocking walls are placed symmetrically, i.e. the blocking walls have the same angular width, and also the swirl channels are placed symmetrically, i.e. within each of the four groups of swirl channels the relative positions of the swirl channels is the same for each group of swirl channels. Hence, when rotating the channel entrance faces for example from the first to the second angular position, the number of swirl channels within a group that are blocked by an associated blocking wall is the same for each group of swirl channels. For example, in <FIG>, each blocking wall blocks one swirl channel and after a <NUM>° rotation, shown in <FIG>, each blocking wall blocks two swirl channels.

In other embodiments, as illustrated on <FIG>, the four blocking walls are placed symmetrically, as in <FIG>, but the swirl channels are placed asymmetrically, i.e. within each of the four groups of swirl channels the relative positions of the swirl channels differ from group to group. Hence, the number of swirl channels blocked by a blocking wall are not the same for each blocking wall. As illustrated on <FIG>, one blocking wall is for example blocking two swirl channels while another blocking wall is only blocking one swirl channel.

In some embodiments the cavity peripheral wall <NUM> comprises a first part 50a and a second part 50b, radially delimiting respectively a first cavity portion and a second cavity portion. The first cavity portion is the portion of the cavity where the gas is injected for starting a vortex flow. Hence, in these embodiments, the swirl channels are comprised within the first part 50a of the cavity peripheral walls. In other words, in these embodiments, the swirl channels are traversing the first part 50a from the channel entrance at an outer side of the first part 50a to the channel exit at an inner side of the first part 50a. An example of a first part 50a of the cavity peripheral wall, that is separated from the second part, is shown in <FIG>.

In embodiments, the wall thickness of the first part 50a comprising the swirl channels is thicker than the wall thickness of the second part 50b. In this way the wall thickness of the first part 50a can be adapted according to the length of the swirl channels and the wall thickness of the second part 50b can be reduced.

In embodiments, the first part 50a comprising the swirl channels can be rotated with respect to the second part 50b. In this way, for performing the rotation from the first to the second angular position, the second part 50b can for example remain stationary. Hence in this way, for performing the rotation it is not necessary to rotate the entire cavity peripheral wall delimiting the cavity.

In some embodiments, the first part 50a is made of a material that is different from the first part 50b. For example, the first part 50a comprising the swirl channels is made of stainless steel and the second part 50b is made of quartz.

In embodiments the cavity peripheral wall <NUM> comprises a first part 50a and a second part 50b wherein the second part is electrically insulated from the first part by an insulator such as for example a ceramic insulator. In embodiments the cavity peripheral wall or the first part of the cavity peripheral wall forms an electrode. In embodiments, the first part 50a and the second part 50b form respectively a first and a second electrode, electrically insulated from each other.

As discussed above, the gas redistribution chamber serves to distribute the incoming gas received at the one or more main gas inlets towards the channel entrances of the swirl channels.

In embodiments, as illustrated on <FIG>, the gas redistribution chamber <NUM> comprises a circumferential side <NUM>, illustrated with two dashed circles. One or more wall portions of the circumferential side <NUM> of the gas redistribution chamber are forming the one or more blocking walls. In this example, shown on <FIG>, there are four blocking walls 32a, 32b, 32c, and 32d.

The circumferential side <NUM> of the gas redistribution chamber comprises at least one wall opening for fluidly connecting the distribution channel <NUM> with channel entrances of the swirl channels. The number of openings depends on the number of blocking walls. Preferably, two or more openings are configured for supplying the gas to the entrances of the swirl channels.

In the embodiment shown on <FIG>, there are four blocking walls 32a, 32b, 32c, and 32d separated by four openings 34a, 34b, 34c and 34d. In other words, the one or more wall portions forming the one or more blocking walls correspond to wall portions of the circumferential side of the gas redistribution chamber separating the two or more wall openings from each other.

As further illustrated on <FIG>, the circumferential side <NUM> of the gas redistribution chamber is encircling or partly encircling the outer side <NUM> of the cavity peripheral wall or encircling or partly encircling at least a portion 50a of the outer side of the cavity peripheral wall comprising the channel entrances of the plurality of swirl channels. In this way, by defining a relative rotation of the circumferential side with respect to the entrance channels, the wall portions of the circumferential side <NUM> forming the blocking walls can face the channel entrances channels and hence block the channel entrances.

In embodiments of a gas redistribution chamber, as shown in <FIG>, the blocking walls are symmetrically distributed with respect to circumferential side <NUM> and each of the blocking walls is identical, i.e. they have for example the same angular width. In other embodiments as illustrated on <FIG>, there are two blocking walls 32a and 32b having a different angular width when compared to blocking walls 32b and 32d. In <FIG>, a cross-section of a vortex chamber is shown comprising the gas redistribution chamber of <FIG>. Using blocking walls having different angular widths, increases the flexibility for rotating the channel entrances with respect to the blocking walls to an increased number of rotational positions for blocking more or less channel entrances.

In embodiments, the gas redistribution chamber <NUM> further comprises an outer wall <NUM> defining an outer periphery of the gas redistribution chamber and wherein the one or more main gas supply inlets traverse the outer wall <NUM> to supply the gas to the redistribution channel. As illustrated on <FIG>, the redistribution channel <NUM> is located between the circumferential side <NUM> and the outer wall <NUM> of the gas redistribution chamber.

The gas redistribution chamber is for example made of or partly made of metal, such as for example stainless steel.

The swirl generator according to the present disclosure is not limited to swirl channels having channel exits located on a radial circumferential wall of the cavity. In embodiments, as illustrated on <FIG>, the cavity <NUM> of the vortex chamber <NUM> is radially delimited by a cavity peripheral wall <NUM> and axially delimited by at least a cavity axial wall <NUM> and wherein each swirl channel <NUM> is traversing the cavity axial wall <NUM> from the channel entrance at an outer side of the cavity axial wall to the channel exit at an inner side of the cavity axial wall. In other words, the thickness of the cavity axial wall <NUM> is adapted as function of the dimensions of the swirl channels.

The exemplary embodiment shown on <FIG>, comprises an axial cavity wall <NUM> having six swirl channels <NUM>. In this embodiment, the cavity <NUM> has a cylindrical shape and a further cavity axial wall <NUM> located opposite the cavity axial wall <NUM> comprising the swirl channels is further axially delimiting the cavity.

For embodiments having a cavity axial wall <NUM> comprising the swirl channels, a gas redistribution chamber <NUM> is provided that comprises an axial side facing the outer side of the cavity axial wall <NUM>. In these embodiments, one or more wall portions of the axial side of the gas redistribution chamber are forming the one or more blocking walls for blocking the axial entrances of the swirl channels.

In the embodiment shown on <FIG>, the vortex chamber <NUM> comprises a gas outlet <NUM> located on the cavity axial side that comprises the swirl channels. In other embodiments, the gas outlet <NUM> can be located in the cavity axial wall <NUM> opposite the cavity axial wall comprising the swirl channels.

The gas redistribution chamber <NUM> and the cavity axial wall of the embodiment of <FIG> are shown in more detail in <FIG>. As schematically illustrated <FIG>, the gas redistribution chamber <NUM> comprises at least one main gas supply inlet <NUM>, in this example one gas supply inlet <NUM> is shown, and further comprises a redistribution channel <NUM> configured for transporting the gas from the one or more main gas supply inlets <NUM> to the channel entrances of the swirl channels. Therefore, the axial side of the gas redistribution chamber comprises at least one wall opening for fluidly connecting the redistribution channel <NUM> with the channel entrances of the swirl channels. In the embodiment shown on <FIG>, there are three wall openings 34a,34b,34c through the axial side of the gas redistribution chamber allowing to fluidly connect the gas redistribution channel <NUM> with the channel entrances of the swirl channels <NUM>.

Preferably, the axial side of the gas redistribution chamber comprises two or more wall openings configured for supplying the gas to the entrances of the swirl channels. In these embodiments, the one or more wall portions forming the one or more blocking walls correspond to wall portions of the axial side of the gas redistribution chamber separating the two or more wall openings from each other.

In the embodiments having swirl channels located in a cavity axial wall, the vortex chamber <NUM> is configured for relatively rotating the cavity axial wall <NUM> with respect to the one or more blocking walls of the gas redistribution chamber <NUM> for performing the rotation from the first to the second angular position and vice versa. The arrow on <FIG> and <FIG>, indicates a rotational direction.

In <FIG>, the rotatable part <NUM> includes not only the cavity axial wall <NUM> but also the cavity peripheral wall <NUM> and the stationary part <NUM> corresponds in this example to the gas redistribution chamber <NUM>. In other embodiments, the cavity axial wall <NUM> is rotatable and forms the rotational part, while the cavity peripheral wall <NUM> remains stationary and generally also the gas redistribution chamber remains stationary.

In some embodiments, not the entire cavity axial wall <NUM> is rotatable but only a portion of the axial cavity wall is rotatable, namely the portion of the cavity axial wall that is comprising the swirl channels.

In the embodiment shown on <FIG> the swirl channels are not exactly aligned with the central axis Z but the swirl channels have an inclination angle with respect to the central axis. This allows to generate a vortex flow pattern within the cavity.

In embodiments, between the rotatable part, i.e. the cavity axial wall <NUM> comprising the swirl channels, and the stationary part, i.e. the gas redistribution chamber <NUM>, a mechanical seal is placed in order to obtain an airtight rotational interface. In other embodiments, a lubricating fluid is located between the cavity axial wall <NUM> comprising the swirl channels and the gas redistribution chamber <NUM> to obtain an airtight rotational interface. In further embodiments an airtight bearing can be used as an interface element between the rotating and the stationary part. In some embodiments, a low leakage can be acceptable if the amount of leakage is much lower when compared to the overall gas flow rate through the swirl channels.

In embodiments, the relative rotation of the entrance channels with respect to the one or more blocking walls is performed manually, while in other embodiments the rotation is motorized.

In <FIG> an embodiment is schematically shown wherein a shaft <NUM> interconnects the rotatable part <NUM> with a lever <NUM> for manually rotating the rotatable part <NUM> with respect to the stationary part <NUM>. On the other hand, in <FIG> an embodiment is schematically shown wherein a shaft <NUM> interconnects a rotatable part with a motor <NUM>, for example a stepped motor.

Depending on the details of vortex chamber embodiments, as discussed above, the rotatable part can for example be the first part 51a of the cavity peripheral wall that comprises the swirl channels. In other embodiments, the rotatable part can be the entire cavity peripheral wall <NUM>.

In <FIG>, a further embodiment is schematically shown wherein a shaft <NUM> is coupled on one side with the rotatable part <NUM> and on the other side is coupled with a spring element <NUM>. The spring element <NUM> is made of a heat-expansive material and a thermal connection <NUM> thermally couples the spring element with the cavity peripheral wall. In this way, if the walls of the cavity heat up, the spring element <NUM> will expand and this will result in a rotation of the shaft and hence a rotation of the rotating part. The thermal coupling of the spring with the cavity peripheral wall can for example be realized with gas vapour heat pipe, a liquid head transfer system or through direct thermal contact.

According to a further aspect of the invention a plasma reactor is provided comprising a vortex chamber according to the present disclosure. The plasma reactor can be a vortex type or reverse vortex type plasma reactor.

Vortex and reverse-vortex reactors are effective at stabilizing a plasma discharge. However, they work in limited range of flow rates as the swirl channels require a specific flow velocity and pressure in order to successfully form a vortex or a reverse vortex flow. For instance, a flow rate that is too low might not form a vortex flow pattern, while a flow rate that is too high will cause too much pressure strain on the channel entrances. Moreover, the vortex flow pattern can change significantly over usable flow rates, influencing plasma characteristics. With the vortex chamber according to the present disclosure, the number of operational swirl channels can be adjusted during operation of the plasma reactor. In this way, plasma reactors comprising a vortex chamber according to the present disclosure become capable of sustaining wider ranges of power, flow rate, pressure and gas mixtures.

An example of an application wherein a plasma reactor is used is the process of recycling CO<NUM> gas. Such a recycling process involves splitting the CO<NUM> gas molecules into products such as CO and O<NUM>.

In these embodiments, the gas that is transported via the gas distribution chamber to the swirl channels and injected in the cavity of the vortex chamber is CO<NUM>. Within the cavity of the vortex chamber, a plasma is created and through interaction of the CO<NUM> gas molecules with the plasma the CO<NUM> gas molecules are dissociated and the resulting products such as CO and O<NUM> are extracted through the gas outlet of the vortex chamber. In other embodiments a gas mixtures is used, for example a mixture of CO<NUM> and CH<NUM>.

The vortex chamber of the present disclosure can advantageously be used with for example a gliding arc discharge reactor.

As discussed above, in embodiments of vortex chambers for plasma reactors, the vortex chamber comprises one or more electrodes.

The use of the vortex chamber according to the present disclosure is however not limited to plasma reactors. The vortex chambers can also be used in the domain of for example combustion devices wherein the cavity of the vortex chamber is part of a combustion chamber. The advantages of using a vortex chamber according to the present disclosure that are applicable for the plasma reactor, as discussed above, are also applicable for a combustion chamber wherein gas is injected as a vortex flow.

Claim 1:
A vortex chamber (<NUM>) comprising a cavity (<NUM>) elongating along a central axis (Z) and a swirl generator, said swirl generator comprising
• a plurality of swirl channels (<NUM>) configured for introducing a gas flow into the cavity (<NUM>) as a vortex flow about the central axis, each swirl channel comprising a channel entrance and a channel exit,
said swirl generator further comprises
• a gas redistribution chamber (<NUM>) comprising
i) one or more main gas supply inlets (<NUM>) for receiving a gas,
ii) a distribution channel (<NUM>) configured for distributing the gas received from said one or more main gas supply inlets to the channel entrances of said swirl channels,
iii) one or more blocking walls (32a, 32b, 32c, 32d) configured for blocking and unblocking one or more entrances of the plurality of swirl channels,
and wherein the vortex chamber is configured for relatively rotating the channel entrances with respect to the one or more blocking walls from a first angular position to at least a second angular position and vice versa, and further characterised in that in said second angular position the one or more blocking walls block a larger number of channel entrances than when in said first angular position.