The invention relates to a device for separating a fluid into two components. Such a device is for instance known from the Netherlands patent number NL1035215. The device of NL1035215 comprises for instance a pump and a separation channel.

It is an object of the invention to simplify the device of NL1035215.

The device of the type stated in the preamble according to the invention comprises for this purpose:

- two concentrically disposed cylindrical walls, wherein at least one of the two walls is provided on its side facing toward the other wall with grooves extending in a first direction;

- rotation means for rotating at least one of the two walls about its longitudinal axis, wherein rotation of the at least one wall thrusts the fluid in a second direction which lies at an angle relative to the first direction, wherein the thrust fluid is separated into a first component displacing in the grooves in the first direction and a second component displacing in the second direction;

- first discharge means onto which the grooves debouch for discharging the first component, and

- second discharge means for discharging the second component.

An advantage of the device according to the invention is that thrust is imparted to the fluid by the rotation of the one wall, wherein the fluid is separated into two components during thrust. The device in this way functions as both pump and separator, and no additional pump is necessary. The device can hereby take a simple and/or compact form.

When the grooves are disposed in the rotatable wall, the thrusting of the fluid takes place through the grooves. When the grooves are disposed in the non-rotatable wall, the rotatable wall preferably has a determined roughness, this roughness imparting thrust to the fluid. The grooves can optionally be disposed in both walls.

The fluid can be separated into two components in simple manner by the device according to the invention. Heavier and lighter particles are in particular separated from each other. Particles with mutually differing temperatures, i.e. warm and cold particles, can for instance be separated from each other. Alternatively or additionally, particles of differing chemical composition can for instance be separated from each other.

Depending on the resonance frequency of the different components in the fluid, the components will be carried further along in the thrust flow of the fluid or particles will form swirls in the grooves. The first direction of the grooves and the second direction of the thrust main flow lie at an angle relative to each other, this angle preferably being greater than 0° and smaller than 90°. Because the grooves lie neither parallel nor perpendicular to the direction of thrust or second direction of the fluid, the swirls in the grooves can flow out at an angle, making it possible to separate the first component of the fluid flow in the grooves from the remaining fluid flow, i.e. the second component thereof.

The distance between the two walls is preferably small relative to the resonance frequency. The distance between the two walls is more particularly smaller than three times the groove depth of the grooves. This ensures that all of the fluid comes within the range of influence of the grooves, whereby all the fluid is subjected to the separating action of the grooves. In a highly preferred embodiment the distance is smaller than twice the groove depth.

In another preferred embodiment the grooves of the groove structure are substantially parallel to each other. This is advantageous for the manufacture of the grooves in the walls, although it is likewise possible according to the invention to arrange curved or conical grooves.

In another preferred embodiment of the device according to the invention the grooves have a breaking-wave structure in cross-section. Such a wave structure is found to effect a good separation between different components of a fluid. Such a wave structure can also thrust the fluid efficiently in the second direction. The waves preferably comprise here a wave crest which overhangs relative to the groove cavity located downstream of the wave crest. The swirls of the first component formed in the groove are thus protected to some extent relative to the main flow of the fluid, i.e. the second component, so that the swirls can be readily carried away in the groove cavities.

The device comprises in practical manner a motor for rotating driving of the at least one wall. The motor is for instance an electrically driven motor connected to for instance a battery or to the mains electricity.

In an embodiment of the device according to the invention the inner cylindrical wall is formed by the outer surface of a hollow cylinder, wherein channels through which fluid can flow are disposed between the cavity of the cylinder and the outer surface and wherein fluid is suctioned via the cavity and the channels to the space between the two walls. The channels extend radially here from the cavity; The number of channels can be chosen as desired. The cavity can for instance be connected to an outlet of a ventilation system or be disposed in a space to be ventilated, so that air suctioned in by the device can be separated from the ventilation system or the space in the device according to the invention. After separation of the fluid one of the two components can for instance be disposed of to the outside and the other component can be fed back to the space to be ventilated. At a cold outdoor temperature, for instance lower than 20°C, warm particles can for instance be fed back to the space for the purpose of heating the space, and cold particles can be discharged to the outside. At a warm outdoor temperature, for instance higher than 20°C, cold particles can on the other hand also be fed back to the space for the purpose of cooling the space, and warm particles can be discharged to the outside. It is alternatively possible for particles such as hydrocarbons to be separated from the other particles in air, such as oxygen and nitrogen, wherein the hydrocarbons can be discharged to the outside and the oxygen and nitrogen can be fed back to the space.

The cylinder can be disposed in a housing, wherein an inner surface of the housing forms the outer cylindrical wall. The housing can be fixedly disposed here, wherein the inner wall is the rotating wall.

In yet another embodiment of the device according to the invention a film is arranged on at least one wall, which film comprises the grooves. This embodiment provides the advantage that the walls can be manufactured in simple manner from a random suitable material, for instance a metal, since the grooves need not be arranged in this material. The grooves can be easily arranged in the film, which is for instance manufactured from a plastic, for instance by means of pressing or laser processing the film. The film can then be arranged in simple manner on the wall or the walls. An additional advantage hereof is that the film can be easily chosen as desired, for instance subject to the particles for separation, while the device can be a standard device. The film can also be replaced during the lifespan of the device by another film optionally having a different groove pattern. When the film with grooves is arranged on the fixedly disposed wall, it is optionally possible for a film with a determined surface roughness to be arranged on the rotating wall for the purpose of thrusting the fluid. The rotating wall itself can in that case take a smooth form, wherein the film imparts the determined degree of roughness for thrusting the fluid.

The invention will be further elucidated with reference to figures shown in a drawing, in which:

Figure 1 shows a vertical longitudinal section through an embodiment of a device according to the invention;

Figures 2A and 2B shows a detail of the longitudinal section in the area of the two concentric walls of figure 1 ; and

Figure 3 shows a detail view of the rotating wall of figure 2.

Figure 1 shows a device 1 according to the invention. Device 1 comprises a housing 2 in which is disposed a hollow cylinder 3 rotatable relative to housing 2. Radially extending channels 6 are disposed between a cavity 4 of cylinder 3 and an outer surface 5 of cylinder 3. Cylinder 3 is connected via (ball) bearings 7 to the housing and is driven rotatingly by for instance an electric motor 8. An inner surface 9 of housing 2 extends concentrically round the outer surface 5 of cylinder 3. Housing 2 is disposed on a base 14.

Figures 2A and 2B show a detail of the two concentric walls, i.e. outer surface 5 of cylinder 3 and inner surface 9 of housing 2. Figure 3 shows a detail view of wall 5. These figures show that walls 5, 9 are provided on their side facing toward the other wall with grooves 10 extending in a first direction 11. Rotation of wall 5 in the direction 12 causes a fluid F to be thrust in a direction of thrust 13 by the standing walls of grooves 10 of wall 5. Thrust of the fluid F causes the fluid F to be suctioned into the space between the two walls 5, 9 via channels 6 and cavity 4. Device 1 in this way operates as a pump for suctioning fluid F.

It is noted that in the shown embodiment both the fixedly disposed wall 9 and the rotating wall 5 are provided with grooves. Only the fixedly disposed wall 9 or only the rotating wall 5 can alternatively be provided with grooves. If only the fixedly disposed wall 9 is provided with grooves, it is advantageous for rotating wall 5 to have a determined degree of roughness, this roughness imparting thrust to the fluid.

During thrusting of the fluid F between the two walls 5, 9 the fluid F is separated by grooves 10 into a first component Fl and a second component F2. This separation of fluid F takes place in that a part of the fluid F is caught in groove cavity 10 and there forms a swirl of particles of the first component Fl . The lighter particles in particular will be caught in the swirl, while heavier particles will be flung therefrom and will move in the direction of thrust 13. Component Fl therefore consists of the relatively light particles and component F2 of the relatively heavy particles. The angle between grooves 10 and the direction of thrust 13 is preferably greater than 0° and smaller than 90°, the angle lying for instance between 40° and 70°. The two components Fl, F2 are hereby each displaced in a different direction, and so separated in effective manner.

It is noted that the separation is subject to the resonance frequency of the different components. It is thus possible for instance to separate cold and warm air from each other, since cold air has a different resonance frequency than warm air. It is thus also further possible to separate for instance nitrogen and oxygen from each other from normal air, or hydrocarbons from oxygen and nitrogen from normal air.

Figures 2 A and 2B show the groove structure of the two walls 5, 9 in more detail. Grooves 10 have a breaking- wave shape wherein a wave crest 15 overhangs relative to the groove cavity 10 located downstream of wave crest 5.

Grooves 10 debouch onto a first discharge 16 for discharging the first component Fl , and the space between the two walls 5, 9 debouches onto a second discharge 17 for discharging the second component F2.

It is noted that the invention is not limited to the shown embodiments but also extends to variants within the scope of the appended claims.