Method and device for the decantation of oil contained in a gas stream
View Patent ↗In this process, a gas stream containing the oil to be separated is circulated between an inlet zone and an outlet zone, and a calm vacuum zone is created where the oil is recovered and evacuated, after having been captured. According to the invention, the gas stream is passed in contact with a porous media, one face of which is in contact with the calm vacuum zone. The drops of oil are thus captured by the porous media and sucked through this media to arrive in the calm zone. This process is applicable to decanters of oil at impacters and also to cyclone separators, in particular in the automotive field.
1. A method for decanting oil contained in a gas stream by means of a device, the method providing for:
circulating the gas stream containing oil to be separated between an inlet area and an outlet area of the device;
arranging at least one intermediate area provided with at least one filter element for capturing drops of oil contained in the gas stream; and
creating at least one calm area in which the oil is collected and discharged, after having been captured, the at least one calm area being subjected to a vacuum through a communication channel arranged between the at least one calm area and the outlet area,
the device comprising a separation wall arranged to separate the at least one calm area from the or each intermediate area,
wherein the gas stream is passed in contact with at least one porous medium, one face of which is in communication with the calm area, in such a manner that oil drops are captured by the porous medium and are suctioned through the porous medium to arrive in said calm area, and
wherein the or each intermediate area defines at least one main gas stream passage configured for the flow of a main gas stream, and said at least one filter element defines at least one secondary gas stream passage configured for the flow of a secondary gas stream from the or each intermediate area towards said calm area, said at least one main gas stream passage being separate from said at least one secondary gas stream passage.
2. A device for decanting oil contained in a gas stream comprising:
an inlet area for the gas stream containing oil to be separated;
an outlet area for the de-oiled gas;
at least one intermediate area provided with at least one filter element for capturing drops of oil contained in the gas stream;
at least one calm area where the captured oil is collected and discharged;
a separation wall arranged to separate the at least one calm area from the or each intermediate area; and
a communication channel arranged between the at least one calm area and the outlet area, so as to subject the at least one calm area to a vacuum,
wherein said at least one filter element comprises at least one porous medium placed at the interface between the or each intermediate area and the calm area, in such a manner that the drops of oil are captured by the porous medium and suctioned through the porous medium in order to arrive in said calm area, and
wherein the or each intermediate area defines at least one main gas stream passage configured for the flow of a main gas stream, and said at least one filter element defines at least one secondary gas stream passage configured for the flow of a secondary gas stream from the or each intermediate area towards said calm area, said at least one main gas stream passage being separate from said at least one secondary gas stream passage.
3. The device according to claim 2 , wherein
the intermediate area or areas are intermediate chambers in each of which is transversely disposed an impactor, wherein each impactor comprises a porous medium of a generally planar appearance, and a closed volume placed behind the porous medium and connected to the calm area of oil recovery.
4. The device according to claim 3 , wherein
at least one impactor has a central portion and a peripheral portion, the central portion having a permeability to the gas stream that is substantially lower than that of the peripheral portion.
5. The device according to claim 4 , wherein
the central portion is formed by a layer of low porosity, the permeability of the layer of low porosity with respect to the gas stream representing less than 50% of the permeability of the rest of the porous medium.
6. The device according to claim 4 , wherein
the central portion comprises a solid wall, the peripheral portion being formed by the porous medium, wherein the solid wall being placed against the downstream face of the porous medium.
7. The device according to claim 3 , wherein
at least one closed volume is arranged next to the calm area, the device comprising a partition wall arranged in such a manner as to separate the respective closed volume from the calm area, the partition wall preserving at least one duct putting in fluid communication the respective closed volume and the calm area, said at least one duct is located at the bottom of the closed volume.
8. The device according to claim 3 , wherein
the closed volume placed behind the porous medium is connected to the calm area of oil recovery by a duct, going from a low point of said closed volume and advantageously extending on a side or on the underside of the device.
9. The device according to claim 3 , wherein
the low portion of each impactor and its porous medium occupies the entire width of the corresponding intermediate chamber in such a manner that the oil arriving on the bottom of the impactor cannot bypass the latter.
10. The device according to claim 2 , wherein
the intermediate area is constituted by the internal volume of a cyclone, whereas the calm area is a volume for storing oil located on the side of the cyclone and/or below the cyclone, wherein the porous medium forms the bottom of the cyclone and possibly a fraction or totality of the lateral wall of said cyclone.
11. The device according to claim 2 , wherein
the porous medium is comprised of a metallic grid with intertwined wires, the wires being woven, knitted or braided, in the case of an oil decanter with impactors.
12. The device according to claim 2 , wherein
the porous medium is made from a sintered metal powder base, in the case of a cyclone separator.
13. The device according to claim 2 , wherein
the porous medium is composed of thermoplastic material.
14. The device according to claim 2 , wherein
the porous medium comprises unwoven fibers.
15. The device according to claim 2 , wherein
the porous medium comprises at least two juxtaposed layers of different permeabilities, a first relatively high permeability layer and a second relatively low permeability layer.
16. The device according to claim 2 , wherein
said at least one main gas stream passage extends around said at least one secondary gas stream passage.
17. The device according to claim 2 , wherein
said at least one filter element extends only partially across a cross-sectional area of a respective intermediate area.