Device for separating water from oil or grease

Abstract: A device for separating water from oil or grease of a mixture (12) includes: an external container (1) containing said mixture (12) and having a lower water layer (6) and an upper oil or grease layer (13); a plurality of communicating vessels (2, 3), one inside the other, making vertical labyrinth runs for said water (6) that is discharged from the external container (1) through an outlet duct 7 taking water from the bottom of the innermost communicating vessels (2, 3); an outlet duct (8) for withdrawing oil-grease from said external container (1) and which incoming end is inside the upper layer (13).

Description: The present invention refers to devices to separate a mixture of liquids, particularly concerns a device for separating water from oil or grease to be wasted. It is known that the exhaust oil to be recycled must be separated from water and from sludge. Currently this operation is performed in large settling tanks and needs very long times. Besides the tanks are very bulky and are often located outside, so that in case of strong rains these tanks suffers water infiltration. Document EP 445 576 discloses a device for separating water from oil or grease of a mixture including an external container for said mixture, a plurality of communicating vessels, one inside the other, making vertical labyrinth runs for said water discharged from the external container through an outlet duct 7 taking water from the bottom of the innermost communicating vessels; an outlet duct for withdrawing oil-grease from said external container and which incoming end is inside the upper layer of oil. Said plurality of communicating vessels includes a middle container inside the external container and at least an inner container having said outlet duct connected thereto. The device includes a lower passage between said middle container and said external container near to the bottom of this latter and it includes an upper hole between the middle container and the inner container next to the top of the latter. The main object of the invention is to carry out a quite instant separation of the elements of the liquid mixture by means of a small and easy maintenance device. The device of the present invention is constituted by a container in which coaxial communicating vessels are inserted carrying out labyrinth shaped vertical runs for water that is separated by the mixture introduced from the top, before it is evacuated through an outlet duct. The remaining oil is withdrawn by means of a second outlet duct, placed at an upper height of the outlet water duct, that is fixed or variable due to a float. A filter facilitates the separation of the mixture elements. The invention is now described in detail referring to the attached drawing sheets in witch: figure 1 shows a vertical median section view of the device; figure 2 shows a top view of the device along the horizontal plane A-A of figure 1; figure 3 shows a vertical section view of a variant of the device of figure 1. In figures 1 and 2, the device fit for separating water from oil or grease includes an external container 1, a middle container 2 and an inner container 3. Said coaxial containers are a sort of "communicating vessels" in flow communication so as to make vertical labyrinth runs. For this purpose, a lower passage 4 is carried out in the middle container 2 near to the external container bottom, while the internal container 3 is provided near the top with upper holes 5, for instance eight as shown in figure 2. The numeral 6 indicates water, that is preventively poured into the coaxial communicating vessels and that subsequently flows, because of gravity, from the top, separating itself from the oil. An outlet duct 7 of the water separated by the oil has an end in flow communication close to the inner container bottom and the remaining free end comes out from the external container 1 at a higher level with respect to the upper holes 5. Numeral 8 indicates the outlet duct of the oil and/or grease, fixed to a float 9 that is vertically movable, inside the external container 1. The free end of the outlet oil duct 8 comes out from the external container 1 at a higher level with respect to the free end of the outlet water duct 7. The outlet duct 8 could be fixed at an height greater than the outlet water duct 7. The float 9 has one or more passing holes 10 of the water-oil/grease mixture 12. A net filter 11 is horizontally laying inside the external container 1 so facilitating the separation of the mixture elements. A variant of the device provides that the filter 11 is directly joined to the float 9. The water-oil mixture 12 poured from the top inside the external container 1, because of the resistance offered by the column of lower water, before introduced into the labyrinth run of the communicating vessels, and also because of the filtering action of the net filter 11, separate itself quickly in an upper oil layer 13 and in a lower water layer 6. The water flows out through the labyrinth run and the outlet duct 7, while the oil, withdrawn from the layer 13, is evacuated through the duct 8. The filter 11 helps to prevent the oil passage toward the containers bottom, by virtue of the oil viscosity. Figure 3 shows a variant of the device in which an accessory tank 14, provided onto the external container opening, is provided with a net 15 and with a passthrough duct 16, that withdraws at such a height to overhang a sludge layer. The net 15 supports oiled and/or greased objects, such as rags that can by washed with water flowing from the same outlet water duct 7, properly lifted as in figure 3. Water, oil and grease drop because of the washing, are introduced into the device through the duct 16 and therefore separated by the device according to the invention. The device according to said variant is fit for degreasing tableware or similar objects, for instance with or without detergent addition. Another device variant shown in figure 3 provides that an end of a pipe comes into the inner container 3, near to its top, while the other free end comes out from the external container 1. This pipe evacuates the exceeding air, or introduces air, so obtaining a dampening effect and increasing the oxygen in the water. From experimental tests results that the separation of water from the oil is nearly instantaneous. The device is besides particularly compact and, if realized with suitable sizes, it can also be transportable.

Claims: Device for separating water (6) from oil or grease of a mixture (12) including: an external container (1) for said mixture (12); a plurality of communicating vessels (2, 3), one inside the other, making vertical labyrinth runs for said water (6) discharged from the external container (1) through an outlet duct (7) taking water from the bottom of the innermost communicating vessels (2, 3); an outlet duct (8) for withdrawing oil-grease from said external container (1) and which incoming end is inside the upper of mixture (12); said plurality of communicating vessels (2, 3) includes: a middle container (2) inside the external container (1) and at least an inner container (3), having said outlet duct (7) connected thereto; at least a lower passage (4) between said middle container (2) and said external container (1) near to the bottom of this latter; at least an upper hole (5) between the middle container (2) and the inner container (3) next to the top of the latter; the device (1) being characterized in that an end of a pipe is inside the inner container (3), close to its top, and the other end comes out from the external container (1) for evacuating the exceeding air, or for introducing air, so obtaining a dampening effect and increasing the oxygen in the water. Device according to claim 1 characterized in that the exit ends of said outlet ducts (7, 8) exit from the external container (1) between the tops of the communicating vessels (2, 3) and the upper oil-grease layer (13). Device according to claim 2 characterized in that the outer water duct end (7) is lower than the outer oil-grease duct end (8). Device according to claim 1 characterized in that the input end of the oil-grease (8) is joined to the lower surface of a float (9) supported by the mixture (12). Device according to claim 4 characterized in that the float (9) has at least a passing hole (10) of the mixture (12). Device according to claim 1 characterized in that further includes a filter (11) displaced over the communicating vessels (2, 3) for avoiding the oil or grease fall onto the external container bottom. Device according to claims 4 and 6 characterized in that said filter (11) is joined to the float (9). Device according to claim 1 characterized in that a tank (14) is put at the external container top, said tank (14) having a net (15) supporting oiled objects and a duct (16) passing into the external container (1). Device according to claim 8 characterized in that the free end of the outlet duct (7) feeds the water (6) into the tank (14) from the top. Device according to claim 8 characterized in that the duct (16) has the free end protruding from the tank bottom.

Inventors: MAGI BRUNO, MAGI, BRUNO
Applicants: MAGI BRUNO, MAGI, BRUNO
Application year: 2000
Main classification: B01D17
IPC codes: B01D17