WO2002007851A9

WO2002007851A9 - Device for separating hydrocarbons from water

Info

Publication number: WO2002007851A9
Application number: PCT/NL2001/000567
Authority: WO
Inventors: Siem Jonker
Original assignee: Kessel K A Techniek B V; Siem Jonker
Priority date: 2000-07-21
Filing date: 2001-07-23
Publication date: 2002-11-28
Also published as: WO2002007851A1; NL1015778C2; AU2001286319A1

Abstract

Device for separating hydrocarbons from water, comprising a housing which comprises at least one separating space with an inlet for the water-hydrocarbon mixture and an outlet for at least one of the separated components, wherein the outlet is closable using a float valve, which float valve comprises a hollow float body of a hydrocarbon-resistant plastic.

Description

DEVICE FOR SEPARATING HYDROCARBONS FROM WATER

The present invention relates to a device for separating hydrocarbons from water, comprising a housing which comprises at least one separating space with an inlet for a quasi-continuous flow of a water-hydrocarbon mixture and an outlet for at least one of the separated components, wherein the outlet is closable using a float valve.

Such a device is known for instance for separating petrol or oil from water. Here the petrol is for instance separated from the water contaminated with petrol and stored in the device, while water is drained from the device. In known devices the water-hydrocarbon mixture is carried quasi-continuously into the separating space. The known devices are generally embodied in concrete, wherein use is made of a spherical float valve of metal which closes the outlet to the hydrocarbons. The hydrocarbons remain behind in the separating space. The metal can however be corroded after a time through the action of the hydrocarbons, whereby the float valve no longer functions properly. As a consequence the water drained from the device will still contain a relatively large quantity of hydrocarbons.

¹ The object of the present invention is to provide a device as described above wherein the above stated drawbacks are obviated.

This objective is achieved by the device according to the invention in that the float valve comprises a hollow float body of a hydrocarbon-resistant plastic .

The device according to the invention provides a device with which in simple manner hydrocarbons can be separated from the water and stored, and wherein the float valve can be used in reliable manner for a prolonged period. Because hydrocarbons are not generally water- soluble, two separate liquid layers will be formed in the separating space once the water-hydrocarbon mixture has entered the separating space via the inlet. Hydrocarbons are lighter than water, so that the layer of hydrocarbons floats on the water layer. The entrance to the outlet is herein generally situated close to the bottom of the separating space in the lower layer of liquid, the water, such that the water can be drained via the outlet . However, the dividing line between the water and the hydrocarbons will hereby fall, whereby the layer with hydrocarbons comes into the vicinity of the entrance to the outlet. In order to ensure that the hydrocarbons cannot leave the device via the outlet, the float must therefore close the outlet when the hydrocarbons come too close to the entrance of the outlet. The float valve is equipped for this purpose such that it floats on the water but not on the hydrocarbons . As soon as the water is drained and the dividing line between the water and the hydrocarbons has fallen below the entrance to the outlet, the entrance is closed by the float valve so that the hydrocarbons cannot leave the separating space. The float valve therefore ensures here that only water is drained, and the hydrocarbons remain behind and are stored in the separating space.

In a particular preferred embodiment of the device the hydrocarbon-resistant plastic comprises high density polyethylene (HDPE) . This plastic is particularly suitable owing to its strength and hydrocarbon-resistant properties.

In order to enable precise adjustment of the buoyancy of the float valve, the hollow float body comprises in a further suitable preferred embodiment a determined quantity of a filler material for adjusting a determined specific gravity of the float valve.

The filler material herein preferably comprises sand. The specific gravity, and therefore the buoyancy of the float, can hereby be determined in simple and inexpensive manner.

In .a further particular embodiment of the device according to the invention the determined specific gravity of the float herein lies between the specific gravity of water and the specific gravity of the hydrocarbons. The float will hereby stay afloat on water, but not on the hydrocarbons, and close the outlet to the hydrocarbons as described above . The float valve can be embodied according to the present invention in any appropriate manner. A particularly effective preferred embodiment is however obtained when the float comprises a substantially cylindrical float body with at least one circular closing surface for the outlet arranged on the base of the cylindrical body.

In order to ensure that the water can be drained via the outlet in a steady and controlled manner, in a further preferred embodiment of the device the outlet is arranged in a second space separated from the separating space with an overflowable partition wall. Via the inlet the water contaminated with the hydrocarbons herein enters the first separating space where the separation into two separate layers takes place. At a determined level of the liquid the liquid will flow steadily via the overflowable partition wall into the second space, wherein the separation between hydrocarbons and water is maintained. The partition wall herein also serves as sludge collector in that sludge possibly present in the contaminated water will settle on the bottom of the first separating space.

Although the other components of the device according to the invention can be made from diverse materials, in a particular preferred embodiment the housing, the separating space arranged in the housing, the inlet, the outlet and the partition wall are likewise made from a hydrocarbon-resistant plastic. A strong and reliable device is hereby obtained which owing to its light weight is easy to handle .

The hydrocarbon-resistant plastic herein preferably comprises high density polyethylene (HDPE) . In a particularly efficient and simple preferred embodiment of the device the outlet comprises a discharge channel which comprises at least one substantially vertically running first part in which a number of openings are arranged close to the underside thereof, and wherein the float is arranged in the vertical part and the circular closing surface of the float co-acts with a closing ring arranged in the discharge channel .

So as to enable removal of for instance the sludge collected in the first separating space or the separated hydrocarbons, the device preferably further comprises at least one closable opening arranged on the top side of the housing.

The device preferably further comprises at least one stench-trap for reducing unpleasant odours resulting from the hydrocarbons and sludge collected in the device .

The invention further relates to and provides a float for use in the above described device. The invention is further elucidated with reference to the annexed figures, in which

Figure 1 shows a perspective and partly broken- away view of a preferred embodiment of the device according to the invention; and Figure 2 shows a perspective view of a particular preferred embodiment of an outlet and float body according to the invention.

As shown in figure 1, the device according to the invention comprises in a particular preferred embodiment a housing 1 comprising a first separating space 2 with an inlet 3 for the water-hydrocarbon mixture. Via inlet 3 the water-hydrocarbon mixture enters the separating space where the separation between water and hydrocarbons takes place . Two separate layers are herein formed, wherein the layer of hydrocarbons floats on the layer of water (not shown) . The device further comprises a second space 5 which is separated from separating space 2 with an overflowable partition wall 4 and in which an outlet 6 is arranged. Partition wall 4 also serves here to retain in separating space 2 any solid particles, such as sludge or sand, which may be present in the water-hydrocarbon mixture. The sludge or sand will settle to the bottom of separating space 2 and not therefore enter the second space 5. The outlet 6 arranged in second space 5 comprises a discharge channel 7 which comprises a vertically running first part 8 in which a number of openings 9 are arranged close to the underside thereof, through which openings the water can flow to the entrance 10 of discharge channel 7. Entrance 10 is closable using a float valve 11 arranged in the first vertical part 8. According to the invention the housing 1, the separating space 2 arranged in the housing, inlet 3, outlet 6, partition wall 4 and float valve 11 are preferably made from a hydrocarbon-resistant plastic, in particular high density polyethylene (HDPE) . In the embodiment shown in figure 1 the device further comprises a number of closable openings 12 which are arranged on the top side of housing 1 and which can for instance be used to enable removal from housing 1 of the sludge or sand collected in the first separating space 2 behind partition wall 4, or to discharge the stored hydrocarbons from the second storage space 5. A stench-trap wall 13 is further arranged to prevent noxious odours caused by the hydrocarbons .

In a particular preferred embodiment of the device according to the invention the float valve 11 comprises as shown in figure 2 a hollow cylindrical float body 14 with a circular closing surface 15 arranged on the base of cylindrical float body 14 for the purpose of closing the entrance 15 to discharge channel 7. The float valve is arranged in the vertically running first part 8 of discharge channel 7 in which a number of inflow openings 9 are arranged close to the underside. The hollow float body 14 comprises a determined quantity of a filler material, such as for instance sand 17, for the purpose of adjusting a determined specific gravity of float valve 11 such that the specific gravity of float valve 11 lies between the specific gravity of water and the specific gravity of the hydrocarbons . The float will hereby float on the layer of water but not on the layer of hydrocarbons. When the dividing line 18 between the water layer and the layer of hydrocarbons is situated well above the openings 9 arranged in discharge channel 7 the float 11, because it floats on the water 19, will also be pushed upward to a position above openings 9, wherein entrance 10 to discharge channel 7 is opened and the water 19 can flow via openings 9 and entrance 10 into discharge channel 7 and be drained. Because the water is drained the dividing line 18, and therefore the float 11, will descend until dividing line 18 has fallen to a position just above openings 9 and float 11 will close the entrance 10 to discharge channel 7. In the preferred embodiment shown in the figures the circular closing surface 15 of float valve 11 herein co-acts with the closing ring 16 to ensure a good closure of entrance 10. In order to enable filling of float body 14 with the filler material, there is further arranged on the top side of float body 14 in the embodiment shown in figure 2 a closable filling opening 21 and an eye 22 to allow simple removal of float 11 from the vertical part of discharge channel 7.

Claims

1. Device for separating hydrocarbons from water, comprising a housing which comprises at least one separating space with an inlet for a quasi-continuous flow of a water-hydrocarbon mixture and an outlet for at least one of the separated components, wherein the outlet is closable using a float valve comprising a hollow float body, characterized in that the hollow float body comprises a hydrocarbon-resistant plastic.

2. Device as claimed in claim 1, characterized in that the hydrocarbon-resistant plastic comprises high density polyethylene (HDPE) .

3. Device as claimed in claim 1 or 2, characterized in that the float body comprises a determined quantity of a filler material for adjusting a determined specific gravity of the float valve.

4. Device as claimed in claim 3, characterized in that the filler material comprises sand.

5. Device as claimed in any of the claims 1-4, characterized in that the determined specific gravity of the float valve lies between the specific gravity of water and the specific gravity of the hydrocarbons.

6. Device as claimed in any of the claims 1-5, characterized in that the float valve comprises a substantially cylindrical float body with at least one circular closing surface for the outlet arranged on the base of the cylindrical body.

7. Device as claimed in any of the foregoing claims, characterized in that the outlet is arranged in a second space separated from the separating space with an overflowable partition wall .

8. Device as claimed in any of the foregoing claims, characterized in that the housing, the separating space arranged in the housing, the inlet, the outlet and the partition wall are made from a hydrocarbon-resistant plastic .

9. Device as claimed in claim 8, characterized in that the hydrocarbon-resistant plastic comprises high density polyethylene (HDPE) .

10. Device as claimed in any of the foregoing claims, characterized in that the outlet comprises a discharge channel which comprises at least one substantially vertically running first part in which a number of openings are arranged close to the underside thereof, and wherein the float valve is arranged in the vertical part and the circular closing surface of the float valve co-acts with a closing ring arranged in the discharge channel .

11. Device as claimed in any of the foregoing claims 1-10, characterized in that the device further comprises at least one closable opening arranged on the top side of the housing.

12. Device as claimed in any of the foregoing claims 1-11, characterized in that the device further comprises at least one stench-trap.

13. Float for use in a device as claimed in any of the claims 1-12.