"Apparatus for Removing a. First Liquid from a Second Liquid"
The invention relates to apparatus for removing a first liquid from a second liquid and in particular, but not solely, the removal of oil from the surface of a body of water, such as the sea.
Traditionally, the containment and control of oil slicks have been concentrated on using mechanical means such as floating barrier to physically contain and limit the extent of the oil slick and the use of suitable chemicals to disperse the oil. Both these methods have disadvantages. In the first instance it is difficult to physically contain an oil slick which is on the open sea and may be moving. In addition, the problem is exacerbated if the oil slick extends over a relatively large area.
In the second instance, the effect of chemicals to disperse oil slicks has been of limited effect and it is desirable to use chemicals which have no detrimental effect on the underwater environment and do not contaminate the sea. This of course limits the type of chemicals which can be used.
In accordance with the present invention, apparatus for removing a first liquid from a second liquid, the first liquid substantially floating on the surface of the second liquid, comprises a body adapted to move relative to the surface of the second liquid, a transfer means supported by the body for contact with at least the first liquid and removal of liquid from the surface of the second liquid, and a reservoir mounted on the body for receiving the liquid removed by the transfer means from the surface of the second liquid.
The invention has the advantage o£ "providing a transfer means which removes liquid from the surface of the second liquid.
Preferably, the transfer means continuously removes and transfers liquid to the reservoir as the apparatus moves relative to the surface of the second liquid and typically, the transfer means comprises a movable surface which contacts at least the first liquid, the movable surface comprising means to trap the first liquid in and/or on the surface. Typically, the surface may comprise an absorbent material and the first liquid is absorbed into the body of the material. Preferably, the absorbent material is a foam.
Preferably, the transfer means is in the shape of a cylinder which is rotatably mounted on the body so that the axis of rotation is substantially parallel to the surface of the second liquid.
Typically, the transfer means further comprises means to expel liquid from the movable surface into the reservoir and typically, the reservoir may include
return means which returns second liquid, transferred by the transfer means to the reservoir with the first liquid, back to the second liquid. Typically, the return means comprises an open-ended pipe communicating between the base of the reservoir and the second liquid.
Typically, the body is shaped to channel the first liquid to the transfer means and may comprise two arm portions which are joined at one end by the transfer means, the other end being open to channel the second liquid between the arm portions towards the transfer means.
Typically, the transfer means is provided with drive means such as a hydraulic motor which, when the transfer means is a rotatable cylinder, rotates the cylinder about its axis of rotation.
Preferably, the apparatus is provided with its own propulsion means which is typically, a suitable engine and propeller, and the apparatus may be incorporated into a specially adapted vessel.
Typically, the apparatus is for removing oil, such as crude oil, from the surface of a body of water, such as the sea.
An example of apparatus for removing a first liquid from a second liquid in accordance with the invention will now be described with reference to the accompanying drawings, in which:-
Fig. 1 is a schematic view of apparatus for removing oil from the surface of a body of water;
and, Fig. 2 is a side view of the apparatus shown in Fig. 1.
Fig. 1 is a schematic view of a vessel 10 which comprises a body defined by two horizontal arm sections 11, 12 which float on a body of liquid, such as the sea 22, two vertical bow members 13, 14 which are joined at their upper end by a horizontal cross member 15. At the stem ends of the arm sections 11, 12 a drum 1 is rotatably mounted. The drum 1 has foam material 16 mounted on its cylindrical surface. Adjacent to the drum 1 is an intermediate holding"tank 3 which also serves as a separation tank. Means 17 is provided to expel liquid from the foam material 16 into the reservoir 3. Typically, the means 17 is a scraper and/or a roller which squeezes the material 16.
The vessel 10 is propelled in the direction shown in Fig. 1 by two propellers 18 (only one shown) which are mounted by means of drive shafts 19 (only one shown) on each arm section 11, 12. The propellers 18 and drive shafts 19 are driven by a drive motor 20 in each arm 11, 12, as shown in Fig. 2.
A number of pipes 5 are connected to the base of the reservoir 3 and extend through an oil slick layer 21 into the sea 22. Typically, the pipes 5 are each about 10 feet long.
Two oil pumps 4 are provided, one on each arm 11, 12 which pump oil from the top of the pipes 5 to a main storage reservoir (not shown).
A hydraulic motor 23 is provided which drives the drum
1 and may be used to drive the drum in either the direction shown by the arrows in Figs 1 and 2 or in the opposite rotational direction. A power pack 24 is mounted on the cross arm 15 and supplies power to the propeller drive motors 20 and the hydraulic motor 23.
In use, the vessel 10 floats on the sea 22 and is propelled by means of the propellers 18 which are driven by the drive shafts 19 and the motor 20 which takes power from the power pack 24. As the vessel 10 moves through an oil slick the drum 1 is rotated by the hydraulic motor 23 and as the foam material 16 on the surface of the drum 1 is in contact with- the oil slick 21 oil is absorbed into the foam 16 and is carried round to the separation means 17 by means of rotation of the drum. The separation means 17 may remove oil from the material 16 by a scraping mechanism and/or a rolling mechanism so that the oil passes into the separation tank 3.
The pipes 5 are approximately 10 feet long and are open at both ends so that when there is no oil in the separation tank 3 the water level in the pipes 5 is at approximately the same height as the level of the sea 22. When oil enters the separation tank 3 it floats on top of the water column in the pipes 5 and as the oil level in the separation tank 3 increases the oil/water interface moves down the pipes 5 as the weight of oil on top of the water in the pipes 5 increases". Any water which has been mixed with the oil which enters the separation tank 3 will gradually sink towards the oil/water interface and re-enter the sea 22 through the pipes 5. Hence, the separation tank 3 and the pipes 5 act to separate sea water from oil removed from the oil slick 21.
When the oil/water interface in the pipes 5 reaches a predetermined level towards the bottom of the pipes 5 a switch (not shown) is triggered which activates the oil pumps 4 and transfers oil from the top end of the pipes 5 to a main oil reservoir or reservoirs (not shown) . Conveniently, the main reservoir or reservoirs may comprise oil barrels mounted on the arms 11, 12 which are filled with oil by the pumps 4. The oil barrels may be detached from the arms 11, 12 when full and transferred to a supply boat and replaced with empty barrels.
The invention has the advantage of physically removing oil from the surface of a body of water, such as the sea, and does not rely solely on chemical means to disperse the oil 21 on the sea 22 or trying to physically limit the extent of the oil slick.