GB2286597A

GB2286597A - Device for absorbing water from oil

Info

Publication number: GB2286597A
Application number: GB9403288A
Authority: GB
Inventors: Frederick Howard Howlett
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-22
Filing date: 1994-02-22
Publication date: 1995-08-23
Also published as: GB9403288D0

Abstract

The device comprises an elongate permeable container 11 charged with particles of a water absorbing material (eg a cross-linked polymer) and a weighting material (eg lead shot), the particle size of which is larger than that of the water absorbing material so that, as the bag is placed on the bottom and the water absorbing material in contact with the water absorbs water and expands, the weighting material causes the bag to tilt progressively and expose fresh unused water absorbing material to the water. <IMAGE>

Description

WATER EXTRACTOR DEVICE This invention relates to a water extractor device and has particular application to the removal of water from hydrocarbon fuel or oil.

It is well known in the art that in most tanks for hydrocarbon fuels or oils water condenses in the tank, or is entrained with the fuels or oils, and such water tends to settle out and, when the specific gravity of the fuel or oils is less than that of water, the water settles on the bottom of the tank and can adversely affect the tank or the apparatus to which the fuel or oils is being supplied.

It is also well known in the art to remove water collected at the bottom of a tank by inserting into the tank a captive flexible elongate water pervious container, partially charged with a water absorbing material and a weighting means.

The flexible container is preferably held captive by a tether, attached to one end region of the elongate container and by which the flexible container can be controllably inserted into a fuel tank, conveniently through the filler opening thereof, lowered to the tank bottom and, subsequently, removed from the tank through the opening by which it was entered the tank.

Certain water absorbing materials for use with such flexible containers are well known in the art and often have the ability to absorb up to 15 times their own weight of water.

The weighting means proposed todate for such prior art water extraction devices comprise a single solids body or a fine granular material, such as sand.

There is however a problem in obtaining an efficient usage of water extractor devices proposed by the prior art arrangements in that, when the container is first inserted into the fuel tank, it is normally charged with a water absorbing material and weighting means having an initial volume less than 10% of the volume of the container. With the weighting material comprising a single weight said weight will settle in the bottom regions of the container and when the weights means comprise a fine granular weighting material, such as sand, such fine particle material settles in the bottom of the container. With the empty upper regions of the container having a specific gravity less than water, the flexible containers tends to adopt a substantially stable vertical position on the bottom of the tank.Thus, and particularly with tanks having a relatively shallow water deposit below the fuel or oil, only a small part of the water absorbing material will be exposed to the water in the tank and the greater part of the water absorbing material in the container remains above the water level.

In practise, whilst those particles of water absorbing material in contact with the water will absorb water and become swollen thereby, the swollen particles of water absorbing material tend to elevate the unaffected water absorbing material and the water absorbing material which is elevated into the fuel or oil is, thereby, rendered ineffective.

The present invention seeks to provide a flexible elongate water absorbing device including a water absorbing material and a weighting means, and wherein the weighting means are effective to render the water absorbing material within the container more efficient in absorbing water from the bottom regions of the tank.

According to the present invention there is provided a water absorbing device comprising an elongate, flexible water and fuel or oil permeable container, partially charged with a water absorbing material and a weighting means, characterised in that the water absorbing material is in particle form, the weighting means is in particle form, and the particles of the weighting means are larger than the particles of the water absorbing material.

Preferably the mean minimum dimension of the particles defining the weighting means is greater than twice the mean minimum dimension of the particles of the water absorbing material.

Preferably the weighting material comprises a relatively dense plastics or metallic material.

Preferably the weighting means comprise ferrous or non-ferrous or synthetic solid spherical particles.

Preferably the water absorbing material is a material capable of absorbing more than five times its own weight of water, more preferably more than eight times its own weight of water and most preferably more than twelve times its own weight of water.

In one preferred embodiment in accordance with the invention the water absorbing material comprises a salt of a cross-linked carboxylic acid or a mixture of a salt of a crosslinked carboxylic acid, potato, rice or wheat based starch, a carboxylmethyl cellulose, hydroxyethyl cellulose, polyacrylamide or starch grafted polymers.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Fig 1 shows a water absorbing device in accordance with the invention, partially cross-section, when newly inserted into a fuel tank and Fig 2 shows a cross-section through the device shown in Fig 1 after a period of time in the fuel tank.

In the embodiment illustrated in Fig 1 a flexible container comprises an elongate flexible tube 11 of a water and fuel or oil permeable material, such as a loosely woven natural or synthetic material or a perforated material. The tube 11 has one end lia firmly closed and defining the bottom of the tube 11 and it other end llb, defining the top end of the tube 11, closable by a tethering cord 12. The diameter of the tube 11 is such as to allow the tube 11 to nass readily through an opening 13a into a tank 13, and which opening 13a may conveniently comprise the filler opening for the tank 13, and to be withdrawn back through the opening 13a when the tube 11 is fully expanded.

The tube 11 is partially charged with a water absorbing material 14, comprising a salt of a cross-linked carboxylic acid, in fine granular form, and with a weighting material 15, such as lead shot.

The amount of water absorbing material 14 placed in the tube 11 is preferably less than one thirtieth of the volume of the tube 11, to prevent the tube 11 from being stressed by the water absorbing material when fully charged with water, and the amount of weighting material 15 included in the tube 11 is simply sufficient to cause the partially charged tube 11 to sink down to the bottom of the tank 13 and to act as ballast to retain the tube 11 on the bottom of the tank 13.

After charging the neck llb of the tube 11 is closed, as by the tether 12 and which may conveniently comprise a simple piece of cord of sufficient length to allow the end 11b of the tube 11 closed by the tether 12 to reach the bottom of the tank 13 whilst leaving sufficient of the tether 12 outside the tank to facilitate withdrawal of the tube 11.

With the tube 11 charged and closed said tube 11 is then ready to be inserted into the tank 13, through the opening 13a, and lowered to the bottom of the tank 13 by the tether 12. As the tube 11 nears the bottom of the tank 13 the extreme leading end regions of the bottom ila pass through the interface 16 of the fuel or oil contents F of the tank 13 and the water W collected in the tank 13 and, when the bottom 11a of the tube 11 contacts the bottom of the tank 13, the tube 11 may initially adopt a substantially vertical position, with the tethered end 11a uppermost.

Thus, in this position, only those regions of the bottom lla below the interface 16 are exposed to the water W and, because in accordance with the invention the particles of water absorbing material 14 are smaller than the particles of lead shot weighting material 15, some part of the water absorbing material 14 will always be at the bottom ila of the tube 11 and thereby exposed to the water W in the bottom of a tank, and this part of the water absorbing material 14 will immediately start to absorb water and expand forming a coherent gel.

As the water absorbing material 14 exposed to the water W takes in water and expands, the water absorbing material 14 within the fuel or oil F and the weighting means 15 are lifted within the tube 11 by the expanding water absorbing material gel. The elevation of the water absorbing material 14 in the fuel or oil F, and elevation of the weighting means 15, by the upwardly expanding column of water absorbing material gel increases the height of the column of material within the tube 11 and positively elevates the centre of gravity of the column of material within the tube 12.

The elevation of the centre of gravity of the material within the tube 11, with the redistribution of the particles of the weighting material in said column, causes the material-containing lower regions of the bottom ila of the tube 11 to tilt and to lie over, thereby allowing water absorbing material 14 to fall out of the fuel or oil F and become exposed to the water W in the bottom of the tank 13 As the amount of the water absorbing material 14 leaving the fuel or oil F to absorb water increases, the lower regions of the tube 11 become more horizontal, the general direction of expansion of the water absorbing material 14 exposed to the water W becomes more and more horizontal and with the water absorbing gel forcing the weighting means 15 substantially horizontally further and further along the tube, the laying down of the tube 11 becomes easier and easier until substantially the whole of the tube 11 lies horizontal and all the water absorbing material 14 is exposed to the water W. Aft er a period of time the tube 11 can be extracted from the tank 13 by simply drawing in the tethering cord 12, to elevate the charged tube 11, and the tube 11 can be removed through the opening 13a and discarded, or processed to allow the water absorbing material to be reused.

Whilst the present invention has been described by way of example with reference to a specific embodiment the invention is not restricted thereto and many modifications and variations within the scope of the invention will become apparent to persons skilled in the art.

Claims

1. A water extractor device comprising an elongate, flexible water and fuel or oil permeable container, partially charged with a water absorbing material and a weighting means, characterised in that the water absorbing material is in particle form, the weighting means is in particle form, and the particles of the weighting means are larger than the particles of the water absorbing material.

2. A water extractor device according to claim 1 characterised in that the mean minnnum dimension of the particles defining the weighting means is greater than twice the mean minimum dimension of the particles of the water absorbing material.

3. A water extractor device according to claims 1 or 2 characterised in that the weighting material comprises a relatively dense plastics or metallic material.

4. A water extractor device according to claims 1, 2 or 3 characterised in that the weighting means comprise ferrous or non-ferrous or synthetic solid spherical particles.

5. A water extractor device according to any one of claims 1, 2, 3 or 4, characterised in that the water absorbing material is a material capable of absorbing more than five times its own weight of water.

6. A water extractor device according to any one of claims 1, 2, 3 or 4, characterised in that the water absorbing material is a material capable of absorbing more than eight times its own weight of water.

7. A water extractor device according to any one of claims 1, 2, 3, 4 or 5, characterised in that the water absorbing material is a material capable of absorbing more than twelve times its own weight of water.

8. A water extractor device according to any one of the preceding claims characterised in that the water absorbing material comprises a salt of a cross-linked carboxylic acid or a mixture of a salt of a cross-linked carboxylic acid, potato, rice or wheat based starch, a carboxylmethyl cellulose, hydroxyethyl cellulose, polyacrylamide or starch grafted polymers.

9. A water extractor device according to any one of the preceding claims characterised by a tethering cord attached to the neck regions of the permeable container.

10. A water extractor device, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.