GB2295330A - Filter/separator for IC engine fuel - Google Patents

Abstract

The device separates an entrained liquid from a carrier liquid (eg water from fuel) by gravity and includes a container 2 having an inlet 7 and outlet 12 with a collection chamber 6 below the physical level of the outlet. The inlet has a downpipe 8 arranged in a side chamber of the container with the outlet 9 arranged to direct the incoming liquid against a surface 10 such that its velocity is reduced whereby the entrained liquid settles out. A filter 13 may be provided for the outgoing carrier liquid. <IMAGE>

Description

LIQUID SEPARATING/FILTER UNIT This invention relates to liquid separating/filter units, and more particularly, but not exclusively, to units for removing contaminating water from liquid hydrocarbons such as liquid hydrocarbons commonly used as fuels for internal combustion engines.

It is known that liquid hydrocarbon fuels for internal combustion engines, as a result of the several distribution stages between the point of production of the fuel and the instant of usage i.e, at the engine carburettor/injectors, entrains contaminants such as water in addition to particulate solid detritus.

In general, the particulate contaminants arise from the presence of dirt, metal particles etc., which often occur in piping systems; in fuel tanks the latter including storage; transit and the vehicle fuel tanks. Such contaminants are conventionally removed by means of mechanical filtering arrangements such as those formed of, for example a wire or plastics mesh.

Similarly, it is possible for contaminant liquid, usually water, to be introduced into a fuel handling chain as above mentioned. For example, water can readily enter a fuel supply and distribution chain from atmospheric conditions and chemical/physical conditions arising from the nature of the fuel storage, transport, and in use i.e., whilst a motorist is filling the petrol tamk of his vehicle.

To deal with such contamination of liquid hydrocarbons intended for use as a fuel for an internal combustion engine it is well known to pass the fuel during its final transfer from a vehicle fuel tank or the like to the point of utilisation i.e., carburettor/fuel injector arrangements through a filter system.

The known systems are of a relatively complex construction and are thus, in a situation where a primary objective of manufacturers is to minimise costs, likely to involve cost levels that are considered to be economically unacceptable to the vehicle trade.

This situation is of high significance for the lower priced cost range of motor vehicles.

In other words in the vehicle price range at which the minimising of the production cost factor is possibly at its most important and crucial.

It is an object of the present invention to provide a separator unit for at least reducing to acceptable limits water contaminant content in a hydrocarbon for use as a fuel for prime movers at a cost level comparing favourably with the cost of known separator units.

Broadly according to the present invention there is provided a separator unit for separating a liquid having a first specific gravity from a carrier liquid having a second specific gravity different from the first specific gravity, the unit including a container for the liquids to be separated, the container having an inlet for the liquids, and an outlet for the carrier liquid; said container providing a contaminant collection chamber at a level lower than the physical level of said carrier liquid outlet; wherein the inlet to the container connects with means for introducing the carrier liquid and any contaminant therein into the chamber in such manner that the velocity thereof is reduced to a level such that comtaminants are able gravitationally to separate out from the carrier liquid and to collect in said chamber.

Conveniently the means for introducing the liquids into the chamber is arranged to discharge the liquids into the container at a predetermined level above the maximum depth of the container.

In particular, the outlet of the liquids introducing means is so formed that as the liquids to be separated are released into the chamber, the latter presenting a much greater flow area to the incoming liquids, the liquids flow velocity falls to a level enabling the gravitational separation of liquid contaminant from the liquid.

Preferably, said change in fluid flow is arranged to produce a change in the inlet liquids velocity within the ratio range 20 to 1 and 100 to 1 with a convenient ratio of the order of 50 to 1.

Preferably the liquids are discharged in such manner as to impact against a spreader surface located at the base of a side tube/chamber to the aforesaid chamber.

Conveniently, liquid introduction means includes a tube depending lengthwise of said side tube/chamber.

If desired there is additionally provided a mechanical filtering barrier, the latter being operationally located between the liquids inlet and the carrier liquid outlet to enable a mechanical filtering action for liquid passing therethrough following the separating action.

Preferably, any such the mechanical filter forms an inner chamber to the container the bottom of which inner chamber is located above the contaminant collecting chamber.

For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawings in which: Figure 1 is a cross sectional view of a liquid separator unit incorporating the concepts of the invention, taken along a planne indicated by the line I-I of Figure 2; Figure 2 is a cross sectional view of a the unit of Figure 1, when incorporating a mechanical filter for filtration of particulate contaminants; Figure 3 is a plan elevation of Figure 2; and Figure 4 is an elevation of the unit of Figures 2 and 3 in the direction of the arrow II, Referring now to the drawings and more particularly to Figures 1 and 3 the separator unit 1 of the invention includes a hollow container 2 depending downwardly from a top plate assembly 3. Preferably the container is formed from a transparent material.The container, as may be particularly noted from Figures 1 and 3 has a wall 4 with a generally cylindrical configuration 4 except for a laterally extending side chamber 5. The base 6 of the container is convex downwardly. The container is non-removably secured to the top plate assembly 3.

A connection 7 is provided for receiving the liquids to be separated, the connection 7 connecting internally of the top plate assembly 3 with a downwardly depending tube 8 whose lowermost end 9 terminates just above the base of the side chamber 5. As may be seen from Figure 1 the bottom of the side chamber defines a surface 10 against which liquids flowing from the lowermost end of the tube are directed. The surface 10 an be conveniently regarded as a spreader surface for the incoming liquids.

As will be noted from Figure 1 the lowermost end of the tube 8 is located above the lowermost region of the container 2.

Water contaminated liquid introduced into the inlet connection 7 travels downwards through the tube 8 to be directed against the spreader surface 10. As will be appreciated it is at this point that the incoming liquid effectively directed across the full area of the chamber and in so doing is able to spread into this greater area.

This sudden change in area available to the incoming liquids results in a reduction the velocity of the incoming contaminated liquid to such an extent that any contaminant liquid with a specific gravity less than that of the carrier liquid is able to settle out under the action of gravity as the carrier liquid already in the container is effectively displaced i.e., pushed, by incoming liquids flowing down the tube 8, upwardly of the container towards an outlet 12 located in the top plate assembly 3.

It will be appreciated that solids denser than the density of the carrier liquid can also settle out during the liquids separation process.

The heavier liquid i.e., water separating from the lighter liquid i.e., petrol, settles downwardly to accumulate at the bottom 6 of the container 2. In practice, it is convenient to specifiy a maximum level for accumulated water this is indicated by the line marked MAX in the Figure 1.

The unit of the invention is essentially regarded as a disposable item and it is therefore intended that when the level of water accumulated in the chamber attains the specified maximum level the separator unit should be replaced.

Since in the case of the motor vehicle the quantity of water normally expected to be entrained in the fuel is of relatively small quantities the unit of the invention is anticipated as having a considerable usage life.

As has been mentioned it is possible to incorporate a mechanical filter within the unit of the invention for the purposes of providing additional means for removing particulate material which has not settled out under the action of gravity. A separator unit in accordance with the invention and incorporating a mechanical filter 13 operationally interposed between the liquid inlet and outlet of the unit is shown in Figure 2. Since, except for the mechanical filter, the construction of the unit of Figure 2 is otherwise the same as that already discussed in relation to Figure 1 further discussion of the unit of Figure 2 is not thought necessary.

The container 2 and the top assembly 3 can be secured one to the other by an ultrasonic welding process. If desired, the two parts may be connected one to the other by use of an adhesive.

In a further modification of the unit the filter can take the form of a length of filtering material which is folded concertinawise into a cylindrical form. The thus folded filter is provided with top and bottom caps. The top cap is apertured to receive a mounting bolt or the like.

Claims (11)

1. A separator unit for separating a liquid having a first specific gravity from a carrier liquid having a second specific gravity different from the first specific gravity, the unit including a container for the liquids to be separated, the container having an inlet for the liquids, and an outlet for the carrier liquid; said container providing a contaminant collection chamber at a level lower than the physical level of said carrier liquid outlet; wherein the inlet to the container connects with means for introducing the carrier liquid and any contaminant therein into the chamber in such manner that the velocity thereof is reduced to a level such that comtaminants are able gravitationally to separate out from the carrier liquid and to collect in said chamber.

2. A separator uni as claimed in claim 1, and in which the means for introucing the liquids is arranged to discharge the liquids into the container at a predetermined level above the maximum depth of the container.

3. A separator unit as claimed in claim 1 or 2, and in which the outlet of the liquids introducing means is so formed that as the liquids to be separated are released into the chamber, the latter presenting a much greater flow area to the incoming liquids whereby the liquids flow velocity falls to a level enabling the gravitational separation of liquid contaminant from the liquid.

4. A separator unit as claimed in claim 3, and in which said change in the fluid flow velocity within a ratio range of 20 to 1 and 10 to 1.

5. A separator unit as claimed in claim 3, wherein the ratio is of the order of 50 to 1.

6. A separator unit as claimed in claim any of claims 1 to 5, and in which the liquids are discharged in such manner as to impact against a surface effectively defining said spreader surface.

7. A separator unit as claimed in claim 5, and in which said spreader surface is located at the base of a side tube/chamber to the aforesaid chamber.

8. A separator unit as claimed in claim 7, and in which the liquid introduction means includes a tube depending lengthwise of said side tube/chamber.

9. A separator unit as claimed in any of the preceding claims, and in which there is additionally provided a mechanical filtering barrier, the latter being operationally located between the liquids inlet and the carrier liquid outlet to enable a mechanical filtering action for liquid passing therethrough following the separating action.

it). A separator unit as claimed in claim 8, and in which the mechanical filter forms an inner chamber Lo the container the bottom of which inner chamber is located above the contaminant collecting chamber.

11. A separator unit constructed and arranged to operate substantially as here in before described with reference to Figures l,3 and 4 or Figure 2 of the accompanying drawings.