GB2122105A

GB2122105A - Water-gas separator

Info

Publication number: GB2122105A
Application number: GB08217489A
Authority: GB
Inventors: Robert Steuart Gladstone
Original assignee: Coopers Filters Ltd
Current assignee: Coopers Filters Ltd
Priority date: 1982-06-16
Filing date: 1982-06-16
Publication date: 1984-01-11
Also published as: ES8404869A1; ES523329A0; GB2122106A; SE8303386D0; FR2528716B1; GB8315853D0; FR2528716A1; DE3321688A1; GB2122106B; IT8348507A0; SE8303386L

Abstract

Water droplets are removed from air being fed to an I.C. engine by causing the air to change direction, in passage from inlet slot 7 to outlet 6, adjacent to a wire mesh pad 9 backed by impervious wall 8, so that entrained water droplets impinge on the pad and flow down it to outlet 11. <IMAGE>

Description

SPECIFICATION Improvements in and relating to air cleaners This invention relates to air cleaners and in particular to apparatus for at least reducing the amount of liquid entrained in an airstream entering an air cleaner. Where a conventional air - cleaner is used two filter the airflow to an internal combustion engine, it is often important to remove entrained liquid to -at least reduce it to an acceptable level. Paper air filters are not wellsuited to handling mixed liquid air flows. Water vapour is fairly well tolerated and may improve combustion efficiency. On the other hand, the levels of entrained liquid are often extremely high in the vicinity of road vehicles travelling at speed in wet weather.

Known liquid separators make use of centrifugal force and/or a sudden change of airstream direction which causes the heavier water particles/droplets to become ballistically separated from the airstream onto some form of collector surface which is connected to a drain aperture or channel. These known separators are not particularly efficient and it has been proposed that the airstream should be passed through a coarse wire mesh. The latter is known for its ability to coalesce droplets of liquid from an airstream, but where the throughput of wet air is high, the mesh may become "plugged" releasing quantities of water in the downstream direction At low temperatures the mesh may also-ice up.

According to the present invention a liquid separator comprises a casing containing liquid collector means in the form of a foraminous reticulated structure, and having an inlet and an outlet, the inlet being configured to create an inlet gas flow towards said collector means whereat said flow is caused to undergo a change of direction such that said droplets are ballistically separated from the gas flow and are received on the collector means. Preferably the inlet is in the form of a slot effective to accelerate the liquid droplet containing gas flow towards the collector means. The collector means is preferably constituted by a wire mesh pad on an impermeable support.

Preferably also, the liquid collector is so disposed as to be self-draining, liquid outlet means being provided for removing collected liquid to the outside of the casing.

Where the inlet communicates directly with a liquid-laden gaseous atmosphere, it is preferred that the margins of the inlet are shaped to deflect and/or exclude liquid which may collect on the external or internal surface of the casing. In particular, it is important to minimise the amount of such liquid which becomes entrained by the gas flow into the inlet.

As previously stated, it is advantageous to make the liquid collector means self-draining, under gravity. It is also convenient to make the gas flow generally upwardly over the liquid collector, i.e. against gravity, to enhance the separation effect.

In order that the invention be better understood preferred embodiments of it will now be described with reference to the accompanying drawing in which:~ Figure 1 is a cross-sectional side view of a liquid separator according to the invention, and Figure 2 is a cross-sectional side view of a modified liquid separator according to the invention.

In the figures, a casing 5 has an outlet 6 and a slot inlet 7. A liquid collector comprising an impermeable support 8 and a layer of steel wire mesh 9 is mounted inside the casing so that gas entering through the slot 7 has to undergo an abrupt change of.direction from slightly downwards (relative to the top of the casing) to a vertical or near vertical path along the surface of the-mesh 9, before passing around the end of an impermeable retaining cap 4, towards the outlet.

The cap 4 serves to minimise re-entrainment of liquid collected on the mesh, whilst an outlet 11 serves to drain the latter. In Figure 2 collector tubes 12 serve to accomplish this function, to the sides of the casing.

The slot has an upper lip in the form of an external channel 3 disposed to prevent liquid dripping directly into the inlet. The lip also has an internal channel 13 to serve the same purpose internally of the casing. The opposed edge 14 of the slot is also rounded, to smooth the inlet gas flow.

It will be appreciated that Figure 2 features two slots and two liquid collectors, as well as a differently directed outlet. Two slots enable a greater throughput.

In one practical embodiment based on Figure 1, the casing was generally rectangular with a slot dimension 2 in the range 20 to 30 mm, the exact size being selected so that for a given slot width, the peak flow velocity into the casing was about 20 m/s. The dimension 1 was about 40 mm, the wire mesh 9 being about 12 mm thick. The separator exhibited an overall pressure drop (from inlet to outlet) of about 55 mm of water.

On test with air artificially loaded with large quantities of water (by spraying), the separator removed about 85% of the water supplied to it. It was extremely effective.

1. Apparatus for separating liquid from a gas flow containing liquid droplets, the apparatus comprising a casing containing liquid collector means in the form of a foraminous reticulated structure having an inlet and an outlet, the inlet being configured to create an inlet gas flow towards said collector means whereat said flow is caused to undergo a change of direction such that said droplets are ballistically separated from the gas flow and are received on the collector means.

2. Apparatus according to claim 1 wherein the inlet is in the form of a slot effective to accelerate the liquid droplet containing gas flow towards the collector means.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in and relating to air cleaners This invention relates to air cleaners and in particular to apparatus for at least reducing the amount of liquid entrained in an airstream entering an air cleaner. Where a conventional air - cleaner is used two filter the airflow to an internal combustion engine, it is often important to remove entrained liquid to -at least reduce it to an acceptable level. Paper air filters are not wellsuited to handling mixed liquid air flows. Water vapour is fairly well tolerated and may improve combustion efficiency. On the other hand, the levels of entrained liquid are often extremely high in the vicinity of road vehicles travelling at speed in wet weather. Known liquid separators make use of centrifugal force and/or a sudden change of airstream direction which causes the heavier water particles/droplets to become ballistically separated from the airstream onto some form of collector surface which is connected to a drain aperture or channel. These known separators are not particularly efficient and it has been proposed that the airstream should be passed through a coarse wire mesh. The latter is known for its ability to coalesce droplets of liquid from an airstream, but where the throughput of wet air is high, the mesh may become "plugged" releasing quantities of water in the downstream direction At low temperatures the mesh may also-ice up. According to the present invention a liquid separator comprises a casing containing liquid collector means in the form of a foraminous reticulated structure, and having an inlet and an outlet, the inlet being configured to create an inlet gas flow towards said collector means whereat said flow is caused to undergo a change of direction such that said droplets are ballistically separated from the gas flow and are received on the collector means. Preferably the inlet is in the form of a slot effective to accelerate the liquid droplet containing gas flow towards the collector means. The collector means is preferably constituted by a wire mesh pad on an impermeable support. Preferably also, the liquid collector is so disposed as to be self-draining, liquid outlet means being provided for removing collected liquid to the outside of the casing. Where the inlet communicates directly with a liquid-laden gaseous atmosphere, it is preferred that the margins of the inlet are shaped to deflect and/or exclude liquid which may collect on the external or internal surface of the casing. In particular, it is important to minimise the amount of such liquid which becomes entrained by the gas flow into the inlet. As previously stated, it is advantageous to make the liquid collector means self-draining, under gravity. It is also convenient to make the gas flow generally upwardly over the liquid collector, i.e. against gravity, to enhance the separation effect. In order that the invention be better understood preferred embodiments of it will now be described with reference to the accompanying drawing in which:~ Figure 1 is a cross-sectional side view of a liquid separator according to the invention, and Figure 2 is a cross-sectional side view of a modified liquid separator according to the invention. In the figures, a casing 5 has an outlet 6 and a slot inlet 7. A liquid collector comprising an impermeable support 8 and a layer of steel wire mesh 9 is mounted inside the casing so that gas entering through the slot 7 has to undergo an abrupt change of.direction from slightly downwards (relative to the top of the casing) to a vertical or near vertical path along the surface of the-mesh 9, before passing around the end of an impermeable retaining cap 4, towards the outlet. The cap 4 serves to minimise re-entrainment of liquid collected on the mesh, whilst an outlet 11 serves to drain the latter. In Figure 2 collector tubes 12 serve to accomplish this function, to the sides of the casing. The slot has an upper lip in the form of an external channel 3 disposed to prevent liquid dripping directly into the inlet. The lip also has an internal channel 13 to serve the same purpose internally of the casing. The opposed edge 14 of the slot is also rounded, to smooth the inlet gas flow. It will be appreciated that Figure 2 features two slots and two liquid collectors, as well as a differently directed outlet. Two slots enable a greater throughput. In one practical embodiment based on Figure 1, the casing was generally rectangular with a slot dimension 2 in the range 20 to 30 mm, the exact size being selected so that for a given slot width, the peak flow velocity into the casing was about 20 m/s. The dimension 1 was about 40 mm, the wire mesh 9 being about 12 mm thick. The separator exhibited an overall pressure drop (from inlet to outlet) of about 55 mm of water. On test with air artificially loaded with large quantities of water (by spraying), the separator removed about 85% of the water supplied to it. It was extremely effective. CLAIMS

3. Apparatus according to claim 1 or claim 2 wherein the collector means is a foraminous reticulated structure constituted by a wire mesh pad on an impermeable support.

4. Apparatus according to any preceding claim wherein the collector is so disposed as to be selfdraining, liquid outlet means being provided for removing collected liquid to the outside of the casing.

5. Apparatus according to any preceding claim wherein the margins of the inlet are shaped to deflect and/or exclude liquid which may collect on the external and/or internal surface of the casing and flow towards said inlet.

6. Apparatus according to any preceding claim wherein the collector is at least in part approximately vertically disposed and the gas flow is initially directed towards the collector and is then caused to flow generally upwardly over the surface of the collector.

7. Apparatus for separating liquid from a gas flow containing liquid droplets substantially as herein before described with reference to and.as illustrated by the accompanying drawing.