GB2222100A - Air water separator - Google Patents

Abstract

An air water separator comprises a chamber 28 into which moist air under pressure is introduced, an outlet 34 for compressed air and an outlet for separated water, said latter outlet comprising a small bore tube 36 leading from a location 38 where water collects in the chamber to a position for draining outside the chamber, said tube being of sufficient length and bore to inhibit substantial outflow of air when the chamber contains no water, and the air inlet 30 and chamber being arranged so that where the air is introduced into the chamber it is subjected to substantial deceleration, so that the air will have a residence time sufficient to cause water to separate therefrom and collect at the bottom of the chamber. Said air inlet 30 is spiral and the chamber may be lined with a felt material 32. The separator may be attached to a compressed air supply for an underground cutting device (Fig. 1). <IMAGE>

Description

Improvements Relating to Separating Devices ##1#11#####1####1#1-1#111#1---l1llr##lll This invention relates to separating devices, and in particular concerns a device for separating moisture from air.

It is frequently required that for various reasons moisture should be separated from air in that it is often required that air should be made substantially dry. In one such application, it is required that substantially dry air under pressure be supplied to the interior of an underground working device in particular an underground cutting device, to ensure that the dust generated by the cutting action does not penetrate into the cutter as such dust could result in clogging of the cutter working mechanism and controls. By supplying an interior chamber of the cutter with air under pressure, if there are any avenues of entry for dust into such chamber, such dust entry will not take place as the compressed air will constantly bleed through such entries keeping the interior dust free.However, if the air contains substantial amounts of moisture, there can be a tendency for the moisture to settle out of the air and collect as water in the chamber. The presence of water is almost as bad as dust, and therefore it is necessary that the air should be substantially moisture free when it is supplied to the chamber.

In such applications, it is easiest and least expensive to simply draw air from atmosphere, but atmospheric air almost invariably will contain substantial amounts of moisture and it therefore becomes a problem of taking steps to remove the moisture from the air before it is supplied for example to a cutter device as described above.

Typical apparatus for removing moisture from air comprises heating apparatus involving an appropriate heating source. The utilisation of heating source of course increases costs and often it is not viable to utilise in the case of an underground cutting device, a conventional heating apparatus for removing moisture from the air which is supplied to the cutting device.

The present invention however, provides a novel form of air water separator which is simple in construction, making relatively inexpensive as compared to a conventional heating apparatus, but which is efficient in operation.

In accordance with the present invention an air water separator comprises a chamber into which air under pressure and containing moisture is introduced, an outlet for compressed air and an outlet for separated water, said outlet for water comprising a small bore tube leading from a location where water collects in the chamber to a position for draining outside the chamber, said tube being of sufficient length and bore to inhibit substantial outflow of air when the chamber contains no water, and the air inlet and chamber being arranged so that where the air is introduced into the chamber it is subjected to substantial deceleration, so that the air will have a residence tank sufficient to cause water to separate therefrom and collect at the bottom of the chamber.

The technical effect of such construction is that when the air is introduced into the chamber, it is decelerated, typically by being caused to execute a swirling motion and as a result of this deceleration and residence in the chamber, the water separates out from the air, and collects at the bottom of the chamber where it in due course covers the adjacent ends of the small bore water outlet pipe, and the prevailing pressure in the chamber is such that it forces the water out of the pipe to a drain position from whence the water can be discharged. Compressed air is caused to flow from the outlet of the chamber.

When the air under pressure is first supplied to the chamber, i.e. when there is no water therein, the air will flow through the pipe with a progressively reducing velocity due to the friction between the air and the inner wall of the pipe so that there is minimal loss of compressed air during this period. Typically, the pipe may be of the order of 4mm diameter and of a length of , the pipe being coiled, turned or spiralled as required having dur consideration to the configuration of the chamber.

The device according to the invention may be a separate unit incorporated in a compressed air supply line leading to an operating apparatus, or it may be embodied in the apparatus.

The invention provides a simple, inexpensive and effective means for separating air from water and in the example of an underground cutting device described above, the separating apparatus preferably comprises a separate unit which will be located adjacent the cutting device when it is in use in an underground passage.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, wherein: Fig. 1 is a side view of a cutter assembly and separator unit according to the invention when in position in an underground passageway; and Fig. 2 is a perspective sectional elevation of the separator unit as shown in Fig. 1.

Referring to the drawings, in Fig. 1 reference 10 indicates an underground passageway typically a sewer in which is located a cutter unit or assembly 12 and an air water separator unit 14 according to the present invention. A compressed air pipe 16 supplies compressed air to the separator 14, whilst an outlet pipe 18 from the separator supplies compressed air to the interior of the cutter unit 12, in order to flood same with compressed air to ensure that there is no ingress of dust into the cutter unit in operation.

The cutter unit in fact may be for cutting apertures in lining sleeves applied to the sewer for the rehabilitation of same in the manner as indicated in U.K. Patent No. . The cutter bit is indicated by 20.

T h e p r e s e n t i n v e n t i o n i s c o n c e r n e d w i t h t h e construction of the separator Irl and this is shown in more detail in Fig. 2. The separator as shown comprises essentially a cylindrical casing 22 with end caps 24 and 26 sealing the casing 12 to provide an interior chamber 28. Air is supplied to the interior chamber 28 through the cap 26 by means of a spiral inlet 30 which leads the incoming air onto the inner wall of the casing 22 to cause same to spiral or swirl around the inside of the chamber. This is to ensure that the air will be decelerated as it enters the chamber, and in this regard the chamber may be lined with a felt material 32 of synthetic textile fibres such as polyester fibres.

At the other end, the cap 24 is provided with an air outlet 34 which connects with the pipe 18 for supplying air to the unit 12.

Typically the air whichis introduced into the unit 14 will be atmospheric air containing moisture, and the purpose of the unit Irl is to separate the moisture from the air so that it will collect as water in the base of the chamber 32 and so that essentially dry air will be emitted from outlet 34. The water does in fact collect in the base of the chamber 32, and its displacement from the chamber is achieved by means of a small bore pipe 36 which has an inlet 38 located at the base of the chamber so that it will be submerged in the collected water, and the small bore tube has an outlet 40 from which water can drain, the outlet being to the exterior of cap 24 as shown.The tube 36 is of sufficient length and sufficiently small diameter to ensure that when there is no water in the separator i.e. when air is supplied initially, there will be minimum loss of air through the small bore pipe due to the effects of friction. As the water collects, so it will cover the water inlet 38, and then the pressure inside the unit 14 when air-is being passed therethrough, will drive the water through the pipe 36 and it will drip from the outlet 40 so that it is prevented effectively from reaching the cutting unit 12.

This principle of air/water separation has been shown to be extremely effective, and whilst it is shown as being embodied in a separate unit 14, the unit could be embodied in the apparatus 12 if desired. The invention clearly has a wide application and can be used generally where air and water separation are required.

Claims (2)

1. An air water separator comprises a chamber into which air under pressure and containing moisture is introduced, an outlet for compressed air and an outlet for separated water, said outlet for water comprising a small bore tube leading from a location where water collects in the chamber to a position for draining outside the chamber, said tube being of sufficient length and bore to inhibit substantial outflow of air when the chamber contains no water, and the air inlet and chamber being arranged so that where the air is introduced into the chamber it is subjected to substantial deceleration, so that the air will have a residence tank sufficient to cause water to separate therefrom and collect at the bottom of the chamber.

2. An air water separator substantially as hereinbefore described with reference to the accompanying drawings.