Air Cleaners DESCRIPTION

The invention relates to air cleaners, wet dust- -extraction units, or self-induced spray scrubbers.

Background Art

The invention is an improvement on the air cleaners described in our British Patent Specification 1,037,789. The air cleaners described in our earlier Patent Specification work very well provided that the water level is maintained, and the apparatus is level. Otherwise, air escapes cleaning or has to be forced through an unnecessary amount of water. These limitations limit usefulness in.vehicles, ships, mines and tunnels.

Disclosure of Invention

An air cleaner according to the invention comprises a tank f cleaning liquid, an extensible or .flexible feed tube for air and an outlet at the end of the feed tube including means for maintaining the outlet at the level of the cleaning liquid. This makes it possible for the cleaner to be used with various levels of cleaning liquid and when the cleaner itself is not level.

The means for maintaining the outlet level is preferably means for floating the outlet at the surface of the

cleaning liquid. In use, the liquid surface tends to be depressed by the feed air forming a supporting cushion, and there is some turbulence, but the outlet can be maintained substantially at the level of the liquid surface. The pressure of feed air tends to lift the outlet out of the water, so the outlet should be made reasonably heavy.

The outlet may be provided with floats, guides with reference to the inside of-the tank, dampers to mitigate buffetting by the motion of the cleaning liquid, and/or baffles to reduce carry over of liquid out of the tank. These may be attached to the outlet, to the inside of the tank, or independent.

The outlet preferably has a low aspect ratio in plan, that is to say it is preferably rounded or circular rather than long and thin. The space under the outlet i preferably divided into separate chambers in such a way that a change in pressure in one chamber (due for instances to tilting of the outlet) has minimal effect upon the pressure in the other chambers. A similar effect can be achieved by providing two or more extensib feed tubes, possibly connected together or independent. The outlet may be provided around the edge with a skirt for depending into the liquid, and the skirt is preferably provided with an indented edge. Each of the modifications tends to reduce the pressure under the

^" BU outlet if part of the edge of the outlet should _jd.se _Q MM

relative to the surface of the cleaning liquid, and this induces a righting moment to stabilize the outlet over the liquid.

Brief Description ^' of Ωr ^' awTήgs

Figure .1 is a vertical section through an air cleaner; Figure 2 is a vertical section perpendicular to that of Figure 1 and including a modified outlet; Figure 3 is a section through a modified air cleaner;

Figure 4 is a vertical section perpendicular to that of Figure 3 and including a modified outlet; Figure 5 is a vertical section through another air cleaner; and

Figure 6 is an isometric view _of a urther modified, outle of the feed tube.

Best.Mode of Carrying Out the ^{' "} Invention In Figures 1 anς. 2 the cleaner comprises a chamber 10 having, a tank of cleaning liquid, as its lower part. An extensible feed tube 12 for air enters at one side of the chamber, and ends with an outlet 14. The outlet 14 is provided with floats 16, weights 18, hydraulic dampers 20 which also function as guides for the outlet in the tank, and baffles 22. Alternative air outlets 24 from the chamber to fan are provided.

Figures 3 and 4 are very similar to Figures 1 and 2, but

. the space under the outlet 14 is divided by sheets 26 into separate chambers 28. The outlet 14 is provided around the edge with a skirt 30 indented with "dogs teeth" 32.

In Figures 5 and 6 also the same reference numerals h been used to indicate corresponding parts. In Figure the feed tube 12 is quadrupled, and each branch leads a separate chamber 28 divided off from the others by sheets 26 and surrounded by. a skirt 30. The outlet 14 box shaped. ^" Industrial Applicability

An air cleaner according to the invention can be used removing dust xrom the atmosphere, for example at the coal face. Air is drawn through by a fan (not shown) at the outlet, and leaves the entrained dust in the liquid. On installation and prior to use, the air cleaner is preferably levelled so as to keep the inclination of the outlet in operation to a minimum.

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