WO2005115587A1

WO2005115587A1 - A filter cleaning apparatus and an associated cleaning method

Info

Publication number: WO2005115587A1
Application number: PCT/IT2004/000300
Authority: WO
Inventors: Sergio Musciacchio
Original assignee: Altair SRL
Current assignee: Altair SRL
Priority date: 2004-05-25
Filing date: 2004-05-25
Publication date: 2005-12-08
Anticipated expiration: 2006-11-25

Abstract

Apparatus (32) for cleaning a filter (10) includes a stationary hollow member having at least one aperture (37) for the intake of a cleaning fluid and a plurality of holes (40) for the exit of this cleaning fluid. The apparatus (32) can be fitted to the outside of the filter (10) in such a way that the cleaning fluid exiting from the said holes (40) is directed at the outer surface of the filter (10). It is preferable if the hollow body includes a coil/shaped length of tube (34).

Description

A filter cleaning apparatus and an associated cleaning method

The present invention relates to an apparatus for cleaning a filter, in particular a filter for an industrial vacuum plant, and to an associated method of cleaning.

Such filters, which are typically tubular in shape, are installed within a chamber into which a fluid is caused to flow, bringing dust and other particles with it. As it flows inwards from the outside of the filter, the fluid is freed of this dust and any other particles, which are trapped in the filter wall, and, once cleaned, it flows out of the filter once again.

In order to maintain the efficiency of the filter, its filtering surfaces must be cleaned periodically.

The object of the present invention is to provide an apparatus for cleaning these surfaces as fully and accurately as possible in a short time and at a low cost, and which is reliable and lasts well.

This object is achieved according to the invention by providing an apparatus including a stationary hollow member with at least one aperture for entry of a cleaning fluid and a plurality of exit holes for this fluid, the said apparatus being locatable outside the filter in such a way that the cleaning fluid coming out of the said holes is directed at the outer surface of the filter.

Since it can be arranged outside the filter, the apparatus of the invention is able to achieve thorough and effective cleaning. In addition, since it includes no movable parts, it significantly reduces the risk of blockages or breakdowns . It should be noted here that although the definition as "stationary" rules out the possibility of the apparatus including any components which would be deliberately moved in relation to one another in use (translatable nozzles or the like, for example) , it does not rule out the possibility of the entire apparatus or parts thereof being subject to small and not deliberately determined movements, due for example to thermal expansion, the resilience of the apparatus itself, the flow of the cleaning fluid through it or the like.

An additional object of the invention is to provide a method for cleaning a filter by means of apparatus of the type described above, in which, the cleaning fluid flowing from the holes in the hollow member is substantially directed at least at a portion of and preferably at all the outer filtering surface of the filter.

Further characteristics and advantages of the present invention will become apparent from the detailed description which follows, provided purely by way of non-limitative example, with reference to the appended drawings, in which: Figure 1 is a schematic perspective view of a filter fitted in a dust-removing chamber and having an associated cleaning apparatus according to the invention, Figure 2 is an exploded view of elements shown in Figure 1, Figure 3 is a perspective view of a filter with associated cleaning apparatus according to the invention, and Figure 4 is a perspective view of a cleaning apparatus according to the invention. A tubular filter 10 is ^' located in use (see Figure 1) in a dust-removing chamber 12 with a passage 14 for -the intake (see arrows 16) of a fluid which is cleaned of any dust or other particles carried along with it as it flows from the outside to the inside of the filter 10, flowing back into the outside environment once it is cleaned of the dust particles carried along with it (see arrows 20) . The filter 10 is disposed in the chamber 12 (see Figure 2) with its longitudinal axis 22 orientated vertically. It has a plurality of hooks 24 protruding radially outwardly from its top for removably securing it to a support plate 26, disposed in the chamber 12 and lying in a plane orthogonal to the axis 22, and having a central hole 28 for the purified fluid to flow out of. In particular, the plate 26 has circumferentially spaced through-bolts 30, which the hooks 24 can engage and disengage in a bayonet coupling as a result of rotation of the filter 10 about the axis 22.

The cleaning apparatus 32 is disposed (see Figures 3 and 4) around the outer surface of the filter 10. It comprises a stationary hollow body formed by a length of tube shaped as a coil 34 with its ends connected by an additional straight portion of tube 36 with an aperture 37 in its median portion for coupling with a connector sleeve 38 for supplying a cleaning fluid, in particular compressed air, supplied by a compressor which is not shown in the drawings. The rectilinear tube 36 is disposed parallel to the axis 22 of the filter 10.

A plurality of holes 40, preferably evenly spaced, are formed in the inner surface, facing the filter 10, of the spiral tube 34, for the cleaning fluid to flow out through. Preferably, the diameter of the tube 34, 36 is between 10 and 18mm, while the diameter of the holes 40 is between 1.5 and 2.5mm, with the holes being spaced by a distance of between 14 and 26mm, and the pitch of the coils of the tube 34 is between 70 and 130mm.

The apparatus 32 also includes means for selectively fixing it to the support plate 26 for the filter 10. These selective fixing means comprise a ring 42 secured to the upper portion of the hollow member and having a plurality of circumferentially spaced hooks 44 on its outside. The hooks 44 can form a bayonet coupling with the bolts 30 through the support plate 26, in the same way as the hooks 24 on the top of the filter 10, that is as a result of rotation of the cleaning apparatus about the axis 22 of the filter 10.

Whenever the filter 10 needs to be cleaned, it is sufficient simply to supply compressed air through the connector sleeve 38. The air flows through the tube portions 34, 36 and exits through the holes 40, being directed at the outer surface of the filter 10 and exerting a forceful mechanical action which detaches any accumulated impurities. These are collected (see Figure 1) in a waste container 46 arranged under the chamber 12 and which can be emptied periodically.

The cleaning action has been found to be particularly effective when the flow of compressed air is pulsed. It is advantageous if the speed of the compressed air as it leaves the holes 40 and hits the outer wall of the filter 10 is of between 167 and 238 m/s and the distance between the holes 40 and the facing portion of the- filtering surface is of between 5 and 15mm. It is preferable if the dimensions of the apparatus 32 are such that it extends along the entire length of the filter 10 so that it is able to clean the whole filter at the same time. However, if necessary it is possible to use apparatus of different dimensions from those of the filter 10 or to partially use an apparatus having the dimensions of the filter 10 so that the cleaning fluid can be directed only at particular areas.

The apparatus 32 can be made of any material such as metal, a plastics or composite material and the like. In any event, since it is essentially constituted by hollow components, it is light and does not weigh too heavily on the support plate 26.

The cleaning apparatus 32 does not impede the normal operation of the filter 10 and can therefore be left permanently in place around this latter. When necessary, during maintenance or inspection operations for example, it can easily be removed along with the filter 10 by rotating it about the axis 22 and releasing the hooks 44 from the bolts 30 on the support plate 26. The apparatus is then separated from the filter 10 by a simple axial movement.

Naturally, the principle of the invention remaining unchanged, manufacturing details and embodiments can vary widely from those those described and illustrated purely by way of non-limitative example, without departing thereby from the scope of the invention.

Claims

1. Apparatus (32) for cleaning a filter (10), comprising a stationary hollow member having at least one aperture (37) for the intake of a cleaning fluid and a plurality of holes (40) for the exit of said cleaning fluid, the said apparatus (32) being locatable outside the filter (10) in such a way that the cleaning fluid exiting from the holes (40) is directed at the outer surface of the filter (10) .

2. Apparatus (32) according to Claim 1, in which the said hollow member comprises a coil-shaped portion of tube (34) , the ends of which are connected by a further portion of tube (36) , the said holes (40) being formed in the inwardly-facing surface of the coiled portion (34) of tube.

3. Apparatus (32) according to Claim 2, in which the said further portion of tube (36) is substantially rectilinear and has an intake aperture (37) in its median portion, connected to a sleeve (38) for the intake of the cleaning fluid.

4. Apparatus (32) according to Claims 2 or 3 , in which the diameter of the said tube (34, 36) is between 10 and 18mm.

5. Apparatus (32) according to any preceding Claim, in which the diameter of the said holes (40) is between 1.5 and 2.5 mm and they are spaced by a distance of between 14 and 26 mm.

6. An apparatus (32) according to any preceding Claim, in which the said holes (40) are spaced equidistantly.

7. An apparatus (32) according to any Claim from 2 to 6, in which the pitch between the coils of the coil-shaped portion of tube (34) is between 70 and 130 mm.

8. An apparatus (32) according to any preceding Claim, in which the said apparatus (32) includes means for selectively fixing it to the support structure of the filter (10) .

9. An apparatus (32) according to Claim 8, in which the said selective fixing means include a ring (42) secured to the upper portion of the hollow member and having a plurality of outwardly protruding spaced hooks (44) able to engage bolts (30) associated with the said support structure.

10. A method of cleaning a filter (10) by the use of an apparatus (32) according to any preceding Claim, in which the cleaning fluid flowing out of the holes (40) in the hollow member is substantially directed at at least a portion of the outer filtering surface of the filter (10) .

11. A method according to Claim 10, in which the cleaning fluid flowing out of the holes (40) in the hollow member is directed simultaneously over the entire outer filtering surface of the filter (10) .

12. A method according to Claim 10 or Claim 11, in which the said cleaning fluid is compressed air.

13. A method according to any preceding Claim 10 to 12, in which the stream of cleaning fluid through and out from the hollow member is pulsed.