GB2174204A - Cleaning apparatus - Google Patents

Abstract

An apparatus is described for cleaning an outer generally cylindrical surface of an article, for example the outer generally cylindrical surface of a dissolved oxygen electrode. The cleaning apparatus has a cylindrical cage 1 with a plurality of through openings in its circum extending cylindrical surface. The cage is open at one axial end 6 for the axial insertion therewithin of the generally cylindrical portion of the article to be cleaned. A cylindrical drum 7 with an open end adjacent the open end of the cage is coaxially mounted within the cage for rotation about its axis. At least one brush 9 extends inwardly of the drum and sweeps the outer generally cylindrical surface of the article as the drum rotates. Drum 10 is rotated by electric motor 4 via reduction gearing 5. <IMAGE>

Description

SPECIFICATION Cleaning apparatus This invention relates to cleaning apparatus.

More particularly, but not necessarily exclusively, it is concerned with apparatus suitable for cleaning the cylindrical head of a dissolved oxygen electrode.

Such electrodes are commonly employed for measuring the oxygen content of water. When the electrode is submerged in water for an extended period of time, algae tend to build up on the surface of the electrode membrane.

In order that reliable readings can be produced, it is important that the membrane be maintained in a clean condition and also that there should be a constant flow past the membrane surface. In the past, a number of instrument measurement techniques have been adopted with a view to dealing with these problems. None has been entirely satisfactory.

We describe below a preferred embodiment of cleaning apparatus in accordance with this invention, the apparatus comprising: a cylindrical cage with a plurality of through openings in its circumextending cylindrical surface, the cage being open at one axial end for the axial insertion therewithin of a generally cylindrical article (such as the head of a dissolved oxygen electrode) to be cleaned; a cylindrical drum with an open end adjacent the open end of the case and coaxially mounted within the cage for rotation about its axis; and at least one brush extending inwardly of the drum and adapted to sweep the outer surface of said article as the drum rotates.

Desirably (as in the case of cleaning dissolved oxygen electrodes), the apparatus is adapted to be fully submerged in use, and includes a motor housing in which are mounted a small electric motor and a reduction gear therefor; the output drive shaft from the reduction gear passing through rotary shaft seal means isolating the motor housing from the liquor in which the cleaning apparatus is submerged, and being directly connected to the drum.

The drum preferably carries two axially spaced brushes which extend only partway circumferentially within the drum, the sweeps of the two brushes axially overlapping. We find that in this arrangement the rotation of the drum causes the brushes to create a turbulent paddle-wheel effect which both enhances the cleaning effect and, in the case of the dissolved oxygen electrode, ensures a constant flow past the membrane surface.

The invention is hereinafter more particularly described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a preferred embodiment of cleaning apparatus in accordance with the present invention in a side elevational view; and Figure 2 shows a sectional view taken along the line ll-il in Fig. 1.

The illustrated embodiment of cleaning apparatus includes a cylindrical cage 1 with a plurality of through openings 2 in its circumextending cylindrical surface, and a motor housing 3 within which are mounted a small electric motor 4 such as that available under the trade mark MAXON and a cooperating reduction gear head 5 such as the MAXON 2938.806-0500.

As shown in Fig. 2, the cage 1 has an opening 6 at one axial end. Coaxially mounted within the cage is a cylindrical drum 7 which is open at one end 8 adjacent the opening 6 of the cage. The drum 7 carries two brushes 9 suitably made of commercially available polyethylene brushstrip, a material commonly used for insulating the opening edges of doors, windows and the like. The end 10 of the drum 7 opposite the open end 8 is closed and joined to a shaft 11 which passes through two shaft seals 12, the shaft 11 being coupled, as by means of a grub screw 13 to the output drive shaft 14 of the reduction gear 5. Powerline 15, which may for example be coupled to a 12 volt car battery for portable use of the cleaner on site passes out through the end wall 16 of motor housing 3 through an opening which is sealed by a suitable O-ring 17 and gland 18.By means of this arrangement and the shaft seals 12, the interior of the motor housing 3 is sealed against the ingress of fluid, enabling the cleaning apparatus to be fully immersed during a cleaning operation.

If an article to be cleaned is inserted through the open ends 6 and 8 of the cage and drum (or alternatively the cage and drum are pushed over the end of an article to be cleaned), and the cleaner is operated to drive the drum rotatively, the brushes 9 will sweep the external surface of the article. As will be seen from Fig. 2, the brushes extend only partway circumferentially within the drum 7, there being substantial openings 19 allowing fluid to continuously flow through the openings 2 in the cage, through the openings 19 in the drum and past the article being cleaned.

The brushes 9 are positioned so that their respective sweeps overlap. The effect of the rotating brushes is to create an internal paddle-wheel effect within the drum causing turbulent flow and increasing the cleaning effectiveness of the apparatus.

The illustrated embodiment of apparatus is particularly easy to assemble. The reduction gear 5 and motor 4 are fixed in position by means of screws 20 received in a central block 21 with the shaft 11 extending through axial opening 22 in block 21 and through the two shaft seals 12. The drum 10 is then threadedly attached to the end of shaft 11.

The cage 1 and the outer casing of the motor housing 3 are then simply screwed on to the respective ends of the block 21, an intermediate O-ring 23 being included for the casing of the motor housing 3 to ensure a fluid-tight connection.

We have found that the above described embodiment of cleaning apparatus is very effective with conventional dissolved oxygen electrodes in maintaining the electrode membrane surface clean. The apparatus can be employed intermittently on site or may be permanently placed in position over the oxygen electrode and be driven directly from the existing D.C. power pack, in which case the cleaning apparatus may be left in position.

Claims (7)

1. Apparatus for cleaning an outer generally cylindrical surface of an article, the apparatus comprising: a cylindrical cage with a plurality of through openings in its circumextending cylindrical surface, the cage being open at one axial end for the axial insertion therewithin of the generally cylindrical portion of said article; a cylindrical drum with an open end adjacent the open end of the cage and coaxially mounted within the cage for rotation about its axis; and at least one brush extending inwardly of the drum and adapted to sweep the outer generally cylindrical surface of said article as the drum rotates.

2. Apparatus according to Claim 1 adapted to be fully submerged in use; said apparatus including a motor housing in which are mounted a small electric motor and a reduction gear therefor; the output drive shaft from the reduction gear passing through rotary shaft seal means adapted to isolate the motor housing from liquor in which the cleaning apparatus is submerged, and being directly connected to the drum.

3. Apparatus according to Claim 1 or Claim 2, wherein the drum carries two axially spaced brushes each of which extends only part way circumferentially within the drum, the sweeps of the two brushes axially overlapping.

4. Cleaning apparatus for use in conjunction with a dissolved oxygen electrode adapted to be submerged in use in an aqueous liquor, the cleaning apparatus comprising apparatus according to both claims 2 and 3, wherein said cylindrical drum has at least one through opening in its circumferential wall, the arrangement being such that rotation of the drum causes the brushes to create a turbulent paddle-wheel effect which in addition to achieving a cleaning effect on the dissolved oxygen electrode, causes a flow of liquor past the membrane surface of said dissolved oxygen electrode in use.

5. Cleaning apparatus according to Claim 4, permanently installed over a generally cylindrical dissolved oxygen electrode and adapted to be driven either intermittently or continuously from the power pack for said dissolved oxygen electrode.

6. Apparatus according to any preceding Claim, wherein each brush comprises a length of brushstrip.

7. Cleaning apparatus substantially as hereinbefore described with reference to and as shown in the accompanying drawings.