Title of Invention

AN ELECTRODE ASSEMBLY

Abstract

The invention relates to an electrode for an electrochemical process, the electrode comprising a generally tubular electrode body, an elongate support member extending through the electrode body, spacer means connected between the electrode body and the support member for maintaining the inner surface of the electrode body spaced from the support member, and electrical conductor means in the space between the support member and said inner surface and electrically connected to said inner surface characterized in that the electrode body is made of relatively brittle material and, to support the electrode body while limiting radial and axial force applied thereto, said spacer means comprises resilient portions engaged with the electrode body for resiliency maintaining the spacing between the electrode body and the support member and the spacer means comprises locating means defining the longitudinal position of the electrode body relative to the support member, said electrical conductor means contacting the inner surface of the electrode body at a plurality of positions spaced along the electrode body.

Full Text

ELECTRODE ASSEMBLY The invention relates to an electrode. In our EP-08837OOB we have described and claimed an electrode for use in electrochemical treatment of metal reinforced concrete, the electrode comprising a generally cylindrical body formed of porous material, the body having an external surface and an internal surface, a power supply conductor in use, being in electrical contact with the interna! surface and with a supply of electrical current. The body wall is porous to allow ingress of gas and is preferably formed of a titanium suboxide of the formula TiOK where is 1.55 to 1.95. When electrode bodies are required to be supported at their extreme ends, in electrochemical cells, rather than being encased in concrete, it is often necessary to provide specially shaped end caps. If these are simply attached with adhesives, the adhesives often fail in the extremely aggressive electrochemical environment. If mechanical means of attachment is used, then the electrode material itself is subject to mechanical forces, which may damage the body if the material is brittle, since the wall of the body will not withstand high compressive and torsional forces when end caps are inserted. Such strains arise for example when too much force is used to tighten up nuts and can cause the body to fracture. It is one object of the invention to provide an electrode having a generally tubular body and end fittings which are easy to assemble and fix in place without any major mechanical stresses being applied to the body. It is another object of the invention to provide such an electrode in which the end fittings tend to align an elongate support for the internal electrode. According to the invention in one aspect there is provided an electrode comprising a generally tubular body having an external surface and an internal surface, an elongate rod extending between the ends of the body and having at least one end fitting at an end of the body, a power supply conductor being present in the annulus between the rod and the inner surface and in contact with that inner surface, and in use, in connection with a power supply. Preferably an end fitting in the form of a cap is present at one or both ends of the tubular body to close one or both ends, the or each cap having an inner end portion shaped to hold and contribute to the centralisation of the cap and engage the inner surface of the end portion of the body without stressing the body. Most preferably the engaging means of the inner portions comprises radially spaced apart flexible flutes or vanes. Most preferably the flutes or vanes are at an angle to the true radial direction such that once compressed the flutes or vanes will be bent in the same radial direction to further assist the centralisation. Most preferably the flutes or vanes are sufficiently tough and flexible to provide an element of flexibility in the axis of the end cap with respect to the axis of the tubular body, thus reducing bending stresses on the body, and also allowing the use of bodies with slightly variable internal diametric tolerances. It is also preferred that the inner end portions of the caps each define a socket to receive an end portion of the rod to space the two end caps at an appropriate distance to ensure that electrochlorination of water for, instance, swimming pools. Accordingly, the present invention provides an electrode for an electrochemical process, the electrode comprising a generally tubular electrode body, an elongate support member extending through the electrode body, spacer means connected between the electrode body and the support member for maintaining the inner surface of the electrode body spaced from the support member, and electrical conductor means in the space between the support member and said inner surface and electrically connected to said inner surface characterized in that the electrode body is made of relatively brittle material and, to support the electrode body while limiting radial and axial force applied thereto, said spacer means comprises resilient portions engaged with the electrode body for resiliency maintaining the spacing between the electrode body and the support member and the spacer means comprises locating means defining the longitudinal position of the electrode body relative to the support member, said electrical conductor means contacting the inner surface of the electrode body at a plurality of positions spaced along the electrode body. In order that the invention may be well understood it will now be described by way of example only with reference to the accompanying diagrammatic drawings, in which; Figure 1 is an exploded perspective view of one anode assembly of the invention; Figure 2 is a longitudinal sectional view of the anode of Figure 1; Figure 3A is a perspective view of one end cap and Figure 3B is an end view thereof; Figure 4 is a perspective view of an extension cap, and Figure 5 is an enlarged view of the area on Figure 2 marked 'V and showing the end of the anode from which a wire emerges. The anode assembly includes two elongate tubes 1, 1A arranged end to end. The tube 1 is made of titanium suboxide available under the registered trade mark EBONEX. The tube 1A is moulded of a plastics. The wall of the tube 1 is solid along its length, whereas the tube 1A is solid save for a slot 2 at one end 3. The tube 1 contains an elongate support rod 4 which holds two caps El, E2, in place, as will be explained below. A conductor wire 5 formed of titanium spring metal is present as a spiral about the rod 4 and has a straight tail 6 which emerges from the tube 1A at the end 3. This will be explained in better detail below. As shown in Figures 3A and 3B, the cap El consists of a cylinder having two longitudinal end portions 10, 11, separated by a shoulder 12. End portion 10 is shorter than the end portion 11. Six vanes are shown, but the number is not critical. The vanes are arranged so that they will flex in the same direction. The end portion 11 has inwardly turned reverse facing longitudinal spring tongues 15 located to be snap-engaged in slots 16 near the ends of the rod 4. An inner partition 17 is present to separate the two end portions and an inner shoulder 18 is present in the end portion 11, to act as an abutment for the end of the rod 4 so that the tongues 15 will align with the slots 16. The cap El is received in and engages in one end of the tube 1. The second end cap E2, has the same vane or fluting as El, but differs in the presence of hole 19, whereby the electrical connection wire passes through E2. The end portion 10 of E2 is illustrated to be as interference fit with tube 1 A. (This joint however could be made with an adhesive or with a friction or other welding technique). Tube 1A is present in this illustration to provide a smooth seal surface to allow the electrode to pass through the wall of the electrochemical cell, and so that the electrical connection from the power supply is outside the cell and easy to access. The wire 6 passes through the end of tube 1A through a hole, which is provided with a sealing system, such as is illustrated. Sealant can be injected into hole 2 and fill the annulus around the wire preventing any leakage of electrolyte through the end of tube 1A. The electrical connection can be made directly to the exposed end of wire 6, but in this example, the tube 1A is provided with a short threaded stud 25, around which can be bent the end of the wire 5, supported by washer 27, to present a neat terminal for the electrical connection. Typically the electrode is assembled by inserting the straight part 6 of wire 5 through hole 19 in E2 and then pressing tube 1A into place on E2 with wire 5 extending through the tube 1. Rod 4 is then placed into the socket in E2 and engaged with the clip. An assembly tool, not shown, is then used to "wind up" the spring part of wire 5, thus reducing its diameter such that the body 1 can be slid over it and onto tlie flutes of E2 probably with a slight rotation. Because the vanes flex in the same direction, they will tend to bend and reduce the overall diameter of the cap and act as a self-centring system. The spring is then released and allowed to engage on the internal surface of tube 1. El is then pressed into place, also with a slight rotational movement until it is captured by the clip engaging into rod 4, also with the flutes acting as a self-centring system similar to E2. Washer 26 is added and the wire bent around stud 25. Finally sealant is injected into slot 2. The flutes can also accommodate tubes of different diameters, as well as some flexibility to eliminate bending stresses. The support rod is positively engaged at both ends, which capture the rod and eliminates both compressive and extensive forces on the ceramic tube. Because all the parts lock together mechanically, there is no need for adhesives. WE CLAIM: 1. An electrode for an electrochemical process, the electrode comprising a generally tubular electrode body (1), an elongate support member (4) extending through the electrode body, spacer means (El, E2) connected between the electrode body and the support member for maintaining the inner surface of the electrode body spaced from the support member, and electrical conductor means (5) in the space between the support member and said inner surface and electrically connected to said inner surface characterized in that the electrode body (1) is made of relatively brittle material and, to support the electrode body while limiting radial and axial force applied thereto, said spacer means (El, E2) comprises resilient portions (13) engaged with the electrode body for resiliency maintaining the spacing between the electrode body and the support member and the spacer means comprises locating means (15) defining the longitudinal position of the electrode body relative to the support member, said electrical conductor means contacting the inner surface of the electrode body at a plurality of positions spaced along the electrode body. 2. The electrode as claimed in claim 1, wherein said spacer means comprises two spacer members (El, E2) positioned at respective ends of the electrode body (1) and each comprising resilient portions (13) engaged with the electrode body. 3. The electrode as claimed in claim 1 or 2, wherein said resilient portions comprise a plurality of flutes extending outwardly into engagement with the inner surface of the electrode body. 4. The electrode as claimed in claim 1 or 2, wherein said resilient portions comprise a plurality of flexible vanes extending outwardly into engagement with the inner surface of the electrode body. 5. The electrode as claimed in claims I, 2, 3 or 4, wherein said locating means comprises a spring tongue (15) projecting from the spacer means and operable to snap engage an aperture (16) formed in the elongate support member. 6. The electrode as claimed in any one of the preceding claims, wherein said spacer means comprises two caps at respective ends of the electrode body and operable to close the electrode body at said ends. 7. The electrode as claimed in any one of the preceding claims, wherein said spacer means has an end fitting (El) comprising a tubular portion (11) having a plurality of outwardly extending flexible vanes (13) and a shoulder portion (12) adjacent the tubular portion for engaging the inner surface and an end of the electrode body, said end fitting comprising electrode mounting means in the form of another tubular portion (10) extending from the shoulder portion (12) away from the first-mentioned tubular portion and having a plurality of outwardly extending flexible vanes (14). 8. The electrode as claimed in any one of the preceding claims, wherein said electrical conductor means (5) comprises spring means for resiliently contacting the inner surface of the electrode body. 9. The electrode as claimed in any one of the preceding claims, wherein the electrical conductor means (5) is a coiled helical spring for being wound up to enable it to be entered into said electrode body and then released so that its coils unwind and expand into electrical contact with the inner surface of the electrode body. 10. The electrode as claimed in any one of the preceding claims, wherein said electrode body is made of electrically conductive ceramic material, for example titanium suboxide, or said electrode body is made of ceramic material having a coating of electrically conductive material thereon. 11. An electrode for an electrochemical process, substantially as herein described with the reference to the accompanying drawings.

Documents:

in-pct-2002-1608-che abstract.pdf

in-pct-2002-1608-che claims.pdf

in-pct-2002-1608-che correspondence-others.pdf

in-pct-2002-1608-che correspondence-po.pdf

in-pct-2002-1608-che description (complete).pdf

in-pct-2002-1608-che drawings.pdf

in-pct-2002-1608-che form-1.pdf

in-pct-2002-1608-che form-18.pdf

in-pct-2002-1608-che form-26.pdf

in-pct-2002-1608-che form-3.pdf

in-pct-2002-1608-che form-4.pdf

in-pct-2002-1608-che form-5.pdf

in-pct-2002-1608-che pct.pdf

in-pct-2002-1608-che petition.pdf