WO2006032095A1 - Demountable electrode housing - Google Patents

Abstract

An electrocoagulation cell (9) having an outer housing (10, 10A) and a demountable electrode housing (40, 40A) which is releasably retained within the outer housing (10, 10A) whereby the electrode housing (40, 40A) which contains an electrode assembly (33, 34, 52) may be removed from the outer housing (10, 10A) for clearing and maintenance when required.

Description

"DEMOUNTABLE ELECTRODE HOUSING" This invention relates to a demountable electrode housing or electrode assembly which may be releasably retained within an outer housing connected to a source of electrolyte or liquid requiring to be processed by electrode assembly.

Hitherto one example of an electrocoagulation cell containing a plurality of electrodes was an electrocoagulation cell described in International Publication 2004/046051. In this reference a plurality of electrodes which comprised unipolar or electrically connected electrodes and bipolar or non electrically connected electrodes was retained within an electrocoagulation cell comprising a plurality of individual longitudinal grooves or channels wherein an opposed pair of channels on each side of the electrocoagulation cell releasably retained a respective electrode. Each electrode was provided with an upstanding integral tab having a slot for retaining a busbar assembly comprising a threaded bar functioning as a means for electrically connecting each electrode to a power supply electrically connected to the threaded bar by power leads releasably attached to the threaded bar at each end thereof. In this arrangement unipolar electrodes were releasably attached to the threaded bar by nuts located on each side of an individual electrode. This arrangement was advantageous because an entire set of unipolar electrodes could be removed from the electrocoagulation cell for cleaning and maintenance and replaced by another set of electrodes connected to each other by a similar busbar assembly. However while an entire set of electrodes could be removed from an electrocoagulation cell as described for cleaning and maintenance purposes and replaced by a substitute electrode assembly it was still necessary for the electrocoagulation cell to be subject to cleaning and maintenance and this was not only time consuming but difficult to carry out if the electrocoagulation cell was located in a relatively inaccessible position. In this regard it had to be borne in mind that if cleaning and maintenance of the EC cell was not carried out frequently then the operational lifetime of the EC cell was substantially reduced. It is therefore an object of the invention to provide a demountable electrode housing which may reduce the abovementioned disadvantage of the prior art.

The invention therefore provides an electrocoagulation cell having an outer housing and a demountable electrode housing which is releasably retained within the outer housing whereby said electrode housing containing an electrode assembly may be removed from the outer housing for cleaning and maintenance when required.

The outer housing of the EC cell may comprise an inlet for passage of influent which may be wastewater requiring treatment or processing by the EC cell. However this may not be necessary if the electrode housing is provided with an inlet. The outer housing may also be provided with an outlet if desired. Preferably the outer housing may also comprise an upper compartment having retaining means for the electrode housing exemplified by a retaining flange and/or a pair of opposed bearing walls surrounding an aperture for insertion of the electrode housing. The recess may be located in an internal partition of the outer housing which separates the upper compartment from a lower compartment. The outer housing may also be provided with an open top or removable lid or cover for insertion of the electrode housing when required.

Preferably the lower compartment has an open side wherein the electrode housing may rest on a base of the outer housing and have an inlet for reception of waste water which extends through an open side of the outer housing. The electrode housing is preferably elongate and may then have a bottom or base wall which contacts the base of the outer housing.

However in another embodiment the outer housing may have one or more bearing walls which define an internal recess for the electrode housing with an inlet for the electrode housing located in the recess. In this arrangement there is no requirement for an internal partition separating the outer housing into an upper compartment and lower compartment.

If required there may be provided attachment means between the outer housing and the electrode housing such as by the use of fasteners extending between co-aligned apertures between the electrode housing and the outer housing. However such attachment means may be avoided if the electrode housing is of sufficient weight to be securely retained within the outer housing.

The advantage of using an electrode housing which is demountable leads to advantages in use because upon removal of one electrode housing which requires cleaning or maintenance then this can be replaced by another electrode housing containing a clean set of electrodes. This means that in another aspect of the invention there may be provided a method of cleaning or maintenance of an EC cell which includes the steps of: (i) removing a first electrode housing containing a set of electrodes which require cleaning from an EC cell housing or outer housing; and

(ii) replacing said first electrode housing with a second electrode housing containing a clean set of electrodes which is retained within the EC housing or outer housing.

It will also be appreciated that the method of the invention will also involve replacing the electrode housing used in step (ii) when their electrodes become soiled or when they require cleaning by the first electrode housing after it has undergone cleaning and maintenance. In regard to the electrodes used in the electrode housing of the invention they are preferably removable from the electrode housing and in one example an electrode assembly may be used as described in WO 2004/046051 which publication is reproduced herein in its entirety. This electrode assembly comprises a busbar arrangement attaching each electrode to a threaded bar by fasteners inclusive of nuts and washers.

Reference may be made to a preferred embodiment of the invention as shown in the attached drawings wherein:

FIG 1 is a corner perspective view of the electrocoagulation cell or outer housing with the electrode housing removed for clarity; FIG 2 is another perspective view of the outer housing of FlG 1 from another corner;

FIG 3 is another perspective view of the outer housing from the top thereof containing the electrode housing; FIG 4 is a similar view to FIG 1 showing the electrode housing retained within the outer housing;

FIG 5 is a top plan view of the electrode housing containing a number of electrode plates;

FIG 6 is a perspective view of the electrode housing and one assembly of electrode plates attached to each other by a busbar;

FIG 7 is a perspective view of the electrode housing containing two spaced busbar assemblies interconnecting separate arrays of electrode plates with each array partially removed from the electrode housing for clarity; FIG 8 is a top plan view of the arrangement of electrode housing and two busbar assemblies shown in FIG 7; and

FIG 9 is a top plan view of an electrocoagulation cell that has been modified to the outer housing shown in FIGS 1 to 4;

In the electrolytic cell 9 having outer housing 10 shown in FIGS 1 to 4, the housing 10 has an open top 12, a front wall 13, a rear wall 14, base 15, drain aperture 16, upper side wall 18, lower side wall 19, flange 20, outlet elbow fitting 21 , outlet pipe 22, conduit 23 which extends through upper side wall 18 for conveying electrical connection leads 56 and 57 to electrode plates 52 as described hereinafter and electrical conduit 24. Cell 9 is supported by mounting platform 25 supported by struts 26.

On the side of housing 10 opposed to side walls 18 and 19 there is provided upper side wall 18A which is opposed to side wall 18 and an open side 26 leading in to lower compartment 39. In the open top 12 of housing 10 best shown in FIG 3, there is shown upper compartment 28 having base partition 29, retaining rib 30, outlet aperture 31 and cut out 32. There is also shown aperture 65 in internal partition 29 to accommodate electrode housing 40. Electrode housing has a lower part 40A that extends into lower compartment 39 of outer housing after passing through aperture 65 as best shown in FIG 4.

In the electrode housing 40 shown in FIGS 3, 4, 5, 6, 7 and 8, the electrode housing 40 as best shown in FIG 5, has an open top compartment

42 having opposed flanges or walls 43 and 44 and wall 45 interposed between flanges 43 and 44 having channels 47 separated by ribs or spacers 46.

There is also provided a planar area 48 adjacent electrode plates 52. There is also provided as shown in FIG 6 a locating flange 49 and recess 50 for engaging with rib 30 of cell 10 when electrode housing 40 is inserted into housing 10 as described herein and as shown in FIG 3. The electrode housing 40 also has an elongate part 51 which occupies the major part of the length of housing 40 which has an internal compartment 61 occupied by electrode plates 52. As shown in FIG 5 internal compartment 61 has another side 37 opposite to wall 45 also having channels 47 and spacers 46.

There is also provided in FIG 6 adjacent electrode housing 40 a plurality of electrode plates 52 each having tabs 53 adjacent top edges 54. Each tab has a slot 38 best shown in FIG 8 through which extends busbar assembly 33 having threaded bar 55A.

Bar 55A is retained in each slot of electrode plates 52 so that each of electrode plates are aligned in a series alignment. The bar 55A is maintained in position to electrode plates 52 by securing means comprising nuts 59 and washers 60. In this embodiment each nut 59 is screw threadedly engaged to bar 55A.

As best shown in FIGS 3, 7 and 8 there is shown another busbar assembly 34 having threaded bar 55 which are also connected to slots 38 of electrode plates 52 wherein bar 55A is maintained in position by nuts 59 and washers 60.

As best shown in FIG 3 each busbar assembly 33 and 34 is connected by lead connections 56 and 57 which are each connected to a power source (not shown). Each lead connection 56 and 57 extends into conduit 58 which is attached to side wall component 18 of cell 10 by retainer

35.

Each busbar assembly 33 and 34 is as previously described in International Publication WO 2004/046051 and form connected electrodes or unipolar electrodes 52A as shown in FIG 7. These electrodes may be cationic or anionic depending upon the polarity of the power supplied through connections 56 and 57. The remaining unconnected electrodes 52B as shown in FIG 7 are bipolar and are charged by the energised electrolytic solution passing through cell 9. In operation influent may pass through inlet 62 of electrode housing 40 shown in FIG 4 through inlet conduit 63. The influent is then passed through electrodes 52 in internal compartment 61 of electrode housing 40 before passing out of electrode housing 40 before occupying at least part of upper compartment 28 before exiting cell 9 through outlet aperture 31 and outlet pipe 22.

However the principle of the invention is shown in the preferred embodiment described above where electrode housing 40 is releasably retained within an outer housing 10 by initially extending electrode housing 40 through aperture 65 best shown in FIG 3 until base 66 of electrode housing 40 contacts base 15 of housing 10 as shown in FlG 4. In this procedure inlet 62 of electrode housing 40 passes through cut out 32 and as described above and locating flange 49 engages with mating rib 30 of housing 10 as shown in FIG 3. In a modification to the outer housing 10 shown in FIGS 1 to 4, FIG 9 shows an alternative outer housing 10A having an inner compartment 28A which has a U-shaped rib 3OA surrounding a recess 65A. There is also provided electrode housing 70 having opposed side edges 71 , planar region 72 and a locating flange 73 which hooks over top edge 77 of U shaped rib 3OA. Recess 65 is provided with inlet 74. There is also provided drain aperture 76 in outer housing 10A. Electrode housing 70 is also provided with channels 47 and ribs 46 for insertion of electrode plates (not shown).The top of electrode housing 40A may be located 18-25mm below top edge 78 of outer housing 10A to allow for incorporation of busbar assemblies 33 and 34. When electrode housing 40 or 4OA is retained within outer housing 10 or 10A as described above each of busbar assemblies 33 and 34 may be already connected to electrode plates 52A as described above. This only requires the attachment of connection leads 56 and 57 to respective busbar assemblies 33 and 34 to complete installation of electrode housing 40 within outer housing 10.

It is also within the scope of the invention that nonpolar or electrically connected plates may be installed in electrode housing 40 as one unit or as multiples thereof and bipolar or non-electrically connected electrodes may be installed within electrode housing 40 separately to the non polar electrodes.

In a further modification electrode housing 40 may be releasably retained within housing 10 by appropriate releasable attachment means such as interference fit or by clamp means for example before installation of an electrode assembly comprising unipolar plates and associated busbar assemblies as well as bipolar electrode plates.

Another advantage of the demountable electrode housing is the fact that it ensures that electrodes are in the correct configuration and having the relevant spacing required. Sometimes it is only necessary to clean the electrode housing with the electrodes retained therein and thus it may only be necessary to remove the electrodes from the electrode housing at longer intervals.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. An electrocoagulation cell having an outer housing and a demountable electrode housing which is releasably retained within the outer housing whereby said electrode housing which in use contains an electrode assembly may be removed from the outer housing for clearing and maintenance when required.

2. An electrocoagulation cell as claimed in claim 1 wherein the electrode housing contains an electrode assembly.

3. An electrocoagulation cell as claimed in claim 1 or 2 wherein the outer housing has an inlet for passage of wastewater requiring treatment in use.

4. An electrocoagulation cell as claimed in any preceding claim wherein the outer housing is provided with an inner partition forming an upper compartment and a lower compartment and said partition is provided with an aperture for insertion of said electrode housing.

5. An electrocoagulation cell as claimed in claim 4 wherein the electrode housing is provided with a locating flange adjacent an upper end thereof which locates about an internal retaining rib located in the outer housing.

6. An electrocoagulation cell as claimed in claim 4 or 5 wherein the electrode housing rests on a base wall or floor of the outer housing and said outer housing has an open side through which extends an inlet conduit which communicates with a hollow interior of the electrode housing.

7. An electrocoagulation cell as claimed in claim 1 or 2 wherein the outer housing has one or more internal ribs or walls surrounding or defining a recess for insertion of the electrode housing.

8. An electrocoagulation cell as claimed in claim 7 wherein the electrode housing is provided with a top locating flange which engages with an upper edge of an adjacent wall of the recess.

9. An electrocoagulation housing as claimed in claim 7 or 8 wherein there is provided a pair of opposed walls or ribs defining said recess.

10. An electrocoagulation housing as claimed in any one of claims 7 to 9 wherein there is provided a U shaped internal rib surrounding the recess.

11. A method of cleaning or maintenance of an electrocoagulation cell which includes the steps of: (i) removing a first electrode housing containing a set of electrodes which require cleaning from an EC cell housing or outer housing; and

(ii) replacing said first electrode housing with a second electrode housing containing a clean set of electrodes which is retained within the EC housing or outer housing.

12. A method as claimed in claim 11 which includes a further step of replacing the electrode used in step (ii) when maintenance of the electrodes is required by the first electrode housing after it has undergone cleaning or maintenance.