ARRANGEMENT IN FRAME USED IN ELECTROLYSIS PROCESS
BACKGROUND OF THE INVENTION
[0001] The invention relates to a frame to which a diaphragm used in an electrolysis process is attachable and to the inside of which an electrode is adaptable, the frame comprising at least: an elongated first vertical bar and an elongated second vertical bar; and a horizontal bar for connecting first ends of the vertical bars.
[0002] The invention further relates to a profile piece for a frame used in an electrolysis process, the profile piece being an elongated piece made at least mainly from a plastic material.
[0003] The invention still further relates to a corner piece for a frame used in an electrolysis process.
[0004] Electrolysis is a known step used in the production process of metal. Electrolysis takes place in a basin, wherein are arranged electrolyte, positive electrodes, i.e. anodes, and negative electrodes, i.e. cathodes. Depending on the case, either the cathodes or the anodes are arranged within a frame provided with a porous diaphragm. Typically, the frame is U-shaped, a bag sewn from electrolysis cloth being arranged around it. Solutions are also known, wherein sheets made from electrolysis cloth are attached to the flank surfaces of the frame. A problem in known solutions is that the dimensions of the electrolysis basins and electrodes employed vary, whereby frames having special dimensions always have to be provided for each production unit. This causes much extra costs and inconvenience.
BRIEF DESCRIPTION OF THE INVENTION
[0005] The object of the present invention is to provide a novel and improved frame for fastening a diaphragm and, furthermore, a novel profile piece and corner piece, allowing frames having the desired dimensions to be easily created.
[0006] The frame of the invention is characterized in that the frame comprises at least a first corner piece and a second corner piece, both comprising a first connecting element and a second connecting element arranged at a predetermined angle with respect to each other, that the vertical bars comprise at least one profile piece, which form third connecting elements at a first end of both vertical bars, that the horizontal bar comprises at least one profile piece, which forms fourth connecting elements at both ends of the hori-
zontal bar, that the connecting elements of the corner pieces and the connecting elements of the vertical bars are arranged within each other in the longitudinal direction of the vertical bars, and that the connecting elements of the corner pieces and the connecting elements of the horizontal bar are arranged within each other in the longitudinal direction of the horizontal bar.
[0007] The profile piece of the invention is characterized in that at least one end of the profile piece comprises connecting elements for connecting the profile piece to the frame.
[0008] The corner piece of the invention is characterized in that the corner piece comprises first connecting elements and second connecting elements for fastening components included in the frame, and that an angle of a predetermined magnitude is arranged between said connecting elements.
[0009] The essential idea of the invention is that the frame is assembled from components that can be interconnected, i.e. elongated profile pieces and at least two corner pieces. In the joints between the profile pieces and the corner pieces, the connecting elements are arranged within each other by pushing the components longitudinally.
[0010] An advantage of the invention is that a modular frame can be built rapidly and easily from the components according to the invention. Due to the modular structure, the frame can be dimensioned according to the need and assembled for example not until at the electrolysis plant. The invention enables storage and transport of the components of the frame in a small space. The frame can be assembled rapidly when the frame is really needed, thus eliminating the need to store large frames. In addition, the components of the frame are relatively easily replaceable should they wear or break. The joints between the components can be opened by detaching the components from each other in the longitudinal direction. This eliminates the need for any fastening screws or the like. Accordingly, the frame can be assembled quickly. The components only need to be sawn into the desired length and the connecting elements be inserted within each other.
[0011] The essential idea of a preferred embodiment of the invention is that the profile piece comprises at least one elongated space of the length of the entire piece, the space providing connecting elements at both ends of the profile piece. When a profile piece of the desired length is cut, the cut end also shows a space into which a connecting piece can be inserted.
[0012] The essential idea of a preferred embodiment of the inven-
tion is that an elongated stiffening piece is arranged in at least one space in the profile piece. The stiffening piece may serve as a connecting element between successive profile pieces and a corner piece. In addition, the stiffening piece may serve to increase the rigidity of the structure.
BRIEF DESCRIPTION OF THE FIGURES
[0013] The invention will be described in detail in the attached drawings, wherein
Figure 1 schematically shows an electrolysis process, in which the frame according to the invention can be used,
Figure 2 is a schematic side view of a frame provided with a diaphragm and employed in an electrolysis process,
Figure 3 is a schematic view from direction A of the frame provided with a diaphragm according to Figure 2,
Figure 4 is a schematic side view of another frame of the invention,
Figure 5 is a schematic view of a frame profile of the invention taken in section at point B - B,
Figure 6 is a schematic perspective view of a frame profile of the invention,
Figure 7 is a schematic perspective view of a stiffening profile adaptable within a frame profile according to the invention,
Figure 8 is a schematic side view of a corner piece of the invention,
Figure 9 is a schematic view from direction D of the corner piece of Figure 8,
Figure 10 is a schematic side view of a third frame of the invention,
Figure 11 schematically shows a possible supporting bar structure taken in section at point C - C,
Figure 12 schematically shows an alternative supporting bar structure taken in section at point C - C, and
Figure 13 is a schematic view from direction E of a possible way to fasten the supporting bar shown in Figure 4 to a frame.
[0014] For the sake of clarity, the figures show the invention in a simplified manner. Like numerals are employed to designate like parts.
DETAILED DESCRIPTION OF THE INVENTION
[0015] Figure 1 shows an electrolysis process in a simplified manner. In this example, nickel electrolysis is concerned. Herein, an electrolysis
basin 1 contains a nickel sulphate mixture as electrolyte 2. In addition, the desired number of positive electrodes, i.e. anodes 3, and negative electrodes, i.e. cathodes 4, is also arranged in the basin 1. As anodes 3, plates cast from lead, or what are known as soluble anodes, can be used. As cathodes 4, thin seed plates can be used, onto whose surface the nickel separated from the solution or from the anode 3 is stratified during the process. In the solution of Figure 1 , the cathode 4 is arranged in a space defined by a diaphragm 5 and a frame 6. A diaphragm refers to a porous partition separating the electrolytes, and it may be manufactured from electrolysis cloth. The diaphragm 5 is fastened to the frame 6 as is more clearly shown for instance in Figures 2, 3 and 5. Nickel is supplied as a nickel sulphate solution into a space defined by the diaphragm, around the seed plate serving as the cathode 4. Herein, the frame 6 may be called a cathode frame. Alternatively, the anode may be arranged in a space defined by the diaphragm and the cathode outside the diaphragm. In this case, the frame 6 can be called an anode frame.
[0016] Since the electrolysis process and the associated electrochemical processes are known to a person skilled in the art, they need not be described in detail in the present application.
[0017] Figure 2 shows a substantially U-shaped frame 6 comprising two vertical bars 7 and 8, and a horizontal bar 9 at the lower part of the frame 6. In addition, the upper part of the frame 6 may comprise a horizontal supporting bar 10 for supporting the vertical bars 7 and 8 at the upper end of the frame. The frame 6 is made from a material that endures the demanding conditions of electrolysis. Such materials include for instance polypropylene (PP), which endures well the chemical strain and mechanical strain caused by the electrolyte and also the relatively high temperature in an electrolysis process, which may be about 70 to 80°C. Both sides of the flank surfaces of the vertical bars 7 and 8, and also the horizontal bar 9 of the frame 6 may also comprise fastening grooves 11 for fastening the diaphragm 5.
[0018] Figure 3 shows the frame 6 of Figure 2 seen from direction A. The diaphragm sheets 5 may be fastened in a separate step to a fastening strip 12, whereby the diaphragm 5 and the fastening strip 12 together form a diaphragm element 13. The fastening strip 12 may comprise fastening elements that can be pushed into the fastening grooves 11 in the frame 6. Such a diaphragm element 13 is arranged on both sides of the frame 6. Alternatively, the diaphragm sheets may be fastened by means of a separate fastening strip
to the fastening grooves 11. The fastening strip may be of an elastic material, such as rubber, for example. The edges of a diaphragm sheet are pushed by means of the fastening strip into the fastening groove, where they remain by means of friction generated by the fastening strip. Instead of a sheet-like diaphragm, a diagram sewn in the form of a bag can be employed, its upper end being open to allow the bag to be pulled around the frame 6. The frame 6 according to the invention is thus applicable irrespective of from which material the diaphragm 5 is manufactured or if it is of type sheet, bag or element.
[0019] Figure 4 shows a modular frame 6 according to the invention without a diaphragm 5. As Figure 4 shows, a first vertical bar 7 consists of two adjoined profile pieces 14a and 14b, and, correspondingly, a second vertical bar 8 consists of profile pieces 14c and 14d. If need be, the vertical bars 7 and 8 can be formed from one, two or more profile pieces. Furthermore, the horizontal bar 9 can also be formed from one or more profile pieces 14e. The profile pieces 14a to 14d can be cut into the desired length from profile bars of a predetermined length. The profile bars can have a length of 1 m or 2 m, for example, and their profile could be similar to the one shown in Figure 6. Profile pieces 14a to 14d are connectable to each other in succession by the use of a stiffening piece shown later in Figures 5 and 7. When connecting the profile pieces, which are transverse to each other, a corner piece 15 can be used. As Figure 4 shows, the ends of the lower profile pieces 14b and 14d of the vertical bars 7 and 8 are connected to the first and second ends of the horizontal profile piece 14e by means of corner pieces 15a and 15b. The joints between the profile pieces are denoted by reference numeral 16 in Figure 4 and the joints between the profile pieces and the corner pieces are denoted by reference numeral 17. Pieces of a suitable length can be cut from the profile 14, or the like, shown later in Figure 6, which can then be joined to achieve a frame 6 of the desired height. The width of the frame 6, in turn, can be affected by cutting the profile piece 14e of the horizontal bar 9 into a suitable length or by connecting several profile pieces of the desired length in succession. Thus, the solution of the invention enables the formation of frames 6 having different dimensions by using the frame profiles 14 and the connecting pieces. Such a frame 6 can be assembled at the installation site, thus enabling the adjustment of the dimensions of the frame 6 exactly correct. In addition, the frame profiles and the connecting pieces only take up little space during transport and storage. Furthermore, the construction formed from modules allows damaged
components to be replaced, which considerably saves costs. Figure 4 also illustrates how the profile pieces 14a to 14e and the corner pieces 15 may be provided with a fastening groove 11.
[0020] The length of the supporting bar 10 may be longer than the width of the upper end of the frame 6, in which case the ends of the supporting bar 10 are provided with support sections 10a and 10b, which are able to hold the frame 6 in the basin 1.
[0021] Figure 5 shows a cross section of a profile piece 14. The frame profile 14 shown in the figure is usable both in the vertical bars 7, 8 and in the horizontal bar 9. The profile piece 14 can be made from a suitable plastic material for instance by extrusion. The elongated profile piece 14 comprises a longitudinal space 18, into which an elongated stiffening piece 19 can be arranged. In addition, the space 18 serves as a connecting element of the profile piece 14 along its entire length. The stiffening piece 19 may also be made from a suitable plastic material for instance by extrusion. The cross section of the stiffening piece 19 substantially corresponds to the cross section of the space 18. A longitudinal opening 20 may lead from the space 18 to the outer surface of the profile piece 14. The opening 20 facilitates the manufacture of the profile piece 14. The space 18 also facilitates manufacture by different casting techniques, since, due to the space 18, large mass concentrations are not formed in the profile piece 14 that would complicate the manufacture and impair the quality of the profile piece 14. The cross section of the space 18 may be essentially H-shaped, whereby a good ratio of rigidity to weight is achieved, since the profile piece 14 comprises several vertical and horizontal walls. Furthermore, the profile piece 14 may comprise a first protruding part 21 and a second protruding part 22, which are able to protect the diaphragm 5 against damage caused by the electrode during installation of the electrode, for example.
[0022] Profile pieces 14 of the desired length can be cut from the frame profile shown in Figure 6. Consequently, profile pieces of different lengths do not have to be stored, nor do frames that take up much space have to be kept in storage. In addition, the space 18 constitutes a connecting element of the length of the entire profile piece and is able to receive projecting connecting elements of other components. Even if such a profile is cut at whichever point, its both ends comprise connecting elements. In addition, the profile piece 14 may comprise two or more longitudinal spaces, of which at least one space forms a connecting element at both ends of the profile piece
14.
[0023] The stiffening profile shown in Figure 7 can be manufactured from a plastic material that is either similar to or different from that of the frame profile. Stiffening pieces 19 of the desired length can be cut from the stiffening profile and they can be inserted into the space 18 at the ends of the profile pieces 14a to 14e. If the stiffening pieces 19 are not directly subjected to the effect of the electrolyte, they can also be manufactured from a material that does not endure electrolysis. Accordingly, in some cases, the stiffening profile may also be of metal or plastic-coated metal. However, the stiffening profile is typically manufactured from a suitable plastic material for instance by extrusion. The cross section of the stiffening piece 19 can be H-shaped as shown in the figure, whereby it comprises both horizontal sections 19a and vertical sections 19b, which makes it rigid as regards bending and twisting.
[0024] The stiffening piece 19 may be arranged substantially along the entire length of the vertical bar 8 in the manner shown in Figure 4, whereby it is able to stiffen the structure of the vertical bar and simultaneously serve as a connecting element between profile pieces 14c and 14d, connected to each other's extensions. If the profile pieces are sufficiently rigid as such, a shorter stiffening piece 19' may be used, which extends a predetermined length over the joint 16 between the profile pieces 14a and 14b.
[0025] Figure 8 shows a corner piece 15, usable for joining the profile pieces 14. The corner piece 15 comprises first connecting elements 23 and second connecting elements 24, arranged at a predetermined angle F with respect to each other. Angle F is typically 90°, but another angle can also be used when necessary, depending on the shape of the frame 6. The connecting elements 23 and 24 shown in the figure comprise a protruding part whose cross sectional shape may substantially correspond to the cross sectional shape of the longitudinal space 18 in the profile piece 14, as Figure 9 shows. This being so, the projecting connecting elements 23 and 24 can be inserted longitudinally into the end of the profile piece 14 to be connected, hereby achieving a joint 17 between the corner piece 15 and the profile piece 14. On the other hand, the cross sectional shape of the projecting connecting element 23, 24 does not necessarily have to correspond to the shape of the space 18; instead, it is essential that the connecting element 23, 24 is inserted sufficiently deep into the profile piece in order for it to be sufficiently firm to receive the stress loading the joint, and, further, to be sufficiently tight to generate the nee-
essary fastening forces, even without any separate fastening means. Accordingly, the connecting element 23, 24 does not necessarily comprise for instance the vertical section 24a and/or sections 24b. The corner piece may be manufactured from a suitable plastic material by casting, for instance by injection moulding.
[0026] In an application of the corner piece 15, the connecting element 23, 24 may be a recess 25 provided in the corner piece 15 and adapted to receive the stiffening piece 19. Alternatively, at least one end of the profile piece 14 may comprise a projecting connecting element 26, which can be inserted into the recess 25. The depth of the recess 25 is dimensioned deep enough, and, further, the cross section of the recess 25 is dimensioned by taking into account the stiffening piece 19 or the projection 26. Such a construction is illustrated in Figure 8 by broken lines 25 and 26.
[0027] Figure 10 shows still another application of the frame 6 of the invention. Herein, a so-called anode frame is involved, since the anode 3 is arranged in the space defined by the frame 6 and the diaphragm 5. The anode 3 may be a lead plate. Since the anode 3 may cause gases that are hazardous to health to be formed in the surrounding airspace from the solution 2 being processed, the upper end of the frame 6 is closed and the gases generated are collected into an exhaust pipe 27 and conveyed to further processing. The supporting bar 10 can be used to close the upper end of the frame 6. The supporting bar 10 can be made from the profile piece 14e of the invention, which can be fastened by means of fastening pieces 28 to the upper end of the first and second vertical bar 7, 8. The supporting bar 10 can also be fastened to the vertical bar 7, 8 without the fastening piece 28, for instance by using a screw joint. Figures 11 and 12 show possible constructions for the profile piece 14e in more detail.
[0028] Figure 10 further shows that the corner pieces 15c and 15d may comprise branches 29 and 30 of a predetermined length. The branches 29 and 30 may have equal or different lengths. The branch 29 can constitute part of the vertical bar 7, 8. In addition, the branch 30 may constitute at least part of the horizontal bar 9. The branches 29, 30 of the corner piece 15 may be provided with projecting connecting elements 23 or, alternatively, they may comprise a recess 26 for the stiffening piece 19 or the like. Accordingly, the profile pieces 14a and 14c can be connected by the joint 17 to the corner pieces 15c and 15d. On the other hand, in some cases, the branches 29 may
be dimensioned long enough to eliminate the need for profile pieces 14a and 14c. Furthermore, a joint 31 is provided between the branches 30. In the joint 31 , the stiffening piece 19 may join the corner pieces 15c, 15d together. Alternatively, one branch 30 comprises a protruding part and the other branch comprises a recess.
[0029] Another alternative is to form an integrated horizontal bar 9 whose both ends comprise corner pieces 15 for connecting the vertical bars 7, 8.
[0030] Figure 11 shows the cross section of a feasible supporting bar construction. The supporting bar 10 comprises a longitudinal space 18 and a longitudinal opening 20, which allow an anode 3, provided with a supporting element 32, to be inserted into position in the longitudinal direction of the supporting bar 10. In this case, the anode 3 will be supported by the supporting bar 10. The ends of the supporting bar 10 can be sealed for instance with suitable end pieces. The space 18 can be connected to an exhaust duct 27 for sucking gases from the inside of the frame 6.
[0031] Figure 12 shows an alternative supporting bar 10 whose upper part comprises an opening 20 that corresponds at least to the width of the anode 3 and through which the lead plate or the like, acting as the anode 3, can be inserted into position. A recess can be provided in the supporting bar 10 for the supporting element 32 of the anode 3. Seals 33 can be arranged between the recess and the supporting element 32. The gases generated inside the frame 6 can be sucked into the exhaust duct 27. The diaphragm 5 can be fastened tightly to the supporting bar 10 for instance by means of the fastening grooves 11.
[0032] A supporting bar of the kind shown in both Figure 11 and Figure 12 can be fastened with the fastening piece 28 to the upper ends of the profile pieces 14a and 14c of the invention. The fastening piece 28 may comprise a projecting connecting element that can be inserted into the space 18 in the profile piece 14a, 14c. The fastening piece 28 can be fastened to the supporting bar 10 with suitable fastening elements, such as screws, or it may comprise a portion longitudinally adaptable to the space 18 in the supporting bar 10. The supporting bar 10 may also be fastened for instance with screws or by welding to the upper end of the vertical bars 7, 8.
[0033] Figure 13 shows a fastening piece 28 comprising projecting connecting elements 40 that can be inserted into the space 18 in the profile
piece 14. The fastening piece 28 comprises a first opening 41 and a second opening 42, into which the first supporting bar 10c and the second supporting bar 10d, respectively, can be inserted. Thus, the frame 6, provided with such a fastening piece 28, comprises supporting bars 10c, 10d on both its sides. The supporting bars 10c, 10d may extend at the upper end of the frame 6 such that they constitute the supporting sections 10a and 10b. When required, the joint between the fastening piece 28 and the profile piece 14 can be secured with a separate fastening element, such as a screw or a rivet. The cross section of the supporting bar 10c, 10d may be for instance a rectangle or an l-profile. The material of the supporting bar 10c, 10d may be for instance a plastic material or a composite.
[0034] Furthermore, according to the principle of the corner piece 15, a T-piece can be formed, to which three profile pieces are connectable. Such a T-piece can be used for instance at the upper end of a vertical bar.
[0035] When needed, some suitable glue or sealing substance, such as silicon, can be arranged in the joints 16, 17 and 31.
[0036] It is to be noted that the frame profile and joint components of the invention are applicable to the formation of frames having a shape other than U-shape.
[0037] Let it be mentioned that the components comprised by the frame of the invention may also be of a composite material, for instance of a mixture of a suitable plastic material and a reinforced fibre. Furthermore, in addition to the above-mentioned extrusion, injection moulding can also be used to manufacture the profile pieces.
[0038] The drawings and the related description are only intended to illustrate the inventive idea. The details of the invention may vary within the scope of the claims. Accordingly, the solution of the invention is applicable for use in all kinds of electrolyses that require the fastening of a diaphragm.