MOULD FOR THE MANUFACTURE OF CERAMIC PACKING MEMBERS

Abstract

A mould for manufacturing a packing member from a liquid ceramic composition. The mould including a first part and a second part, wherein the first part and/or the second part comprise an open mould cavity and wherein the first and second parts are operable to engage to form a closed mould cavity, wherein the mould further includes a reservoir forming member, and wherein the mould is operable to be moved from an open position in which the first and second parts are at least partially spaced such that the reservoir member forms a reservoir cavity and the mould cavity is open, to a partially closed position in which the location of the reservoir cavity has moved with respect to the mould cavity and/or the volume of the reservoir cavity has reduced, and then to a closed position in which the first and second parts are engaged such that the mould cavity is closed.

Claims

1. A mould for manufacturing a packing member from a liquid ceramic composition, the mould comprising a first part and a second part, wherein the first part and/or the second part comprise an open mould cavity and wherein the first and second parts are operable to engage to form a closed mould cavity, wherein the mould further comprises a reservoir forming member, and wherein the mould is operable to be moved from an open position in which the first and second parts are at least partially spaced such that the reservoir member forms a reservoir cavity and the mould cavity is open, to a partially closed position in which the location of the reservoir cavity has moved with respect to the mould cavity and/or the volume of the reservoir cavity has reduced, and then to a closed position in which the first and second parts are engaged such that the mould cavity is closed.

2. The mould according to claim 1, wherein the first and second parts each comprise an open mould cavity.

3. The mould according to claim 2, wherein the mould cavities of the first and second parts are open partial mould cavities and the first and second parts of the mould are operable to engage such that the partial mould cavity of the first part aligns with the partial mould cavity of the second part to form a closed enlarged mould cavity.

4. The mould according to claim 1, wherein the first and/or the second parts comprise a plurality of open mould cavities.

5. The mould according to claim 1, wherein the mould cavity comprises texturing that is operable to produce surface structures on the packing member.

6. The mould according to claim 1, wherein the reservoir member comprises a first reservoir member arranged on the first mould part and a second reservoir member arranged on the second mould part, wherein the first and second reservoir members are operable to cooperatively engage to form a reservoir cavity.

7. The mould according to claim 6, wherein the first and second reservoir members comprise male and female reservoir members.

8. The mould according to claim 1, wherein the first and/or second mould part comprises side reservoir members extending along opposing sides of the mould cavity of the mould part.

9. The mould according to claim 1, wherein the first and/or second mould part comprises a base reservoir member.

10. The mould according to claim 1, wherein the first and/or second mould part is resiliently deformable.

11. The mould according to claim 1, wherein the material forming the first and/or second mould part has a shrinkage rate of up to 1%.

12. The mould according to claim 1, wherein the mould parts comprise cooperating retaining members operable to assist with maintaining the alignment of the mould parts.

13. The mould according to claim 1, wherein a mould part comprises a reinforcing member.

14. The mould according to claim 13, wherein the reinforcing member protrudes from the mould part to provide a guiding member.

15. A moulding apparatus for use in the production of a packing member from a liquid ceramic composition, the moulding apparatus comprising a mould according to claim 1 and a guiding member operable to arrange the mould in the open position.

16. The moulding apparatus according to claim 15, wherein the guide member is operable to arrange the mould in an open position in which a portion of the mould parts are abutting and a portion of the mould parts are spaced.

17. A process for producing a packing member for use in a packed bed comprising the steps of: a. arranging a mould comprising a first part and a second part wherein the first part and/or the second part comprise an open mould cavity and wherein the mould further comprises a reservoir forming member, in an open position wherein the first and second parts are at least partially spaced such that the reservoir member forms a reservoir cavity and the mould cavity is open; the mould may be according to claim 1 or be a mould apparatus according to claim 15; b. at least partially filling the reservoir cavity of the mould with a liquid ceramic composition; c. moving the mould to a partially closed position such that the location of the reservoir cavity moves with respect to the mould cavity and/or the volume of the reservoir cavity reduces; and d. moving the mould to a closed position wherein that the first and second parts are engaged to close the mould cavity such that a portion of the liquid ceramic composition is held within the closed mould cavity to produce a green body; and e. optionally, heating the green body; f. demoulding the green body; and g. optionally, calcining the green body to produce a packing member.

18. A packing member for use in a packed bed obtainable by moulding a liquid ceramic composition in a mould according to claim 1.

19. The packing member according to claim 1, wherein the packing member is formed from a cast moulding composition or slip.

20. The packing member according to claim 19, wherein the packing member is formed from a gel-cast composition.

21. (canceled)

22. (canceled)

23. (canceled)

24. (canceled)

25. (canceled)

26. A reactor comprising a catalyst bed wherein the catalyst bed comprises a packing member according to claim 18.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0127] The invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0128] FIG. 1 shows a top perspective view of a first embodiment of a mould according to the present invention.

[0129] FIGS. 2A and 2B show a top view of a second embodiment of a mould according to the present invention.

[0130] FIG. 3A shows a top perspective view of a first embodiment of a mould apparatus which is formed of the mould according to the second embodiment in an open position.

[0131] FIG. 3B shows a top view of the mould apparatus of FIG. 3A.

[0132] FIG. 4A shows a top perspective view of the mould apparatus of FIG. 3A with the mould in a partially closed position.

[0133] FIG. 4B shows a top view of the mould apparatus of FIG. 4A.

[0134] FIG. 5 shows a perspective view of a packing member according to the present invention.

DESCRIPTION OF EMBODIMENTS

[0135] FIG. 1 shows a mould 10 according to a first embodiment of the invention. Mould 10 is substantially cuboidal and is formed of a first mould part 100 and a second mould part 200. First part 100 and second part 200 each contain about half of the mass of mould and each are formed of a resiliently deformable two-part silicone-based rubber.

[0136] First mould part 100 is formed of substantially cuboidal body 102. Body 102 has a rectangular inner face and a rectangular outer face. The inner face forms an inside face of the mould and the outside face forms an outside face of the mould when the mould parts are engaged. Body 102 also has a rectangular front face, rear face, and two side faces.

[0137] The inner face of body 102 has a grouping of twelve discrete generally hemispherical partial mould cavities 104 that contain surface texturing on the moulding surfaces of the cavities. The mould cavities are arranged in a grouping of four rows with three cavities 104 per row. The partial cavities 104 are spaced equidistantly from adjacent mould cavities to form a grid-like grouping arrangement located laterally centrally on the inner face. The first row is located proximal to, and parallel with, but spaced from, the edge of the inner face that is adjacent to the front face of the body 102 and the last (fourth) row is located proximal to, and parallel with, but spaced from the edge of the inner face that is adjacent to the rear face. The first row is closer to its abovementioned edge than the last row is to its respective abovementioned edge. Extending along either side of the grid-like grouping of partial cavities 104 protrudes side reservoir member tongues 106a and 106b. Side reservoir member tongues 106a, 106b are generally cuboidal shaped with a convex upper face and which extend longitudinally along the inner face from the edge that is adjacent to the front face to just after the last row of partial cavities 104. Side reservoir members 106a, 106b are connected at the bottom end (i.e. the end proximal to the rear face of body 102) via base reservoir member tongue 106c. Base reservoir member 106c is the same height as side reservoir members 106a and 106b and it extends laterally across the inner face to connect reservoir members 106a and 106b. Reservoir members 106a, 106b are integrally connected at each end of base reservoir member 106c to form a generally U-shaped enclosure that surrounds the grid-like grouping of partial cavities 104 on both sides and at the bottom (i.e. the end proximal to the rear face of body 102). This enclosure forms part of a reservoir cavity 108, in which the partial cavities 104 are located. The reservoir cavity has a laterally extending mouth in the form of an open end that extends between the ends of the side reservoir members that are not connected to the base reservoir member. As such, the mouth is arranged between the first row of partial cavities and the edge of the inner face that is adjacent to the front face of the body 102.

[0138] Mould part 100 further has two sets of three post-dosing cube-shaped retaining members 110a,b that is integrally formed on two sides with the inner face and the side reservoir members. Each of the post-dosing retaining members extends outwardly from the inner face and side reservoir members. The first set of retaining members 110a is arranged along the outer side face of side reservoir member 106a (relative to the reservoir cavity), and the second set of retaining members 110b is arranged opposite to the first set on the outer side face of side reservoir member 106b. The three retaining members of each of sets 110a and b are equidistantly spaced longitudinally down the inner face from the adjacent retaining member of the set and each retaining member is directly opposite a corresponding retaining member on the opposite side reservoir member.

[0139] Inner face of body 102 is formed of dosing retaining tongue member 112 spaced from, located below, and extending parallel with, base reservoir member 106c, and proximal to, and extending parallel with, but spaced from, the edge of the inner face that is adjacent to the rear face. Dosing retaining member 112 is a generally cuboidal protrusion and extends laterally across body 102 and is spaced from the side edges.

[0140] An elongate recess 114 is located on the inner face between the mouth of the reservoir cavity 108 and proximal to, but spaced from, the edge of the inner face that is adjacent to the front face of the body 102. Recess 114 is positioned relatively laterally centrally on the inner face between, and spaced from, the side edges of body 102. Recess 114 is generally oval shaped. Recess 114 is generally coterminous with the width of the mouth of the reservoir cavity.

[0141] First mould part 100 also has three cylindrical spaced reinforcing rods 116 which extend laterally through the centre mass of body 102 from one side face to the other side face at three different points along body 102. Rods 116 protrude out from the side faces on both sides so that there are three protrusions on either side of the first mould part 100 to act as guide members. Rods 116 are spaced equidistantly along the longitudinal length of body 102.

[0142] Second mould part 200 (not shown) is the same as first mould part 100 but has inwardly extending female equivalents of the reservoir members and retaining members. As such, second mould part 200 has corresponding female reservoir members 206 (not shown) which are cuboidal grooves within the body 202 (not shown) suitable for receiving the reservoir members of the first mould part 100, and also female retaining members 210 (not shown) and 212 (not shown) which allow the male retaining members 110, 112 to fit within so that they are engaged, and hold the first and second mould parts 100, 200 in alignment. When the first mould cavity 100 and second mould cavity 200 are engaged together the partial cavities 104, 204 form closed enlarged generally spherical mould cavities 304 (not shown).

[0143] In use, mould 10 is arranged in an open position wherein the first mould part 100 and second mould part 200 are partially spaced so that the dosing retaining members 112, 212 are cooperatively engaged to hold the first and second mould parts 100, 200 in alignment and so that reservoir members 106, 206 (not shown) are sufficiently engaged such as to form a reservoir cavity in which the base reservoir member forms the base of the cavity and all of the mould cavities are open. In this configuration, the front faces of the mould parts are spaced and the rear faces of the mould parts are not.

[0144] In this initial a configuration, the initial reservoir cavity 108 can be filled with a liquid ceramic composition. This is done by dropping the liquid composition from above the spaced front faces of the mould parts into the mouth of the reservoir cavity 108. The liquid composition received will be held in cavity 108 and will also enter and fill the mould cavities 104, 204 that are within the initial reservoir cavity.

[0145] Mould 10 can then be then moved to a partially closed position by further engaging the side reservoir members 106, 206 in a graduated manner from the base reservoir member upwards toward the mouth of the reservoir cavity. This action results in the closure of the initial reservoir cavity, which closes some of the now filled mould cavities, but by further engaging the side reservoir members the reservoir cavity is moved further up mould 10 towards the front faces of the mould parts. The relocated reservoir cavity carries any remaining composition that was not taken up by the initially filled mould cavities. This has the effect of transferring a portion of the liquid ceramic composition higher up the grouping of cavity members to thereby allow for the composition to move from the relocated reservoir cavity 108 into the previously empty open mould cavities that now fall within the relocated reservoir cavity 108.

[0146] The mould parts 100, 200 can then be moved to a closed position in which the reservoir members 106, 206, and post-dosing retaining members are fully engaged, thereby closing the reservoir cavity and also closing all of the mould cavities so that the liquid ceramic composition is held within the closed mould cavities 304. Any excess composition is captured in recess 114.

[0147] The composition is held within the mould cavities 304 until a green body is produced; optionally, with heating of the green body.

[0148] The green body can then be de-moulded and the green body calcined to produce a packing member.

[0149] FIGS. 2A and 2B show a second embodiment of a mould 20 according to the present invention. Mould 20 is substantially cuboidal and has a first mould part 300 and a second mould part 400, as shown in FIGS. 2A and 2B. First mould part 300 and second mould part 400 are largely structurally the same as the first mould part 100 and second mould part 200 of the first embodiment. Mould 20 has all of the features as described in the first embodiment, unless stated otherwise below.

[0150] First and second mould parts 300 and 400 comprise a larger number of partial cavities, 305 and 405 respectively. There are eleven linear co-terminal and parallel rows of partial cavities 305, 405 with 15 cavities per row.

[0151] Side reservoir member tongues 306a and 306b are located on first mould part 300 and extend longitudinally along the inner face from just after the last row of partial cavities 305 to the edge of the inner face that is adjacent to the front face of the body 302. Side reservoir member tongues 306a and 306b, as well as base reservoir member tongue 306c, thereby enclose the partial cavities 305 and the elongate recess 314 located on the inner face of body 302. Side reservoir members 406a and 406b are located in the same way on second mould part 400.

[0152] The number of post-dosing cube-shaped retaining members 310a,b that are integrally formed on two sides with the inner face and the side reservoir members 306a,b has increased to seven on each side compared to the first embodiment. There are also seven corresponding female retaining members 410a,b on the second mould part 400. There are eight evenly spaced reinforcing rods 316 which extend laterally through the centre mass of each of the mould parts in the same way as in the first embodiment.

[0153] FIGS. 3 and 4 show a first embodiment of a mould apparatus 30 according to the present invention. The mould apparatus 30 is formed of a mould 20 according to the above described second embodiment and two guiding members 450. Guiding members 450 are fixed in a vertical orientation. Each guiding member 450 has two cuboidal shaped grooves 452 running longitudinally down the guide member at a slight diagonal so that the distance between the two grooves 452 is smaller at the bottom of the guiding member 450 than at the top of guiding member 450. The grooves of each guide member are arranged to face toward and directly oppose a corresponding groove of the other guide member.

[0154] Reinforcing rods 316, 416 can fit into grooves 452 on the respective sides of the mould parts to allow the mould 20 to travel along the grooves and to be held vertically so that the front face of mould parts 300 and 400 are pointing upwards and the rear face is pointing downwards.

[0155] In use, mould 20 is arranged in an open position by rods 316 and 416 entering grooves 452 at the bottom of the guide member and moving the mould up the guiding member 450 until the front faces of mould parts 300 and 400 are toward the top of guiding member 450 (FIG. 3A). As mould parts 300 and 400 are moved up the guiding member 450 the mould parts 300 and 400 become spaced at the upper end due to the grooves 452 being outwardly slanted, to give an open position in which an initial reservoir cavity is formed in the space between the mould parts. In this position the dosing retaining members 312, 412 are cooperatively engaged at the lower end of the mould to hold the first and second mould parts 300, 400 in alignment and to allow for a large reservoir cavity to be formed in which the base reservoir member forms the base of the cavity and all of the mould cavities are open.

[0156] In the open position, the initial reservoir cavity 308 can receive a liquid ceramic moulding composition by dropping the liquid composition from a dosing member arranged above the spaced front faces of the mould parts into the mouth 454 of the reservoir cavity 308. The liquid composition received is held in initial reservoir cavity 308 and fills any mould cavities 305, 405 that are within the initial reservoir cavity.

[0157] Mould 20 can then be moved to a partially closed position, as shown in FIGS. 4A and 4B, by moving the mould down the guiding member along the grooves to further engage the side reservoir members 306, 406 and inner faces of the mould parts in a graduated manner from the base reservoir member upwards toward the mouth of the reservoir cavity. In the partially closed position, the side reservoir members and inner mould faces are further engaged to move the reservoir cavity further up mould 20 towards the front faces of the mould parts. This action closes the initial reservoir cavity thereby also closing the filled mould cavities that were arranged within the initial reservoir cavity. The relocated reservoir cavity carries any remaining composition that was not taken up by the initially filled mould cavities. This has the effect of transferring a portion of the liquid ceramic composition higher up the grouping of cavity members to thereby allow for the composition to move from the relocated reservoir cavity 308 into the previously empty open mould cavities that now fall within the relocated reservoir cavity 308. The relocated reservoir cavity is also able to receive additional composition from the dosing member. In a partially closed position, the base of the reservoir cavity is eventually formed by abutment of the inner faces of the mould parts.

[0158] The mould parts 300, 400 can then be moved to a closed position in which reservoir members 306, 406, and post-dosing retaining members 310 are fully engaged, thereby closing the reservoir cavity 308 and also closing all of the mould cavities to hold the liquid ceramic composition within the closed mould cavities. Any excess composition is captured in recess 314, 414.

[0159] By way of example, a supported catalyst was produced using mould apparatus 30 and a moulding composition formed by mixing the components provided below using the following method.

[0160] The alumina powder, pore former and dispersant were mixed to form a powder mixture. An aqueous monomer solution containing the chain forming monomer, the chain linking monomer and the water was added to the powder mixture to form an aqueous slurry. The catalyst and initiator were then added to the aqueous slurry. The amounts of each component in the resulting slurry were:

TABLE-US-00001 Amount Alumina powder 475 Pore former 60 g Dispersant 12.25 g Polymerisable monomer 16.3 g Crosslinking member 8.2 Catalyst 3 ml Initiator 8 ml Water 135 g

[0161] The resulting aqueous slurry was then cast into the reservoir cavity of mould 20 from a dosing member arranged above mould 20 while mould 20 was in the open position. Mould 20 was then gradually moved from the open position to partially closed positions with further addition of the aqueous slurry. Mould 20 was then arranged into the closed position. Once the slurry had gelled into a plurality of solid green bodies within the closed enlarged mould cavities the green bodies were then demoulded. At this point the green bodies had a rubbery, jelly-like consistency. The green bodies were then left to dry at room temperature for 24 hours. The dried green bodies were then fired to 1450° C., at which point the binder and pore formers were burnt off to leave solid, porous, packing members.

[0162] The packing members were then dipped in an aqueous solution containing catalytic material Ni(NO.sub.3).sup.2 before drying at 500° C. This catalytic material impregnation step was repeated two more times to produce supported catalysts.

[0163] The supported catalysts produced had a macrostructure and surface structure as shown in supported catalyst 500 of FIG. 5. Supported catalyst 500 has macrostructure in the form of a cylindrical cog shape with a plurality of bores (5 in total) extending through the longitudinal length of the support and a plurality of spaced longitudinally orientated castellations (10 in total) that project radially outwards from the support. The macrostructure of supported catalyst 500 further has a depression 502 in the upper face of the support 500. Each of the castellations of the cog are tapered in depth such that the supported catalyst 500 has a largest outer width F at the base (38.0 mm) to a smallest outer width E at the upper face of supported catalyst 500 (35.1 mm). Each castellation is further tapered in width, from a widest point at the base of supported catalyst 500 to a narrowest width at the upper face of supported catalyst 500.

[0164] Support catalyst 500 has surface structures extending over substantially the whole outer face of the supported catalyst 500. The surface structures are generally in the form of interconnected hexagon-shaped ridges 502.

[0165] In this manner, packing members having improved properties may be manufactured using open vertical filling at the high quantity required in the necessary timespan to achieve a commercially viable production.

[0166] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0167] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0168] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0169] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.