GB1592394A

GB1592394A - Reaction column for adsorption and ion-exchange resins

Info

Publication number: GB1592394A
Application number: GB43031/77A
Authority: GB
Original assignee: Kernforschungszentrum Karlsruhe GmbH
Current assignee: Forschungszentrum Karlsruhe GmbH
Priority date: 1976-11-06
Filing date: 1977-10-17
Publication date: 1981-07-08
Also published as: DE2650884C2; FR2369861A1; FR2369861B3; DE2650884A1

Description

(54) REACTION COLUMN FOR ADSORPTION AND ION-EXCHANGE RESINS (71) We, KERNFoRscHuNGszENTRuM KARLSRUHE GESELLSCHAFT MIT BESC HRAENKTER HAFTUNG, formerly GESELLSCHAFT FUER KERNFORSCHUNG MBH, of Postfach 3640, D-7500 Karlsruhe 1, Germany (Fed Rep); a German body corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment :- The invention relates to a reaction column for adsorption and ion-exchange resins, more especially for macroporous adsorption resins used for separating tributyl phosphate frdm aqueous process solutions, comprising a column tube, closed at both ends and having supply and. discharge apertures for the materials to be processed.

Resins such as are used in reprocessing irradiated nuclear fuels are generally solids which show a tendency to collect a rapid static charge. As a result thereof, it is not possible to convert the material as usual in the manner of a homogeneous suspension of the material which is poured into a tube from above and from which the liquid phase is permitted to be discharged. In this method of operation, the resin remains adhering in the upper region of a column in thin layers and also in the form of lumps, between which cavities are formed.

A further characteristic of the said resin is that its volume increases when substances dissolved therein from liquids are adsorbed, and vice versa. As a result fissures, cracks and holes are formed in the homogeneous suspension which interfere with the optimal function of the ion exchange column.

An object of the present invention is to provide a reaction column of the aforesaid kind which permits adsorption and ionexchange resins to be stacked gas-free in the form of a homogeneous column-shaped unit and to take into account the changing volume of the material as well as enabling the resin to be removed without having to dismantle the column.

According to the present invention, there is provided a reaction column for adsorption and ion-exchange resins, especially for macroporous adsorption resins for separating tributyl phosphate from aqueous process solutions, comprising a column tube closed at both ends with inlet and outlet openings for the materials to be processed, in which a space for receiving the resin is located in the column, which space is sealed at the top and bottom by means of liquid-permeable, resin-impermeable frits, the top frit being vertically adjustable and the inlet and outlet openings for the solution to be treated being located outside the space beyond the given frit, in which said top frit is formed in a piston which acts, from above, in a cylinder projecting into the space, whereby a tube is used as connecting rod, which tube opens towards the space and is provided at its upper end with a removable closure stopper.

An embodiment of the invention is that the lower frit is penetrated from below by a charging pipe for charging the resins into the space.

Preferably, the inlet tube for the liquid to be treated and the outlet tube for the treated liquid are connected adjoining the space below the lower frit and the space over the readily adjustable frit respectively.

Further preferably, the stopper is rotatably retained by means of a sliding ring in a cup-shaped guide bush and is axially retained by an engaging pin passing through an eccentric bore.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawing, in which the single figure is a front view, partly in section, of a reaction column in accordance with the present invention.

The column substantially comprises three structural groups: 1. The column base formed of stainless steel (parts 21 to 24); 2. The column shaft or the actual column tube formed of glass (uart 25); and 3. The column head formed of stainless steel (parts 1 to 20) The column base comprises a base support 21, a frit 22, and a charging pipe 23 which is passed through the frit 22 into the interior space 28 of the column. The base support 21 is cup-shaped, and the frit 22 is mounted on the upper surface of the space 27 formed in the cup.

The ion-exchange resin suspension or sludge is charged into the space 28 through the charging pipe 23. The inlet pipe 24 to the space 27 is the inlet for the solutions to be brought into contact with the resin. The spaces 27 and 28 hence only communicate via the frit 22, which is permeable to the solutions but not to the resin.

The column shaft comprises a surfaceground glass tube 25, having two couplings 26 and 34. The column shaft serves to receive the resin and permits observation thereof.

The column head is substantially formed of a piston housing 1 into which an outlet pipe 29 is inserted. A cylinder 30 is attached on the underside of the housing 1, in which cylinder 30 the piston 31, including its connecting rod 2, is vertically displaced. The connecting rod 2 is formed as a tube having a cavity 32 and opens into the space 28 and is used as supply and discharge conduit for resin to the interior space 28 of the column.

The space 33 above the piston 31 commune cates with the outlet pipe 29 and is let into the piston housing 1. The piston housing 1 and glass tube 25 are attached to one another by means of a sealed coupling 34.

The piston 31 has apertures 35 formed therein through which liquid can transfer from the internal space 2 , via frit 3, into the space 33 and the outlet pipe 29 respectively. In order at the same time to prevent the ion-exchange resin in the space 28 from being discharged, the frit 3, which is impermeable to the resin, is inserted in the piston 31. A sealing ring 4 is provided on the outer edge of the piston 31 acting as a seal relative to the cylinder 30.

The upper portion of the piston housing 1 is sealed relative to the connecting rod 2 by means of soft rubber sealing rings 7 which, by means of a union nut 5 screwed onto a boss 36, are pressed against the connecting rod 2, the sealing rings 7 being located in the boss 36 between threespacmg rings 6. A removable closure stopper is inserted in the upper end of the connecting rod 2, the stopper comprised of an insert 8, a threaded bolt 37 having a clamping sleeve 9, a knurled nut 10 and an O-ring 11. The mobility of the piston 31 and the connecting rod 2 in the cylinder 30 is caused by a clamping bolt 14 having a guide bush 38, which bolt 14, by means of the nut 39, is screwed into an abutment means. The abutment means comprises a connecting web 17, which by means of spacing bolt 18 is securely screwed onto the piston housing 1 by the screw coupling 19 and 20.

The clamping bolt 14, with handwheel 16, is formed into a guide bush 38 at its lower end. An engaging pin 15 is eccentrically passed through guide bush 38 so that it does not contact insert 8, but is carried past it. The bush 38 is thus rotatably retained against insert 8, nut 10 and bolt 37 and remains axially retained for as long as the pin 15, as illustrated, is passed through its eccentric bore. During a tum to the right of the clamping bolt 14, the piston 31 is pressed downwards by the connecting rod 2 in the cylinder 30, a turn to the left pulls it up. To prevent friction between metal and metal, a sliding ring 12 and a sliding disc 13 formed of plastics material is incorporated between the friction surfaces. The insert 8 is lockable with the connecting rod 2 by means of a bayonet-type closure 40 by twisting and may be removed from the rod 2, together with components 9, 10, 11, 12 and 37 located on the closure stopper.

Open turning the handwheel 16, the clamping bolt 14 is vertically reciprocated, together with the guide brush 38. During upward motion, the connecting rod 2 is carried upwardly with the bolt 14 by means of the pin 15, without executing any rotation.

The piston 31 thus moves upwardly; in the reverse direction of rotation the piston 31 is forced downwardly by means of the parts 10, 13 and 8. In this manner, it is possible to adapt the space 28 accurately to the given volume of resin.

The column may now be used to build up the ion-exchange resin column from below in the apparatus, whereby a substantially homogeneous unit is attainable. The changing volume of the resin is equalised by the displacement of piston 31.

Due to the connecting rod 2 being formed as a tube, the column may be emptied of resin by removal of the stopper. Removal of resin from the top of the column is necessary since emptying downwards is substantially impossible due to the varying characteristics of ion-exchange resins.

Furthermore, the construction of the connecting rod 2 permits ion-exchange resin to be poured in a dry state from above into the space 28 of the column.

Summarised, the advantages of the present invention comprise the provision of a gas-free, homogeneous column of ionexchange resins together with means enabling simple emptying of the resin from the apparatus. Further, it is possible to charge dried resin material to provide an ionexchange column having adequate characteristics in certain cases.

WHAT WE CLAIM IS: 1. A reaction column for adsorption and ion-exchange resins, especially for macroporous adsorption resins for separating tributyl phosphate from aqueous process

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. which is passed through the frit 22 into the interior space 28 of the column. The base support 21 is cup-shaped, and the frit 22 is mounted on the upper surface of the space 27 formed in the cup. The ion-exchange resin suspension or sludge is charged into the space 28 through the charging pipe 23. The inlet pipe 24 to the space 27 is the inlet for the solutions to be brought into contact with the resin. The spaces 27 and 28 hence only communicate via the frit 22, which is permeable to the solutions but not to the resin. The column shaft comprises a surfaceground glass tube 25, having two couplings 26 and 34. The column shaft serves to receive the resin and permits observation thereof. The column head is substantially formed of a piston housing 1 into which an outlet pipe 29 is inserted. A cylinder 30 is attached on the underside of the housing 1, in which cylinder 30 the piston 31, including its connecting rod 2, is vertically displaced. The connecting rod 2 is formed as a tube having a cavity 32 and opens into the space 28 and is used as supply and discharge conduit for resin to the interior space 28 of the column. The space 33 above the piston 31 commune cates with the outlet pipe 29 and is let into the piston housing 1. The piston housing 1 and glass tube 25 are attached to one another by means of a sealed coupling 34. The piston 31 has apertures 35 formed therein through which liquid can transfer from the internal space 2 , via frit 3, into the space 33 and the outlet pipe 29 respectively. In order at the same time to prevent the ion-exchange resin in the space 28 from being discharged, the frit 3, which is impermeable to the resin, is inserted in the piston 31. A sealing ring 4 is provided on the outer edge of the piston 31 acting as a seal relative to the cylinder 30. The upper portion of the piston housing 1 is sealed relative to the connecting rod 2 by means of soft rubber sealing rings 7 which, by means of a union nut 5 screwed onto a boss 36, are pressed against the connecting rod 2, the sealing rings 7 being located in the boss 36 between threespacmg rings 6. A removable closure stopper is inserted in the upper end of the connecting rod 2, the stopper comprised of an insert 8, a threaded bolt 37 having a clamping sleeve 9, a knurled nut 10 and an O-ring 11. The mobility of the piston 31 and the connecting rod 2 in the cylinder 30 is caused by a clamping bolt 14 having a guide bush 38, which bolt 14, by means of the nut 39, is screwed into an abutment means. The abutment means comprises a connecting web 17, which by means of spacing bolt 18 is securely screwed onto the piston housing 1 by the screw coupling 19 and 20. The clamping bolt 14, with handwheel 16, is formed into a guide bush 38 at its lower end. An engaging pin 15 is eccentrically passed through guide bush 38 so that it does not contact insert 8, but is carried past it. The bush 38 is thus rotatably retained against insert 8, nut 10 and bolt 37 and remains axially retained for as long as the pin 15, as illustrated, is passed through its eccentric bore. During a tum to the right of the clamping bolt 14, the piston 31 is pressed downwards by the connecting rod 2 in the cylinder 30, a turn to the left pulls it up. To prevent friction between metal and metal, a sliding ring 12 and a sliding disc 13 formed of plastics material is incorporated between the friction surfaces. The insert 8 is lockable with the connecting rod 2 by means of a bayonet-type closure 40 by twisting and may be removed from the rod 2, together with components 9, 10, 11, 12 and 37 located on the closure stopper. Open turning the handwheel 16, the clamping bolt 14 is vertically reciprocated, together with the guide brush 38. During upward motion, the connecting rod 2 is carried upwardly with the bolt 14 by means of the pin 15, without executing any rotation. The piston 31 thus moves upwardly; in the reverse direction of rotation the piston 31 is forced downwardly by means of the parts 10, 13 and 8. In this manner, it is possible to adapt the space 28 accurately to the given volume of resin. The column may now be used to build up the ion-exchange resin column from below in the apparatus, whereby a substantially homogeneous unit is attainable. The changing volume of the resin is equalised by the displacement of piston 31. Due to the connecting rod 2 being formed as a tube, the column may be emptied of resin by removal of the stopper. Removal of resin from the top of the column is necessary since emptying downwards is substantially impossible due to the varying characteristics of ion-exchange resins. Furthermore, the construction of the connecting rod 2 permits ion-exchange resin to be poured in a dry state from above into the space 28 of the column. Summarised, the advantages of the present invention comprise the provision of a gas-free, homogeneous column of ionexchange resins together with means enabling simple emptying of the resin from the apparatus. Further, it is possible to charge dried resin material to provide an ionexchange column having adequate characteristics in certain cases. WHAT WE CLAIM IS:

1. A reaction column for adsorption and ion-exchange resins, especially for macroporous adsorption resins for separating tributyl phosphate from aqueous process

solutions, comprising a column tube closed at both ends with inlet and outlet openings for the materials to be processed, in which a space for receiving the resin is located in the column which space is sealed at the top and bottom by means of liquid-permeable, resin-impermeable, frits, the top frit being vertically adjustable and the inlet and outlet openings for the solution to be treated being located outside the space beyond the given frit, in which said top frit is formed in a piston which acts, from above, in a cylinder projecting into the space, whereby a tube is used as connecting rod, which tube opens towards the space and is provided at its upper end with a removable closure stopper.

2. A reaction column as claimed in claim 1, in which the lower frit is penetrated from below by a charging pipe for charging the resins into the space.

3. A reaction column as claimed in claim 1 or 2, in which the inlet tube for the liquid to be treated and the outlet tube for the treated liquid are connected adjoining the space below the lower frit and the space over the vertically adjustable frit respectively.

4. A reaction column as claimed in any preceding claim, in which the stopper is rotatably retained by means of a sliding ring in a cup-shaped guide bush and is axially retained by an engaging pin passing through an eccentric bore.

5. A reaction column substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.