AU617345B2

AU617345B2 - Process and device for regenerating ion-exchange material

Info

Publication number: AU617345B2
Application number: AU20882/88A
Authority: AU
Inventors: Dieter Krzossa; Karl Scharff
Original assignee: Gruenbeck Wasseraufbereitung GmbH
Current assignee: Gruenbeck Wasseraufbereitung GmbH
Priority date: 1987-07-09
Filing date: 1988-07-08
Publication date: 1991-11-28
Anticipated expiration: 2008-07-08
Also published as: AU2088288A

Description

6 7

PA

4 5 p !AU-AI -20828 WELTORGANISATION FOR GEISTIGES EIGENTUM INTERNATIONALE ANMELDUNG VEROFFENTLICHT NACH DEM JRAG OIBER DIE INTERNATIONALE ZUSAMMENARBEIT AUF DEM GEBIET DES PA IENTWESENS (PCT) (51) Internationale Patentklassifikation 4 Internationale Ver6ffentlichungsnummer: WO 89/ 00453 B~lJ49/0 Al(43) Internationales Verbffentlichungsdatum: 26. Januar 1989 (26.0 1.89) (21) Internationales Aktenzeichen: PCT/EP88/00618 (74) Anwalt: PROFER, Lutz, Harthauser Stra~e 25d, D- 8000 Mflnchen 90 (DE).

(22) Internationales Anmeldedatum: 8. Juli 1988 (08.07.88) (81) Bestimmungsstaaten: AT (europtiisches Patent), AU, (31) Prioritiitsaktenzeichen: P 37 22 639.8 BE (europaisches Patent), BG, CH (europdisches Pa- P 38 05 813.8 tent), DE (europaisches Patent), DK, FI, FR (europdisches Patent), GB (europaisches Patent), HU, IT (32) PrioritAtsdaten: 9. Juli 1987 (09.07.87) (europtiisches Patent), JP, KR, LU (europdisches Pa- 24. Februar 1988 (24.02.88) tent), NL (europaisches Patent), NO, RO, SE (euro- (33) riortlitland, DE pfisches Patent), SU, US.

Veriiffentlicht (71) Anmielder (fiir alle Bestimmungsst'aaten ausser US): Mit internationalem Recherchenbericht.

GR{YNBECK WASSERAUFBEREITUNG GMBH [DE/DE]; Industriestrage 1, D-8884 H6chstddt (DE).

(72) Erfinder;und Erfinder/Anmelder (nurfiir US) SCHARFF, Karl [DE/ AUSTRALIAN DE]; Hofrat Strobel-Strage 29, D-8884 H-6chstddt KRZOSSA, Dieter [DE/DE]; Matthias-Clau- 1 3 FEB 989 dius-Strage 20, D-4156 Willich (DE).

PATENT OFFICE (54) Title: PROCESS AND DEVICE FOR REGENERATING ION-EXCHANGE MATERIAL (54) Bezeichnung: VERFAHREN UND VORRICHTUNG ZUR REGENERATION VON IONENAUSTAUSCHER-

MATERIAL

(57) Abstract The ion-exchange material to be regenerated is introduced into a container and arranged between an anode 26) and a cathode (4, 27). During regeneration, an alternating voltage or a pulsating direct voltage is applied through the anode 26) or another electrode (18, 22).

The process is even more efficient if the frequency of' the alternating voltage is regularly changed. Said regeneration process is used, for example, in water purification stations or electrolytic installations.7/ 16- 14 (57) Zusammenfassung Die Erfindung betrifft emn Verfahren und eine Vorrichtung zur 33 31 rial. Erfindungsgemiss ist emn Behalter vorgesehen, in den das zu regenerierende Austauschermaterial eingebracht ist. Das Ionenaustau- 29 schermaterial ist zwischen einer Anode 26) und einer Kathode 2 27) angeordnet. Wahrend des Regenerierens wird 0ber die Anode 32 3 26) oder eine weitere Elektrode (18, 22) eine Wechselspannung oder eine pulsierende Gleichspannung eingetragen. Das Verfahren wird noch ef- 35 1 fektiver, wenn die Frequenz der Wechselspannung oder der pulsieren- 2. den Gleichspannung regelmiissig verAndert wird. Das erfindungsgemilsgen oder gavanischen Betrieben einsetzbar.j 1~ .k PROCESS AND APPARATUS FOR REGENERATION OF ION EXCHANGE MATERIAL The invention relates to a process for regeneration of ion exchange material, in which the ion exchange material within a liquid is exposed to a constant voltage field. Furthermore, the invention refers to an apparatus according to the preamble of Claim 9.

Such a process and a corresponding apparatus is known from the US-PS 2,812,300. The tank comprises an anode side and a cathode side which are divided by a o. diaphragm. The conductivity of the liquid is increased o ooby the addition of an electrolyte. The ion mobility is low in such a case.

15 According to a further process the regeneration of ion exchange material is performed in a o chemical manner.

It is the object of the invention to provide a process of the above-described kind in which a fast regeneration of ion exchange material is obtained in a simple manner. Furthermore an apparatus for carrying out the process shall be provided.

The object is achieved by a process of the above kind which is characterized in that the direct voltage field is superposed by an alternating voltage field or a pulsating direct voltage field, having a predetermined frequency. The apparatus for achieving the object is characterized in Claim 11. The apparatus is simply arranged. It allows a fast and low-cost ion exchange regeneration with low current consumption.

Lurther embodiments of the invention are characterized in the sub-claims.

An electrolyte is not required, because an electro-magnetic alternating field is applied, whereby an ion acceleration and increase of conductivity is obtained.

*4 ~NT .~a 2 Further features and advantages of the invention will stand out from the description of embodiments with respect to the Figures. In the Figures: Fig. 1 is a lateral view of a first embodiment of the invention in schematic representation; Fig. 2 is a diagrammatic representation of a modified embodiment; Fig. 3 is a schematic representation of a further modified embodiment; Fig. 4 is a schematic representation of a still further modified embodiment; Fig. 5 is a schematic representation of another modified embodiment; and Fig. 6 is an embodiment modified with respect to Fig. 3.

The embodiment shown in Fig. 1 comprises a tank 1. In this tank there is the ion exchange material 2 to be regenerated. On both opposite sides of the tank electrodes in form of a cathode 3 and an anode 4 are inserted into the ion exchange material such that both electrodes have a distance from each other and the ion exchange material is present between both electrodes.

The two electrodes are connected with a direct current source 5. Moreover, between both electrodes and in a distance thereto a further electrode 6 as well immerging into the ion exchange material is provided which is connected with an alternating current source or generator 7, resp. Furthermore, a control means 8 is provided. A liquid 9, preferably usual tap water, is put into the tank and the level of the liquid extends upwardly beyond the level of the filled-in ion exchange material.

In operation a direct voltage preferably in the order of 30 V to 380 V and in particular between 50 V to 260 V is applied to the electrodes 3, 4. At the same time an alternating voltage or a pulsating direct voltage is applied by the alternating current source 7. Preferably, this alternating voltage lies in the region of 1 KHz to 10 MHz -3and in particular between 10 Khz to 10 MHz. The control means 8 controls the apparatus such that after a period of about 3 minutes the frequency of the alternating voltage and/or the pulsating direct voltage is changed. Respective further changes are made in corresponding periods. The period may differ as a function of the apparatus dimensions, but it should not be selected shorter than 2 seconds and preferably about 8 seconds or not less than about 1 minute, resp.

In case that the ion exchange material to be conditioned is an aluminosilicate or resin which is used in softening water and which is loaded with calcium or magnesium cations, then these cations are replaced by hydrogen ions. The calcium and magnesium cations enter into the liquid and are removed together therewith.

As far as the parts shown in the following embodiments correspond to those in Fig. 1, they are referenced by the same reference numeral.

In the embodiment shown in Fig. 2 there is an upright tank 1 in which the anode 4 is provided immediately above the bottom. The anode is formed as a sheet metal perforated by a plurality of holes, preferably as a platinum-covered anode. In a small distance below the anode there is a sieve plate 10 having a mesh size selected such that the sieve carries the ion exchange material 2 to be regenerated which is on top thereof. The ion exchange material 2 is filled into the tank up to a maximum predetermined level 11. A cathode 3 extending across the cross-section of the tank is provided in a distance above the predetermined level.

A further sieve plate 10' is provided in a small distance above the cathode. These sieve plates serve the purpose that no resin may enter the inlet and outlet conduits. At the bottom there is a liquid supply conduit 12 which is adjustable by a valve 13 to be operated by the control means 8. At the top of the tank there is a liquid discharge conduit 14 which is adjustable by a valve 15 which may be operated J 0 i l I I i L "I i -4by the control means 8. A flushing water inlet 31 with a valve 33 is provided above the material 2 to be regenerated.

At the same time the anode 4 is connected with the alternating current source 7.

In operation water is introduced through the liquid supply conduit 12 up to a level such that the liquid also covers the cathode 3. Thereupon the direct voltage and the alternating voltage or pulsating direct voltage are switched on in the same manner as in the above-described embodiment.

The frequency of the alternating voltage or pulsating direct voltage is periodically changed as in the above embodiment.

The valves 13, 15 and 33 are controlled such that the liquid flows slowly through the tank. The liquid thereby takes away the exchanged ions. In the above-described embodiment therefore the calcium and magnesium ions are transported away.

The tank 1 may be the same container which is for example used for water conditioning and in particular water softening, and therefore not only the reconditioning of the ion exchange material, but also the water treatment itself is performed in the tank. To this end the top of the container is connected with a raw water inlet 16 and a clean water outlet 17.

The embodiment shown in Fig. 3 differs from the one shown in Fig. 2 in that a third electrode 18 is provided.

This electrode is situated in a tubular projection 19 which is fluidly connected with the interior of the tank. The projection 19 lies in a distance above the anode 4 and below the predetermined level 11. The wall between the interior j proper of the tank and the projection is formed by a sieve 30 20 which allows water to pass, but retains ion exchange material. The third electrode 18 is connected with the alternating current source. The two electrodes 3 and 4 are connected with the direct current source only. The superposition of direct voltage and alternating voltage or pulsating direct voltage is performed through the third V 'fl"m t t= electrode 18. The operation mode is identical to the one of the embodiment shown in Fig. 2.

The embodiment shown in Fig. 4 comprises, in addition to the projection 19 with the third electrode, a similarly designed second projection 21 with a fourth electrode 22 and a respective separative sieve 23. The two electrodes are operated with differing frequencies. In operation the first frequency which better corresponds to the respective impedance is applied to the third electrode and, when changing the frequency, the alternating voltage having the second frequency is applied to the fourth electrode 22.

In the above-described embodiments the anode is provided at the bottom. This design serves for regeneration of ion exchange material where settled-down cations have to be exchanged, i.e. for example the above-mentioned calcium and magnesium cations.

In case that, however, an ion exchange material is to be regenerated where settled-down anions have to be exchanged, for instance sulfate, carbonate, chloride or nitride anions, then a pole reversal is made such that the bottom electrode is formed as a cathode and the other electrode as an anode.

In the embodiment shown in Fig. 5 an upright tank 24 is provided having a bottom electrode therein which is formed as a first cathode 25 extending across the cross-section of the tank immediately above the bottom thereof for the purpose of a cascade type regeneration operation. A sieve corresponding to the sieve 10 is again arranged immediately Sbelow the cathode and in a small distance therefrom. In the same manner as in the previous embodiments the opposite electrode, i.e. the anode 26, is arranged in a distance above the predetermined level 11. This anode extends across the complete cross-section of the tank and is formed as a mesh or sieve. Again material to be conditioned must be filled in up to a predetermined level 11 in the same manner as in

-Y

dr2 i 'o N rL -6the previous embodiments. The electrode which is opposed to the anode 26, i.e. a second cathode 27, which also extends across the complete cross-section of the tank, is provided above the predetermined level 11. A sieve plate 10' corresponding to the sieve plate 10 is provided immediately thereabove and in a small distance from the cathode 27. The electrode3 25, 26 and 27 are connected with the direct current source 5. The anode 26 is additionally connected with the alternating current source 7.

In operation ion exchange material 28 having previously taken up anions to be exchanged by regeneration is above the sieve 10. Correspondingly ion exchange material 29 having previously taken up cations to be exchanged by regeneration is above the anode 26. Tap water is supplied through the liquid supply conduit for regeneration up to a level which at least extends above the second cathode 27.

In the same manner as in the embodiments shown in the Figures 2 to 4 a flushing water inlet 30, 31 is provided at a side of the tank immediately above the material 28, 29 to be regenerated. The respective supply is adjustable by means of respective valves 33, 34, 35 which are operated by the control means 8. At the same time a flushing water outlet 32 is provided at the side of the tank which is substantially opposite to the water inlet 30 and the outlet is adapted to be controlled by a valve which is again controlled by the control means 8. The flushing water together with the anions exchanged from the material 28 can be discharged through the flushing water outlet 32.

In the above-described embodiment the alternating voltage is applied through the anode 26. The alternating voltage may be applied through a separate electrode corresponding to the electrodes 18 or 18 and 22 in the previous embodiments.

The embodiment shown in Fig. 5 is again a water conditioning apparatus where the water to be conditioned is -7- -iB- 7 supplied through conduit 16. In the ion exchange material 29 cations, for example calcium and magnesium cations, are exchanged. The water then passes further through the second ion exchange material 28, where anions, such as sulfate anions, are exchanged. The above-described regeneration can then be performed in the same tank without transferring the ion exchange materials.

Besides of a water conditioning plant, the regeneration may also be used in further plants, such as electroplating shops.

According to an embodiment the distance between anode and cathode amounts to 45 cm and the resin bed thickness or level to 35 cm. The applied direct voltage amounts to about 150 V. The rate of flow of the water supplied through conduit 12 during the regeneration operation is selected such that the direct current is about 1100 mA. During a first period an alternating voltage having a frequency of 100 KHz is applied which is periodically replaced by a frequency of 400 KHz.

The period or cycle for switching over between the two different frequencies is in the order of several minutes and depends on the change in conductivity of the resin bed.

The switch over is preferably made when the conductivity in the cathode space is about 200 or higher of the conductivity of the raw water, i.e. a conductivity of 100 is/cm or higher. The cycle should, however, not be shorter than 2 seconds, preferably about 8 seconds and not shorter than about 1 minute.

The applied voltage and flushing current is adjusted such that for a given amount of ion exchange material the current is substantially below 2 A in order to avoid a production of too much oxygen at the anode.

Basically the direct voltage is selected to be in the order of 30 V to 380 V and particularly preferable between 50 V and 260 V. The alternating voltages or pulsating direct

J

I v4V wL L' 1 L. II 8 voltages can be selected in the region of 1 KHz to 10 MHz and preferably between 10 KHz to 10 MHz.

During regeneration the direct current field is pole reversed in regular intervals for at least 10 seconds and preferably about 2 to 3 minutes in order to allow material takeh' up by the electrodes, for example calcium at the cathode, to dissolve again.

A particular reason for having the plurality of small holes in the electrode is to allow the liquid stream to flush away the oxygen or hydrogen, resp., gathering at the electrodes.

In the above-described embodiment the variation of the alternating voltage is performed by a respective direct switch over between the first and the second frequency. In a modified embodiment the variation is performed by a continuous frequency variation between a first and a second frequency value.

In the embodiment shown in Fig. 6 the electrode 18 of Fig. 3 is replaced by a reticularly designed electrode which extends in perpendicular direction within the container between cathode 3 and anode 4 and substantially transversely to the line connecting the cathode and the anode.

The reticular portion is formed virtually as a ring segment, thus comprises a gap 41.

-i~

Claims

1. Process for regeneration of ion exchange material, wherein the ion exchange material in a liquid is exposed to a direct voltage field, characterized in that the direct voltage field is superposed by an alternating voltage field or pulsating direct voltage field, having a predetermined frequency.

2. Process according to Claim 1, characterized in that the alternating voltage field or the pulsating direct voltage field has a frequency with varying value.

3. Process according to Claims 1 or 2, characterized in that direct current 15 generated by the direct voltage field in the region of 70 to 10,000 mA and/or frequency for the alternating voltage field or the pulsating voltage field in the region of 10 KHz to 10 MHz is used.

04. Process according to any of the Claims 1 to 3, 20 characterized in that a frequency variation 0 4 is performed in periods of 1 minute or longer. t

5. Process according to any of the Claims 1 to 3, characterized in that the frequency is continuously varied periodically between a first and a second frequency value.

6. Process according to Claim characterized in that the period of the frequency variation is at least 2 seconds.

7. Process according to Claim characterized in that the period of the variation is substantially 8 seconds.

8. Process according to 6, characterized in that the period of the frequency variation is 1 minute or longer.

9. Process according to any of the Claims 1 to 8, ;AAVS i characterized in that the direct voltage field is momentarily pole reversed in intervals of time.

Process according to any of the Claims 1 to 9, characterized in that a liquid stream passes through the ion exchanged material.

11. Apparatus for regenerating ion exchange material comprising a tank receiving the material and a liquid, and an electrode formed as an anode and an electrode formed as a cathode for applying a direct voltage field, characterized in that an electrode for superimposing an alternating voltage field or a pulsating direct voltage field to the direct current field is provided. S 15

12. Apparatus according to Claim 11, characterized in that one of the electrodes from a group of anode and cathode is arranged at the bottom side of the tank and the other electrode of the 20group of anode and cathode is arranged above the material as an opposite electrode. 0

13. Apparatus according to CLaims 11 or 12, characterized in that the electrodes comprise a plurality of holes therethrough.

14. Apparatus according to Claims 12 or 13, characterized in that a sieve plate supporting the material is provided below the bottom side electrode and in a distance therefrom, and that a further sieve plate is provided above the other electrode and in a distance therefrom.

15. Apparatus according to any of the Claims 11 to 14, characterized in that the electrode for applying the alternating voltage field or the pulsating direct voltage field is arranged between the anode and the cathode. (tMW I_ j_ I 11

16. Apparatus according to Claim characterized in that the electrode is arranged at a side of the tank or as a reticular portion extending within the interior of the tank in perpendicular direction transversely to the connecting line between anode and cathode.

17. Apparatus according to Claim 16, characterized in that a sieve-type intermediate wall is provided between the electrode and a portion supporting the material.

18. Apparatus according to any of the Claims 11 to 14, 0 characterized in that the anode is selected as electrode for applying the alternating voltage field S: 15 or the pulsating direct voltage field.

S19. Apparatus according to any of the Claims 11 to S 4 18, 0 characterized in that a liquid discharge is 0 provided above the material level.

20 20. Apparatus according to any one of Claims 12 4 .and 13 to 19 when appended to Claim 12, characterized in that the bottom side S" electrode is formed as cathode and the opposite electrode as anode.

21. Apparatus according to any one of Claims 12 and 13 to 19 when appended to Claim 12, characterized in that the bottom side electrode is formed an anode and the opposite electrode as cathode.

22. Apparatus according to Claim 20 or 21, characterized in that a further electrode of the type corresponding to the bottom side electrode is provided above the opposite electrode and in a distance therefrom. DATED this fifth day of September 1991. N4 jJ I-. 12 GRUNBECK WASSERAUFBEREITJNG GMBH, by its Patent Attorneys, GRANT ADAM'S COMPANY. 0* 4, 0 00 0 0 O 00 o #0 00 0 0 0 0004 4 Ot 000000 On. 0 00 #000 00 0 00 0$0 4 j~tI~ ~T 13 PROCESS AND APPARATUS FOR REGENERATION OF ION EXCIIANGE MATERIAL ABSTRACT 1. Process and apparatus for regeneration of ion exchange material. 2.1 In conventional regeneration processes for ion exchange material diaphragms must be provided and eletrolytes must be added in order to obtain a sufficient con- ductivity. A process shall therefore be provided which avoids this requirement, and an apparatus for carrying out the process. 2.2 According to the invention a tank is provided into which the exchange material to be regenerated is charged. The ion exchange material is arranged between an anode 26) and a cathode 25, 27). During regeneration an alternating voltage or a pulsat- ing direct voltage is applied through the anode (3, 26) or a further electrode (18, 22). The efficiency of the process is increased, if the frequency of the alternating voltage or of the pulsating direct voltage 4 is regularly varied. 2.3 The inventive regeneration process may be used for example in water conditioning plants or electroplating shops. 3. (Fig.