JPS6259630B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for regenerating an ion exchange resin in a multi-bed sugar solution desalting apparatus, which aims to obtain a highly purified treated liquid and to significantly reduce the amount of water for regeneration and the amount of water used for washing. It is something. Conventionally, in the desalting of sugar solutions, etc., a cation tower (hereinafter referred to as K tower) filled with a strongly acidic cation exchange resin and an anion tower (hereinafter referred to as A tower) filled with a weakly basic anion exchange resin or a strongly basic anion exchange resin have been used. A double-bed ion exchange device is used, and when treating sugar solution with this double-bed ion exchange device, the sugar solution is passed through the K column and then the A column in a downward flow, and the regeneration of both columns is also carried out. In this case, a so-called downflow regeneration method is used, in which the regeneration agent is passed through in a downward flow for regeneration. Although this conventional downflow regeneration method has a simple device and easy regeneration operation, it has the drawbacks that the treated liquid has low purity, requires a large amount of regeneration water, and generates a large amount of washing water.

In order to increase the purity of the treated liquid, this problem can be easily solved by performing upward flow regeneration of the K tower, as has been conventionally done in water treatment equipment.
In other words, a collector for discharging recycled waste liquid is installed in the upper layer of the strongly acidic cation exchange resin, and at the same time the regenerant and extruded water are introduced from the bottom of the ion exchange tower, supporting fluids such as air and water are introduced from the top of the ion exchange tower. The regenerated waste liquid or extrusion water and the support fluid are allowed to flow in, and the strongly acidic cation exchange resin is held under pressure by the inflow pressure of the support fluid and regenerated. When the strongly acidic cation exchange resin is regenerated in an upward flow in this way, the lower layer is more regenerated, so when the sugar solution is passed in a downward flow, the amount of leakage of salts can be significantly reduced.

However, this conventional upflow regeneration has the disadvantage that the strongly acidic cation exchange resin in the upper part of the collector becomes ineffective in terms of ion exchange, and even with this upflow regeneration, the regeneration water and It has no effect on reducing flushing wastewater.

When desalting a sugar solution using a multi-bed desalting device, a large amount of water for regeneration is required and a large amount of regeneration wastewater is generated due to organic contamination of the anion exchange resin. In other words, the sugar solution that is the liquid to be processed, especially the sugar solution of starch sugars such as starch, glucose saccharified with acids and enzymes, starch syrup, maltose, and oligosaccharides, contains a large amount of salts due to impurities in the raw material starch. In addition, there are large amounts of organic substances that originally exist in the raw material starch and organic substances that are by-products during saccharification, and as the usage cycle increases, these organic substances irreversibly adsorb to the anion exchange resin, causing so-called organic contamination. receive. Since these organic substances are generally polymeric, they are irreversibly adsorbed by the anion exchange resin, reducing the rate of ion diffusion within the anion exchange resin particles, thereby reducing the cleaning effectiveness of the caustic soda regenerant. do. Furthermore, some of these organic substances have carboxylic acid groups, and as these organic substances are irreversibly adsorbed onto the anion exchange resin, when the anion exchange resin is regenerated with caustic soda, this carboxylic acid The group becomes sodium type, and this sodium type carboxylic acid group has the property of being easily hydrolyzed, so it hydrolyzes to produce caustic soda during washing after regeneration, so the pH of the washing wastewater decreases. There is also a phenomenon in which the temperature does not decrease easily.

It should be noted that the sugar solution to be treated, especially starch sugar solution such as glucose solution, is unstable to alkalis.
When the water becomes alkaline, the sugar decomposes and produces colored components, so washing should generally be continued until the pH of the washing water drops to below 10. If the anion exchange resin is contaminated with organic matter, the pH of the washing wastewater may remain around 12, even if it is washed with water that is approximately 12 times the amount of water that is normally used to fill the anion exchange resin. Therefore, in some cases, the amount of water washing water discharged from the A column reaches 20 times or more the capacity of the filled anion exchange resin.

In this way, when desalting a sugar solution using a double-bed desalting device, the water washing efficiency of tower A in particular decreases as the usage cycle increases, and therefore a large amount of recycled water is required, and an even larger amount of washing is required. Although wastewater is generated, it is not desirable to use a large amount of recycled water in today's era of resource conservation, and since the washing wastewater contains BOD such as coloring components, it is not possible to simply use the washing wastewater. It is not preferable that the amount of waste water for washing increases because it is not possible to discharge the water just by neutralizing the sodium chloride and biological treatment is required.

In addition, in order to reduce the amount of washing wastewater, the water treatment equipment circulates the washing wastewater from the A tower to the regenerated K tower, and continues this circulation until the amount of caustic soda in the washing wastewater from the A tower decreases. It is. It is possible to apply this method to a multi-bed desalination equipment for sugar solution processing, but the anion exchange resin in a multi-bed desalination equipment for sugar solution processing is incomparable to the anion exchange resin used in water treatment equipment. Since there is a large amount of organic contamination, and as mentioned above, a large amount of organic matter having carboxylic acid groups is also adsorbed to the anion exchange resin, the amount of caustic soda in the washing wastewater does not decrease easily. Therefore, compared to the case of water treatment equipment, it has to be circulated for a considerably longer time, and a considerable portion of the regenerated H-type strongly acidic cation exchange resin in the K tower is converted into Na-type during the circulating water washing. This causes a problem in that the capacity of the K tower becomes insufficient during the important desalting operation of the sugar solution.

The present invention solves the above-mentioned drawbacks of the conventional double-bed desalination equipment, obtains a highly purified treated liquid, and effectively utilizes the cation exchange resin packed in the K tower to significantly reduce the amount of water for regeneration and the amount of water used for washing. The purpose is to reduce the

The present invention consists of a K tower in which the upper part of a strong acidic cation exchange resin is filled with a small amount of weakly acidic cation exchange resin, and a collector is attached near the interface between both cation exchange resins, and a weakly basic anion exchange resin or a strong basic anion exchange resin. A sugar solution desalination device is constructed by A tower filled with exchange resin, and the sugar solution is passed through the K tower and then the A tower in a downward flow, and when regenerating the cation exchange resin in the K tower, At the same time as the regenerating agent flows in from the lower part of the K tower, a supporting fluid such as air or water flows in from the upper part of the K tower, and the regenerated waste liquid and the supporting fluid flow out from the collector to hold the strongly acidic cation exchange resin under pressure. At the same time, the weakly acidic cation exchange resin is regenerated before, during or after the regeneration of the strongly acidic cation exchange resin, and when regenerating the A tower, the regenerant is regenerated in the downward or upward flow. The anion exchange resin is regenerated by flowing into the K tower and the A tower.
The towers are connected by closed circulation piping for washing water, and the washing water is circulated in a downward flow, and the sodium ions contained in the washing wastewater from the A tower are removed by the weakly acidic cation exchange resin in the K tower. The present invention relates to a method for regenerating an ion exchange resin for a sugar solution desalting device.

The present invention will be explained in detail below based on the drawings.

The drawing is an explanatory diagram showing the flow of a desalting apparatus for a glucose solution obtained by saccharifying starch, which is an example of an embodiment of the present invention. A strongly acidic cation exchange resin 2 is filled in the K column 1, and a small amount of a weakly acidic cation exchange resin 3 is filled in the upper part thereof. The filling amount of the strongly acidic cation exchange resin 2 is determined by the amount of glucose stock solution processed per cycle and the amount of cations contained in the glucose stock solution.
The filling amount is usually such that the resin layer height is around 300 mm regardless of the composition of the stock solution or the processing amount. The filling of the weakly acidic cation exchange resin 3 corresponds to a so-called ineffective resin in the upflow regeneration of the water treatment device, and one purpose is to prevent the strong acid cation exchange resin 2 from flowing during the upflow regeneration. A collector 4 for discharging recycled waste liquid is attached near the interface between the strongly acidic cation exchange resin 2 and the weakly acidic cation exchange resin 3, and a recycled waste liquid outflow pipe 5 is connected to the collector 4. In this embodiment, the collector 4 is horizontal, but a plurality of rigid collectors each having an inlet made of a slit or the like at the tip are inserted from above the weakly acidic cation exchange resin 3, and the inlet is It may be located near the interface between the strongly acidic cation exchange resin 2 and the weakly acidic cation exchange resin 3.

A raw solution inflow pipe 6 is connected to the upper part of the K tower 1, and an inflow pipe 7 for supporting water during upward flow regeneration is connected to the upper part of the K tower 1. Note that an acid injection pipe 8 is connected to the support water inflow pipe 7. Next, one end of the connecting pipe 9 is connected to the lower part of the K tower 1, and the other end of the connecting pipe 9 is connected to the upper part of the A tower 10. A column A 10 is filled with a weakly basic anion exchange resin 11, and a collector 4' for discharging recycled waste liquid is placed in the upper layer of the weakly basic anion exchange resin 11.
A recycled waste liquid outflow pipe 5' is connected to the collector 4'. As mentioned above, glucose produced from starch as a raw material contains a large amount of salts due to impurities in the raw material starch, and starch sugar is unstable to alkalis, so the A column 10 generally has a low regeneration efficiency. is excellent, and the PH of the processing solution is
Use a weakly basic anion exchange resin that does not significantly increase The filling amount of the weakly basic anion exchange resin 11 is determined by the amount of resin in the lower part of the collector 4', as in the case of the K tower, and the amount of glucose stock solution processed per cycle and the amount of anions contained in the glucose stock solution. do. Note that the weakly basic anion exchange resin 11 in the upper part of the collector 4' is an ineffective resin in upward flow regeneration, and is filled to a resin layer height of approximately 300 mm regardless of the composition of the stock solution or the amount of treatment. Note that the collector 4' may also be a rigid collector as in the case of the K tower 1. Furthermore, A tower 1
An inflow pipe 7' for supporting water during upward flow regeneration is connected to the upper part of the tower 0, and a treated liquid outflow pipe 12 at the lower part of the tower A 10 is connected to the upper part of the tower 0. In addition, washing water inflow pipes 13 and 13' and backwash water outflow pipe 1 are connected to the raw solution inflow pipe 6 and the connecting pipe 9 near the inlet of the A tower 10, respectively.
4 and 14' are connected, and a regenerant inflow pipe 15, a backwash water inflow pipe 16, and a blow pipe 17 are connected to the connecting pipe 9 near the outlet of the K tower 1. Further, in the same way, a regenerant inflow pipe 15', a backwash water inflow pipe 16' and a blow pipe 1 are connected to the processing liquid outflow pipe 12.
Connect 7'. In addition, one end of the washing water circulation pipe 18 is connected to the processing liquid outflow pipe 12, and a washing water storage tank 19,
The other end of the wash water circulation pipe 18 is connected to the stock solution inflow pipe 6 via the circulation pump 20, thereby forming a closed circulation system for the wash water. Note that 21 and 21' are support plates for the ion exchange resin, and in addition to the support plates 21 and 21', the lower part of the strongly acidic cation exchange resin 2 or the weakly basic anion exchange resin 11 is filled with, for example, silica stone as a support bed. You may. In this embodiment, the A column has an upward flow regeneration flow, but in the present invention, the A column does not particularly need to be an upward flow regeneration flow, and may be a down flow regeneration flow. Furthermore, in both the K tower 1 and the A tower 10, water is introduced from the upper part of the ion exchange tower as a supporting fluid in order to prevent fluidization of the ion exchange resin during upflow regeneration, but in some cases, water may be introduced as a supporting fluid. may be used as a supporting fluid.

Next, the operation in the present invention will be described. When desalting a glucose stock solution, the glucose stock solution is passed through the regenerated K tower 1 and A tower 10 in this order in a downward flow. That is, the glucose stock solution was flowed into the K tower 1 from the stock solution inflow pipe 6, and the effluent from the K tower 1 was flowed into the A tower 10 using the connecting pipe 9 to remove organic substances such as salts and pigment components in the glucose stock solution. The glucose treatment liquid is made to flow out from the treatment liquid outflow pipe 12. In order to further improve the purity of the treated liquid, a mixed bed demineralization tower (not shown) is connected to the treated liquid outflow pipe 12.
The processing liquid can also be further processed.

When the prescribed amount of the glucose stock solution has been passed, water is introduced into the K tower 1 and the A tower 10 in the same manner, and after replacing the glucose in the towers with water, the following regeneration operation is performed.

First, in the K tower 1, backwash water flows in from the backwash water inflow pipe 16, and backwash water is passed through the backwash water outflow pipe 16.
After that, backwashing is performed by a conventional method, and then the flow of backwash water is stopped, and the strongly acidic cation exchange resin 2 and the weakly acidic cation exchange resin 3 are settled. Since the specific gravity of the weakly acidic cation exchange resin 3 is smaller than that of the strongly acidic cation exchange resin 2, the two cation exchange resins do not mix even when backwashing is performed, and the weakly acidic cation exchange resin 3 is mixed as shown in the drawing. The strongly acidic cation exchange resin 2 can be formed in the upper layer part and the strongly acidic cation exchange resin 2 in the lower layer part. Note that if the pressure loss in the K tower 1 is not so large at the end of passing the glucose stock solution, the backwashing step can be omitted.

After backwashing and settling are completed, 5 to 10% hydrochloric acid is flowed in from the regenerant inflow pipe 15 at an upward flow of LV2m/H, and at the same time as the hydrochloric acid is inflow, support water is injected from the support water inflow pipe 7. The downward flow flows in at around LV2m/H, and the regenerated waste liquid and supporting water are discharged from the regenerated waste liquid outflow pipe 5 via the collector 4. When the support water is introduced, a small amount of hydrochloric acid is injected into the support water through the acid inflow pipe 8 to make the pH of the support water acidic at around 1.

By filling the upper part of the collector 4 with the weakly acidic cation exchange resin 3 and letting supporting water flow in from the upper part of the K tower 1, downward pressure is applied to the packed resin layer, so even if the regenerant is passed in an upward flow. The strongly acidic cation exchange resin 2 can be regenerated by upward flow without being fluidized, and since the acid is added to the supporting water, the weakly acidic cation exchange resin 3 can also be regenerated. After a specified amount of hydrochloric acid is introduced from the regenerant inflow pipe 15, extruded water is introduced from the regenerant inflow pipe 15, and the recycled waste liquid is discharged from the regenerated waste liquid outflow pipe 5, thereby removing residual water from the strongly acidic cation exchange resin 2. Push out the regenerant that is present. Note that during the extrusion, the support water continues to flow in from the support water inflow pipe 7, but the injection of hydrochloric acid from the acid injection pipe 8 is stopped as soon as a specified amount has been injected.

After the inflow of extruded water in an amount approximately equal to the filling capacity of the strongly acidic cation exchange resin 2 is completed, the washing water is introduced from the washing water inflow pipe 13 and the washing water is sent to the blow pipe 1.
Let it flow from 7. It should be noted that the amount of washing water is sufficient to be about three times the filling capacity of the strongly acidic cation exchange resin 2, but during the extrusion described above, an amount about four times the filling capacity of the strongly acidic cation exchange resin 2 is used as extrusion water. In this case, the washing with water can be omitted.

On the other hand, the A tower 10 is also regenerated as described above during or after the K tower 1 is regenerated. That is, backwash water is introduced through the backwash water inflow pipe 16', backwash water is discharged from the backwash water outflow pipe 14', and backwashing is performed in a conventional manner. Note that this backwashing can be omitted if there is a reason similar to that described for K tower 1. After settling the weakly basic anion exchange resin 11, a 2 to 4% caustic soda solution flows in from the regenerant inflow pipe 15' at an upward flow of LV5m/H, and at the same time as the caustic soda solution flows in, the supporting water Support water flows in from the inlet pipe 7' at a downward flow rate of about LV2m/H, and the regenerated waste liquid and support water flow out from the regenerated waste liquid outflow pipe 5' via the collector 4'. In the same way as explained for K tower 1, downward pressure is applied to the packed resin bed in A tower 10, so even if the regenerant is passed in an upward flow, the weakly basic anion exchange resin 11 is not fluidized. Can be regenerated in upstream flow. After a predetermined amount of caustic soda solution is introduced from the regenerant inflow pipe 15', the regenerant inflow pipe 15'
The regenerant remaining in the weakly basic anion exchange resin 11 is pushed out by letting extrusion water flow in and flowing out from the regenerated waste liquid outflow pipe 5'. Note that even during the extrusion, the support water continues to flow in from the support water inflow pipe 7'. After a volume of extruded water approximately equal to the filling capacity of the weakly basic anion exchange resin 11 in the lower part of the collector 4' is injected from the regenerant inflow pipe 15', washing water is inflowed from the washing water inflow pipe 13' to complete the washing process. The waste water flows out from the blow pipe 17'. It should be noted that the amount of washing water is sufficient to be about 3 times the filling capacity of the weakly basic anion exchange resin 11, but during extrusion, about 4 times the filling capacity of the weakly basic anion exchange resin 11 is used as extrusion water. In this case, the washing with water can be omitted. As mentioned above, due to organic contamination of the anion exchange resin, a considerable amount of caustic soda remains in the washing water and its pH is high. Therefore, in the past, washing was continued until the pH of the washing waste water became 10 or less, but in the present invention, washing is stopped when a specified amount of water has been washed, regardless of the pH of the washing waste water.

After washing the K tower 1 and the A tower 10 with a specified amount of water, in the present invention, the circulation pump 20 is driven to carry out circulation washing using the closed circulation piping formed by the connecting pipe 9 and the washing water circulation pipe 18. That is, the washing water in the washing water storage tank 19 is transferred to K using the circulation pipe 18.
The water is supplied to the upper part of the tower 1, the water flowing out from the lower part of the tower K is supplied to the upper part of the tower A 10 using the connecting pipe 9, the water flowing out from the lower part of the tower A is returned to the washing water storage tank 19, and this process is repeated.

By this operation, sodium ions contained in the outflow water from the A tower 10 can be effectively removed by the weakly acidic cation exchange resin 3 packed in the upper part of the K tower 1. Note that while the circulation continues, the pH of the water flowing out of tower A gradually decreases, and when the pH reaches 10 or less, this circulation cleaning is terminated. After the circulation cleaning is completed, the glucose stock solution is passed through and the K
The water in tower 1 and A tower 10 is replaced with a glucose stock solution, and then the glucose stock solution is passed through.

As described above, in the present invention, circulation cleaning is performed after a specified amount of water washing is completed, so even if the anion exchange resin is contaminated with organic matter and the washing effect is reduced, the amount of water drained from the K tower and A tower will be reduced. In both cases, only about three times the amount of filled ion exchange resin is generated, and the sodium ions in the outflow water of the A column 10 during circulation cleaning are effectively removed by the weakly acidic cation exchange resin 3 packed in the upper part of the K column 1. To solve the conventional drawbacks such as the insufficient capacity of the K tower during the desalting operation of the sugar solution by applying no ionic load to the regenerated strongly acidic cation exchange resin 2. Can be done. In addition, a weakly acidic cation exchange resin has a larger ion exchange capacity and a higher regeneration efficiency than a strongly acidic cation exchange resin. Therefore, by using a weakly acidic cation exchange resin in the upper part of the collector 4, Compared to the case where a strongly acidic cation exchange resin is used for the purpose, the removal capacity of sodium ions can be increased per the same filling capacity, and the weakly acidic cation exchange resin can be regenerated by a simpler regeneration method. Can be done. That is, in this embodiment, the weakly acidic cation exchange resin was regenerated by injecting a small amount of hydrochloric acid into the support water and passing dilute acidic water through it. Regeneration can be carried out even if a relatively large amount of hydrochloric acid is injected from the acid injection pipe 8. Therefore, the structure of the apparatus can be simplified and the regeneration time will not be extended. On the other hand, if a strongly acidic cation exchange resin is used as the filler resin in the upper part of the collector 4, its regeneration efficiency is poor, so it cannot be regenerated with dilute acidic water, and if hydrochloric acid is injected in spots, the regeneration is incomplete. Therefore, it is necessary to use a commonly used reproducing equipment, which complicates the apparatus and lengthens the reproducing time.

The amount of acid used for regenerating the weakly acidic cation exchange resin in the present invention is determined depending on the amount of sodium ions to be removed during circulation cleaning, and the amount of acid used is approximately equal to the total equivalent of the sodium ions. It is sufficient to use an acid, and it is sufficient to use 1 equivalent of hydrochloric acid per weakly acidic cation exchange resin in the upper part of the ordinary collector 4.

Regarding the regeneration of the weakly acidic cation exchange resin, in addition to the above-mentioned regeneration method, depending on the case, it may be possible to regenerate it alone before or after regenerating the strongly acidic cation exchange resin. Note that it is also possible to store the recycled waste liquid of the strongly acidic cation exchange resin, and to regenerate the weakly acidic cation exchange resin with this recycled waste liquid.

The present invention is not limited to the purification of starch sugar solutions such as the glucose solution described in the embodiments, but can be applied to the purification of any sugar solution whose stock solution contains organic substances that may contaminate an anion exchange resin.

As described above, the present invention improves the purity of treated water by upstream regeneration of the K tower, and exchanges cations in the upper part of the collector, which in conventional upstream regeneration was filled only for the purpose of preventing fluidization during regeneration. By actively regenerating the resin and circulating and cleaning the K and A towers after regeneration, the amount of regeneration water and washing water can be reduced without reducing the ion exchange capacity of the regenerated strongly acidic cation exchange resin at the bottom of the collector. In addition, by using a weakly acidic cation exchange resin as the cation exchange resin filled in the upper part of the collector, the sodium removal capacity can be increased and the device can be simplified. , the benefits to industry are significant.

Examples of the present invention will be described below.

Example (1) Method of the present invention Cation resin column for upflow regeneration (column diameter 50
mm, height 3000mm) strongly acidic cation exchange resin Amberlite (registered trademark (hereinafter the same)) IR-120B
2.6 and weakly acidic cation exchange resin Amberlite
Filled with 390ml of IRC-50. Note that the collector was attached to the interface between both cation exchange resins. In addition, an anion resin column for upstream regeneration (column diameter 65 mm, height
2500 mm) was filled with weakly basic anion exchange resin Amberlite IRA-934 (however, the amount of resin at the bottom of the collector was 3.33), which had been used for 240 cycles in an actual glucose refining device, and the following regeneration was performed. That is, in the cation resin column, 8% hydrochloric acid was injected from the bottom of the column at a flow rate of LV2 m/H, and supporting water containing 30 g of 35% hydrochloric acid was injected in small portions from the top of the column at a flow rate of LV1.5 m/H. The recycled waste liquid and supporting water were discharged from the collector.

Next, after pushing out the regenerating agent at the bottom of the collector with the water volume 1/- resin, the flow rate is SV12 with a downward flow, and the water volume is 3.
/--Cleaned the resin. On the other hand, in the anion resin column, 3% sodium hydroxide was injected from the bottom of the column at a flow rate of LV6 m/H, and supporting water was passed from the top of the column at a flow rate of LV1.5 m/H. The recycled waste liquid and supporting water were discharged from the collector. Next, after pushing out the regenerating agent at the bottom of the collector with the water amount 1/- resin, the flow rate is SV15 with a downward flow, and the water amount 3/-
-Cleaned the resin.

The amount of regenerating agent used is Amberlite IR-120B.
uses 442g of 35% hydrochloric acid, Amberlite IRA
-93 was 167g of 100% sodium hydroxide.

Next, using a closed circulatory system as shown in the drawing,
The cation resin column and anion resin column were circulated and washed until the pH of the water flowing out of the anion resin column reached 10.

Note that the flow rate of circulation washing was set to SV15 for the anion resin column.

Then 2000mg of total cations as CaCO ₃ /,
Total anions 2580mg as CaCO ₃ /, sugar concentration 46%
(wt%) of glucose stock solution was passed through an anion resin column at SV4, and the average conductivity was 3μ.
Treated water of υ/cm was obtained.

(2) Conventional method The same strongly acidic cation exchange resin Amberlite is used in each of the cation resin column and anion resin column for downflow regeneration with the same dimensions as in the method of the present invention.
Filled with IR-120B2.6 and the same weakly basic anion exchange resin Amberlite IRA-933/33,
I performed the following playback. In the cation resin column, after passing 10% hydrochloric acid (the amount of regenerant used is the same as in the method of the present invention) at a flow rate of SV4, it is extruded with a water volume of 1/- resin, and water washing is performed in a downward flow at a flow rate of SV12 for 3
/--Done with resin. In addition, in the anion resin column, after passing 4% sodium hydroxide (the amount of regenerant used is the same as in the method of the present invention) at a flow rate of SV4, it is extruded with a water volume of 1/- resin, and water is washed with a downward flow at a flow rate of SV15. This was done until the pH of the water reached 10. As a result, 60 ml of washing waste water flowed out from the anion resin column. Next, when the same glucose stock solution as in the present invention was passed through an anion resin column at SV4, treated water with an average conductivity of 60 μυ/cm was obtained.

As is clear from the above examples, in the conventional method, 60 ml of washing waste water flows out from the anion resin column, whereas in the method of the present invention, only 3/- resin flows out from the packed resin volume, that is, 10
This resulted in a significant reduction in the amount of water used for washing. Furthermore, the purity of the liquid to be treated was also significantly increased.

[Brief explanation of the drawing]

The drawing is an explanatory diagram showing a flow of an embodiment of the present invention. 1... Cation tower (K tower), 2... Strongly acidic cation exchange resin, 3... Weakly acidic cation exchange resin, 4... Collector, 5... Regenerated waste liquid outflow pipe, 6... Raw solution inflow pipe,
7... Support water inflow pipe, 8... Acid injection pipe, 9... Connecting pipe, 10... Anion tower (A tower), 11... Weakly basic anion exchange resin, 12... Processing liquid outflow pipe, 13...
Washing water inflow pipe, 14... Backwash water outflow pipe, 15...
Regenerant inflow pipe, 16... Backwash water inflow pipe, 17...
Blow pipe, 18... Rinsing water circulation pipe, 19... Rinsing water storage tank, 20... Circulation pump, 21... Support plate.

Claims (1)

[Claims] 1. A cation tower in which a small amount of weakly acidic cation exchange resin is filled above a strongly acidic cation exchange resin and a collector is attached near the interface between both cation exchange resins, and a weakly basic anion exchange resin. A sugar solution desalting device is composed of an anion column filled with a resin or a strong basic anion exchange resin, and the sugar solution is passed downstream through the cation column and the anion column in order, and the cation exchange resin in the cation column is drained. During regeneration, a regenerating agent is introduced from the lower part of the cation tower, and at the same time a supporting fluid such as air or water is introduced from the upper part of the cation tower, and the regenerated waste liquid and the supporting fluid are discharged from the collector to form a strong acid. The cation exchange resin is held under pressure and regenerated by upward flow, and the weakly acidic cation exchange resin is regenerated before, during or after the regeneration of the strongly acidic cation exchange resin, and when the anion column is regenerated, a regenerating agent is used. The anion exchange resin is regenerated by flowing the water in a downward or upward flow, and when cleaning the cation and anion towers after regeneration, the cation and anion towers are connected through closed circulation pipes for cleaning water. Regeneration of ion exchange resin in a sugar solution desalting equipment characterized by circulating water in a downward flow and removing sodium ions contained in the washing wastewater from the anion tower using a weakly acidic cation exchange resin in the cation tower. Method. 2. A method for regenerating an ion exchange resin in a sugar solution desalting device according to claim 1, wherein the sugar solution is a starch sugar solution. 3. In regenerating the cation column, a regenerating agent is introduced from the lower part of the cation column, and at the same time, a supporting fluid, which is acidic water to which an acid has been added, is introduced from the upper part of the cation column, and the recycled waste liquid and the supporting fluid are allowed to flow out from the collector. The sugar solution removal method according to claim 1 or 2, wherein the strongly acidic cation exchange resin is retained and regenerated, and the weakly acidic cation exchange resin is regenerated in a downward flow while the strongly acidic cation exchange resin is being regenerated. Method for regenerating ion exchange resin in salt equipment.