JP2010099648A - Water purifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water purifier for removing an impurity ion in water using an ion exchange resin capable of effectively utilizing the ion exchange resin. <P>SOLUTION: A resin container 21 filled with the ion exchange resin 35 is provided with a cone-shaped water distributor 27 at the upper central part of the container 21 so as to distribute the water from the distributor 27 uniformly in the container 21. The resin container 21 is also provided with a water collector at the lower central part of the container 21 for collecting the water in the container, and a water collecting pipe possesses an air vent port at its upper part. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a deionizer that is provided in, for example, a wire electric discharge machine and removes impurity ions in water using an ion exchange resin.

  Electric discharge machining is a machining method in which a part of a workpiece is removed by an arc discharge repeated at a short cycle between an electrode and the workpiece. It is mainly used when processing hard metals that cannot be processed by machining techniques. If this electric discharge machining technique is used, a complicated outline can be formed in extremely hard steel or exotic metal (for example, titanium or carbide). However, due to the characteristic of removal processing by electric discharge between the electrode and the workpiece, the workpiece can only be processed if it is a material (conductor) that conducts electricity. The EDM surface tends to become brittle due to repeated melting and re-solidification. The electrode of the electric discharge machining is moved along the surface of the workpiece so as to be in a very close position without contacting the workpiece. Then, the spark melts and evaporates a part of the surface of the workpiece, thereby forming innumerable minute recesses on the surface of the workpiece. Particles removed from the workpiece by melting or evaporating are washed away by a dielectric liquid (processing fluid) filled between the electrode and the workpiece.

  The electric discharge machining technique is roughly classified into die-sinking electric discharge machining and wire electric discharge machining, and the present invention relates to wire electric discharge machining. Wire electrical discharge machining is performed by sending a thin wire of metal (mainly brass) close to the workpiece. The wire is supplied from the bobbin at a constant speed and is held by the upper and lower guides. In wire electric discharge machining, water or oil is used as a machining fluid, but the present invention relates to a method using water as a machining fluid.

  In the processing fluid circulation system when water is used as the processing fluid, in order to maintain the water quality at a certain condition (electrical conductivity), the ion exchange resin is used in the processing fluid (hereinafter simply referred to as water). Impurity ions are removed. This ion exchange resin loses its ability when used for a certain period of time and saturated. For this reason, for example, management such as reactivation using hydrochloric acid and caustic soda is performed (see, for example, Patent Document 1).

JP-A-60-135128

  Conventionally, saturated ion exchange resins have been regenerated and reused with regenerative chemicals as described above.For example, the amount of resin used is small, and it is expensive to install a regenerating facility for a small amount of ion exchange resin. In such a case, a pre-regenerated ion exchange resin is filled in a water container (resin cylinder) and used, and after the ion exchange resin is saturated, the ion exchange resin inside the resin cylinder is replaced with a regenerated one. It has become common to adopt this method.

  By using such a container for water flow, even if the same amount of ion exchange resin is filled, the water flow efficiency is increased, and the exchange interval can be reduced by using the filled ion exchange resin more efficiently. Can be extended. If the replacement interval can be extended, the operation management becomes easy and the cost for maintaining the water quality can be reduced.

  On the other hand, in the conventional deionizer, the inlet pipe may be provided at a position eccentric from the central axis with respect to the container filled with the ion exchange resin. In such a case, water is not uniformly distributed in the container, and a single flow phenomenon of water occurs in the container. When this single flow phenomenon occurs, a portion where water does not spread occurs, so that the water flow efficiency is lowered and the ion exchange rate is reduced. In such a state, since the ion exchange resin is not effectively used and the life is not extended, improvement has been demanded.

  In addition, generally in a pure water device, air may remain in the container, but the remaining air is driven to the upper part by the water accumulated in the container at the start of water flow and is accumulated in the upper part of the container. Form. The conventional deionizer did not have a structure for escaping the air in the air reservoir to the outside of the container. When the air pool becomes larger than a predetermined value, a portion where the water does not spread is generated in the container, and the ion exchange resin filled in the container is exposed to the air pool and does not allow the water to pass well. In such a state, as in the case where the inlet pipe is in a position eccentric from the central axis, the ion exchange resin is not effectively used and the life is not extended, so that improvement has been demanded.

  The present invention has been made in view of the above-mentioned problems, and distributes water uniformly in the container to suppress the single flow phenomenon of the water in the container and to suppress the expansion of the air pool, thereby An object of the present invention is to obtain a deionizer capable of improving the ion exchange rate by eliminating the unspread locations and effectively utilizing the ion exchange resin.

  In order to solve the above-described problems and achieve the object, the deionizer according to the present invention has a water distribution part provided at the center of the upper part of the container filled with the ion exchange resin, and water distributed from the water distribution part. However, water is distributed at a uniform density in the container, and a water collecting part for collecting the water in the container is provided at the lower center of the container.

  Furthermore, the deionizer of the present invention has an air vent hole in the upper part of the water collecting pipe in order to let air in the air pool formed in the upper part of the container escape. By providing an air vent hole in the upper part of the water collecting pipe, the air in the air pool is easily pushed out from the air vent hole via the water collecting pipe and the outlet pipe. Thereby, even if an air pocket is generated in the container, air is quickly discharged from the air vent hole.

  According to this invention, the water distribution unit is provided in the upper center of the container so that the water distributed from the water distribution unit is distributed at a uniform density in the container, and further collects the water in the container. Is provided at the center of the lower part of the container, so that water is evenly distributed in the container and the phenomenon of one-sided flow of water in the container is suppressed, and the expansion of the air pool is suppressed by the air vent hole in the upper part of the water collection pipe. As a result, the portion where water does not spread is eliminated and the ion exchange rate is improved, so that the ion exchange resin can be effectively used.

  Hereinafter, embodiments of a deionizer according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment FIG. 1 is a water circulation system diagram of a machining fluid supply device of a wire electric discharge machine. FIG. 2 is a longitudinal sectional view of a deionizer according to the present invention. FIG. 3 is a side view showing details of the cone-shaped member (water distribution unit). FIG. 4 is a side view showing the details of the water collecting section provided at the lower end of the water collecting pipe. FIG. 5 is a cross-sectional view taken along the line AA of FIG. 4 showing the cross-sectional shape of the water collecting port provided in the water collecting portion. FIG. 6 is a longitudinal sectional view of a conventional deionizer shown in comparison. In FIGS. 2 and 6, the arrows indicate the movement of water.

  In FIG. 1, the machining fluid supply device of the wire electric discharge machine is a circulation system including a pure water device 20 according to the present invention. A wire electric discharge machine (not shown) performs electric discharge machining using water in the machining tank 51. The water used in the processing tank 51 is transferred from the processing tank 51 to the septic tank 53 by gravity. The water stored in the dirty liquid tank 53 is pressurized by the pump 41 and fine particles are removed by the filter 31, and then transferred to the clean liquid tank 55. The water in the clear liquid tank 55 is circulated by the deionizer 20 attached to the clear liquid tank 55 to maintain the water quality. The treatment amount and water quality conditions for the circulation treatment vary depending on the specifications of the wire electric discharge machine, but in the present embodiment, they are as follows as an example.

Water volume: 17.6 l / min
Water quality: 7-14 μS / cm at 25 ° C. (electrical conductivity)

  The ion exchange resin used for maintaining the water quality is prepared by mixing a strongly basic anion (anion) exchange resin and a strongly acidic cation (cation) exchange resin in an appropriate ratio in a mixed bed. The amount of resin varies depending on the specifications of the target wire electric discharge machine, but as an example, in the deionizer of the present embodiment, it is as follows.

Cation exchange resin: 9 l
Anion exchange resin: 9 l
Total: 18l

  By mixing 9 l of cation exchange resin and 9 l of anion exchange resin, a wet mixed resin having an exchange capacity of 0.5 mg equivalent / ml can be obtained. The amount of resin to be filled is determined by the resin life, but the life in the above resin amount is conventionally about 4 months. In addition, in order to extend this lifetime, the amount of filled resin may be increased. For example, a resin of about 30 L may be used.

[Pure water purifier structure]
In FIG. 2, the deionizer 20 is provided in a cylindrical resin cylinder (container) 21 filled with an ion exchange resin 35 formed by mixing a cation exchange resin and an anion exchange resin, and in the upper center of the resin cylinder 21. An inlet / outlet pipe head 22 and a water collecting pipe 23 extending from the inlet / outlet pipe head 22 along the central axis of the resin cylinder 21 are provided. The resin cylinder 21 is made of, for example, stainless steel. For large size (30 l), FRP may be used.

  The ion exchange resin 35 is filled in almost the entire resin cylinder 21. Each of the ion exchange resins 35 (ion exchange resin particles) has a spherical shape with a diameter of 0.5 to 1 mm, and adsorbs ions on the surface thereof. If ions are adsorbed on the entire surface, the ion exchange ability is lost and the life is reached.

[Entrance / exit piping head]
The inlet / outlet pipe head 22 is provided at the upper part of the resin cylinder 21 to which the inlet pipe 11 and the outlet pipe 12 are connected, and is provided at the lower part of the connecting part 25 so as to face the inside of the resin cylinder 21 and flow into the inlet pipe 11. And a cone-shaped member (water distribution part) 27 that sprays (distributes) the water into the resin cylinder 21 at a uniform density. The water collecting pipe 23 extends so as to penetrate the cone-shaped member 27 coaxially. That is, the cone-shaped member 27 forms an annular chamber around the water collecting pipe 23. An inlet pipe 11 communicates with the annular chamber. A slit-shaped water spout for sprinkling water into the resin cylinder 21 at a uniform density is formed in the tapered outer peripheral wall of the annular chamber. The slit-shaped water spout is an extremely long slot extending in the axial direction of the cone-shaped member 27, and works effectively to spray water uniformly in a shower shape. The water collecting pipe 23 is made so as to penetrate the cone-shaped member 27.

[Cone-shaped member (distribution part)]
FIG. 3 shows the details of the cone-shaped member 27. The cone-shaped member 27 is made of a resin such as plastic and has a substantially hollow truncated cone shape. The cone-shaped member 27 has a tapered surface whose outer peripheral portion is divided into two stages, and slit-shaped water spouts 27a and 27b are formed on the tapered surface divided into the two stages, respectively. The water spouts 27a and 27b extend in the vertical direction and are entirely formed at equal intervals over the entire circumference. Further, a mounting flange portion 27c is provided in the large-diameter portion having a truncated cone shape. The flange portion 27c is threaded around, and the cone-shaped member 27 is screwed into the inlet / outlet piping head 22 by the thread of the mounting flange portion 27c and fastened. It is arranged toward the inside of 21 (FIG. 2).

[Water collection piping and water collection section]
As shown in FIG. 4, the water collection pipe 23 is made of a pipe-like material such as vinyl chloride, and the tip (lower end) is closed by a tip cap 23a. The water collecting portion 29 is configured by forming a plurality of slit-shaped water collecting ports 29 a in the horizontal direction at the lower end portion of the water collecting pipe 23 extending along the central axis of the resin cylinder 21. As shown in FIG. 5, the slit-shaped water collection port 29 a is formed to face both side surfaces of the water collection pipe 23. The water collection port 29a is formed by cutting with a thin disc-shaped incisor or grinding with a thin disc-shaped file, like the water spray ports 27a and 27b. The sprinkling ports 27a and 27b and the water collecting port 29a are not necessarily slit-like long holes, and may be a large number of small holes, for example, as long as uniform watering and uniform water collecting are possible.

  An air vent hole 60 is formed in the upper part of the water collecting pipe 23. The position of the air vent hole 60 is at the upper part of the water collecting pipe 23 and immediately below the portion where the water collecting pipe 23 penetrates the cone-shaped member 27 coaxially. The diameter of the air vent hole 60 is preferably smaller than the particle size of the ion exchange resin particles 0.5 to 1 mm so that the ion exchange resin particles are not clogged or washed away. In addition, only the air is discharged from the air vent hole 60 by making the total opening area of the air vent hole 60 sufficiently smaller than the total slit area of the water collection port 29a and sufficiently increasing the discharge resistance against water. Set as follows. In the present embodiment, four circular holes having a diameter of 0.3 mm are provided as air vent holes 60 at equal intervals in the circumferential direction. The four air vent holes 60 are formed at a position 120 mm from the upper end of the water collecting pipe 23 (10 mm below the lowest end of the cone-shaped member 27). In the present embodiment, the air vent hole 60 is a circular hole, but the air vent hole 60 is not limited to a circular one, and may have any shape as long as it has the same opening area. For example, a shape similar to the water collecting port 29a may be used, and in this case, a slit-like long hole shape having a width of 0.254 mm and a length of 1 mm is formed.

[Shaping of water spout and water collecting port]
The dimensions of each part of the cone-shaped member 27 and the water spray ports 27a and 27b are as shown in FIG. Moreover, the dimension of each part of the water collection part 29 and the water collection port 29a is as showing in FIG.4 and FIG.5. The inventors have confirmed through experiments that optimal watering and water collection can be achieved by making the shape of the watering hole and the water collecting port shown in the schematic diagram. That is, in the resin cylinder 21 filled with 18 L to 30 L of the ion exchange resin 35, the slit width of the water spray port is 0.2 to 0.4 mm, the slit length is 17 to 19 mm, the number of slits is 70 to 90, It was confirmed that optimal watering and water collection were possible by setting the slit width to 0.2 to 0.3 mm, the slit length to 12 to 14 mm, and the number of slits to 20 to 30.

  In addition, although the water collection piping 23 of this Embodiment has extended outside after penetrating the cone-shaped member 27 which comprises a water distribution part coaxially, arrangement | positioning of the water collection piping 23 is not restricted to this. . That is, if the cone-shaped member 27 and the water collecting portion 29 exist on the central axis of the resin cylinder 21, the object of the present application can be almost achieved, and water is uniformly sprinkled in the resin cylinder 21. However, as in the present embodiment, the water collecting pipe 23 is disposed on the central axis of the resin cylinder 21, and the cone-shaped member 27 is coaxially penetrated to minimize the resistance to the water flow. And the most efficient.

[Operation]
In the water purifier 20 having such a configuration, when the water flow into the water purifier 20 is started, the water sprayed into the resin cylinder 21 from the water spouts 27 a and 27 b of the cone-shaped member 27 is the bottom of the resin cylinder 21. It is gradually filled from. At this time, the air remaining in the resin cylinder 21 is pushed up and accumulates in the upper part of the resin cylinder 21 to form an air reservoir. Further, the water injected from the inlet pipe 11 by the ion-exchange resin pump 45 pressurizes the air in the air reservoir. The air that has lost the escape is pushed into the water collection pipe 23 from the air vent hole 60 formed in the water collection pipe 23 and is discharged out of the resin cylinder 21 through the outlet pipe 12 together with the collected water. . As a result, the air reservoir in the upper part of the resin cylinder 21 disappears, and the ion exchange resin filled in the resin cylinder 21 can be well distributed without being exposed to the air reservoir. Not only when air remains in the resin cylinder 21 at the beginning of use of the deionizer 20, but also when air enters with water from the inlet pipe 11 during use, as described above. Since air is quickly discharged out of the deionizer 20, an air pocket is not formed, and the ion exchange resin 35 in the resin cylinder 21 is not exposed to air, so that water does not reach the ion exchange resin 35. Nothing will happen.

  Further, in the pure water device 20 having such a configuration, water flows into the pure water device 20 from the inlet / outlet piping head 22 by the ion exchange pump 45, and the pressure of the pump 45 causes a shower-like shape from the cone-shaped member 27. Watered. At this time, since the cone-shaped member 27 is provided in the upper center of the resin cylinder 21 and the water spout is formed as a slit-like hole extending vertically in the cone-shaped portion, the cone-shaped member 27 is formed over the entire circumference. Are uniformly distributed in the resin cylinder 21, and no single flow phenomenon of water occurs in the resin cylinder 21.

The water uniformly distributed in the resin cylinder 21 descends in the resin cylinder 21 due to the pressure in the resin cylinder 21 by the pump 45 and its own weight. In the process, the ion exchange resin 35 is brought into contact with water to perform ion exchange. The water that has come into contact with the ion exchange resin 35 adsorbs cations such as Na ⁺ ions to the cation exchange resin. In addition, the anion in water is replaced with the reactive group of the anion exchange resin, and the anion is changed to OH ⁻ ion. Then, H ₂ O is generated by H ⁺ supplied from the cation exchange resin and OH ⁻ supplied from the anion exchange resin. In this way, most of the charged impurities are removed. The water from which the impurity ions have been removed is sucked from the water collecting section 29 by the pressure in the resin cylinder 21 by the pump 45 and is discharged from the outlet pipe 12.

[Conventional deionizer]
FIG. 6 is a longitudinal sectional view of a conventional deionizer shown in comparison with the present embodiment as described above. In FIG. 6, in the conventional deionizer 120, the water ejection nozzle 127, the water collection pipe 123, and the water collection portion 29 provided at the tip of the water collection pipe 123 are separated from the central axis of the resin cylinder 21. Was in place. For this reason, a single flow phenomenon occurred, and a portion where water did not spread like the region indicated by D in the figure occurred and the ion exchange rate was reduced.

  Further, in the conventional deionizer 120, the air remaining in the resin cylinder 21 is driven to the upper part by the water accumulated in the resin cylinder 21 and accumulated on the upper part of the resin cylinder 21 to form an air pocket shown in FIG. To do. The conventional deionizer 120 did not have a structure that actively releases the air in the air reservoir F to the outside. When the air reservoir F becomes larger than a predetermined value, a portion where the water does not spread in the resin cylinder 21 occurs, and the ion exchange resin filled in the resin cylinder 21 is exposed to the air reservoir and passes through the water well. I will not let you.

[Life comparison data]
The inventors conducted a monitor test in order to compare the lifetimes of the ion exchange resins of the conventional water purifier 120 shown in FIG. 6 and the water purifier 20 of the present embodiment, and collected life comparison data. Table 1 shows the life comparison data. Table 2 is a table showing the working conditions used in Table 1. The test was conducted using all 18 l of the same type of water purifier, changing the processing conditions and the processing time.

  As shown in Table 1, the ion exchange resin life of the deionizer 20 of the present embodiment is extended by 30% or more on average as compared with the conventional deionizer 120 shown in FIG. That is, the deionizer 20 of the present embodiment has a structure that can utilize the ion exchange resin more efficiently than the conventional deionizer 120, and the function improvement as a deionizer has been proved.

[Influence of vent holes]
The deionizer 20 of the present embodiment is also characterized by having the air vent hole 60 as described above. The air vent hole 60 mainly discharges residual air in the resin cylinder 21, but may discharge source water. That is, a part of the source water sprinkled from the sprinkling ports 27 a and 27 b of the cone-shaped member 27 may be directly discharged from the air vent hole 60 without passing through the ion exchange resin 35. If the source water is directly discharged from the air vent hole 60, the capacity of the water purifier 20 may be reduced. Therefore, the inventors conducted an experiment to confirm the influence of the presence or absence of the air vent hole 60 on the pure water device 20.

  FIG. 7 is a circuit configuration diagram in which an experiment for confirming the influence of the presence or absence of air vent holes was performed. As shown in FIG. 7, an electrical conductivity sensor 63 is set in the outlet pipe 12, the source water in the first tank 61 is pumped up by the pump 45, passed through the deionizer 20, and then discharged to the second tank 62. The electrical conductivity of the water discharged from the deionizer 20 was detected. Then, this experiment was performed with and without the air vent 60 and compared with the case with the air vent 60. FIG. 8 is a graph showing the results. In FIG. 8, the vertical axis represents the electrical conductivity (water quality) [μS / cm] of the discharged water, and the horizontal axis represents the water passage time [hour] to the deionizer 20.

  In the above circuit, when raw water having an electrical conductivity of 134 μS / cm was passed through the pure water device 20 from the inlet pipe 11, the electrical conductivity of the outlet water of the outlet pipe 12 was immediately after the water flow (0 to 8 hours). In the case of no air vent hole, 0.06 to 0.09 μS / cm, and in the case of air vent hole, 0.1 to 0.2 μS / cm. It was confirmed that it was almost negligible in use. On the other hand, as a result of comparing the ion exchange life of the deionizer 20 as the elapsed time of passing water when the electrical conductivity of the water at the outlet of the outlet pipe 12 reaches 14 μS / cm in the same experiment, the case where there is no air vent is about It was confirmed that the life reached in 15 hours when the air vent hole was provided, but the life reached in about 18 hours, and the provision of the air vent hole 60 extended the life of the deionizer 20.

  As described above, the deionizer according to the present invention is useful when used in, for example, a machining liquid supply device of a wire electric discharge machine, and in particular, a machining liquid that maintains the water quality by circulating the water in a clear liquid tank. Suitable for feeding device.

It is a circulation system diagram of the water of the processing liquid supply apparatus of a wire electric discharge machine. It is a longitudinal cross-sectional view of the pure water device concerning this invention. It is a side view which shows the detail of a cone-shaped member (water distribution part). It is a side view which shows the detail of the water collection part provided in the lower end part of water collection piping. It is arrow sectional drawing which follows the AA line of FIG. 4 which shows the cross-sectional shape of the water collection port provided in the water collection part. It is a longitudinal cross-sectional view of the conventional pure water device shown compared with this Embodiment. It is a circuit block diagram of the experiment which confirms the influence of the presence or absence of an air vent hole. It is a figure of the graph which shows the experimental result which confirms the influence of the presence or absence of an air vent hole.

11 Inlet pipe 12 Outlet pipe 20 Pure water device 21 Resin tube (container)
23 Water collection pipe 23a End cap 25 Connection part 27 Cone-shaped member (water distribution part)
27a, 27b Slit (drain)
27c Mounting flange 29 Water collecting part 29a Slit (water collecting port)
31 Filter 35 Ion exchange resin 41, 43, 45 Pump 51 Processing tank 53 Soil tank 55 Clear liquid tank 60 Air vent hole 61 First tank 62 Second tank 63 Electrical conductivity sensor

Claims (7)

In a deionizer that removes impurity ions in water using ion exchange resin,
An inlet pipe for flowing water,
An outlet pipe for draining water;
A container filled with an ion exchange resin mixed with a cation exchange resin and an anion exchange resin;
A water distribution unit that is provided in the upper center of the container and is connected to the inlet pipe and distributes water flowing from the inlet pipe at a uniform density in the container;
A water collecting portion provided at the lower center of the container and connected to the outlet pipe to collect water in the container and flow out to the outlet pipe;
A water purifier characterized by comprising The water distribution part has a conical part with a small diameter side directed inward of the container, and a slit-like water spout extending in the vertical direction is formed in the conical part over the entire circumference. Item 5. A deionizer according to item 1. An upper portion is coaxially passed through the conical portion of the water distribution portion, connected to the outlet pipe, and provided with a water collection pipe extending to the lower portion in the container along the central axis of the container;
The said water collection part is provided in the lower end part of the said water collection piping, and has the slit-shaped water collection port formed in multiple numbers in the horizontal direction at the lower end part of the said water collection piping. Pure water device. 4. The pure water according to claim 3, wherein at least one air vent hole having a short side or a minimum diameter smaller than an ion exchange resin particle diameter is provided in a wall surface near the conical portion above the water collecting pipe. vessel. The container is filled with the ion exchange resin,
The water spout has a slit width of 0.2 to 0.4 mm, a slit length of 17 to 19 mm, and a slit number of 70 to 90,
The pure water according to any one of claims 1 to 4, wherein the water collecting port has a slit width of 0.2 to 0.3 mm, a slit length of 12 to 14 mm, and a number of slits of 20 to 30. Water container. The deionizer according to any one of claims 1 to 5, wherein the ion exchange resin is a wet mixed resin having an exchange capacity of 0.5 mg equivalent / ml. The deionizer according to any one of claims 1 to 6, wherein the impurity ions are generated during wire electric discharge machining.

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