JPS6341066Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a support bed for holding an ion exchange resin to form an ion exchange resin layer in an ion exchange resin column.

At the bottom of the ion-exchange resin tower, a supporting bed is usually provided, which is a disc-shaped perforated plate with a large number of distribution holes distributed over the entire surface of the plate. Such a support bed may be made of vinylidene chloride resin netting, nylon netting, or stainless steel netting, which does not allow the ion exchange resin to pass through between two perforated plates, but allows only the liquid to pass through.
Those with a structure in which a net-like body such as a steel wire mesh is inserted, or those with a structure in which a strainer with slits cut through each circulation hole of a perforated plate through which the liquid passes through, but not through which the ion exchange resin passes. It has been known. Such a support bed is required to have characteristics such as allowing the liquid to flow evenly over the entire surface of the support bed, not creating any blind spots in the support bed, and having high mechanical strength.

In the above-mentioned perforated plate support bed, during the liquid passage process for ion exchange resin treatment, a certain amount of pressure loss is generated to distribute the liquid to be treated evenly throughout the support bed. Since the number and diameter of the perforated holes in the perforated plate are determined within a range that increases dispersibility and does not impair mechanical strength, no inconvenience occurs during the liquid passage process, but after the liquid passage process is completed,
During the backwashing process, in which backwash water is introduced from the bottom of the ion exchange resin column to flow the ion exchange resin and the ion exchange resin is washed or the anion and cation exchange resins are separated in a mixed bed, the following disadvantages occur: occurs.

That is, the flow rate of backwash water in the backwash process is usually
Since the flow rate is lower than that of water flowing in the liquid flow process, the pressure loss when passing backwash water through the perforated plate support bed is small, which reduces the dispersibility of backwash water, and the backwash water flows through the support bed. The ion exchange resin is concentrated in a part of the flow holes and is not dispersed over the entire support bed, creating a so-called blind spot on the support bed and preventing the ion exchange resin from flowing as a whole. There was a drawback that the resin was not completely separated.

The present invention eliminates the drawbacks of the conventional perforated plate support bed for ion exchange resin in ion exchange towers as described above, does not cause any trouble during the liquid flow process, and supports the backwash water during the backwash process. The object is to provide a supporting floor that is evenly distributed over the entire floor and does not create blind spots.

Next, the present invention will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional front view of an example of an ion exchange resin column in which the supporting bed of the present invention is employed. A fluid inlet/outlet 2 is provided at the top of the ion exchange resin column body 1, a support bed 5 is provided at the bottom, a fluid inlet/outlet 3 is provided at the bottom, and the support bed 5 is filled with an ion exchange resin 4.

Fig. 2 is a schematic longitudinal cross-sectional front view of an example of the supporting floor of the present invention;
3 is a schematic bottom view of the support bed shown in FIG. 2, FIG. 4 is a schematic plan view of an example of a thin plate-like impermeable elastic body constituting the support bed of the present invention, and FIGS. 5 and 6 are thin plate-like FIG. 3 is an explanatory diagram illustrating the action of an impermeable elastic body.

As shown in FIG. 2, the supporting bed 5 is formed between two perforated plates 21 and 24, and, when viewed from the side of the ion exchange resin layer of the ion exchange resin tower, the support bed 5 includes a mesh body 22, then a thin plate-like impurity. Transparent elastic bodies 23 are stacked and sandwiched, and these are fixed. The two disk-shaped perforated plates 21 and 24 have a diameter, for example, on the entire plate surface.
A large number of communication holes 25 having the same diameter of about 20 mm are formed at substantially the same position on each perforated plate.

The ratio of the total open area of the flow holes 25 of each perforated plate to the cross-sectional area of the ion exchange resin tower body 1, the so-called open pore ratio, is determined within the range where the perforated plate does not lose its mechanical strength and the flow rate during the liquid flow process. It is selected from a range that does not cause the liquid pressure loss to become excessively large, and is preferably about 5 to 15%, for example.

The materials constituting the perforated plates 21 and 24 include:
If it is chemically stable against acids, alkalis, etc. and has high mechanical strength, for example, synthetic resin plates such as vinyl chloride resin plates, acrylic resin plates, etc., or rubber-lined steel plates. , stainless steel plate, etc. can be used, and any other conventionally known materials may be used.

The net 22 does not allow the ion exchange resin to pass through, but allows only the liquid to pass through, and is chemically stable and has good mechanical strength. Conventionally used vinylidene chloride resin nets, nylon nets, Stainless steel mesh etc. are good.

The impermeable elastic body 23 has a thin plate shape, and when laminated with the perforated plates 21 and 24, small communication holes 26 are formed at substantially the same position as the communication holes 25 of the perforated plates and have a smaller diameter than the communication holes 25. is formed.
The diameter of the small flow hole 26 is preferably determined so that the flow rate of backwash water passing through the small flow hole 26 in the backwashing process is within the range of 1 to 4 m/sec. and small flow hole 2
The area around 6 is as seen in Figures 3 and 4.
A plurality of slits 31 are cut radially from the center of the hole to the periphery of the communication hole 25 or to the vicinity of the inner side or the outer side of this periphery.

This slit 31 performs the following function.
Figures 5 and 6 explain the action of the slit. Figure 5 shows the flow during the liquid flow process, that is, when the liquid flows in the direction of the arrow, and Figure 6 shows the flow during the backwash process, that is, when the backwash water is flowing. This shows when the flow is in the direction of the arrow.
During the liquid passage process, as shown in FIG.
5, the opening area of the small flow hole 26 increases, and the flow rate increases accordingly. On the other hand, during the backwash process, even if the backwash water flows upward, it is blocked by the net-like body 22 and the portion sandwiched by the slits 31 remains as it is, so that the small flow holes 26 remain open. No change occurs in pore area.

The materials constituting the impermeable elastic body 23 include:
A thin plate-shaped material that is stable against acids, alkalis, etc., maintains elasticity, and has a thickness that allows it to bend from the periphery of the flow hole 25 to an extent that does not excessively increase pressure loss during the liquid passage process, such as ethylene. Those made of propylene rubber, chloroprene rubber, silicone rubber, etc. are suitable.

Porous plate 21, mesh body 22, impermeable elastic body 23
and perforated plate 24 in this order to form the supporting floor of the present invention, each of these is adhesively fixed with an adhesive that is stable against acids, alkalis, etc., or tightened and fixed with bolts, etc. An appropriate method is taken.

The support bed 5 obtained in this way has bolt holes 2
It is attached to the bottom of the ion exchange resin tower body 1 at a predetermined position by means of bolts inserted into the ion exchange resin tower body 1 .

Next, a case will be described in which ion exchange treatment is carried out using the ion exchange resin tower provided with the support bed 5 of the present invention.

In the liquid passing step, as shown in FIG. 1, the liquid to be treated flows in through the fluid inlet/outlet 2, is brought into contact with the ion exchange resin 4 in the tower to perform ion exchange, and the treated liquid flows out through the fluid inlet/outlet 3. At this time, the liquid to be treated flows uniformly over the entire area of the ion exchange resin layer and reaches the support bed 5 at the bottom as a treatment liquid. The processing liquid flows into the flow holes 25 of the perforated plate 21, flows through the net-like body 22, and reaches the small flow holes 26 of the impermeable elastic body 23. When the processing liquid flows through the small flow hole 26, since the slit 31 is cut around the small flow hole 26, the fifth
As shown in the figure, the portion sandwiched by the slit 31 is bent downward to expand the opening area of the small flow hole 26, allowing the flow to flow without increasing pressure loss. The processing liquid that has passed through the small flow holes 26 flows through the flow holes of the porous plate 24, flows out from the fluid inlet/outlet 3, and is collected.

When the ion exchange ability of the ion exchange resin decreases due to the liquid passage step, a step of regenerating the ion exchange resin is performed, but a backwashing step is performed as a preliminary step.

In the backwashing process, as shown in FIG. 1, backwash water is caused to flow in through the fluid inlet/outlet 3 and discharged through the fluid inlet/outlet 2. Backwash water flows through the circulation holes 2 of the perforated plate 24 of the support bed 5.
5. The water flows through the small flow holes 26 of the impermeable elastic body 23, the mesh body 22, and the flow holes 25 of the perforated plate 21 in this order and comes into contact with the ion exchange resin layer to perform backwashing.
At this time, as shown in FIG. 6, the peripheral part of the small communication hole 26 cannot be bent because it is in contact with the net-like body 22, and the opening area of the small communication hole 26 does not increase, so the pressure loss is as follows. It increases compared to that in the liquid passage process. Therefore, even if the flow rate of backwash water is relatively low, its dispersibility is improved and the water flows from the entire support bed, eliminating dead spots on the support bed.As a result, the ion exchange resin flows throughout the entire support bed, allowing ion exchange. Washing of the resin or separation of both negative and positive ion exchange resins can also be effectively carried out.

As described above, according to the supporting bed of the present invention, water can be collected and dispersed uniformly in the liquid passage process and the backwashing process, and no blind spots are created in the supporting bed, so that stable treated water can be obtained.

What has been explained above and shown in the drawings is related to typical examples to aid understanding of the present invention, and the present invention is not limited to these examples and may include other modifications within the gist of the invention. It is something that can be taken.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional front view of an example of an ion exchange resin tower provided with the supported bed of the present invention, Fig. 2 is a schematic longitudinal cross-sectional front view of an example of the supported bed of the present invention, and Fig. 3 is a support shown in Fig. 2. FIG. 4 is a schematic plan view of an example of an impermeable elastic body constituting the supporting floor of the present invention, and FIGS. 5 and 6 are explanatory diagrams illustrating the action of the impermeable elastic body. In the figure, 1 is the ion exchange resin tower body, 5 is a support bed, 21 and 24 are perforated plates, 22 is a mesh body, 2
3 is a thin plate-like impermeable elastic body, 25 is a communication hole, 2
6 is a small communication hole, and 31 is a slit.

Claims (1)

[Scope of utility model registration request] In the support bed of the ion exchange resin in the ion exchange resin tower, the ion exchange resin layer is placed between two perforated plates having a large number of communication holes at substantially the same position and having substantially the same diameter over the entire plate surface. A net-like body that does not allow the ion-exchange resin to pass through, but a thin plate-like impermeable elastic body, is successively sandwiched from the side.
The impermeable elastic body has a small communication hole smaller than the communication hole in substantially the same position as the communication hole of the perforated plate, and the small communication hole allows the liquid to flow through the hole. A support bed for an ion exchange resin in an ion exchange resin column, characterized in that a plurality of slits are cut radially around the hole so that the area around the hole is bent when the resin flows through the column.