JPH0248432Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cathode structure for an ion exchange membrane electrolytic cell. More specifically, the present invention relates to a cathode structure for a multi-chamber vertical ion-exchange membrane electrolytic cell.

As a multi-chamber vertical diaphragm method electrolytic cell, many electrolytic cells are known, such as the Diamond Shamlock type DS type, the Hooker type H type, and the Showa Denko type SD type. In these electrolytic cells, an expandable electrode coated with titanium, titanium alloy, etc. is used as an anode, and the distance between the electrodes is usually adjusted by this anode.

On the other hand, when salt water is currently electrolyzed using the diaphragm method, the resulting caustic soda has a low concentration of 10-12%, so it takes a lot of energy to raise the concentration to about 50%, and the 50% caustic soda obtained Usually contains about 1% salt. Therefore, this causes an adverse effect on the products or equipment materials of customers who use this caustic soda. Therefore, for example, the specifications for liquid caustic soda for chemical fibers (synthetic fiber grade 1)
No.), the NaCl content is 45% caustic soda aqueous solution and is 0.07% or less. For this reason, many proposals have been made regarding the purification of caustic soda using the diaphragm method, but none have been definitive, and no examples have been found of this being carried out industrially.

In place of this diaphragm method, the ion exchange membrane method in which a cation exchange membrane is interposed between the cathode and the anode is attracting attention, and the number of cases of conversion to this method is increasing. However, once a diaphragm method electrolytic cell is installed, the equipment costs are high, and it is virtually impossible to completely abolish it and convert to the ion exchange membrane method. Therefore, the inventors of the present invention conducted intensive studies on an efficient conversion method, and as a result, they completed the cathode structure of the present invention.

That is, the present invention relates to a cathode structure that is expandable and capable of arbitrarily adjusting the distance between the active surfaces of both electrodes when converting a diaphragm electrolytic cell into an ion exchange membrane electrolytic cell. However, it goes without saying that the present invention can also be applied when manufacturing a new ion exchange membrane method electrolytic cell.

The cathode structure in the present invention consists of two electrode plates made of perforated plates or mesh plates and a plurality of conductive rods installed in parallel between the two electrode plates. A non-conductive elastic material is interposed between the conductive rod and the cathode, and the conductive rod and the cathode are electrically connected by a means other than the elastic material, which enables adjustment of the electrode distance and electrical connection. It is something that has been trained.

Since the cathode of the present invention is usually made of relatively inexpensive mild steel, it has the advantage that it can be improved or manufactured at low cost, and it can be easily welded and assembled. Furthermore, when considering expansion at the anode, there is a large electrical resistance between the support rod and the spring connection, resulting in a large voltage loss, but this invention concerns the cathode, which is made of mild steel, so it has low electrical resistance and little voltage loss. It also has advantages. It also has excellent features that effectively serve purposes such as convection of the electrolyte and dissipation of electrolytically generated gas.

To explain this more specifically, in the anode expansion method, since the spring portion and the conductive portion are common, the structure is such that the voltage loss due to titanium, titanium alloy, etc. in this portion must be extremely large.

On the other hand, if the anode is fixed and the cathode is used to shorten the gap, in other words, if the cathode of the present invention is used to adjust the gap, the voltage loss will be very small, and the material is generally mild steel. Therefore, processing is easy,
Furthermore, it can be made into the most efficient shape.

Next, the present invention will be explained in more detail with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of the cathode structure of the present invention, and 1 indicates a cathode. Although not shown in the figure, it usually has a network structure. Reference numeral 2 denotes conductive rods, which are usually arranged in parallel and have their ends connected to the cathode of the tank. There is no particular limitation on the shape of the conductive rod, and it may be a round rod or a square rod. FIG. 2 is a sectional view (cross-sectional view) taken from part A in FIG. 1, and 3 is an elastic material for adjusting the distance between poles. In this figure, it has a semicylindrical shape, that is, a split pipe, and this is the preferred shape. However, the conductive rod 2 and the cathode 1 may have other shapes.
There is no need to limit the shape as long as the conductive rod and cathode are pressed against each other by connecting at several points.

In the present invention, the electrode spacing is adjusted by inserting a non-conductive elastic material such as fluorine resin or polypropylene resin between the conductive rod and the cathode, and other means are used for electrical connection. That is, as shown in FIG. 2, after adjustment is made by inserting an elastic material 3 made of resin for adjusting the spacing having a predetermined width, the bolt 4 and nut 5 are assembled in a form that is slightly narrower than the predetermined width. By finely adjusting the width of the conductive rod 2 and the cathode 1 as shown in FIG. 3, the conductive rod 2 and the cathode 1 are electrically connected. This combination of bolts and nuts is the most preferable, but it is not limited to this. The electrode gap adjustment is performed using a non-conductive material, and the electrical connection is made by another means, such as interposing multiple conductive wires or plates between the conductive rod and the cathode. This can be done by letting In the present invention, since the non-conductive elastic material 3 remains as a part of the structure, it is desirable to use a resin that is resistant to corrosion under electrolytic conditions, such as fluororesin or polypropylene.

As mentioned above, the cathode structure according to the present invention uses a non-conductive material as the elastic material, and the conductive rod and the cathode are electrically connected by separate hands.The advantages are ease of processing and installation. Ease of use can also be mentioned.

The cathode structure according to the present invention includes a spacer between the cation exchange membrane and the cathode, which wraps the anode with the cation exchange membrane when the diaphragm electrolytic cell described above is used as an ion exchange membrane electrolytic cell. It is used in ion exchange membrane electrolytic cells by interposing it.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the cathode structure of the present invention, Fig. 2 is a sectional view (cross-sectional view) taken from section A in Fig. 1, and Fig. 3 is a cross-sectional view of section C in Fig. 2. It is an enlarged view. 1... cathode, 2... conductive rod, 3... non-conductive elastic material, 4... bolt, 5... nut.

Claims (1)

[Scope of utility model registration request] It consists of an electrode plate made of two perforated plates or a mesh plate and a plurality of conductive rods installed in parallel between the two electrode plates, and there is a conductive rod between the electrode plate and the conductive rod under electrolytic conditions. An ion-exchange membrane method salt that is characterized in that an electrically conductive elastic material for electrode distance adjustment made of a resin having corrosion resistance is interposed, and the electrically conductive rod and the cathode are electrically connected by means other than the elastic material. Cathode structure for electrolytic cells.