JPS6038470B2 - Filter press type ion exchange membrane electrolyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter press type ion exchange membrane electrolytic cell.

In recent years, research has been conducted on so-called ion exchange membrane electrolysis using an ion exchange membrane as a method of electrolyzing an aqueous alkali chloride solution to obtain caustic alkali and chlorine.As an electrolytic cell for this purpose, a filter press type electrolytic cell has been developed. , has been developed.

The present inventor has constructed a large number of ion exchange membranes, anode chamber frames, and anode chamber frames so that cathode chamber frames and anode chamber frames are respectively located on both sides of the ion exchange membrane.
As a result of various studies on so-called monopolar filter press type ion exchange membrane electrolytic cells, which are constructed by arranging cathode chamber frames and tightening them, we have found that the electrolytic current can be maintained at around 10 to 100 KA without excessively increasing the electrolytic current. The purpose of the present invention is to provide a filter press type ion exchange membrane electrolytic cell that can maintain a high production amount of electrolyzed products and make the electrolytic plant compact. The present invention is a filter press type in which a large number of ion exchange membranes, cathode chamber frames, and anode chamber frames are arranged and tightened so that the cathode chamber frames and anode chamber frames are respectively located on both sides of the ion exchange membrane. In an ion exchange membrane electrolytic cell, a partition wall is interposed between each of the plurality of chamber frames to form a plurality of unit blocks, and a cathode and anode chamber are attached to the plurality of cathode chamber frames constituting the unit blocks. This is a filter press type ion exchange membrane electrolytic cell in which the anodes attached to the frame are electrically connected in parallel, and the unit blocks are electrically connected in series.

The cathode chamber frame and anode chamber frame of the present invention have a frame-like shape with a notch in the center.

A cathode or an anode is attached to the central notch to form a cathode chamber frame or an anode chamber frame. The central notch in the chamber frame to which the electrodes are attached becomes the cathode chamber or the anode chamber when the electrolytic cell is assembled. For that reason, metal is preferable.

Since the cathode chamber frame comes into contact with caustic alkali, it is preferably made of an alkali-resistant metal such as iron, nickel, iron-nickel alloy, iron-nickel-chromium alloy, or the like.

Further, since the anode chamber frame comes into contact with chlorine, the material thereof is preferably a chlorine-resistant metal such as titanium or titanium-palladium alloy. In addition, when using a metal room frame,
In order to reduce the weight and make the device more compact, it is preferable to use a hollow chamber frame in which the edges of the frame-shaped chamber frame are hollow bodies that serve as passages for gas and liquid.

Iron, iron-nickel alloy, or iron-nickel-chromium alloy is used as the material for the cathode, and titanium coated with a platinum group metal or its oxide is used as the anode.

These cathodes and anodes can have a net shape or a sag shape, and specifically, an expanded metal can be used. Attachment of such an electrode to the chamber frame involves welding the electrode to the lead twill for energizing the electrode attached to the chamber frame.
This can be achieved by attaching by other means.

A filter press type ion exchange membrane electrolytic cell of the present invention using the cathode chamber frame and anode chamber frame described above will be explained with reference to FIG.

To assemble the filter press type ion exchange membrane electrolytic cell of the present invention, first, the cathode chamber frame 2 and the anode chamber frame 3 are positioned on both sides of the ion exchange membrane 1. An exchange membrane is arranged to form a unit block 12, and the chamber frame, ion exchange membrane, and partition wall are connected to a fixed frame 5 and a floating frame 6 so that multiple sets of unit blocks are arranged with the partition wall 4 in between. Arrange between.

A puller member 7 is provided on both sides of each negative/anode chamber frame, and the puller member 7 is hooked onto a pair of side bars 8 provided on both sides of the fixed frame. This is an array of .

After arranging the ion exchange membrane and the partition wall between the cathode and anode chamber frames arranged in this manner as described above, the floating frame 6 is moved toward the fixed frame 5 by the hydraulic pump 6' or other means. Then, sandwich and tighten the chamber frame, ion exchange membrane, and partition wall between the fixed frame and the floating frame. The diluting means is preferably the one described above, but is not limited thereto. In each unit block, cathode chamber frames and anode chamber frames are arranged alternately through an ion exchange membrane, and the cathode attached to each cathode chamber frame and the anode attached to each anode chamber frame are electrically connected to each other. connected in parallel. Such electrical connections are made by the aforementioned lead 9,
This is done via a bus bar 18 that electrically connects each lead shank. Regarding the relationship between the number of cathode chamber frames and the number of anode chamber frames constituting each unit block, when the number of cathode chamber frames is n, the number of anode chamber frames can be selected from n-1, n, and n+1. .

In particular, considering the material and manufacturing of the partition wall, it is preferable that the number of anode chamber frames be n-1, where n is the number of cathode chamber frames. In such a case, the chamber frames located at both ends of each unit block serve as cathode chamber frames.

Further, the number n of cathode chamber frames is preferably 2 to 17. The reason for this is that by keeping the number of cathode chamber frames within the above range and constructing a unit block from positive and cathode chamber frames, the electrolytic current of the electrolytic cell can be maintained at 10 to 10 A.

However, if the number of cathode chamber frames is made larger than 17, an electrolytic cell with an electrolytic current of 100 KA or more can be obtained. The number of anode chamber frames is naturally specified from the relationship between the numbers of negative and anode chamber frames and the range of the number of cathode chamber frames.

Note that ion exchange membranes do not need to be placed at both ends of the unit block, and as a result, the number of ion exchange membranes is equal to the sum of the number of cathode chamber frames and the number of anode chamber frames minus 1. becomes. Although each unit block constituting an electrolytic cell does not necessarily have to be composed of the same number of chamber frames, it is preferable to equalize the current density of each unit block and maintain constant electrolytic conditions. Preferably, each unit block is composed of the same number of chamber frames selected from the range of the number of chamber frames described above. A saturated or nearly saturated aqueous alkali chloride solution is supplied to the anode chamber of the unit block thus formed, and water or a dilute aqueous caustic alkali solution is supplied to the cathode chamber.

The electrolytic products produced here (caustic alkaline aqueous solution and hydrogen in the cathode chamber, chlorine and dilute aqueous alkali chloride solution in the anode chamber) are taken out from these cathode and anode chambers. Therefore, although not shown, the chamber frame is provided with means for supplying an electrolyte and means for taking out an electrolyzed product. An electrolytic cell is formed in this way, but in order to improve the sealing effect, a packing may be interposed between the ion exchange membrane and the green part of the chamber frame, or a packing may be inserted between the ion exchange membrane and the electrode. In order to prevent damage due to contact with the membrane, a gas-liquid flowable spacer may be provided between the electrode and the ion exchange membrane. Such unit blocks are arranged with partition walls 4 in between, and the unit blocks are electrically connected in series.

This electrical connection can be achieved by connecting adjacent unit blocks using bus bars 11. Various values are selected for the number of unit blocks depending on the desired production amount of electrolyzed products, but from a manufacturing point of view, it is 2 to 3.
It is preferable to use two pieces. The combination of the number of chamber frames constituting a unit block and the number of unit blocks can be freely selected and combined to provide the most economical and compact electrolytic cell. The partition wall is interposed between the unit blocks that are electrically connected in series, and its main function is to prevent the unit blocks from being electrically connected to each other through the chamber frame and the liquid within the chamber frame. This prevents the chamber frame from being electrically corroded.

In addition, the liquid and gas in the chamber frames located on both sides of the partition wall are prevented from mixing through the partition wall. The material of the partition wall is required to be electrically insulating so that it can be used as a prototype.

Specifically, the partition wall may be made of the electrically insulating material itself, or the surface of the partition wall may be electrically insulatingly treated. The material of this external partition wall is required to have corrosion resistance against liquids and gases that come into contact with it. Therefore, when the partition wall comes into contact with caustic alkali, natural rubber or alkali-resistant synthetic resins such as ethylene-propylene resin, epoxy resin, fluorine-based synthetic resin, etc. can be used. In addition, if the partition wall comes into contact with chlorine, use chlorine-resistant synthetic resins such as polyester synthetic resins, fluorine-based synthetic resins (tetrafluoroethylene polymer,
Tetrafluoroethylene-ethylene copolymer, etc.) can be used.

The partition wall may be in the form of a plate made of the above-mentioned synthetic resin alone, or may be formed by coating a base such as a metal plate with the above-mentioned synthetic resin. Furthermore, when one side of the partition wall is in contact with caustic alkali and the other side is in contact with chlorine, each side can be made resistant to alkali and chlorine by using the above-mentioned synthetic resin.

It is preferable to make the above-mentioned work wall from an alkali-resistant material from the viewpoint of cost and manufacturing.To do this, as mentioned above, it is necessary to form unit blocks so that the chamber frames located at both ends of the wall serve as cathode chamber frames. The purpose can be achieved by configuring the . Furthermore, although the partition walls described so far are separate from the room frame, they are not necessarily limited to this.
The object can also be achieved by creating a structure in which the chamber frames located at both ends of each unit block act as cross-cut walls as described above, and the present invention includes this.

Note that the chamber frames at both ends of the electrolytic cell of the present invention are held down by a fixed frame and a floating frame, respectively, and are sealed to prevent the liquid inside the chamber frame from leaking. A sealing member may be interposed between them.

In the electrolytic cell of the present invention, at a predetermined current density, the production amount of electrolyzed products is proportional to the number of all chamber frames constituting the electrolytic cell, and by increasing the number of all chamber frames, a high production amount can be maintained. can.

Moreover, the electrolytic current of an electrolytic cell is proportional to the number of chamber frames constituting one unit block. Compared to an electrolytic cell having the same production capacity as the invented electrolytic cell, the electrolytic current can be kept low. Since a rectifier with a relatively low current capacity, for example, about 10 to 100 KA can be used, and a busbar with a relatively low current capacity can be used, the manufacturing cost of the electrolytic plant can be reduced and the manufacturing process can be simplified. Furthermore, when converting the conventional mercury method electrolysis to ion exchange membrane electrolysis, mercury method electrolysis equipment such as a rectifier can be effectively used during the conversion.

That is, most of the rectifiers used in mercury electrolysis plants have a current capacity of 10 to 100 KA, and in the present invention, by appropriately changing the number of chamber frames constituting a unit flock, such various capacities can be adjusted. The rectifier can be repurposed. Furthermore, the production capacity of the electrolytic cell of the present invention can be increased by increasing the number of unit blocks, so when using a rectifier with the same current capacity, an electrolytic cell that does not form the above-mentioned unit blocks is used. Compared to the conventional method, an electrolytic plant with the same production capacity can be made from a smaller number of electrolytic cells, making the electrolytic plant more compact.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an electrolytic cell of the present invention and a diagram showing electrical connections. 1... Ion exchange membrane, 2... Cathode chamber frame, 3
...Anode chamber frame, 4...Partition wall, 5...
...Fixed frame, 6...Floating frame, 6'...Hydraulic pump, 7...Chicken pulling member, 8...Side bar,
9...Reed Haru, 10, 11. ．．・．． ．．・Husbah, 1
2...Unit block.

Claims (1)

[Scope of Claims] 1 A large number of ion exchange membranes, anode chamber frames, and cathode chamber frames are arranged and tightened so that the cathode chamber frames and anode chamber frames are located on both sides of the ion exchange membrane, respectively. In a filmless electrolytic cell, a partition wall is interposed between each of the plurality of chamber frames to form a plurality of unit blocks, and a cathode and anode chamber frame are attached to a plurality of cathode chamber frames constituting the unit block. A filter press type ion-exchange membrane electrolytic cell in which the anodes attached to the block are electrically connected in parallel, and the unit blocks are electrically connected in series. 2. Claim 1, in which the unit block is composed of n cathode chamber frames and n-1 anode chamber frames, with the cathode chamber frames and the anode chamber frames alternately arranged through an ion exchange membrane. Filter press type ion exchange membrane electrolytic cell. 3. The filter press type ion exchange membrane electrolytic cell according to claim 2, wherein n is 2 to 17. 4. The filter press type ion exchange membrane electrolytic cell according to claim 1, comprising 2 to 32 unit blocks. 5. The filter press type ion exchange membrane electrolytic cell according to claim 1, wherein the partition wall is electrically insulating.