JPS6344830B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an apparatus for electrolyzing water under alkaline conditions under pressure.

The electrolyzer of the present invention is a bipolar electrolyzer with a frame laminate of filter press construction.

The principle of electrolyzers is very well known. This device has a cell equipped with electrodes and containing an electrolyte. Ions move toward the electrodes in the direction of the electric field due to the effect of the electric field created between the electrodes. Anions move to the anode and cations move to the cathode. When the ions reach the electrode, they lose their charge and become neutral atoms. In the case of water electrolysis, an electrolytic solution made by adding caustic potassium to water is generally used. The reaction on the electrode generates hydrogen on the cathode and oxygen on the anode. The anode and cathode are separated by a diaphragm. Replenish consumed water. The electrolyte is supplied through a supply channel at the bottom of the cell.
Oxygen gas and hydrogen gas generated at each electrode are collected at the top of the cell.

Various types of devices are already known for the electrolysis of water. Generally, two adjacent electrode plates are separated by at least one frame which in combination with the electrode plates forms a cell containing an electrolyte. The cell is divided into two compartments by a diaphragm, each containing an anolyte and a catholyte. Since this device is equipped with an electrolytic plate assembly, it has a frame stack, which is clamped with a clamping system between two clamping plates. A gas recovery orifice is provided at the top of each compartment, and an electrolyte inlet is provided at the bottom. In some devices, each electrode has an anode plate on one side and a cathode plate on the other side, and is called a bipolar electrode.

Some bipolar devices operate at high temperatures and pressures. Operating under pressure improves yields.

Leakage of electrolyte through the joint surfaces created by the generally flat annular surface of the frame must be prevented. This liquid leakage often causes corrosion and creates a pressure difference between the anode chamber and the cathode chamber. The seal must be controlled when the operating pressure is increased.

SUMMARY OF THE INVENTION The object of the present invention is to provide a satisfactory sealing method for an electrolyzer having a filter press structure. Due to this sealing system, even if electrolyte leaks, it can be recovered and recirculated. At the same time, it is possible to prevent leakage of the electrolyte supplied to the cell and leakage of gas generated during electrolysis. It also acts as a barrier against water and can also detect leaks. This method can be applied to electrolyzers operating at pressures above 30 bar and temperatures above 80°C.

The electrolysis device according to the invention has an annular support surface that extends outwardly from the cell assembly consisting of a diaphragm separating compartments containing a pressurized electrolyte supplied via at least one supply channel and each electrode plate. The spacer is housed in a laminate of annular spacers that serve as the joint surface facing the outside, and the gas generated by electrolysis is discharged into the passage. A recovery groove is provided, and the groove is housed in the support surface of the frame and includes a discharge means for discharging electrolyte leaking from the joint surface.

Another feature of the invention is that an annular distribution groove is formed in each support surface of the frame at each joint surface, the circumference of the groove being shorter than the annular recovery groove and at a pressure higher than the electrolyte pressure. At the point where water is supplied.

Hereinafter, embodiments will be described with reference to the accompanying drawings.

The device shown in FIGS. 1-3 comprises a collection of electrolytic cells 1 arranged in a jacket constituted by an annular frame 2. The apparatus shown in FIGS. The stacked annular frames 2 are housed in a container 3 consisting of a body and a closed lid. The frame stack 2 is clamped between two clamping plates 4, 5 arranged inside the container. A space 6 between the inside of the frame group and the inside of the container 3 is filled with a gas such as nitrogen at approximately the same pressure as the electrolytic solution pressure. Two tightening plates 4, 5
are connected to each other by means of a fastening rod (or its equivalent) which brings the two clamping plates closer to each other by tightening each element located between them.

Each spacer frame 2 inserted between the end plates 4, 5 is annular and has two generally planar annular support surfaces 21, 22 and a central space 23.
have. Each external shape of the frame can be polygonal or cylindrical.

Each cell is formed between two electrode plates 7 and has a diaphragm 8. These electrode plates and diaphragms are arranged alternately and vertically along the longitudinal axis of the device.
The electrode plate 7 is made of nickel, for example. The diaphragm 8 is preferably made of a material that can withstand high temperatures and pressures, such as asbestos board. The electrode plate and the diaphragm together with the spacer frame form a series of compartments 9,10. Among these, an anolyte is contained in a compartment 9, which is located on the anode surface side 71 of the electrode plate 7. On the other hand, the compartments 10 are arranged alternately with the compartments 9, and a catholyte is contained therein.
0 is on the cathode surface 72 side of the electrode plate 7. Each diaphragm 8 seals the entire right-angled section of the central space 23, and its outer periphery is locked in the annular groove of the spacer frame 2. Each electrode plate 7 is fastened between supporting surfaces 21 and 22 of two spacer frames 2. The surface 71 of the electrode plate is in contact with the annular support surface 21 of the frame, and the surface 72 is in contact with the annular support surface 22 of another frame. These surfaces 71,7
2 forms two parallel joint surfaces with the two spacer frames sandwiching them. These two parallel joint surfaces 21-71 and 22-7
2 reaches into the external chamber 6.

A supply channel 24 is formed through at least one clamping plate 4 or 5 for supplying electrolyte to each electrolytic cell. This passage 24 passes horizontally through the entire spacer frame 2 and communicates with each compartment 9 or 10 via a channel 241.

Hydrogen generated at the cathode surface 72 of each electrode plate 7 rises in the corresponding cathode compartment and passes through the conduit 2 above the compartment.
Recovered on 51st. Each guide path 251 has both end plates 4 and 5
It opens into a recovery passage 25 extending horizontally over the entire length between the two. The oxygen generated on the anode surface 71 of each electrode plate 7 rises in the corresponding anode compartment and is collected in the conduit 261 above it. Each channel 261 opens into a collection channel 26 which extends horizontally over the entire length between the two end plates 4,5. These two recovery passages 25, 26 pass through the entire spacer frame.

A recovery groove indicated by 211 or 221 is provided on each joint surface formed between one surface of the electrode plate and the supporting surface of the frame 2 adjacent thereto. The groove 221 is provided on the joint support surface 22 in contact with the cathode surface 72. The groove 211 is provided on the joint support surface 21 in contact with the anode surface 71. These grooves form the annular support surface 21 or 2 of the spacer frame.
It is engraved on 2. Two spacer frames adjacent to each other are provided with two collection grooves 211 and 221 that are symmetrical with respect to the plane of symmetry of the electrode plate between them. These grooves facing each other communicate with each other through one or more holes penetrating the electrode plate interposed therebetween. Each recovery groove has an annular shape, and its circumferential length is longer than the circumferential length of the central space 23. All collection grooves 211, 221
is the discharge passage 2 that horizontally penetrates all the annular frames.
They are connected to each other via 7. Each discharge path 27
are two recovery grooves 2 of the same spacer frame.
11,221 are integrated.

The retrieval groove of the frame which is in contact with the clamping plate, for example 5, communicates with a channel 51 formed in this clamping plate. This conduit 51 is connected to a pipe leading out of the container through the external chamber 6. This pipe is for discharging the liquid collected in the collection groove to a tank (not shown).

A distribution groove, designated 212 or 222, is formed in each joint surface formed between one side of the electrode plate and the adjacent support surface of the frame. The distribution groove 212 is formed in the joint support surface 21 in contact with the anode surface 71, and the distribution groove 222 is formed in the joint support surface 22 in contact with the cathode surface 72. These grooves are carved into the annular support surface 21 or 22 of the spacer frame. On both sides of each electrode plate are two distribution grooves 2 symmetrical with respect to the plane of symmetry of the electrode.
12 and 222 are provided. These mutually opposing distribution grooves communicate with each other via one or more holes penetrating the electrode plate located between them. Each distribution groove is annular and its circumference is larger than the circumference of the central space of the frame and smaller than the circumference of the annular recovery groove. All distribution grooves 212 and 222 are integrated into one another via supply channels 28 that pass horizontally through all spacer frames. Each supply conduit 28 is connected to two distribution grooves 212 and 22 of the same spacer frame.
2, that is, the joint support surface 21 in contact with the anode surface of the electrode.
The groove formed in the joint support surface 22 is integrated with the groove formed in the joint support surface 22 which is in contact with the cathode surface of another electrode. The distribution groove of the frame adjoining the clamping plate, e.g. 5, communicates with a channel 52 formed in the clamping plate. This supply conduit 52 is connected to a supply pipe leading out of the container via an external chamber. This supply pipe is connected to a source of demineralized water. The pressure of the soft water supplied to the distribution channels 212 and 222 is greater than the pressure exerted on the electrolyte in the compartment.

Each of the distribution grooves 212 or 222 is formed such that the electrolyte supply passage 24 can be positioned inside the area formed by the outer periphery of the distribution groove. Each distribution groove also has a gas exhaust passage 25 inside the area formed by the outer periphery of the distribution groove.
and 26 can also be positioned.

The operation of this device will be explained below. Soft water is supplied into the distribution grooves 212, 222 via conduits 52 and 28. The pressure of this soft water is higher than the pressure of the electrolyte in the passage 24 or the compartments 9,10. When there is no leakage, the amount of water supplied to the grooves 212 and 222 is zero, and no water comes out from the outlet of the conduit 51. However, when a gap communicating with the external chamber 6 is created between the opposing surfaces 21 and 71 or 22 and 72 of any joint surface, the nitrogen that has passed through this gap is recovered in the recovery groove 211 or 221.
It is possible to detect nitrogen downstream of the conduit 51. Further, when a gap is created between each groove, soft water is collected into the recovery groove 211 or 221 through the gap. When a gap is created between the groove 212 or 222 and the supply passage 24, soft water flows into the electrolyte, so that a decrease in the soft water in the conduit 52 is observed. When a gap occurs in the central space 23, no leakage of electrolyte occurs, but soft water flows into the compartment where the gap occurs. Due to the positional relationship of the discharge passages 25 and 26 with respect to the distribution groove, hydrogen and oxygen do not leak to the outside.

It will be understood that the invention may be modified in various ways, modifications may be made in detail, and equivalent measures may be employed without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electrolysis device according to the present invention. Second
The figure is a detailed view of the cross section shown in FIG. FIG. 3 is a partial view of the AA cross section in FIGS. 1 and 2. 1... Electrolytic cell, 2... Spacer frame, 3...
Container, 4, 5... Tightening plate, 6... Outer space, 7... Electrode plate, 8... Diaphragm, 9, 10... Compartment, 21, 22...
Support surface, 23... Central space, 24... Supply passage, 25
...Hydrogen recovery passage, 26...Oxygen recovery passage, 71...Anode surface, 72...Cathode surface, 211, 221...Recovery groove, 212, 222...Distribution groove.

Claims (1)

[Claims] 1. A frame 2 having a pressurized container 3 filled with nitrogen, a partition wall 8 and an electrode plate 7 forming an electrolytic cell.
The electrolytic cell is supplied with an electrolytic solution through at least one supply passage 241, and the gas generated by electrolysis is passed through the outlet passage 25.
1,261, the frame 2 has an annular distribution groove 212 provided around the joint surface thereof and for supplying water at a pressure higher than the supply pressure of the electrolytic solution. 222, and an annular collection groove 2 for collecting and discharging liquid leaked due to a defect in the sealing action between the frame 2.
11, 221. An electrolysis device characterized by being provided with. 2. The electrolysis device according to claim 1, wherein the outer periphery of the distribution groove 212 or 222 is entirely positioned within the outer periphery of the collection groove 211 or 221. 3. Each electrolyte inlet passage passes through the stack of spacer frames, and the outer shape of each distribution groove is:
The electrolytic solution according to claim 1, characterized in that the electrolytic solution supply passage 24 is positioned so as to pass within a region defined by the outer periphery of each distribution groove 212, 222. Device. 4. A gas exhaust passage passes through the laminate of the spacer frames, and the outer shape of each of the distribution grooves 212, 222 is such that the gas exhaust passage 25 passes through the area defined by the outer periphery of each distribution groove 212, 222. ,26
2. The electrolytic device according to claim 1, wherein the electrolytic device is positioned such that a 5 A supply duct 28 that communicates the distribution grooves 212 and 222, and the collection groove 211 or 221.
2. The electrolysis device according to claim 1, wherein a discharge duct 27 that communicates with the spacer frame 2 passes through the spacer frame 2. 6 The above distribution grooves 212, 222 and collection grooves 2
11, 221 are orifices 73, 7 provided on both sides of the electrode plate 7 and passing through the electrode plate 7.
4. The electrolytic device according to claim 1, wherein the electrolytic device is in communication with the electrolytic device via the electrolytic device.