JPH0512287Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention relates to a hydrogen generator. More specifically, the present invention relates to a hydrogen generator suitable as a hydrogen gas supply source used in a hydrogen flame ionization detector or carrier gas of a gas chromatograph.

(b) Prior Art A hydrogen generator suitable as a hydrogen gas supply source used for a gas chromatograph detector or a carrier gas has an anode chamber and a cathode chamber configured with a polymer electrolyte diaphragm having a pair of electrodes on both sides. a water supply tank that supplies water to the anode chamber and the cathode chamber through valves, a voltage application means that applies a voltage between the pair of electrodes, and discharges generated hydrogen-containing water from the cathode chamber. It includes a hydrogen release channel extending to the water separation section and an oxygen release channel for discharging generated oxygen-containing water from the anode chamber, and further returns the water separated from hydrogen gas in the water separation section to the water tank. A structure in which a flow path is provided is known.

(c) Problems that the invention aims to solve However, the hydrogen generator using the above electrolyte cell has advantages such as low cost, high efficiency, and high purity, and the advantage that it can perform electrolysis only with pure water without using an electrolyte solution. However, if metal ions are mixed in the pure water, the metals will precipitate inside the cell, especially on the electrode surface, contaminating the cell, and the efficiency of hydrogen generation will suddenly decrease. For this reason, it is necessary to take great care to prevent metal ions from being mixed into the pure water conventionally supplied, and there is also the problem that once the cell becomes contaminated, it cannot be used until it is replaced.

This invention was devised in view of the above situation, and is particularly intended to provide a hydrogen generation device equipped with a mechanism capable of maintaining the hydrogen generation efficiency of the electrolytic cell at a good level.

(d) Means for solving the problem Thus, according to this invention, an electrolytic cell is provided in which an anode chamber and a cathode chamber are constructed using a polymer electrolyte having a pair of electrodes on both sides as a diaphragm, and an anode chamber and a cathode chamber are connected to the anode chamber and the cathode chamber. A water supply tank that supplies water through valves, a hydrogen discharge channel that discharges generated hydrogen-containing water from the cathode chamber and extends to the gas-liquid separation means, and an oxygen discharge flow that discharges generated oxygen-containing water from the anode chamber. The anode chamber and cathode chamber are each equipped with an inert gas introduction conduit and a drainage conduit, and after stopping the water supply to the electrolytic cell, inert gas is introduced into the anode and cathode chambers. control means is provided which can control the residual water in these chambers to be drained from the respective drainage pipes, then introduce water into these chambers, and apply a reverse voltage between the pair of electrodes in this state. A hydrogen generator is provided.

In the hydrogen generating device of this invention, the electrolytic cell that electrolyzes water to generate hydrogen is configured to be able to apply a normal voltage for hydrogen generation and its reverse voltage, and the electrolytic cell can quickly generate gas and gas from within the electrolytic cell. It has a liquid discharge mechanism, and after electrolysis with a normal voltage, a reverse voltage is applied for a predetermined period of time to ionize and dissolve the metal deposited in the electrolytic cell and on the electrode, and this metal ion-containing aqueous solution is transferred to the electrolytic cell. It is characterized in that it is configured so that contamination by metal ions inside the electrolytic cell can be removed by discharging it to the outside.

The electrolytic cell described above has an anode chamber and a cathode chamber configured using a polymer electrolyte diaphragm having a pair of electrodes on both sides, and water introduced into each of these chambers is electrolyzed by a voltage applied between the pair of electrodes. ,usually,
It is configured to generate oxygen in the anode chamber and hydrogen in the cathode chamber. The inert gas introduction conduit and drainage conduit attached to each of the anode and cathode chambers are provided with valves because they are normally not used except for the purpose of discharging gas and liquid from each of these chambers. The valve may be set independently for each drainage pipe and each inert gas introduction pipe, but the valve may be set independently for each drainage pipe and each inert gas introduction pipe, but the valve may be set independently for each drainage pipe and each inert gas introduction pipe. Similarly, each inert gas introduction pipe may be configured such that one supply line from the inert gas supply section is branched to form each inert gas introduction pipe. If there is, one valve may be installed in the supply path before the branch.

The oxygen release channel set in the anode chamber of the electrolytic cell is preferably connected to a normal water supply tank.

When discharging gas and liquid from the anode chamber and cathode chamber of the electrolytic cell in the device of this invention,
Since this is carried out using the inert gas pressure introduced from the above-mentioned inert gas introduction path, it is preferable in terms of drainage efficiency that the flow path other than the drainage pipe be kept secret. Preferably, valves are provided in the oxygen release channel and the hydrogen release channel.

In controlling the device of this invention, after stopping the water supply to the electrolytic cell and before applying a reverse voltage to the pair of electrodes of the electrolytic cell, an inert gas is introduced into the anode chamber and the cathode chamber. The generated hydrogen-containing water and generated oxygen-containing water remaining indoors, in the hydrogen release channel, and in the oxygen release channel are discharged, but this is because hydrogen is generated in the anode chamber and oxygen is generated in the cathode chamber by applying a reverse voltage. However, this operation is necessary to avoid the risk of explosion due to the mixture of hydrogen and oxygen.

In the above-mentioned control, it is preferable that the control is such that when the gas/liquid is discharged from the electrolytic cell by introducing an inert gas, the application of voltage to the electrolytic cell is stopped.

In the device of this invention, the control unit may be instructed to remove the metal deposited inside the electrolytic cell and on the electrodes by applying a reverse voltage whenever the hydrogen generation efficiency decreases. Alternatively, it may be incorporated in advance into the operation of the control unit so as to be performed periodically.

Nitrogen gas is preferred as the inert gas used in the device of this invention.

(E) Effect According to this invention, after hydrogen is generated by electrolysis, an inert gas is introduced into the electrolysis cell, and the generated oxygen-containing water and generated hydrogen-containing water retained in the anode chamber and the cathode chamber are drained. Water is then supplied into each of these chambers and a reverse voltage is applied for a predetermined period of time to dissolve the precipitated metal into the aqueous phase as metal ions, after which the metal ion-containing aqueous solution is forced out of the electrolytic cell by introducing an inert gas. After being discharged to remove contamination by metal ions, water is again supplied into the electrolytic cell and hydrogen generation is continued at a normal voltage.

This invention will be explained in detail below with reference to examples, but the invention is not limited thereby.

(F) Embodiment FIG. 1 is an explanatory diagram of the configuration of an embodiment of this invention. In the figure, the hydrogen generator 1 includes a pure water supply channel a that supplies pure water from the water tank 2 to the electrolytic cell 3;
a hydrogen release channel b for transferring generated hydrogen-containing water from the electrolysis cell 3 to the water separation section 4; an oxygen release channel c for discharging oxygen generated in the electrolysis cell 3 as generated oxygen-containing water; and the water separation section. A return flow path d for returning pure water separated from hydrogen in the separation section from 4 to the water tank 2
, a hydrogen supply channel e for supplying hydrogen separated in the water separation section 4 via a drying section 5 , a pipe f for introducing nitrogen into the electrolytic cell, and a control section 6 .

The electrolytic cell 3 includes a cathode chamber 32 and an anode chamber 33 using a polymer electrolyte diaphragm 31 having a pair of electrodes on both sides, and the cathode chamber 32 includes the hydrogen release channel b and the drainage pipe _g1 . The pure water supply channel a, the oxygen release channel c, and the drainage pipe _g2 are connected to the anode chamber 33, respectively. Further, the pair of electrodes are electrically connected to the control section 6, and this connection is configured to be switchable between positive and negative within the control section. Normally, when hydrogen is generated, the cathode chamber 32 side is connected to the negative electrode, and the anode chamber 33 side is connected to the positive electrode.

The nitrogen introduction pipe f is divided into two pipes f ₁ and f ₂ from the branch A, and near the electrolytic cell 3, one f ₁ is connected to the pure water supply flow path a, and the other f ₂ is a hydrogen discharge flow path. b, respectively.

Further, the oxygen release channel c is connected to the water supply tank 2, and returns the pure water that flows out from the anode chamber 33 together with oxygen to the water supply tank.

Oxygen release channel c, return channel d, hydrogen supply channel e, nitrogen introduction pipes f ₁ , f ₂ and drainage pipe g ₁ ,
G ₂ has solenoid valves Vc, Vd, Ve, Vf ₁ and Vf ₂ , respectively.
, Vg ₁ and Vg ₂ are set, and these solenoid valves are electrically connected to the control section 6 and are respectively operated by electric signals from the control section. Va on the pure water supply channel a is a check valve.

Next, the operation of the device of this invention will be explained.

First, the control unit holds the solenoid valves Vc, Vd, and Ve in the open state and the solenoid valves Vf ₁ , Vf ₂ , Vg ₁ , and Vg ₂ in the closed state, and the cathode chamber side becomes the negative electrode and the anode chamber side becomes the positive electrode. After the electrolytic cell is filled with pure water from the water tank, a constant DC voltage (usually 2 to 3 V) is applied to the electrolytic cell to start electrolysis, and the cathode chamber is connected to the hydrogen anode chamber. Oxygen is generated respectively. The generated hydrogen travels through the hydrogen discharge channel together with pure water, flows into the water separation section, where the hydrogen is separated from pure water, and then advances through the hydrogen supply channel, where it is dried in the drying section, and then the electromagnetic valve is removed. It is then supplied to the supply section. On the other hand, the pure water separated in the water separation section is returned to the water supply tank through the return channel.

Further, oxygen generated in the anode chamber at the same time as hydrogen is released into the oxygen release flow path together with pure water and transferred to the water tank, and the oxygen is released from the water tank.

After the above operation continues for a period of time preset by the controller, the controller operates the device as follows.
First, set the applied voltage of the electrolytic cell to 0V, and then turn on the solenoid valve.
Vc, Vd, Ve are closed and solenoid valves Vf ₁ , Vf ₂ ,
Switch Vg ₁ and Vg ₂ to open state. At the same time, nitrogen is introduced into the nitrogen introduction pipe, and due to this nitrogen pressure, residual hydrogen and pure water are discharged from the cathode chamber of the electrolytic cell, and residual oxygen and pure water from the anode chamber are discharged from the respective drainage pipes. Next, open the solenoid valves Vc, Vd, Ve and close the solenoid valves Vf ₁ , Vf ₂ , Vg ₁ , Vg ₂ to fill the electrolytic cell with pure water, and then reverse the polarity of the electrodes. Connect it and apply the normal reverse voltage (-2V to -3V) to the electrolytic cell for a predetermined period of time (about 30 seconds). Next, after reducing the voltage applied to the electrolytic cell to 0V again, the solenoid valves Vc, Vd, and Ve are closed, and the solenoid valves Vf ₁ , Vf ₂ , Vg ₁ , and Vg ₂ are opened, and the metal in the cathode and anode chambers is removed. Ion-containing water is discharged from each drainage pipe using nitrogen pressure.
After this, the solenoid valves Vc, Vd, and Ve are opened, and the solenoid valves Vf ₁ , Vf ₂ , Vg ₁ , and Vg ₂ are closed, and the polarity of the electrodes in the electrolytic cell is reversed and connected. Perform occurrence.

As a result of the above operation, the metal deposited in the electrolytic cell is dissolved as metal ions by the reverse voltage, and furthermore, this metal ion-containing water is discharged from the electrolytic cell, thereby improving the efficiency of hydrogen generation.

(g) Effects of the invention According to this invention, when the hydrogen generation efficiency of an electrolytic cell decreases due to contamination based on metal ions, the contamination can be easily removed and the electrolytic cell can be continued to be used. Hydrogen can be generated efficiently without the need for replacement. Furthermore, by periodically removing contamination caused by metal ions, damage to the electrolytic cell can be reduced and it can be used for a long period of time.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of this invention. 2... Water supply tank, 3... Electrolytic cell, 4... Water separation section, 5... Drying section, 6... Control section, 31... Electrode, 32... Cathode chamber, 33... Anode chamber, a... ...Pure water supply channel, b...Hydrogen release channel, c...Oxygen release channel, d...Return channel, e...Hydrogen supply channel,
f...Nitrogen introduction pipe, _g1 , _g2 ...Drainage pipe,
Vc, Vd, Ve, Vf ₁ , Vf ₂ , Vg ₁ , Vg ₂ ... Solenoid valve.

Claims (1)

[Claims for Utility Model Registration] An electrolytic cell in which an anode chamber and a cathode chamber are constructed using a polymer electrolyte having a pair of electrodes on both sides as a diaphragm, and a water supply channel that supplies water to the electrolytic cell from a water tank; The anode chamber and the cathode chamber are composed of a hydrogen discharge channel that discharges the generated hydrogen-containing water from the cathode chamber and extends to the gas-liquid separation means, and an oxygen discharge channel that discharges the generated oxygen-containing water from the anode chamber. Each is provided with an inert gas introduction pipe and a drainage pipe for draining residual water in the anode chamber and the cathode chamber, and a control unit configured to be able to switch the voltage applied between the pair of electrodes between positive and negative. A hydrogen generator equipped with: