KR20030065856A - An chlorine-sodium hydroxide electricty decomposition apparatus - Google Patents

Abstract

PURPOSE: An electrolytic cell for producing chlorine-sodium hydroxide is provided to continuously spray a small amount of low pressure supplementary water onto sodium hydroxide solution so that the supplementary water is overflown to the opposite point, and prevent sodium hydroxide from mixing vertically to maintain current in the cathode water tank constantly. CONSTITUTION: In an electrolytic cell comprising an anode water tank(101) in which anode terminal(103) is installed in connection pipe(102) externally installed, and a cathode water tank(104) in which cathode terminal(106) is installed in connection pipe(105) externally installed, wherein ion osmosis membrane(107) is inserted as a diaphragm when connecting the connection pipes(102,105), and anode current and cathode current are flown into the anode terminal(103) and cathode terminal(106) through rectifier(108), the electrolytic cell for producing chlorine-sodium hydroxide is characterized in that an inlet(111') of diluting water inflow pipe(111) on which flow control valve(110) is installed and an outlet(112') of discharge pipe(112) are oppositely installed on the same horizontal axis line in the cathode water tank(104), a gas discharge pipe(113) is installed in an upper axis direction of the cathode terminal(106) at the connection pipe(105) of the cathode water tank(104), and a constant current circuit unit(109) is installed between the rectifier(108) and the cathode terminal(106) and anode terminal(103).

Description

AN CHLORINE-SODIUM HYDROXIDE ELECTRICTY DECOMPOSITION APPARATUS}

The present invention relates to an electrolysis tank that produces chlorine-sodium hydroxide, and in particular, a small / low pressure make-up water is applied to the surface of the sodium hydroxide solution so that the concentration of the sodium hydroxide solution is constant in a cathode tank (sodium hydroxide chamber) in which sodium is produced. By continuously spraying, the replenished water flows to the opposite point and the sodium hydroxide in the lower portion is not stirred upward by the generation of hydrogen gas so that the amount of current in the cathode tank is kept constant.

In general, an electrolysis tank producing chlorine-sodium hydroxide is injected with a certain amount of water into a cathode tank having a cathode terminal, and a certain amount of sodium chloride (NaCL ₂ ) solution is injected into a cathode tank having a cathode terminal. In addition, the cathode tank and the anode tank were connected with an osmotic membrane therebetween.

In this state, when a certain amount of current is injected into the cathode terminal and the anode terminal, chlorine gas is generated in the anode tank, and sodium and hydrogen gas are generated in the cathode tank. In this case, as the amount of sodium generated in the cathode tank increases, the concentration of the solution of the cathode tank, that is, the sodium hydroxide solution increases, and the amount of current increases, so that the amount of chlorine gas produced per unit time increases in the anode tank.

At this time, the production amount of chlorine gas (per unit time) is required to generate a certain amount per unit time continuously according to the use range (water chlorine disinfection, swimming pool chlorine disinfection, etc.), sodium hydroxide in the cathode tank in order to satisfy such requirements To keep the concentration of the solution constant, the blinds were injected with dilution water.

At this time, the dilution water is not injected randomly, but the appropriate amount of dilution water required for dilution using the hydrometer's operation principle of rising and falling due to the change of buoyancy according to the change of the concentration of sodium hydroxide solution in the cathode tank. It was configured to flow into the tank.

As a method using a hydrometer such as the prior application, there are "US Patent No. 4899774" and "US Patent No. 15551468".

First, referring to the US Patent No489977, as shown in FIG. 1, the hydrometer 11 installed in the cathode water tank 10 is electrolyzed to increase the concentration of the sodium hydroxide solution in the cathode water tank 10. When the) is increased, the dilution water introduced into the dilution water distribution chamber 12 through the inflow pipe 14 is introduced into the cathode water tank 10. Then, the sodium hydroxide solution is diluted to lower the concentration of the sodium hydroxide solution to an appropriate concentration. As the hydrometer 11 was lowered down, the dilution water was discharged to the outside through the discharge pipe 13 directly to the outside instead of flowing into the cathode water tank 10.

As such, the hydrometer 11 operates up and down according to the concentration of the sodium hydroxide solution of the negative electrode tank 10, while dilution water flows into and blocks the negative electrode tank 10, thereby maintaining a constant concentration of the sodium hydroxide solution of the negative electrode tank 10. Could.

However, in the above-described invention, when the water flow force of the dilution water is too strong or the quantity is too large, the upper end of the hydrometer 10 is adhered to the wall surface of the dilution water distribution chamber 12 so that the hydrometer 10 does not rise or fall. If not often occurs, the diameter of the inlet of the dilution water inlet pipe 14 is too small (0.3 mm or less) because it is frequently blocked by foreign matter, there was a frequent problem that the inflow of dilution water is blocked.

In addition, referring to US Patent No5551468, as shown in FIG. 2, a hydrometer 21 is installed in the cathode tank 20, and on-off operation of the hydrometer 21 is performed on and off of the cathode tank 20. Install the electric switch device 22 and the controller 23 associated with it and connect it with the electric valve 24, which is an on / off valve of the inlet pipe 25 for introducing dilution water into the cathode tank 20, the cathode tank ( When the sodium hydroxide solution concentration of 20) is increased and the hydrometer 21 is raised, the electric switch device 22 is turned "on", and when the passage of the inflow pipe 25 is opened by the operation of the electric valve 24, the dilution water may be negative water tank ( 20) the concentration of the sodium hydroxide solution in the cathode water tank 20 is blocked while the concentration of the sodium hydroxide solution is lowered and the hydrometer 21 is lowered and the electric switch device 22 is "off" to block the inflow of dilution water. To keep it constant.

This method is a structure in which two electrical devices, namely, the on-off electric switch device 22 and the electric valve 23 are interlocked with the hydrometer 21, and are easily generated electrically and physically, and in particular, sodium chloride (salt) supplementation is performed. And when repairing or cleaning the electrolysis tank, even if a small amount of chlorine gas leaks the terminal corrosion of the electric switch device 22 and the corrosion of the electric valve 24 easily progressed, there was a frequent problem.

In addition, the two previously disclosed inventions in the sodium hydroxide solution of the cathode tanks (10, 20) is a bubble rise of hydrogen gas stirred the entire sodium hydroxide solution of the cathode tank so that the upper and lower ends are always maintained in a single concentration Diluted water and time according to the concentration dilution takes a lot of time, and thus takes a lot of time due to the concentration dilution, there was a problem in that the variable variable production time of the chlorine gas generated in the anode tank.

Therefore, the present invention has been devised in view of the above problems, and discharges the hydrogen gas to the outside so that the sodium hydroxide solution of the negative electrode tank is not stirred up and down, and the negative electrode is supplied by supplying dilution water without a hydrometer and a device connected thereto. In the upper part of a certain height in the lower part of a water tank, it aims at keeping the concentration of sodium hydroxide solution constant.

In order to achieve the above object, the present invention provides a positive electrode tank in which an anode terminal is embedded in an external connector, an anode tank in which an anode terminal is embedded in an external connection tube, and an ion osmosis membrane is inserted into a diaphragm when connecting the connection tubes. In the electrolysis tank, the anode current and cathode current flowing into the anode terminal and the cathode terminal, respectively, are introduced to flow through the rectifier;

In the cathode tank, the inlet of the dilution water inlet pipe having the flow control valve and the outlet of the discharge pipe are installed on the same horizontal axis so as to face each other. The connection pipe of the cathode tank is provided with a gas discharge pipe in the upper axis direction of the cathode terminal. It is to provide an electrolysis tank for the production of chlorine-sodium hydroxide between the rectifier, the cathode terminal and the anode terminal with a constant current circuit device.

1 is a schematic diagram showing a first embodiment of an electrolysis tank for producing general chlorine-sodium hydroxide.

Figure 2 is a schematic diagram showing a second embodiment of the electrolysis tank for producing general chlorine-sodium hydroxide.

3 is a schematic view showing a configuration of the present invention.

Figure 4 is a plan view showing the flow of dilution water in the upper surface of the solution in the negative electrode tank according to an embodiment of the present invention.

5 is a table showing the change in specific gravity of sodium hydroxide by the constant current preset in the dilution water injection amount and the constant current circuit device according to an embodiment of the present invention.

***** Detailed description of symbols for important parts of the drawings *****

101: anode tank 102: connector

103: anode terminal 104: cathode tank

105: connector 106: cathode terminal

107: ion osmosis membrane 108: rectifier

109: constant current circuit device 111: inflow pipe

111 ': inlet 112: exhaust pipe

112 ': discharge port 113: gas discharge pipe

Referring to the configuration and the embodiment of the present invention in detail with reference to the accompanying drawings 3 as follows.

Figure 3 is a schematic diagram showing the configuration of the present invention, Figure 4 is a plan view showing the flow of dilution water in the cathode tank of the present invention, Figure 5 is a dilution water injection amount and constant current circuit device according to an embodiment of the present invention This diagram shows the specific gravity of sodium hydroxide by the set constant current.

The configuration of the present invention is a cathode terminal (101) in which the positive electrode terminal 103 is installed in the connection pipe 102, which is installed at a predetermined height at the lower surface, and the cathode terminal (), which is installed at a predetermined height in the lower surface. An anode osmosis membrane 107 is inserted into the diaphragm when the cathode tank 104 and the connecting pipes 102 and 105 are installed, and the anode current flowing into the anode terminal 103 and the cathode terminal 106 is respectively installed. In the electrolysis tank, the cathode current is formed to flow through the rectifier 108,

The inlet 111 'of the dilution water inlet pipe 111 and the outlet 112' of the discharge pipe 112 are installed on the same horizontal axis on the upper side of the cathode tank 104 with the flow control valve 110 installed thereon. The gas discharge pipe 113 is installed in the connecting tube 105 of the cathode water tank 104 in the upper axis direction of the cathode terminal 106, and the rectifier 108, the cathode terminal 106, and the anode terminal 103 are installed. The constant current circuit device 109 is provided between the two parts.

In addition, the water level of the cathode tank 104 is always maintained at the height 'h1' of the inlet 111 'of the inlet pipe 111 and the outlet 112' of the outlet pipe 112.

In addition, each of the connection pipes 102 and 105 is installed so that the lower pole is positioned at a predetermined height 'h2' or more from the lower surface of each of the anode tank 101 and the cathode tank 104, the union 114 coupling method and flange coupling method (Not shown) is preferable.

In addition, the upper end of the gas discharge pipe 113 is located above the water level surface of the cathode tank (104).

In addition, the positive electrode tank 101, the negative electrode tank 104 and the ion osmosis membrane 107 is a non-conductive material, such as fiberglass (glass fiber), concrete, polyvinyl chloride (PVC) and chemical resistance materials and chlorine gas and It is made of a material that has chemical resistance to sodium hydroxide.

Reference numeral 115, 115 'is a pipe connecting the anode tank 101 and the connection pipe 102, and chlorine gas is discharged to the pipe 115.

The present invention configured as described above supplies the brine (sodium chloride solution), which is a saturated solution, to the anode bath 101 in a state where the anode bath 101 and the cathode bath 104 are coupled, and the discharge pipe 112 to the cathode bath 104. Fill the water until it is overflowing.

Therefore, the water level of the cathode tank 104 is such that the bottom height 'h1' of the outlet 112 'of the discharge pipe 112 and the inlet 111' of the inlet pipe 111 at the bottom of the tank.

Thereafter, an external electric current is supplied to the positive electrode terminal 103 and the negative electrode terminal 106.

At this time, the external electricity is converted into a low current (1-20 amp) and low voltage (4-10V) through the rectifier 108 to the constant current circuit device 109, the positive electrode terminal 103, the positive electrode current is negative terminal A cathode current is supplied to 106 to cause electrolysis in each tank.

That is, in the anode tank 101, salt (NaC |) is electrolyzed to decompose into Na + (sodium) ions and Cl-(chlorine) ions, and the chlorine ions are pulled toward the anode terminal 103 to form chlorine gas. It is discharged to the outside and introduced into where necessary, sodium ions are selectively passed through the ion osmosis membrane 107 to the cathode water tank 104 having the negative electrode terminal 106 to combine with water (H 2 O) NaOH (sodium hydroxide) Becomes

In the process of combining sodium ions with OH (-) of water, H (+) is separated into hydrogen gas (H2) and discharged into the atmosphere through the gas discharge pipe 113 at the upper side of the negative electrode terminal 106.

Therefore, as the hydrogen gas is discharged to the outside, the stirring phenomenon of the solution in the cathode water tank 104 does not occur or is very small.

In addition, the sodium hydroxide is located in the lower portion of the cathode tank 104 by the specific gravity difference with water.

Thereafter, as the electrolysis continues, the concentration of sodium hydroxide in the cathode tank 104 is increased, and thus the concentration of sodium hydroxide is increased so that the amount of current is increased in the cathode tank 104 and the anode tank 101, and thus, chlorine gas and The rate and amount of sodium hydroxide and hydrogen gas produced are increased.

At this time, in order to prevent the concentration of sodium hydroxide in the cathode water tank 104 to be higher than a certain value, the appropriate amount (0.3-0.8 liter / min) of dilution water continuously from the initial electrolysis operation to the valve control 110 It is sprayed horizontally to the surface of the solution in the cathode water tank 104 through the inlet pipe 111, and as shown in FIG. 4, the upper layer of the sodium hydroxide solution is diluted and discharged to the outside through the discharge pipe 112 on the opposite side.

The dilution water discharges a constant speed from the inlet pipe 111 and immediately flows to the discharge pipe 112 so that the cathode hydroxide continuously diffuses from the lower layer to the upper layer while minimizing the agitation of the solution in the negative electrode tank 104. It is discharged to the outside of the water tank 104, and the density | concentration of the sodium hydroxide solution in the cathode water tank 104 is made constant.

This requirement of the present invention is also satisfied by the operation of the constant current circuit device 109 provided between the positive terminal 103 and the negative terminal 106 and the rectifier 108 connected thereto.

The constant current circuit device 109 cannot obtain the required amount of current when the concentration of the electrolyte required for the electrolysis in the solution is insufficient, but prevents the current from rising when the concentration of the electrolyte is gradually increased after some time. It is to supply a set constant current, thereby keeping the electrolyte concentration in the solution constant.

That is, the constant current circuit device 109 increases the amount of the electrolyte and keeps the amount of current at the positive electrode terminal 103 and the negative electrode terminal 106 indefinitely without being increased indefinitely at a predetermined constant current amount.

An example of such a constant current circuit device 109 is described below with reference to the table shown in FIG. 5 in the present invention.

In the present invention, when the maximum current flowing through the positive electrode terminal 103 and the negative electrode terminal 106 by the constant current circuit device 109 is 20 amp or less, the specific gravity of sodium hydroxide in the negative electrode tank 104 is 1.022 (15 degrees Celsius). If the solution is less than about 2% of sodium hydroxide in the figure), the amount of electrolyte is not sufficient, so that the required amount of electric charge cannot be transferred, so that an appropriate amount of current cannot be formed, that is, sodium ions (Na +) required for electrolysis in the solution of the cathode water tank 104. The amount of current is insufficient to obtain a proper amount of current.

Therefore, as the amount of electrolyte increases over time, the amount of current increases, and when the specific gravity of sodium hydroxide (NaOH) is 1.1 or more (a solution of about 10% NaOH at 15 ° C in water temperature), the lifetime of the ion osmosis membrane 107 is increased. It is lowered and there is a risk of burns upon handling.

In fact, it is possible to produce a solution of sodium hydroxide (NaOH) with a specific gravity of 1.6 (a solution of about 45-50% of sodium hydroxide (NaOH) at a water temperature of 15 degrees Celsius), but the purpose of the present invention (chlorine disinfection in a simple abnormality, Not suitable for chlorine disinfection in swimming pools, etc.)

Therefore, the constant current circuit device 109 controls the current to gradually increase when the concentration of the electrolyte increases during the operation of the present invention to supply a predetermined constant current, whereby an appropriate amount of electrolyte so that the concentration of the electrolyte in the solution is constant. This is what keeps happening.

In this way, the amount of electrolyte is constantly generated in the solution of the cathode bath 104, and as a result, the electrolyte concentration in the solution is kept constant with almost no width of change due to the dilution of the dilution water described above. At 101, a certain amount of chlorine gas is generated continuously (Faraday's law).

As described above, in the present invention, the gas discharge pipe is installed in the connection pipe of the cathode water tank to directly discharge the hydrogen gas to prevent the sodium hydroxide solution from being agitated in the cathode water tank as a whole, and the dilution water inflow pipe and the dilution water into the cathode water tank. A discharge pipe is installed to continuously discharge a certain amount of dilution water per unit time at a constant pressure on the upper surface of the solution, and discharge it immediately.The current applied to the negative electrode terminal and the positive electrode terminal is controlled by a constant current circuit device to generate a constant amount of electrolyte. To maintain a constant concentration of the electrolyte contained in the solution of the cathodic bath so that a certain amount of chlorine gas is continuously generated in the anodic bath; Compared with the existing electrolysis bath, the concentration of sodium hydroxide solution is smaller and the structure is simpler without physical devices such as hydrometers and electric devices such as electric on-off switches and electric valves. Being effective.

Claims (3)

An anode tank 101 in which the anode terminal 103 is installed in the outer connecting pipe 102, a cathode tank 104 in which an anode terminal 106 is embedded in the connecting pipe 105, and the connection pipe ( The ion osmosis membrane 107 is inserted into the diaphragm when the 102 and 105 are connected, and the anode current and the cathode current flowing into the anode terminal 103 and the cathode terminal 106 respectively are introduced through the rectifier 108. In a bath; The inlet 111 'of the dilution water inlet pipe 111 provided with the flow rate control valve 110 and the outlet 112' of the outlet pipe 112 are installed on the same horizontal axis in the cathode tank 104, In the connecting pipe 105 of the cathode tank 104, a gas discharge pipe 113 is installed in the up-axis direction of the cathode terminal 106, An electrolysis tank for producing chlorine-sodium hydroxide, characterized in that a constant current circuit device (109) is installed between the rectifier (108), the cathode terminal (106) and the anode terminal (103). The method of claim 1, The water level of the water stored in the cathode tank 104 is chlorine-hydroxide, characterized in that the lower height 'h1' of the inlet 111 'of the inlet pipe 111 and the outlet 112' of the outlet pipe 112. Electrolysis bath for sodium production. The method of claim 1, The constant current of the constant current circuit device 109 is chlorine-sodium hydroxide, characterized in that the water temperature of the solution in the cathode water tank 104 is set to 5 ~ 20 amp (ampere) so that the specific gravity of sodium hydroxide is 1.030 ~ 1.090 at 15 degrees Celsius Electrolysis bath for production.