JPS6356942B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a replacement time detection device for a desalination material in a dechlorination device for appropriately detecting the time to replace the desalination material due to residual chlorine leakage in the dechlorination device. Conventionally, as a device for removing sterilizing chlorine from tap water supplied to general households, for example, a dechlorination device, that is, a dechlorination filter using activated carbon as the desalting material, is used to pass tap water through a filter. A dechlorination device is used that removes the chlorine content through adsorption and catalytic action on activated carbon, and the activated carbon is replaced as soon as possible before it loses its desalination effect. Therefore, as a method for detecting the end point of activated carbon in a dechlorination equipment corresponding to the timing of activated carbon replacement, for example, the coloring due to the reaction with residual chlorine caused by adding O-tolidine hydrochloride solution to the treated water from the dechlorination equipment can be used. Therefore, the end point of activated carbon is detected, but in this case, residual chlorine leakage is confirmed by determining the presence or absence of coloration with the naked eye, so it is difficult to determine the coloration, especially when the leakage concentration is low. Another drawback is that the O-tolidine hydrochloride solution used for this end point detection is subject to legal regulation as a potentially carcinogenic substance. In addition, as an alternative method for detecting the end point of activated carbon, for example, there is a method of detecting the end point by the water flow rate of activated carbon. This has the disadvantage that it is not possible to accurately detect the end point of activated carbon because of fluctuations. The purpose of the present invention is to appropriately detect when to replace desalination materials such as activated carbon in a dechlorination equipment without using reagents and without being affected by interfering ions such as Fe ions and Cu ions and pH contained in raw water. The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art. Next, the configuration of an embodiment of the present invention will be explained with reference to the drawings. An inflow pipe 3 for supplying raw water to be treated, such as tap water, is connected to the upper end of the cylindrical filter container 2 of the dechlorinator 1, and the lower end thereof supplies dechlorinated water to each faucet. The outflow pipe 4 is connected, and the inside of the filter container 2 is divided into three filter chambers 7, 8, and 9, an upper, middle, and lower part, via a flange-like separator 6 formed on the outer periphery of the cylindrical communication pipe 5. and each filter chamber 7, 8,
9 is filled with activated carbon 10 as a filter material, which removes chlorine from atoms. Also, a communicating pipe 5 is connected to the lower end of the filter container 2.
A shielding ring 12 for blocking the flow path of the communicating pipe 5 is attached to the middle and lower end of the insulating rod 11 made of an electrically insulating material inserted on the inner axis, and the communicating pipe is divided into two by the ring 12. 5 each communication path 13,
Communication holes 15 are formed in the insulating rod 11 at positions in contact with the filter chambers 7, 8, and 9, and silver electrodes 16 containing plating are formed in the communication passages 13 and 14 of the insulating rod 11. A small noble metal electrode 17, for example platinum or gold, is mounted as a pair of galvanic electrodes 18,19. Therefore, when raw water is supplied to the filter container 2 of the dechlorination apparatus 1 configured as described above through the inflow pipe 3, foreign substances are removed from the raw water through the mesh filter 20 of Saran (trade name) Net. In this state, the activated carbon 10 is passed through the upper communication passage 13 of the communication pipe 5, the intermediate filter chamber 8, the lower communication passage 14 of the communication pipe 5, the lower filter chamber 9, and the mesh filter 21 of the saran net for preventing the activated carbon 10 from flowing out. The water is supplied from the outflow pipe 4 to a faucet etc., and in this state of water flow, each communication passage 13, 14
A galvanic electromotive force is generated from the electrodes 18 and 19 using water as an electrolyte passing through each communication path 13 and 14,
The same electromotive voltage passes through the electrode rod 11 to each electrode 16,
The signal is inputted to an external detection device 23 via an electric wire 22 connected to a terminal 17. Next, FIG. 2 shows the electric circuit of this embodiment,
006P-9V power supply battery B to power switch SW1,
Each resistor R for positive potential stabilization and negative potential stabilization
1, R2, Zener diodes ZD1, ZD2, diodes D1, D2, and capacitors C1, C2. The differential amplifier AMP1 is offset-adjusted via a variable resistor VR1, and its non-inverting side input terminal The galvanic voltage from the upstream electrode 18 is inputted to the input terminal via the input resistor R3, and the galvanic electromotive force from the downstream electrode 19 is inputted to the input terminal on the opposite side via the input resistor R4. An output corresponding to the difference between the input voltage and the amplification factor determined by the input resistors R3, R4 and the return resistors R5, R6 is generated, and the output from the differential amplifier AMP1 is connected to the diode D3, the variable resistor VR2, and the switching In addition to being input to the ammeter M via the switch SW2, the ammeter M is also connected to the power supply battery B check resistor R via the changeover switch SW2, and the pull-up resistor R8 is connected to the output terminal of the differential amplifier AMP1. has been done. Next, the operation of this embodiment will be explained. First, when the inverting and non-inverting side inputs of the differential amplifier AMP1 are both zero, the offset is adjusted via the variable resistor VR1 so that the pointer of the ammeter M indicates the zero range, and then the dechlorinator 1 is connected to the sterilizer. When tap water containing chlorine is passed through as raw water, the chlorine in the raw water is first adsorbed by activated carbon, and its catalytic action causes the reaction 2Cl ₂ + 2H ₂ O4Hcl + O ₂ ...(1), which is desorbed by activated carbon 10. Although a chlorine adsorption zone is formed, there is almost no leakage of residual chlorine in the treated water flowing from the upper filter chamber 7 to the upper communication passage 13 at this early stage of water flow, and therefore the upstream and downstream galvanic electrodes 18 ,19
Since both generate substantially the same electromotive voltage, the output of the differential amplifier AMP1 is substantially zero, and the indicated value of the ammeter M also remains zero and does not change. Note that there are no interfering ions in the raw water under this condition.
Even if Fe ⁺ etc. are included, these interfering ions can be absorbed by activated carbon at a space velocity of SV30 or more.
0, the electromotive voltages of the upstream and downstream galvanic electrodes 18 and 19 both rise to approximately the same degree in response to the degree of interfering ions, so the output of the differential amplifier AMP1 depends on the interfering ions. does not change and remains at zero, and the pointer of the ammeter M also remains at zero, so that the ammeter M will not malfunction due to interfering ions. Next, as the raw water passes through the activated carbon 10, the chlorine in the raw water is adsorbed by the activated carbon 10, and due to the reaction of equation (1), the chlorine 2Cl ₂ in the raw water becomes 4HCl, forming a dechlorination adsorption zone. In addition, as the water flow time elapses, the adsorption zone moves downstream, and at the time when this adsorption zone moves from the upper filter chamber 7 to the middle filter chamber 8, there is no residue remaining in the test water in the upper communication passage 13. As chlorine begins to leak, the leakage amount gradually increases over time, and the residual chlorine concentration in the test water approaches the raw water concentration.In this state, the residual chlorine in the test water, in this case the leaked water, is on the silver electrode 16 and platinum electrode 17 of the galvanic electrode 18 in the upper communication path 13, respectively.

[Table] 1
〓HOCl＋e ⁻ →

Claims (1)

[Claims] 1 The desalination material chamber of the filter material in the filter of the desalination material through which the water to be treated passes is divided into at least three chambers, and each desalination material chamber is connected in series with at least two communication paths, and A pair of electrodes using the water to be treated as an electrolyte is attached to at least two communication paths, and each electrode is separately formed in each communication path in order to detect the time to replace desalination material due to leakage of residual chlorine. A desalination material replacement timing detection device in a dechlorination equipment, characterized by comprising an electromotive force difference detection circuit that detects a difference in electromotive force.