JP2019217655A5 - - Google Patents

Description

The magnetic unit forms a magnetic field perpendicular to the flow direction of the water in the water flowing in the water circulation path. It is known that the formation of such a magnetic field changes the properties of water. That is, since water contains positive ions and negative ions (chargeable substances) such as Ca ²⁺ , Mg ²⁺ , and CO ₃ ^2- , for example, when water crosses the magnetic field formed by the magnetic unit, the electronic excitation action occurs. Which results in fragmentation of the water molecule. Further, due to Lorentz force generated when water crosses the magnetic field, bonds between water molecules are released, and the collective structure of water is reduced. For this reason, the viscosity of water decreases, the permeability of water and the solubility of water improve, and the surface tension decreases. Further, although the pH value changes due to the magnetic treatment, the pH value is small, so that the water in the water tank can be maintained relatively weakly acidic. Incidentally, according to the experiments conducted by the present inventors, the variation of the pH value of that by the magnetically treated water was about 0.4 to 1.0.

The bactericidal action becomes stronger as the amount of ultraviolet irradiation increases. In addition, the amount of ultraviolet irradiation at which an effective bactericidal action is obtained differs depending on the type of bacteria (species of bacteria). Therefore, the irradiation amount of the ultraviolet rays may be determined according to the flow rate (L / min) of the water flowing through the water circulation path and according to the type of bacteria contained in the water.
For example, the amount of UV irradiation required to kill (inactivate) E. coli, Bacillus subtilis, and blue mold by 99.99% is 9000 μW · sec / cm ² , 21300 μW · sec / cm ² , and 36000 μW · sec / cm ² , respectively. Have been. Therefore, if these bacteria in the water, so that it can kill blue mold, by determining the amount of ultraviolet irradiation, E. coli and B. subtilis may also Rukoto killed.

The filtration device is installed to remove unnecessary components contained in water. The unnecessary components contained in the water, dust mixed into the oil-based ink or a water tank for use in an offset printing machine, water stain adhering to the inner wall of the water tank, bacteria carcasses and the like. Therefore, it is preferable to use a filter or an adsorbent capable of removing these unnecessary components in the filtration device.

Hereinafter, specific examples of the present invention will be described with reference to the drawings.
[First embodiment]
FIG. 1 shows the overall configuration of a dampening solution supply system for offset printing according to a first embodiment of the present invention. As shown in FIG. 1, the dampening solution supply system 1 for offset printing (hereinafter, referred to as a water supply system 1) is roughly composed of a main body 100 and a dampening solution treatment unit 200.

In addition to the elements described above, the main body 100 includes a stirrer 180 disposed at the lower end of the drain pipe 147 in the water tank 110, a temperature sensor 181 for detecting the temperature of the water in the water tank 110, and a pH for detecting the pH value of the water. An electrode 182 and a water level electrode 183 for detecting the water level in the water tank 110 are provided. Further, an opening 184 formed on the right side wall of the water tank 110 for discharging the excess water when the water in the water tank 110 exceeds a predetermined water level, a drain port 185 formed at the bottom of the water tank 110, Drainage channels 186, 187 connected to the opening 184 and the drainage port 185, a valve 188 attached to the drainage channel 187, and the like are provided.

[Dampening water treatment unit]
The dampening water treatment unit 200 has a water circulation path 210 having an inlet end connected to the bottom of the water tank 110 and an outlet end connected to the left side wall of the water tank 110, and a water circulation path 210 from the inlet end of the water circulation path 210. A circulation pump 220, a filtering device 230, a magnetic unit 240, and an ultraviolet irradiation device (hereinafter, referred to as “UV device”) 250 are sequentially provided toward the outlet side end. Further, the dampening water treatment unit 200 is provided in the water circulation passage 210 between the circulation pump 220 and the filtration device 230 , and the valves 260 and 261 provided near the inlet end and the outlet end of the water circulation passage 210, respectively. Valve 262 , a flow control valve 263 and a flow meter 264 provided in the water circulation path 210 between the filtration device 230 and the magnetic unit 240, and drainage water branched from the water circulation path 210 between the magnetic unit 240 and the UV device 250. road 265, Bei Eteiru a valve 266 which is attached to the drainage channel 265.

Raw water is supplied into the water tank 110 through the water supply channel 120, and the etchant in the etchant tank 300 is supplied into the water tank 110 through the etchant supply channel 160. Further, the water in the water tank 110 is circulated between the water tank 110 and the dampening water treatment unit 200 by the circulation pump 220, while unnecessary components contained in the water are removed by the filtration device 230, and the water is removed by the magnetic unit 240. The clusters are subdivided into water having properties appropriate for offset printing, such as a reduction in surface tension and maintenance of the pH value, and bacteria and the like contained in the water are killed by the UV device 250.

<Experiment 2: fluctuation of pH value and ORP value>
<1. Experimental method>
Changes in the pH value and ORP value (oxidation-reduction potential) of the water in the water tank 110 during the operation of the water supply system 1 of the above-described embodiment were examined. Further, as a comparative example, a system (comparative example system) in which a photocatalyst device used in the dampening solution supply system described in Patent Document 1 described above is added to the dampening solution treatment unit 200 is configured. during operation, the change in pH value of the water in the water tank 110 and ORP (oxidation - reducing potential) value was also investigated. In addition, in order to set the same operating conditions as in the actual operation, in each of the systems of the embodiment and the comparative example, the dampening solution in the water tank is supplied to the offset printing press, and the excess dampening solution is supplied from the offset printing press. Was recovered and an experiment was performed.

Filtration device Main unit: Two housings (vessels) to which five 500 mm long filters can be installed (primary housing and secondary housing )
Filtering pump: A water in the water tank primary housing, the primary housing Ru is circulated in the order of the secondary housing: A filter five mounting the secondary housing: B filters three to, C filter the two mounting A filters: 3 [mu] m or more Wind type filter capable of removing coarse dust (for preventing clogging of the filter in the secondary housing)
B filter: Wind type filter capable of removing fine dust up to 1 μm C filter: Adsorption filter capable of removing components (pigment, ink oil, etc.) mixed in the fountain solution

It should be noted that the present invention is not limited to the above-described embodiment, and appropriate changes can be made.
For example, the arrangement of the circulation pump 220, the filtration device 230, the magnetic unit 240, and the UV device 250 in the water circulation path 210 is not limited to the examples shown in FIGS. 1 and 2, and the arrangement of the magnetic unit and the UV device 250 may be reversed. . Further, the number of the filtering devices 230, the magnetic units 240, and the UV devices 250 is not limited to one, but may be plural. Further, the numbers of the filtering devices 230, the magnetic units 240, and the UV devices 250 may not be the same.

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