KR20080039355A - Water sterilizer using UV LED with self-generation function - Google Patents

Abstract

The present invention is to devise a sterilization device for water purification using ultraviolet LED in a state in which a separate external power source is unnecessary by securing power through a self-generator using a flow of water in which a constant water pressure such as a water pipe or an underground water pipe exists. It is a sterilizer for water purification using UV-LED with wavelength of 254nm among LEDs. Since power is directly provided through self-generation, it is operated independently without a separate power supply, and operates automatically only when water is supplied. Therefore, a separate on / off switch is not required. Ultraviolet LEDs have the advantages of low power and long life, which makes them highly versatile and allows for semi-permanent UV-LED filters with a lifespan of 50,000 to 10 hours without replacement costs. The structure of the present invention is a structure for irradiating UV-LED to the largest area during the short flow of water, which is supplied while maintaining the residence time for a certain time to increase sterilization effect, such as the method of irradiating the LED by storing in a water storage tank. It is an invention which has little influence on flow rate.

Description

Sterilizer for water supply using ultraviolet LED with self-generation function {Using UV-LED water faucet sterilizer with standalone small size generator}

Due to the many advantages of LED, the utilization technology of LED is accelerating the industrialization very actively with the development of materials and various packaging technology and production manufacturing technology, and this movement is promoting the practical use as LED lighting device. . In particular, white LED technology using UV-LED and RGB phosphors among LED lighting technologies is expected to replace next-generation lighting with good color rendering and efficiency. In addition, the utilization of UV-LED is taking place in place of the short life span and large volume of the existing UV-lamp, and it is possible to secure the accurate wavelength of the sterilization line spectrum. It is expected.

  Conventional sterilization techniques using ultraviolet sterilization lamps are used in some water purifiers because most of the underwater lighting method of sterilization by direct immersion in water. However, a commercial power source is required for driving the lamp, and the installation location is limited because of its large volume and difficulty in handling.

The existing UV sterilization method should be converted to the proper sterilization method for the UV-LED generation, and element technology, material technology, and various applications have been invented and can be directly applied to joint water facilities or water purifiers.

The main feature of UV-LED is that it can be directly irradiated to the object that is weak to heat without first emitting heat rays, and secondly, since it stably emits light immediately after lighting, there is an advantage that it can be turned on only when necessary. Third, it is a long life light source of 50,000 to 100,000 hours, and can reduce the number of light source replacement. Fourth, only the required wavelength (around 254 nm) can be irradiated, so the light utilization efficiency is very high. Fifth, the amount of light can be adjusted by current (no shutter), so electronic control is easy. Sixth, since it can be used in vacuum, it is not affected by pressure and is not affected by breakage or external pressure. Seventhly, it has stable characteristics even at low temperatures, and thus has strong characteristics. LEDs with many of these advantages, in particular, can be driven by the power generated by a small generator through low power consumption, thereby motivating the design of a filter having a water purification function.

The generator for supplying the power of UV-LED is a three-phase generator, and the power generated by the bridge diode is rectified and the rectified power requires the design of a small generator that turns on the UV-LED and the background of the power conversion circuit. . In addition, the design of the pipe structure to minimize the influence on the flow of water and to increase the sterilization effect and the mechanical design of the reflective structure to increase the irradiation ability of the irradiated UV-LED can be referred to as the background of the present invention.

UV-LEDs in the 254nm wavelength range are still expensive, so efficient irradiation methods are urgently needed to commercialize them. In order to increase the utilization of light energy, a design structure for light reflectance or long life of an apparatus used as an accessory is required. In addition, the real-time sterilization mechanism for the flowing water through the implementation of the ultraviolet sterilizer can contribute to various commercialization of the water purification sterilizer in the future.

The generator integrated structure, the power supply through the core of the present invention, and the mechanism structure for effective irradiation of the UV-LED should determine the strength and intensity of the UV-LED in consideration of the amount of water input and the water pressure. In the case of irradiating LED ultraviolet light that is too small for the size of the mechanical structure, the desired sterilization effect may be insignificant. Therefore, the optimal amount of UV-LED power, generator and supercapacitor should be selected according to the water pressure and water inflow.

According to the present invention, when contaminated water is used when waterborne diseases or groundwater is used, when the water is confined using a circulation pump such as a swimming pool or aquaculture farm, or when the contaminated water remains in the pipeline, It is applicable as a means of a system having a purification function of drinking water or water.

As it supplies the load power by itself, it uses a separate device or low power so that no additional safety device is needed and it will affect the commercialization of various LED applications using it.

Ultraviolet rays are electromagnetic waves shorter than those in the visible region, which are longer than X-ray rays. Ultraviolet, which stands for ultraviolet light, is a compound word of Latin, which means transfer, in Latin, and violet, the shortest wavelength in the visible range, and is also called black light.

  As shown in FIG. 1, UVA is classified into UVA (380-315nm), UVB (315-280nm), which is called intermediate wavelength, and UVC (280nm or less), which is called short wavelength and sterilization wavelength, according to the effect of ultraviolet rays on the human body and the environment. Sunlight emits all of UVA, UVB, and UVC, but 99% of the UV light that is absorbed by the ozone layer in the atmosphere and reaches the Earth's surface is UVA. Some of the UVCs also form ozone.

  In the field of UV-LED, in the R & D field, the NTT Institute for Physical Science developed the 210-nm UV-LED using AIN crystals in 2006. In the field of commercialization, Nichia, Japan's Nichia chemical is manufactured using gallium nitride (GaN) system. Technology is recognized as the most common technology. Recently, zinc-oxide (ZnO) materials are used to manufacture UV-LEDs. When a forward voltage (P layer: +, N layer :-) is applied to the LED electrode, the electrons in the conduction band emit light as much energy as they transition to recombine with the balls of the valence band. At this time, the color changes depending on the size of the energy gap (Eg), Eg is determined by the material and the concentration of the semiconductor crystal. When the wavelength range of the light is an ultraviolet region, it is called UV-LED.

  It is known that the sterilization effect is greatest in the case of the wavelength of 254nm. Main applications for lamps of this wavelength can be used for water, air, other surfaces and biological detection devices for sterilization purposes. Used for sterilization and purification of water and air, etc. It is used for research in chemistry, medicine, and biotechnology. The sterilization mechanism by the sterilizing action of ultraviolet light is found to be absorbed and changed by nucleic acid according to the germ line irradiation, causing the metabolism, loss of proliferation ability and death. That is, the nucleic acid (DNA) in the cell is It is characterized by a change in the metabolism, causing a loss of proliferative capacity. Such ultraviolet sterilization has several characteristics, which are effective for all species, and unlike the sterilization method by drugs or heating, it hardly changes the irradiated objects, and the method of use is simple and economical. It is most suitable for. Most substances other than air and water are limited to the sterilization of irradiated surfaces. In addition, the bactericidal effect is characterized by not remaining only during irradiation.

  The sterilization effect by ultraviolet rays is correlated with radiation intensity and irradiation time, and the survival rate of bacteria is reduced almost exponentially with respect to the radiation dose (radiation intensity × irradiation time), and can be expressed by equation (1). .

(1)

(One)

Where S is the survival rate of sterilization, P is the sterilized water after irradiation, P0 is the sterilized water before irradiation, e is the radiation intensity of the sterilization line [㎼ / ㎠], Et is the irradiation time (min), and Q is the survival rate S. 36.8%) is the sterilization dose [선 · min]. The value of Q varies depending on the environment, even for the same species. For example, the value of Q for E. coli in relatively dry room temperature air is about 5 mW / min / cm2, about twice that in humid air, and 3 to 3 on medium. It is a value of about 8 times in 5 times, underwater.

  Reflectances of various materials are relatively easy and moderate, as are transmittances. Reflectance has characteristics to be considered in the design, installation, etc. of a device, and using a material with good reflectance is one means of effectively using germicidal wires. In addition, if the equipment is installed on the wall, ignoring the reflection may cause accidents, so this should be considered. The reflectance of the main material used for sterilization using UV-LED is the highest with 93% of first magnesium oxide deposited, 87% of deposited aluminum, 65-75% of electropolished aluminum, and 30-40% of polished iron. to be. In the present invention, in the case of the reflecting plate, the reflectance is increased by applying electropolished aluminum.

The amount of UV radiation required to kill various bacteria depends on variables such as experimenter, strain, germination stage, environment, and operating conditions. Gram-negative bacteria such as T. cholera and cholera bacteria are about the same as E. coli, 1.5--5 times that of gram-negative bacteria such as P. aeruginosa, Mycobacterium tuberculosis, Pseudomonas aeruginosa, and Bacillus subtilis. need. Conventionally, the unit of the ultraviolet irradiation amount can be represented by μωmin / cm 2.

  There are various factors that affect the sterilization mechanism of ultraviolet rays. When sterilizing water with ultraviolet rays, the sterilization effect depends on the type of germs, water temperature, water transmittance, deterioration of UV output of the lamp, dirt on the surface of the lamp, treatment flow rate, etc. Consideration should be given to the consideration of these factors directly in the instruments and survey methods in order to ensure the bactericidal effect at the minimum time. When immersion type UV sterilization lamp is attached, the water quality is limited to water with high transmittance such as soft water, pure water or ultrapure water, and 45 ° on the axis of the lamp is not investigated because of the refractive index of water. It is slightly longer and the tank is made of stainless steel or Teflon. Resin such as polyethylene or FRP may be deteriorated by ultraviolet rays to contaminate the water, so the material of the tank in the present invention is used as a material that can increase the reflectance and withstand degradation or corrosion for a long time by applying stainless steel.

  The sterilization of water by ultraviolet rays may be performed by irradiating the water in the light on the water (external lighting), the underwater light (inner lighting) and the ultraviolet light glass tube or quartz tube from the outside. Water lamps are cheap to install, easy to repair, and suitable for disinfecting water with impurities. In the case of underwater lamps, facilities can be downsized and can be easily carried out during piping. There are many. In addition, there is a device that sterilizes ozone and UV light using short-wave UV sterilization lamp, and there are some things to be careful about using UV-derived sterilization device. It takes up to several tens of minutes, so it should be discharged after several minutes after lighting. The sterilization effect is limited during the investigation and does not remain, thus reducing the risk of secondary pollution. If possible, sterilize immediately before use. In addition, the valve, the flow meter 205, etc. are installed in front of the sterilizer as much as possible. In addition, since UV sterilization uses light, it is limited to sterilization of UV-irradiated parts. Therefore, if there is a risk of dust or bacteria lumps spilled from water, well water, activated carbon or ion exchanger in the water tank, the sterilization effect can be enhanced by installing a filter in front of the sterilizer.

  Since the filter using UV-LED uses the existing flow without a separate hydraulic pressure control device, the filter must be made to increase the contact surface in order to improve the irradiation efficiency. Therefore, in the present invention, it has an annular structure and is made of a structure that increases the sterilization effect by increasing the permeation rate and the water residence time by using a pipe 206 of a silicon material that withstands water pressure well.

  The power to turn on the UV-LED is generated in the small generator, and the generated power is rectified through the bridge diode and then supplied to the UV-LED through a drive that drives the UV-LED.

  A constant flow rate is required to produce its own power through the generator, and this flow rate is set based on the water supply. Generally, the natural tap water pressure supplied to homes is about 2-4 kg / cm. Even in the case of high-rise apartments, it is usually raised to a high-rise part with a water pressure of 10kg / cm, and a pressure reducing valve is installed in the meter box to force the pressure reduction when the pressure exceeds 3kg / cm. For apartments, the hydraulic pressure test for pipes (steel pipes, PVC, Acorn, Excel, copper pipes, etc.) is usually 15 kg / cm. If the incoming water pressure to the tap water meter is above the specified value, it is more than 1.5㎏ / ㎠ and the generator design was taken into consideration.

  The generator is installed in the inlet 203 to rectify the generated power through the bridge diode (302). The rectified power is charged in the supercapacitor 308 to preserve the generated power. The generator is in the form of a synchronous generator as shown in FIG. When the magnetic flux crossing the conductor changes, a constant electromotive force is generated in the conductor 408 by the electromagnetic induction action. The generator uses Faraday's left-hand law, which induces continuous voltage generation in the coils 401, 402, and 403 by rotational motion. The generator is a rotating magnet type that generates a magnetic force by fixing a magnet that is a source of magnetic force and rotating the coils 401, 402, and 403, and a rotating system that generates a magnetic force by fixing the coil and rotating the magnet therein. There are two types. In the present invention, a rotor-less alternator is applied in order to ensure long life with a brush-free structure.

   As shown in FIG. 4 (a), when three sets of coils A-A ', B-B' and CC 'are disposed on the inner surface of the cylindrical iron core at 120 ° intervals and the magnets are rotated therein, the coils 401, 402 and 403 are respectively Single-phase AC voltages of the same shape are generated. However, the B coil 402 has a voltage change 120 ° later than the A coil. In this way, an AC waveform generated in the coils 401, 402, and 403 of the three sets of A, B, and C is generated, which is referred to as three-phase alternating current. The principle of a generator according to Faraday's law of induction is that the magnetic flux Φ across a given surface in magnetic field B is given by equation (2).

(2)

(2)

Where Φ is the magnetic flux (Weber, Weber), B is the magnetic field (T, Tesla) 1T = 1N / A.m, and A is the area (m2) through which the magnetic field passes. In addition, the induced electromotive force when the coil wound N times has a change in the magnetic field of d Φ during dt is as follows.

(3)

(3)

Where ε is the induced electromotive force (V, volts), d Φ is the change in Φ (Weber, Weber), and dt is the time (s).

  Rotating field type is mainly used for alternator, and on the fixed side, several slots are made in the iron core, and the conductor is put in the slot. When the magnetic pole rotates, attention is paid to the conductor a in the figure. Each time the magnetic pole N · S 403 passes, the change in the positive and negative directions of alternating current is completed once. That is, when the magnetic pole rotates at a speed of once every second, the frequency of the electromotive force obtained in the conductor is 1 Hz. However, increasing the number of poles in the rotor increases the change in electromotive force with each revolution. It has become popular to accommodate both field windings, rectifiers, and three-phase power supplies for rectifiers on the rotor side. This is called a brushless alternator, that is, a brushless alternator. Since there is no slip ring or a brush, the brush does not need to be worn or replaced, so it is easy to repair.

  In general, the frequency of the alternating current obtained when the rotor having the pole number P is rotated N every second has a relationship of f = PN / 2. Since rectification and power conversion of the alternating current in the present invention is less affected by the frequency. There is a value requested from the prime mover for the rotational speed of the generator. When applying a generator by aberration, it is better to set it at a low speed.

Power generated from the generator 201 is rectified through the diode rectifier 302. Three-phase power is produced with 120 ° phase difference, and the generated power is rectified by six six-phase full-wave rectifier circuits, and one of the upper diode and the lower diode is turned on and current flows. The diode of the phase with the largest magnitude of the voltage in the phase power is turned on and the remaining two diodes 305 and 307 are reverse biased to remain off. In the lower portion, the diode 305 of the phase having the largest magnitude in the negative direction among the three-phase power supplies is turned on. In each three-phase full-wave rectifier circuit, each phase's phase voltage,, is the same as

(4)

(4)

(5)

(5)

(6)

(6)

That is, it consists of a 6-pulse rectifier. The average value of the output voltage is the average value for any of the six line voltages and the average value for the current is as shown in equations (7) and (8).

(7)

(7)

(8)

(8)

Considering the waveform rate and the winding structure, the equation is converted into Equation (9).

(9)

(9)

Where Kw is the winding factor (constant related to the layout of the windings taking into account distribution and breakage coefficients), and w is the winding number of the winding inserted in one slot.

The capacity is determined by the size of the generator, as shown in Eq. (10).

(10)

10

Here, the meaning of each variable is K is a proportional constant according to the shape and characteristics of the generator, D is the rotor outer diameter of the generator or the inner diameter of the stator [m], L is the effective length [m] of the generator winding 413, N is RPM Means. Figure 4 (c) shows a longitudinal section of the generator according to the invention. The winding is wound on each stator, and the generated power is three phase power, with each phase having a phase difference of 120 degrees.

  The rectified power is stored in the supercapacitor bank 308 through the DC-DC converter. In order to store and utilize energy in the supercapacitor 311 while supplying the power necessary for the UV-LED 311 to operate, a constant DC voltage is required. Therefore, the power is passed through the power conversion process to obtain the voltage of the required condition through the DC-DC converter. DC-DC converters use step-down converters. The rectified power maintains constant voltage through the DC-DC converter. The step-down converter uses the power MOSFET 303, which is a semiconductor switch, as a switch and a diode 305 in place of the contacts a and c. At this time, the energy of the input power is transferred to the output side through the on-off control of the power MOSFET 303, and the diode 305 is configured to allow the inductor current to flow during the period in which the power MOSFET 303 is switched off. . The inductor current rises linearly during the DT period when the power MOSFET 303 switch is turned on. In addition, diode D 305 remains on during the (1-D) T period when the MOSFET 303 is switched off so that the inductor current falls linearly. In the steady state, the output voltage of the step-down converter is transmitted to the inductor L 306 through the switch during the DT section in which the input energy is switched on. The current of the switch is the inductor current during the DT period, which charges the supercapacitor 311. PWM controller for this purpose is to maintain the constant voltage characteristics by using the micro-controller (304).

  Supercapacitor 311 is another name for an electric double layer electrolytic capacitor (EDLC), and has the same electrical characteristics as a capacitor, but its capacitance is 300 times more than that of a conventional capacitor, and thus used as an energy storage device that can replace or supplement a battery. do. The supercapacitor 311 can store less energy than the battery, but its ability to supply instantaneous peak power for a very short time is 10 to 100 times greater than the battery. Thus, it has the ability to store energy for a few seconds or hours and to supply energy when a large amount of power is needed. These supercapacitors have an energy efficiency of 5 to 10 Wh / Kg, more than 500,000 charge and discharge cycles, and 85 to 90% charge and discharge efficiency. By applying the supercapacitor, it is possible to secure the reliability and quality of the power supply and to compensate for the voltage drop. The stored energy is supplied to the UV-LED 311 through the current controller 301 that can supply the current directly to the UV-LED (311). Various topologies have been proposed, and in the present invention, a commercial current controller 310 which is a constant current device is used.

  For the LED to be on and operating normally, the supply voltage and current in the forward voltage range must be supplied. Larger currents or voltages lose their semiconductor properties and have an absolute effect on their lifetimes.

  UV-LED 202 is turned on to sterilize the water flowing through the tube 206 of silicon material for several seconds while the germicidal line is emitted, so that the light-receiving portion of the UV-LED 202 can be evenly spread. A reflector 204 of conical structure is applied. Since LEDs have narrow light distribution characteristics, it is necessary to expand the inherent light distribution characteristics of LEDs by receiving them and distributing them evenly or by utilizing diffusion lenses. Due to the light distribution characteristic of the LED, it has a light distribution of about 90 ° and reduces the light efficiency by 10 to 15% when the reflecting glove or the diffusion lens is attached. Therefore, the reflector plate 204 made of aluminum electropolishing material having high light reflectivity is attached evenly and as uniformly as possible. The structure reflects the ultraviolet rays so that the sterilized water can be discharged through the discharge port 205. That is, the conical reflector 204 of the light receiving unit has a structure that diffuses the incident ultraviolet rays evenly to the inside of the sterilization chamber 212 as much as possible so that the sterilization target can be transmitted to improve the sterilization power. In addition, in the present invention, the monitoring window 207 using the UV blocking filter is installed in the sterilization apparatus so that the operating state of the UV-L: ED 212 can be monitored so that the operating state during sterilization can be checked. .

Existing water disinfection device requires a separate power source, and the structure is sterilized in the state of restricting the flow of water by flooding the UV-LED. However, the present invention is devised for a water purifier using LED ultraviolet light having a high sterilizing effect. In particular, it can be freely used outdoors, such as in a weak water bath or a field, because it does not require power connection.It is attached to the faucet of public facilities, schools, parks, etc. to protect drinking water from water pollution by using it as a water filter. do.

1 is a spectrum analysis diagram for each light source

2 is a system structural diagram according to the invention

3 is a circuit diagram according to the invention

4 (a) is a conceptual diagram of a generator according to the invention

Figure 4 (b) is a side view of the generator according to the invention

Figure 4 (c) is a longitudinal section of the generator according to the invention

5 is a comparison of characteristics of UV sterilization method and other sterilization method

Claims (6)

Water purification sterilizer using one or several UV-LEDs with independent power type with self-generator that does not need commercial power or battery power by utilizing LEDs with low power consumption UV sterilizer for water purification using UV sterilization method through UV ray indirect irradiation or UV-LED immersion method to apply UV-LED sterilization line Water purification sterilizer with a structure to increase the UV sterilization effect by delaying the flow of water through the pipeline of silicone material made of annular structure The aluminum plate processed by electrolytic polishing is used as a reflecting plate to reflect ultraviolet rays to enhance sterilization effect, and the stainless steel processed by electrolytic polishing method is used to surround the inside. Sterilizers with torso structure designed for contact It converts power generated by small power generator into electric power and converts it to a certain voltage to save power in supercapacitor (EDLC) to prevent self-pollution of sterilizer and to increase sterilization effect by sterilizing water staying in the device. Electrical and Electronic Circuits of Sterilizers with Applied Supercapacitors (EDLC) In order to improve the light distribution characteristic of UV-LED, the reflector with conical structure is attached on the opposite side to reach the ultraviolet rays and at the same time, it reflects the ultraviolet rays evenly toward the wall by the difference of angle of the cone. Device

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