This invention relates to an electrostatically atomizing device being configured to generate a mist of the charged minute water particles by an electrostatically atomization.
Japanese patent application publication No. 2007-21370A discloses a prior art electrostatically atomizing device. The electrostatically atomizing device is configured to generate the mist of the charged minute water particles. The prior art electrostatically atomizing device comprises an emitter electrode, an opposed electrode, a water supply means, a controller, and a high voltage source. The opposed electrode is disposed in an opposed relation to the emitter electrode. The high voltage source is configured to apply voltage between the emitter electrode and the opposed electrode. The water supply means is configured to supply water to the emitter electrode.
After energization of the electrostatically atomizing device, the controller starts the high voltage source to apply the high voltage to the emitter electrode. Consequently, a high voltage electric field is generated between the emitter electrode and the opposed electrode. The water is supplied onto the emitter electrode from the water supply means. The water on the emitter electrode is charged by the high voltage electric field. Therefore, a charged water receives Coulomb force. The charged water is pulled toward the opposed electrode by the Coulomb force so that the charged water is formed into a cone shape. A cone shaped water on the emitter electrode is so-called Taylor cone. When the Taylor cone is formed, the Taylor cone is subjected to the high voltage electric field, thereby having its tip which is highly electrically charged. That is, the Taylor cone has at its tip with a high energy. When the high energy exceeds surface tension of the water, breakup is caused at the tip of the Taylor cone. The breakup is so-called Rayleigh breakup. By the Rayleigh breakup, the charged minute water particles are generated from the tip of the Taylor cone. This generation is so-called electrostatically atomization. In this way, the mist of the charged minute water particles is generated from the tip of the Taylor cone.
However, the prior art electrostatically atomizing device takes time to generate the mist of the charged minute water particles. That is, it is impossible for the electrostatically atomizing device to immediately generate the mist of the charged minute water particles after initiation of a device operation.
The invention is achieved to solve the above mentioned problem. The object of the invention is to provide an electrostatically atomizing device which is configured to generate the mist of the charged minute water particles at short times from the start of the device.
The electrostatically atomizing device in accordance with the present invention comprises an emitter electrode, a water supply means, a high voltage source, and an atomization detecting means. The water supply means is configured to supply water to the emitter electrode. The high voltage source is configured to apply a high voltage to the emitter electrode so as to electrostatically atomize the water on the emitter electrode. The atomization detecting means is configured to detect a condition where the water is electrostatically atomized from the emitter electrode. The feature of the invention resides in that the electrostatically atomizing device further comprises a controller. The controller is configured to control the high voltage source to provide selectively a starting voltage and an operating voltage. The starting voltage is configured to be higher than the operating voltage. The controller is configured to select the operating voltage upon recognition of the condition.
With this configuration, the controller controls the high voltage source to apply the starting voltage when the water on the emitter electrode is not electrostatically atomized. Therefore, it is possible to obtain the electrostatically atomizing device which is configured to generate the mist of the charged minute water particles, immediately. In addition, the controller controls the high voltage source to apply the operating voltage after the atomization detecting means detect the condition where the water is electrostatically atomized from the emitter electrode. Therefore, it is possible to obtain the electrostatically atomizing device which is configured to generate the mist of the charged minute water particles, stably.
It is preferred that the atomization detecting means comprises a discharge current detecting circuit. The discharge current detecting circuit is configured to detect a discharge current flowing from the emitter electrode. The controller is configured to recognize the condition based upon the discharge current.
It is preferred that the electrostatically atomizing device further comprises an opposed electrode. The opposed electrode is disposed in an opposed relation to the emitter electrode. The discharge current detecting circuit is connected to the opposed electrode. The discharge current detecting circuit is configured to detect the discharge current flowing from the emitter electrode to the opposed electrode.
With this configuration, the discharge current detecting circuit is surely capable of detecting the condition. Therefore, it is possible to detect the start of the electrostatically atomization of the water.
It is also preferred that the atomization detecting means comprises a discharge current detecting circuit. The discharge current detecting circuit is configured to detect a discharge current flowing from the high voltage source to the emitter electrode. The controller recognizes the condition based upon the discharge current.
With this configuration, the discharge current detecting circuit is surely capable of detecting the condition. Therefore, it is also possible to detect the start of the electrostatically atomization of the water.
It is preferred that the electrostatically atomizing device further comprises a voltage detecting circuit. The voltage detecting circuit is configured to detect an applied voltage applied to the emitter electrode. The controller controls the high voltage source to keep the applied voltage respectively at the starting voltage and the operating voltage.
In this case, the controller controls the high voltage source to provide the starting voltage and the operating voltage even the applied voltage is differ from the starting voltage and the operating voltage. Therefore, it is possible for the high voltage source to surely apply the starting voltage and the operating voltage even when the applied voltage is differ from the starting voltage and the operating voltage.
It is preferred that the electrostatically atomizing device further comprises an abnormal voltage detecting means. The abnormal voltage detecting means is configured to determine an upper limit and a lower limit of the voltages applied to the emitter electrode. The voltage detecting circuit is configured to detect a voltage value of said applied voltage. The controller is configured to limit when the voltage value becomes higher than the upper limit or becomes lower than the lower limit.
In this case, the applied voltage applied to the emitter electrode is higher than the starting voltage and the operating voltage, and is lower than the upper limit, the abnormal voltage detecting means controls the high voltage source to apply the starting voltage and the operating voltage to the emitter electrode continuously. On the other hand, the applied voltage is higher than the upper limit of the voltage, the abnormal voltage detecting means controls the high voltage source to stop applying the voltage to the emitter electrode. Similarly, the applied voltage is lower than the starting voltage and the operating voltage, and is higher than the lower limit, the abnormal voltage detecting means controls the high voltage source to apply the starting voltage and the operating voltage to the emitter electrode continuously. On the other hand, the applied voltage is lower than the lower limit of the voltage, the abnormal voltage detecting means controls the high voltage source to stop applying the voltage to the emitter electrode. Therefore, even when the high voltage source fails and applies an overhigh voltage to the emitter electrode, the high voltage source is configured to be stopped by the abnormal voltage detecting means.
It is preferred that the electrostatically atomizing device further comprises a protection circuit. The protection circuit is configured to decrease the starting voltage and the operating voltage applied to the emitter electrode when the discharge current becomes higher than a predetermined current.
In this case, even the controller fails and does not control the high voltage source, the voltage applied to the emitter electrode is decreased by the protection circuit. Therefore, it is possible to obtain the electrostatically atomizing device having a high voltage source which is configured to stop applying the high voltage to the emitter electrode when the controller fails.
These and other features and advantages of the present invention will become more apparent from the following best mode for carrying out the present invention and embodiments.
Now reference with drawings is made to explain an electrostatically atomizing device in this invention.
The atomizing barrel 230 has tube shape. The atomizing barrel 230 incorporates the emitter electrode 210, the opposed electrode 220, and the Peltier module 240. The atomizing barrel 230 is formed at its circumference wall with apertures 231. The apertures 231 are configured to pass the air from an outside of the atomizing barrel 230.
The emitter electrode 210 has pole shape. The emitter electrode 210 is formed to have an axis. The emitter electrode 210 is disposed at an inside of the atomizing barrel 230. The emitter electrode 210 is disposed to have the axis aligned to an axial direction of the atomizing barrel 230. The emitter electrode 210 is formed at its tip with an emitter end 211 and its rear end with a flange 212.
The opposed electrode 220 is formed to have ring shape with a circular window 221. The opposed electrode 220 is held at a tip of the atomizing barrel 230. Therefore, the opposed electrode 220 is disposed in an opposed relation to the emitter electrode 210. The opposed electrode 220 is formed with the circular window 221 which is configured to flow the air from the inside of the atomizing barrel 230 to the outside of the atomizing barrel 230. In addition, the opposed electrode 220 is not limited to be formed into the ring shape with circular window 221. Furthermore, the opposed electrode is not limited to be held at the tip of the atomizing barrel 230.
The emitter electrode 210 is configured to be energized by the high voltage source 400. Therefore, the high voltage source is configured to apply a high voltage between the emitter electrode 210 and the opposed electrode 220 so as to generate the high voltage electric field between the emitter electrode 210 and the opposed electrode. The high voltage source 400 includes a transformer to apply a predetermined voltage between the emitter electrode 210 and the opposed electrode 220. The high voltage source 400 is configured to apply a negative voltage to the emitter electrode 210. In this embodiment, the high voltage source 400 is configured to apply a negative voltage of −4.8 kV to −5.0 kV. However, the negative voltage is not limited to −4.8 kV to −5.0 kV. On the other hand, the opposed electrode 220 is grounded.
The Peltier module 240 includes a pair of electrically conductive circuit plate 241, 242, and a plurality of thermoelectric conversion elements 243. The conductive circuit plate 241, 242 is made of an electrical insulation material such as alumina and aluminum nitride. The thermoelectric conversion elements 243 are made of a thermoelectric conversion material such as Bi—Te based. A plurality of the thermoelectric conversion elements 243 are arranged in parallel between the electrically conductive circuit plate 241 and the electrically conductive circuit 242. The conductive circuit plate 241 and 242 is configured to be energized from a power source 700 which is shown in
The electrostatically atomizing device 100 generates the mist of the charged minute water particles as follows. The Peltier module 240 is energized by the power source 700 so that the voltage is applied to the thermoelectric conversion elements 243. Then the thermoelectric conversion elements 243 transfer heat from the conductive circuit plate 241 to the conductive circuit plate 242. Consequently, the thermoelectric conversion element 243 cools the conductive circuit plate 241. When the conductive circuit plate 241 is cooled, the cooling plate 501 which is thermally coupled to the conductive circuit plate 241 is cooled. The cooling plate 501 is thermally coupled to the flange 212 of the emitter electrode 210. Therefore, the emitter electrode 210 is cooled by the cooling plate 501. That is, the Peltier module 240 cools the emitter electrode 210 which are thermally coupled by the cooling plate 501. So, a cooled emitter electrode 210 condenses vapor within surrounding the air into the water on the surface of the emitter electrode 210. That is, the Peltier module is configured to cool the emitter electrode 210 to condense the water to the emitter electrode, thereby supplying the water to the emitter electrode 210. Therefore, the Peltier module functions as the water supply means. In this way, the water is supplied to the emitter electrode 210, thereby being supplied to the emitter end 211. In addition, it is also possible that the emitter electrode 210 is formed to have a porous structure. In this case, the water supplied to the emitter electrode is move to the emitter end 211 by capillary action.
The high voltage source 400 is configured to apply the high voltage between the emitter electrode 210 and the opposed electrode. Therefore, the high voltage source 400 generates the high voltage electrical field between the emitter electrode 210 and the opposed electrode 220. The high voltage electrical field pulls the water which is held on the emitter end 211 toward the opposed electrode 220. In this way, the electrical field forms a small Taylor cone at the water held on the emitter electrode 210. In addition, the electrical field forms a small concentration of the electrical charge at the tip of the Taylor cone. As a result, a small discharge current flows from high voltage source through the emitter electrode 210 to the opposed electrode 220. Subsequently, the middle electrical field is caused between the tip of the small charged Taylor cone and the opposed electrode 220. In this situation, the electrical field forms a medium Taylor cone at the water held on the emitter electrode 210. In addition, the electrical field forms a medium concentration of the electrical charge at the tip of the Taylor cone. As a result, a medium electrostatically atomization is caused with a medium discharge current which flows from the high voltage source through the emitter electrode 210 to the opposed electrode 220. And the medium Taylor cone is pulled toward the opposed electrode 220 by a medium Coulomb force. Then, a high voltage electrical field is caused between the tip of the medium charged Taylor cone and the opposed electrode 220. Consequently, the high voltage electrical field forms a large Taylor cone at the water held on the emitter electrode 210. In addition, the electrical field forms a large concentration of the electrical charge at the tip of the Taylor cone. As a result, a large electrostatically atomization is caused with a large discharge current which flows from the high voltage source through the emitter electrode 210 to the opposed electrode 220. Then, the high voltage electrical field causes a high Coulomb force to the tip of the Taylor cone. Subsequently, breakups are caused at the tip of the Taylor cone. The breakup is so-called Rayleigh Breakup. And finally, according to the Rayleigh breakups which are caused at the tip of the Taylor cone, the mist of the charged minute water particles of nanometer sizes is generated from the Taylor cone of the water which is held on the emitter end 211. The mist of the charged minute water particles of nanometer sizes is negatively charged by the emitter electrode 210 applied with the negative voltage. The mist of the charged minute water particles of nanometer sizes is carried by an ion wind which flows from the emitter electrode 210 to the opposed electrode 220. Then, the mist of the charged minute water particles of nanometer sizes is discharged through the circular window 221 of the opposed electrode 220 and flows along the direction of arrows which are shown in the
Reverting to
The discharge current detecting circuit 500 is provided for detecting the discharge current which flows from the emitter electrode 210 to the opposed electrode 220. The discharge current detecting circuit 500 is defined as an atomization detecting means. The discharge current detecting circuit 500 is connected to the opposed electrode 220 for detecting the discharge current, thereby detecting the discharge current from the emitter electrode 210 to the opposed electrode 220. As above mentioned, the discharge current flows when the electrostatically atomization is caused at the water on the emitter electrode 210. That is, the discharge current detecting circuit 500 is configured to detect a condition where the water is electrostatically atomized from the emitter electrode 210 on the basis of the discharge current which flows from the emitter electrode 210 to the opposed electrode 220. The discharge current detecting circuit 500 is connected to the high voltage source 400 through a diode for sending a current value of the discharge current as a signal. The discharge current detecting circuit 500 is connected to the controller 300 for sending a signal 920 of the current value of the discharge current.
The voltage detecting circuit 600 is configured to detect a voltage value. The voltage detecting circuit 600 is connected to the high voltage source 400, thereby detecting the voltage value of an applied voltage applied to the emitter electrode 210. The voltage detecting circuit 600 is connected to the controller 300 for sending an applied voltage value as a signal 930 shown in
The controller 300 is configured to send a signal 900 to the high voltage source 400 for starting and stopping the high voltage source 400. The controller 300 is configured to control a power on of the high voltage source 400 after energization of the electrostatically atomizing device 100 by the signal 900. The controller 300 is configured to send a discharge voltage adjusting signal 910 to the high voltage source 400 for adjusting the high voltage applied to the emitter electrode 210. Therefore, the controller 300 is configured to control the high voltage source 400 to provide selectively the starting voltage and the operating voltage. The controller 300 is configured to select the operating voltage on the basis of the condition where the water is electrostatically atomized from the emitter electrode 210. In particular, the controller 300 controls the high voltage source 400 to apply the starting voltage to the emitter electrode 210 upon energization of the electrostatically atomizing device 100. Furthermore, the controller 300 controls the high voltage source 400 to apply the operating voltage to the emitter electrode 210 upon recognition of the condition where the water is electrostatically atomized from the emitter electrode 210.
Next, operation of the electrostatically atomizing device 100 is explained with
After elapse of a certain amount of time, the water on the tip of the emitter end 211 is electrically atomized by the starting voltage which is applied continuously. Then, the discharge current is generated between the emitter electrode 210 and the opposed electrode 220. The discharge current increases with enlargement of the Taylor cone. The discharge current detecting circuit is not configured to detect the small discharge current, and is configured to detect the medium discharge current and the large discharge current. When the discharge current becomes higher than the medium discharge current, the discharge current detecting circuit 500 detects the discharge current. The condition where the water is electrostatically atomized is shown by an arrow with reference numeral of 820 in
Furthermore, the electrostatically atomizing device 100 comprises the voltage detecting circuit 600. The voltage detecting circuit 600 is configured to detect the applied voltage applied to the emitter electrode 210. On the basis of the applied voltage, the controller 300 controls the high voltage source 400 to keep the applied voltage respectively at the starting voltage and the operating voltage. In other words, the controller 300 controls the high voltage source 400 to adjust the applied voltage to the starting voltage and the operating voltage. Therefore, it is possible to obtain the electrostatically atomizing device 100 which includes the high voltage source 400 being configured to surely apply the starting voltage and the operating voltage to the emitter electrode 210.
The controller 300 is configured to stop or continuously drive the high voltage source 400 on the basis of the relation of the upper limit, the lower limit, the upper level voltage, and the lower level voltage to the applied voltage which is detected by the voltage detecting circuit 600. In particularly, the controller 300 is configured to continuously drive the high voltage source 400 when the applied voltage is between the upper level voltage and the upper limit. In this case, the controller controls the high voltage source for adjusting the applied voltage to the starting voltage or the operating voltage. The controller is configured to continuously drive the high voltage source when the applied voltage is between the lower level voltage and the lower limit. In this case, the controller 300 controls the high voltage source for adjusting the applied voltage to the starting voltage or the operating voltage. On the other hand, the controller is configured to limit the high voltage source when the applied voltage is higher than the upper limit. Consequently, the high voltage source 400 is configured to never apply an overhigh voltage to the emitter electrode 210. Similarly, the controller is configured to limit the high voltage source when the applied voltage is lower than the lower limit. Therefore, with this configuration, it is possible to obtain a safe electrostatically atomizing device 100.
The protection circuit 410 is configured to control the high voltage source 400 to decrease the applied voltage which is applied to the emitter electrode 210 on the basis of the discharge current which is detected by the discharge current detecting circuit 500. In particularly, the protection circuit 410 is configured to control the high voltage source 400 to decrease the applied voltage when a current value of the discharge current is higher than a predetermined current.
The discharge current detecting circuit 500 is configured to detect the discharge current, and subsequently is configured to send the current value of the discharge current to the protection circuit 410 of the high voltage source 400. The protection circuit 410 is configured to compare the current value of the discharge current to the predetermined current. The protection circuit 410 is configured to stop the high voltage source 400 when the current value of the discharge current is higher than the predetermined value. The protection circuit 410 is configured to drive the high voltage source 400 continuously when the current value of the discharge current is lower than the predetermined value. That is, the protection circuit 410 is configured to control the high voltage source 400 on the basis of the current value of the discharge current.
Therefore, the high voltage source 400 with the protection circuit 410 is configured to never apply the overhigh voltage to the emitter electrode 210. Consequently, the high voltage source 400 is configured to never apply the overhigh voltage to the emitter electrode 210 even the controller 300 or the voltage detecting circuit 600 fails.
As shown in
The high voltage source 400 is configured to apply the high voltage between the emitter electrode 210 and substances which has electrical potential lower than the emitter electrode 210. Therefore, the water on the emitter electrode 210 is electrostatically atomized from the emitter electrode 210. When the water is electrostatically atomized, the discharge current flows from the high voltage source 500B through the emitter electrode 210 to an outside of the atomizing unit 200B. Therefore, the discharge current which flows from the high voltage source 400 to the emitter electrode 210 is detected by the discharge current detecting circuit 500B so that the discharge current detecting circuit 500B generates the signal 920. The signal 920 is send to the controller 300 from the discharge current detecting circuit 500B. Consequently, the controller 300 recognizes the condition on the basis of the signal 920 and controls the high voltage source 400 to apply the operating voltage to the emitter electrode 210.
It is noted that the electrostatically atomizing device 100 in this invention comprises the Peltier module as the water supply means. However, it is preferred that the electrostatically atomizing device comprises a water supply tank instead of the Peltier module 240. In this case, the electrostatically atomizing device further has a water supply path which is configured to supply the water from the water supply tank to the emitter electrode. It is preferred that the water supply path is formed to have a porous structure and is configured to supply water by capillary action. Furthermore, it is possible to change design of the electrostatically atomizing device 400. As one sample, it is possible to use an electrostatically atomizing device without having the opposed electrode. In this case, a housing which incorporates the electrostatically atomizing device acts as the opposed electrode. An energized emitter electrode has a high potential. On the other hand, the housing is not energized by the high voltage source. Therefore, there is a difference in electrical potentials between the emitter electrode 400 and the housing. As a result, the mist of the charged minute water particles is generated from the water on the emitter electrode 400.
Although the present invention is described with particular reference to the above illustrated embodiments, the present invention should not be limited thereto, and should be interpreted to encompass any combinations of the individual features of the embodiments.
Number | Date | Country | Kind |
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2007-306623 | Nov 2007 | JP | national |