SG194319A1 - Electrostatic precipitator - Google Patents
Electrostatic precipitator Download PDFInfo
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- SG194319A1 SG194319A1 SG2013030952A SG2013030952A SG194319A1 SG 194319 A1 SG194319 A1 SG 194319A1 SG 2013030952 A SG2013030952 A SG 2013030952A SG 2013030952 A SG2013030952 A SG 2013030952A SG 194319 A1 SG194319 A1 SG 194319A1
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- particle collection
- voltage
- power supply
- collection unit
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- 239000012717 electrostatic precipitator Substances 0.000 title claims description 56
- 239000002245 particle Substances 0.000 claims description 195
- 230000002547 anomalous effect Effects 0.000 claims description 74
- 238000000034 method Methods 0.000 description 22
- 230000005684 electric field Effects 0.000 description 10
- 235000019504 cigarettes Nutrition 0.000 description 9
- 238000012423 maintenance Methods 0.000 description 9
- 230000002349 favourable effect Effects 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000011109 contamination Methods 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 206010000369 Accident Diseases 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
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- Electrostatic Separation (AREA)
Description
Specification
Electrostatic Precipitator [ Technical Field]
[0001]
The present invention relates to a system for controlling a power supply associated with an electrostatic precipitator which comprises an ionization unit and a particle collection unit, and more particularly, to a system for controlling a power supply associated with an electrostatic precipitator for feeding an ionization unit with a constant current and applying a particle collection unit with a predetermined voltage to allow the electrostatic precipitator to automatically recover and perform normal particle collecting actions after the particle collection unit suffers from an anomalous discharge such as sparking. [ Description of Background Art]
[0002]
As shown in Fig. 9, an electrostatic precipitator comprises an ionization unit 52, a particle collection unit 55, and a power supply 56 for supplying electric power to the ionization unit 55and particle collection unit 55. The ionization unit 52 includes ionization lines 50 and ionization electrodes 51 for charging floating particles in the air through a corona discharge or the like. The particle collection unit 55 comprises particle collection electrode plates 53 and opposing particle collection electrode plates 54 which are alternately arranged at equal intervals by spacers. Then, this electrostatic precipitator is used to maintain a favorable environment by charging floating particles in the air in the ionization unit 52, and collecting charged floating particles in the particle collection unit 55 to remove the floating particles in the air. However, this electrostatic precipitator may encounter difficulties in producing a corona discharge with stability in the ionization unit 52 due to high humidity in the air and/or to continuous collection of particles. This can lead to an anomalous discharge such as sparking, which involves sparks fiercely thrown in the particle collection unit 55, possibly resulting in a lower particle collection efficiency for collecting floating particles in the air, and also resulting in the cause of fire accident when collected floating particles are inflammable.
[0003]
In the past, the ionization unit 52 and particle collection unit 55 are powered from the power supply 56 by several methods which are roughly classified into a constant-voltage method and a constant-current method. The constant-voltage method involves applying a constant voltage to the ionization unit 52 and particle collection unit 55, while the constant- current method involves applying a constant current to the ionization unit 52 but applies a constant voltage to the particle collection unit 35. These power supply methods are implemented by a control unit 57.
[0004]
An electrostatic precipitator which employs the conventional constant-voltage method may suffer from contamination and/or oxidization on the surface of the ionization lines 50 of the ionization unit 50 due to floating particles, as the electrostatic precipitator continues the particle collection. Consequently, a lower current value may be generated by the initially set constant voltage, causing a corona discharge to occur with more difficulties, with the result that the particle collection efficiency is lowered. Moreover, an anomalous discharge such as sparking can be caused by the floating particles collected by and deposited on the particle collection electrode plates 53 and opposing particle collection electrode plates 54 of the particle collection unit 55. Once an anomalous discharge such as sparking occurs, the anomalous discharge such as sparking will continue unless the application of a high predetermined voltage is stopped from the power supply 56 to the particle collection electrode plates 53 and opposing particle collection electrode plates 54. In the worst case, a fire accident could occur. As such, the power supply 56 is prohibited from applying the constant voltage, but as long as the cause of the anomalous discharge is not eliminated, the anomalous discharge such as sparking would immediately follow if the power supply 56 started applying the constant voltage. Thus, the electrostatic precipitator remains missing a function of removing floating particles in the air to maintain a favorable environment, which is expected to the electrostatic precipitator, while the cause of the anomalous discharge is not eliminated.
[0005]
On the other hand, the conventional constant-current method is not affected by a corona discharge or the like or does not suffer from a lower particle collection efficiency, even if a continuous particle collection causes the surface of the ionization lines 50 to be contaminated or oxidized by floating particles, because a constant current is flowing through the ionization lines
50. However, since the particle collection unit 55 is likewise applied with a constant voltage in the constant-current method as well, the conventional constant-current method is similar to the constant-voltage method in that an anomalous discharge such as sparking can occur due to floating particles collected by and deposited on the particle collection electrode plates 53 and opposing particle collection electrode plates 54 of the particle collection unit 55.
[0006]
To address situations as described above, a power supply device has been provided for use with an electrostatic precipitator. This power supply device comprises power supply means for supplying power to electrodes; detecting means for detecting a voltage which is applied to the electrodes when they are being supplied with electric power from the power supply means or detecting an insulation resistance of the electrodes; and determining means for determining whether or not humidity is attributable to a reduced voltage or a reduced insulation resistance of the electrodes detected by the detecting means by supplying the electrodes with power lower than that supplied by the power supply means, specifically, 30 - 100% of the voltage applied by the power supply means and 1 - 30% of the current applied by the power supply means.
In this way, the power supply device determines whether or not a reduced voltage on the electrodes of an associated electrostatic precipitator should be regarded as a critical case caused by an anomalous discharge such as sparking or an immaterial accident caused by humidity or the like, which can be recovered without taking any action therefor. When a critical case is determined, the power supply means is instructed to stop supplying the power to the electrodes to prevent the electrostatic precipitator from damaging, and a maintenance is performed to remove the cause of the trouble. On the other hand, when an immaterial case is determined, the power supply means is allowed to continue the supply of the power to the electrodes, expecting a spontaneous recovery, so that the electrostatic precipitator can continue the function of removing floating particles in the air to maintain a favorable environment (for example, see JP-2008- 68207A). [ Summary of the Invention] [ Problems to be Solved by the Invention]
[0008]
The power supply device for an electrostatic precipitator according to the foregoing patent document is configured to determine whether a reduced voltage on the electrodes of the electrostatic precipitator is caused by a critical trouble or an immaterial trouble such as humidity and can be recovered without taking any actions. When the trouble is determined to be critical, the supply of the power is stopped and maintenance is performed. When the trouble is determined to be immaterial, the power is supplied to the electrostatic precipitator such that it continues the function of removing floating particles in the air to maintain a favorable environment. However, even when the determining means determines a critical case, an anomalous discharge such as sparking can be solved simply by slightly reducing the voltage when the power is supplied to the electrodes. Even in such a case, the power supply means is instructed to stop supplying the power to the electrodes, followed by the maintenance for removing the cause of the trouble. As such, the electrostatic precipitator remains inoperative until the maintenance is over to remove the cause. During this period of time, the electrostatic precipitator cannot only continue the function of removing floating particles in the air to maintain a favorable environment, but the maintenance is more frequently performed.
[0009]
The present invention has been made to address the situation described above, and it is an object of the invention to provide a system for controlling a power supply associated with an electrostatic precipitator, which can stably continue a corona discharge in an ionization unit, and can promptly resume the formation of a normal electric field, even if an anomalous discharge such as sparking occurs in a particle collection unit due to fluctuations in environment or the like, to continue a particle collection action to reduce the frequency of maintenance. [ Means for Solving the Problems)
[0010]
The present invention has been proposed to achieve the foregoing object, and is characterized by comprising the following configurations.
Specifically, the invention according to claim 1 is directed to a system for controlling a power supply associated with an electrostatic precipitator, where the electrostatic precipitator includes an ionization unit for charging floating particles in the air, a particle collection unit for collecting charged floating particles with a coulomb force, and a power supply for supplying electric power to the ionization unit and particle collection unit. The system includes a constant-current control unit for supplying the ionization unit with a constant current which does not cause a predetermined voltage to be exceeded, a sensing unit for applying the particle collection unit with the predetermined voltage and for sensing an anomalous discharge which introduces abrupt fluctuations in the applied voltage and current, a voltage step control unit for issuing a command to the particle collection unit based on anomalous discharge information from the sensing unit to change the predetermined voltage to a level at which no anomalous discharge will occur, and a voltage changing unit for changing the predetermined voltage in response to a voltage change command from the voltage step control unit. The system is characterized in that the power supply is controlled to send the constant current to the ionization unit through the constant-current control unit; the power supply is controlled to apply the particle collection unit with the predetermined voltage through the voltage step control unit; upon occurrence of an anomalous discharge, the voltage step control unit once shuts off the particle collection unit from the power supply; the voltage changing unit subsequently changes the predetermined voltage to a level at which no anomalous discharge will occur, where the changed predetermined voltage is applied to the particle collection unit; and the electrostatic precipitator is allowed to continue a particle collecting action even after the occurrence of the anomalous discharge.
[0011]
Also, the invention according to claim 2 is directed to a system for controlling a power supply associated with an electrostatic precipitator wherein the voltage step control unit outputs a PWM (pulse width modulation) signal having a predetermined value from a CPU (central processing unit) to an amplifier circuit, such that the particle collection unit is applied with the predetermined voltage commensurate with the PWM signal from the voltage changing unit.
[0012]
The invention according to claim 3 is directed to a system for controlling a power supply associated with an electrostatic precipitator according to claim 1, wherein the voltage changing unit includes n resistors (R1<R2...<Rn-1<Rn) arranged in parallel between the particle collection unit and the power supply. When the sensing unit senses an anomalous discharge while a resistor R1 is connected between the particle collection unit and the power supply, the voltage step control unit issues a command to the voltage changing unit to once shut off the particle collection unit from the power supply and subsequently switch the resistor R1 to a resistor R2 having a larger resistance value between the particle collection unit and the power supply, and the particle collection unit is applied with the predetermined voltage. The voltage step control unit subsequently switches (n-2) arranged resistors to resistors R3 - Rn having larger resistance values to change in steps the predetermined voltage, and applies the changed predetermined voltage to the particle collection unit,
[0013]
The first problem solving means performs following actions. Specifically, the ionization unit is applied with a constant current from the power supply through the constant- current control unit to cause a stable corona discharge or the like in the ionization unit to charge floating particles in the air which pass through the ionization unit, The particle collection unit is applied with a predetermined voltage from the power supply through the voltage step control unit to gencrate a stable electric field in the particle collection unit to trap charged floating particles passing therethrough. When the sensing unit senses during the trapping process that an anomalous discharge occurs in the particle collection unit, the particle collection unit is once shut off from the power supply. Subsequently, in response to anomalous discharge information, the voltage changing unit changes the predetermined voltage, and applies the changed predetermined voltage to the particle collection unit, thus eliminating the anomalous discharge and continuing a particle collecting action until a further anomalous discharge occurs. Afterwards, a sequence of the occurrence of the anomalous discharge, temporary shut-off of the power supply, changing of the predetermined voltage, elimination of the anomalous discharge, and continuation of particle collecting action is performed a allowed number of times.
[0014]
In actions by the second problem solving means described above, after the particle collection unit is once shut off from the power supply, the voltage step control unit, in response to the anomalous discharge information, outputs a PWM (pulse width modulation) signal having a predetermined value commensurate with the anomalous discharge information from the
CPU (central processing unit) to the amplifier circuit, to cause the voltage changing unit to apply the particle collection unit with the predetermined voltage commensurate with the PWM signal.
Subsequently, the PWM signal is changed to change in steps the predetermined voltage which is then applied to the particle collection unit such that the particle collecting action is continued even after the occurrence of the anomalous discharge.
[0015]
In actions by the third problem solving means described above, when the sensing unit senses an anomalous discharge while the resistor R1 is connected between the particle collection unit and the power supply, the particle collection unit is once shut off from the power supply, and thereafter, the resistor R1 is switched to a resistor R2 having a larger resistance value between the particle collection unit and the power supply. Then, the resulting predetermined voltage is applied to the particle collection unit, Subsequently, the (n-2) arranged resistors are subsequently switched to resistors R3 - Rn having larger resistance values, to change in steps the predetermined voltage which is applied to the particle collection unit, allowing the electrostatic precipitator to continue a particle collecting action even after the occurrence of the anomalous discharge. [ Effects of the Invention]
[0016]
As described above in detail, the present invention provides advantageous effects as follows.
The invention according to claim 1 can stably continue a corona discharge or the like in the ionization unit, can promptly resume the formation of a normal electric field to continue a particle collecting action even if an anomalous discharge such as sparking occurs, and can advantageously reduce the frequency of maintenance as a whole,
[0017]
In the invention according to claim 2, in addition to the effects described above, the voltage step control unit can freely output a PWM signal commensurate with anomalous discharge information in the CPU, so that the particle collection unit can be applied with a finer predetermined voltage. Advantageously, even if an anomalous discharge once occurs such as sparking, the formation of a normal electric field can be promptly resumed.
[0018]
Further, in the invention according to claim 3, in addition to the effects described above, the voltage step control unit is simply comprised of n resistors arranged in parallel between the particle collection unit and the power supply, and the sensing unit for sensing an anomalous discharge in the particle collection unit. Advantageously, in spite of a simple configuration, the electrostatic precipitator can advantageously resume the formation of a normal electric field promptly even if an anomalous discharge once occurs such as sparking. [ Brief Description of the Drawings]
[0019] [Fig. 1]
Fig. 1 is a conceptual diagram showing an embodiment of the present invention (first embodiment) in which a system for controlling a power supply associated with an electrostatic precipitator is employed in an electrostatic precipitator. [Fig. 2]
Fig. 2 is a block circuit diagram showing a voltage changing unit in the system for controlling a power supply associated with an electrostatic precipitator according to the embodiment of the present invention (first embodiment). [ Fig. 3]
Fig. 3 is a block circuit diagram showing another voltage changing unit in the system for controlling a power supply associated with an electrostatic precipitator according to the embodiment of the present invention (first embodiment). [ Fig. 4]
Fig. 4 is a characteristic graph representing the relationship between the number of smoked cigarettes and a particle collection efficiency when a constant-voltage method is employed for supplying power to an ionization unit. [Fig. 5]
Fig. 5 is a characteristic graph representing the relationship between the number of smoked cigarettes and a particle collection efficiency when a constant-current method is employed for supplying power to an ionization unit (first embodiment). [Fig. 6]
Fig. 6 shows the occurrence of an anomalous discharge which appears within the characteristic graph of the relationship between the number of smoked cigarettes and a particle collection efficiency when a constant-voltage method is employed for supplying power to the ionization unit and particle collection unit. [ Fig. 7]
Fig. 7 shows the occurrence of an anomalous discharge which appears within the characteristic graph of the relationship between the number of smoked cigarettes and a particle collection efficiency when a constant-current method is employed for supplying power to the ionization unit and particle collection unit. [Fig. 8]
Fig. 8 shows the occurrence of an anomalous discharge which appears within the characteristic graph of the relationship between the number of smoked cigarettes and a particle collection efficiency when the ionization unit and particle collection unit are supplied with power by the system for controlling a power supply associated with an electrostatic precipitator according to the embodiment of the present invention (first embodiment). [Fig. 9]
Fig. 9 is a conceptual diagram similar to Fig. 1 showing a conventional system for controlling a power supply associated with an electrostatic precipitator. [ Detailed Description of Preferred Embodiments]
[0021]
Referring to the drawings, a system 1 for controlling a power supply associated with an electrostatic precipitator (hereinafter simply called the "power supply control system") comprises an electrostatic precipitator 2. The electrostatic precipitator 2 comprises an ionization unit 3 for charging floating particles in the air; a particle collection unit 4 for collecting the charged particles by the action of coulomb force; and a power supply 5 for supplying electric power to the ionization unit 3 and particle collection unit 4. The power supply control system 1 comprises a constant-current control unit 6 for applying the ionization unit 3 with a constant current so as not to exceed a set voltage; and a sensing unit 7 for applying the particle collection unit 4 with a predetermined voltage and for sensing an anomalous discharge which can introduce abrupt fluctuations in the applied voltage or current value. The power supply control system 1 further comprises a voltage step control unit 8 for issuing a command, based on anomalous discharge information from the sensing unit 7, to change the predetermined voltage in steps until the particle collection unit 4 is free from the anomalous discharge; and a voltage changing unit 9 for changing the predetermined voltage in response to the voltage changing command from the voltage step control unit 8. The ionization unit 3 is applied with a constant current from the power supply 5 through the constant-current control unit 6, while the particle collection unit 4 is applied with a predetermined voltage from the power supply through the voltage step control unit 8. When the particle collection unit 4 suffers from an anomalous discharge, the particle collection unit 4 is once shut off from the power supply 5 by the voltage step control unit §,
Then, the particle collection unit 4 is applied with a predetermined voltage which has been changed by the voltage changing unit 9 to avoid the anomalous discharge, such that the electrostatic precipitator 2 can continue the particle collecting action even after the occurrence of the anomalous discharge.
[0022]
The electrostatic precipitator 2 is a so-called two-stage charging-type electrostatic precipitator, and comprises the ionization unit 3, particle collection unit 4, and power supply 5 associated with these units. The power supply control system 1 in turn is added to the electrostatic precipitator 2. Specifically, the power supply control system 1 comprises the constant-voltage control unit 6 interposed between the power supply 5 and the ionization unit 4, and also comprises the voltage step control unit 8 including the sensing unit 7 and the voltage changing unit 9 interposed between the power supply 5 and the particle collection unit 4.
[0023]
The ionization unit 3 of the electrostatic precipitator 2 comprises ionization lines and ionization electrodes 11 for charging floating particles in the air through a corona discharge or the like. The ionization lines 10 are connected to a plus (+) terminal 5a of the power supply 5, while the ionization electrodes 11 are connected to a minus (-) terminal 5b of the power supply 5, respectively.
[0024]
The particle collection unit 2 of the electrostatic precipitator 2 comprises particle collection electrode plates 12 and opposing particle collection electrode plates 13 for collecting charged floating particles with the coulomb force. The particle collection electrode plates 12 and opposing particle collection electrode plates 13 are alternately arranged at equal intervals by spacers, and are connected to the power supply 5 so that a high predetermined voltage is applied between the particle collection electrode plates 12 and opposing particle collection electrode plates 13 to form a high electric field therebetween. In addition, high resistors 14 are connected between the respective particle collection electrode plates 12 and the power supply 5.
Then, the particle collection electrode plates 12 are connected to the plus {+) terminal 5a of the power supply, while opposing particle collection electrode plates 13 are connected to the minus (-) terminal 5b.
[0025]
The power supply 5 supplies the ionization unit 3 and particle collection unit 4 of the electrostatic precipitator 2 with a necessary voltage and current, and is not particularly limited in any aspect as long as this condition is satisfied. In Fig. 1, a switch 15 is provided for switching on/off the connection between the power supply 5 and the ionization unit 3 and particle collection unit 4.
[0026]
The constant-current control unit 6 of the power supply control system 1 is configured to send a constant current from the power supply 5 to the ionization lines 10 of the ionization unit 3, for example, a constant current in a range of 0.3 to 2.0 mA. In this event, a proper voltage should be within a range of 7,000 V to 8,000 V. However, this constant-current control unit 6 comprises a known function for preventing the voltage from deviating significantly from the range of 700 V to 8,000 V, for example, preventing the voltage from reaching 10,000 V or more, in order to send a constant current in the range of 0.3 to 2.0 mA as described above.
[0027]
The voltage step control unit 8 of the power supply control system 1 is configured to issue a command for applying the particle collection electrode plates 12 of the particle collection unit 4 with a predetermined voltage, for example, in a range of 1,500 V to 4,500 V from the power supply 5. In this event, a current associated with this operation lies in a range of 0.05 to 0.1 mA. Further, the sensing unit 7 is configured to sense an anomalous discharge which would introduce abrupt fluctuations in the voltage and current applied to particle collection electrode plates 12 of the particle collection unit 4. For example, when a normal electric field is being formed with the particle collection unit 4 being applied with a voltage of 4,000 V and a current of 0.1 mA, the sensing unit 4 senses an anomalous discharge which would cause a sudden change in the environment of the particle collection unit 4 for some reason, giving rise to abrupt fluctuations in the voltage to a range of 2,500 to 3,000 V and in the current to 0.2 mA.
[0028]
Then, when the sensing unit 7 senses the anomalous discharge in the particle collection unit t4, the voltage step control unit 8 receives information indicative of the anomalous discharge. Upon receipt of the anomalous discharge information, the voltage step control unit 3 once shuts off the particle collection unit 4 from the power supply 5 through a switch. Then, putting an eye on the fact that the anomalous discharge can be avoided if the predetermined voltage applied to the particle collection unit 4 is reduced, the voltage step control unit 8 transmits a command to the veltage changing unit 9 to change the predetermined voltage to to such a level at which no anomalous discharge will occur. The voltage changing unit 9, upon receipt of the voltage changing command, reduces the predetermined voltage to a level at which no anomalous discharge will occur, for example, reduces the predetermined voltage by 200 V from 4,000 V, i.e., to 3,800 V. Subsequently, when the particle collection unit 4 again suffers from an anomalous discharge, the power supply control system 1 copes with the anomalous discharge by reducing the predetermined voltage in steps in the procedure described above.
[0029]
In regard to the change of the predetermined voltage by the voltage step control unit 8 and voltage changing unit 9, for example, as shown in Fig. 2, a CPU 20 of the voltage step control unit 8 which has received the anomalous discharge information compares the received anomalous discharge information with previously stored information, determines a predetermined voltage at a level which does not cause the particle collection unit 4 to anomalously discharge, and transmits the resulting voltage changing command to an amplifier circuit 21 in the form of
PWM (pulse width modulation) signal. Then, through the voliage changing unit 9 which is composed of the amplifier circuit 21 which has received the PWM signal, a booster transformer 22, and a booster circuit 23, the particle collection unit 4 is applied with a predetermined voltage commensurate with the PWM signal.
[0030]
Alternatively, the change of the predetermined voltage by the voltage step control unit § and voltage changing unit 9 may be implemented, for example, as shown in Fig. 3.
Specifically, a voltage step control unit 8A issues a command to a voltage changing unit 9A which has n resistors (R1<R2<...<Rn-1<Rn) arranged in parallel between the particle collection unit 4 and the power supply 5. Then, as the sensing unit 7 senses an anomalous discharge while the resistor R1 is connected between the particle collection unit 4 and the power supply 5, the particle collection unit 4 is once shut off from the power supply 5 through a switch. Next, the resistor R1 is switched to the resistor R2 having a larger resistance value between the particle collection unit 4 and the power supply 5, and thereafter, the particle collection unit 4 is applied with a predetermined voltage at a level at which no anomalous discharge will occur, allowing the particle collection unit 4 to recover the normal particle collection even after the anomalous discharge.
Subsequently, the particle collection unit 4 continues the normal particle collection as long as the anomalous discharge does not occur again. Afterwards, (n-2) resistors R arranged between the particle collection unit 4 and the power supply 5 are sequentially switched to resistors R3 - Rn having larger resistance values to change in steps the predetermined voltage which is then applied to the particle collection unit 4, thus allowing the particle collection unit 4 to continue the particle collecting action even after the anomalous discharge.
[0031]
It should be noted that n resistors R have resistance values within several MQ, and are in the relationship of R1<R2<.,.<Rn-1<Rn. While the resistors R are not particularly limited in number, three to five resistors may be a proper quantity.
[06032]
In the following, a detailed description will be given of the operation of the system 1 for controlling a power supply associated with an electrostatic precipitator which is configured as described above.
First, with the power supply 5 remaining ON, air including floating particles such as dust, smoke of cigarette, and the like enters into the ionization unit 3 of the electrostatic precipitator 2 from a direction indicated by an arrow K in Fig. 1. The floating particles in the air are charged through a corona discharge or the like which is present between the ionization lines and the ionization electrodes 11 in the ionization unit 3. Then, due to contamination on and/or oxidization of the surfaces of the ionization lines 10, and the like, associated with a continuous operation of the electrostatic precipitator 2, the corona discharge tends to stably occur with more difficulties unless a higher voltage is applied to the electrostatic precipitator than the initially applied voltage. However, the ionization lines 10 of the ionization unit 3 is applied with a constant current, for example, a constant current in a range of 0.3 to 2.0 mA from the power supply 5 through the constant-current control unit 6, so that even if the ionization lines 10 are contaminated, oxidized, or the like on the surface, the initially applied voltage can be effectively changed to a higher voltage, allowing the corona discharge to occur with stability. Accordingly, the ionization unit 3 is free from degradation in the ability to charge floating particles, and therefore free from degradation in particle collection efficiency due to such influences as contamination, oxidization, and the like on the surfaces of the ionization lines 10. Figs. 4 and 5 show characteristic graphs representing the relationship between the number of smoked cigarettes and the particle collection efficiency in accordance with a constant-voltage method which does not change an initially applied voltage sent to the ionization lines 10, and a constant-current method which sends a constant current to the ionization lines 10, respectively.
[0033]
Further, as the air including the charged floating particles enters into the particle collection unit 4, the charged floating particles are collected by a plurality of particle collection electrode plates 12 or opposing particle collection electrode plates 13 with the coulomb force by a high electric field which is generated by applying a predetermined voltage between a plurality of particle collection electrode plates 12 and a plurality of opposing particle collection electrode plates 13 of the particle collection unit 4. Then, clean air is emitted from the particle collection unit 4 after the particle collection. When an anomalous discharge such as sparking occurs due to a varying environment between a plurality of particle collection electrode plates 12 or opposing particle collection electrode plates 13, possibly caused by floating particles deposited thereon or the like, a high electric field cannot be maintained between a plurality of particle collection electrode plates 12 and a plurality of opposing particle collection electrode plates 13, or a predetermined veltage cannot even be applied to these plates. However, the voltage step control unit 8 and voltage changing unit 9 once stop the predetermined voltage applied from the power supply 5 to the plurality of particle collection electrode plates 12 of the particle collection unit 4, and subsequently change the predetermined voltage in steps to once eliminate the anomalous discharge, and then generate a high electric field again. Thus, even after the anomalous discharge occurs between a plurality of particle collection electrode plates 12 and a plurality of opposing particle collection electrode plates 13, the particle collecting action is continued, though the particle collection efficiency is slightly lowered, thus making it possible to extend a period between maintenances for washing the particle collection unit 4, and the like.
[0034]
Figs. 6 and 7 show the occurrence (indicated by a mark "X") of an anomalous discharge which appears within the characteristic graph of the relationship between the number of smoked cigarettes and a particle collection efficiency, in accordance with the constant-voltage method which does not change the initially applied voltage sent to the particle collection electrode plates 12, and the constant-current method which sends a constant current to the ionization lines 10. Fig. 8 in turn shows the occurrence (indicated by a mark "X") of an anomalous discharge which appears within the characteristic graph of the relationship between the number of smoked cigarettes and a particle collection efficiency in accordance with the step voltage method of the present invention which changes in steps the voltage applied to the particle collection electrode plates 12. A dotted line in Fig. 8 indicates the characteristic of a conventional method.
[0035]
While one embodiment of the present invention has been described above, it should be understood that the present invention is not limited to the particular configuration set forth above, but can be modified as appropriate without departing from the scope and spirit of the invention defined in claims. [ Industrial Availability]
[0036]
The system for controlling a power supply associated with an electrostatic precipitator of the present invention can stably continue a corona discharge or the like in an ionization unit, and can promptly resume normal discharging, even if an anomalous discharge such as sparking occurs, to continue a particle collecting action, thus improving a particle collection efficiency as a whole and extremely enhancing the availability of the electrostatic precipitator when one wishes to reduce the frequency of maintenance.
Claims (3)
- Claims[Claim 1] A system for controlling a power supply associated with an electrostatic precipitator, said electrostatic precipitator comprising an ionization unit for charging floating particles in the air, a particle collection unit for collecting charged floating particles with a coulomb force, and a power supply for supplying electric power to said ionization unit and said particle collection unit, said system comprising: a constant-current control unit for supplying said ionization unit with a constant current which does not cause a predetermined voltage to be exceeded; a sensing unit for applying said particle collection unit with the predetermined voltage and for sensing an anomalous discharge which introduces abrupt fluctuations in the applied voltage and current; a voltage step control unit for issuing a command to said particle collection unit based on anomalous discharge information from said sensing unit to change the predetermined voltage to a level at which no anomalous discharge will occur; and a voltage changing unit for changing the predetermined voltage in response to a voltage change command from said voltage step control unit, said system characterized in that: said power supply is controlled to send the constant current to said ionization unit through said constant-current control unit; said power supply is controlled to apply said particle collection unit with the predetermined voltage through said voltage step control unit; upon occurrence of an anomalous discharge, said voltage step control unit once shuts off said particle collection unit from said power supply; said voltage changing unit subsequently changes the predetermined voltage io a level at which no anomalous discharge will occur, and applies said changed predetermined voltage to said particle collection unit; and said electrostatic precipitator is allowed to continue a particle collecting action even after the occurrence of the anomalous discharge.
- [Claim 2] A system for controlling a power supply associated with an electrostatic precipitator according fo claim 1, wherein said voltage step control unit outputs a PWM (pulse width modulation) signal having a predetermined value from a CPU (central processing unit) to an amplifier circuit, such that said particle collection unit is applied with the predetermined voltage commensurate with the PWM signal from said voltage changing unit.
- [Claim 3] A system for controlling a power supply associated with an electrostatic precipitator according to claim 1, wherein: said voltage changing unit includes n resistors (R1<R2...<Rn-1<Rn) arranged in parallel between said particle collection unit and said power supply, when said sensing unit senses an anomalous discharge while a resistor R1 is connected between said particle collection unit and said power supply, said voltage step control unit issues a command to said voltage changing unit to once shut off said particle collection unit from said power supply and subsequently switch the resistor R1 to a resistor R2 having a larger resistance value between said particle collection unit and said power supply, said particle collection unit being applied with the predetermined voltage, and said voltage step control unit subsequently switches (n-2) arranged resistors to resistors R3 - Rn having larger resistance values to change in steps the predetermined voltage, and applies the changed predetermined voltage to said particle collection unit.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012115013A JP2013230454A (en) | 2012-04-29 | 2012-04-29 | Control system of power supply for electric precipitator |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| SG194319A1 true SG194319A1 (en) | 2013-11-29 |
Family
ID=49458707
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| SG2013030952A SG194319A1 (en) | 2012-04-29 | 2013-04-23 | Electrostatic precipitator |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JP2013230454A (en) |
| CN (1) | CN103372499A (en) |
| SG (1) | SG194319A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105363555A (en) * | 2014-08-28 | 2016-03-02 | 住友金属矿山工程株式会社 | Wet electric dust collector, discharge line used by the same and power supply control device and method for the same |
| JP6395151B2 (en) * | 2014-09-25 | 2018-09-26 | ミドリ安全株式会社 | High voltage power supply for electric dust collector |
| CN108499739B (en) * | 2017-09-30 | 2023-07-07 | 江森自控空调冷冻设备(无锡)有限公司 | High-voltage power supply circuit, high-voltage power supply board and method for controlling high-voltage output |
| KR102017061B1 (en) * | 2017-11-23 | 2019-09-02 | 한전산업개발 주식회사 | Electric Precipitator using Load Balancing Control Process |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3112384B2 (en) * | 1994-08-11 | 2000-11-27 | 川崎重工業株式会社 | Electric dust collector control device |
| JP3279085B2 (en) * | 1994-08-18 | 2002-04-30 | 富士電機株式会社 | Control method of power supply for electric precipitator |
| JP3472555B2 (en) * | 1999-12-15 | 2003-12-02 | 川崎重工業株式会社 | Electric dust collector |
| EP1175943A4 (en) * | 2000-03-03 | 2008-07-02 | Matsushita Ecology Sys Co | Dust collecting apparatus and air-conditioning apparatus |
| JP4618194B2 (en) * | 2006-06-06 | 2011-01-26 | ダイキン工業株式会社 | Discharge device |
| JP5344167B2 (en) * | 2009-07-01 | 2013-11-20 | 株式会社トルネックス | Control device used for discharge device |
-
2012
- 2012-04-29 JP JP2012115013A patent/JP2013230454A/en active Pending
-
2013
- 2013-04-23 CN CN 201310143086 patent/CN103372499A/en active Pending
- 2013-04-23 SG SG2013030952A patent/SG194319A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| CN103372499A (en) | 2013-10-30 |
| JP2013230454A (en) | 2013-11-14 |
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