JPS6135904B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning time detection device for detecting the cleaning time of a dust collection electrode of an electrostatic precipitator.

As an electrostatic precipitator is used, dust such as cigarette tar, dust, and fibers gradually adhere to the dust collection electrodes, but due to this dust adhesion, the distance between the dust collection electrodes narrows in some areas through the dust. During this time, spark (arc) discharge occurs. Arc discharge stops when the attached dust is burned, so it only occurs in pulses. However, during discharge, the voltage between the electrodes becomes 0, so if discharge occurs frequently, the voltage between the electrodes cannot rise sufficiently, resulting in a significant drop in dust collection ability, and the electrodes must be cleaned.

Conventional cleaning time detection devices include one that measures the amount of light transmitted to measure the amount of dust attached to the dust collection electrode, one that measures leakage between the dust collection electrodes, and one that measures the air resistance between the electrodes. be. However, in the above case, there is a risk of false detection due to dirt on the light source and light receiving element, and in case of humidity, the rate of change in air resistance due to adhesion of dust is too small in case of , making it difficult to detect subtle changes. Both methods have problems in terms of reliability in detecting the cleaning time, and for the above reasons, it is also difficult to change the cleaning time, which poses a problem.

In addition, focusing on the fact that arc discharges occur more frequently as the dust collection electrode becomes more contaminated, we convert the occurrence of arcs into electrical signals, and use a comparison circuit to compare the number of arcs to a standard value using an analog or digital method. Conventionally, it has also been done to generate a signal to operate a device for removing dust accumulated on the electrodes.
-105376 etc.

However, in these devices, when the power is turned off, the signal supplied to the comparator circuit is cleared and the integrated value is not stored, and cleaning is not possible until the number of arcs has reached the reference value after the power is turned on. Since this is not displayed, there is a problem in that there is a time difference in the display time of the cleaning time during continuous use and during intermittent use, making it impossible to accurately display the cleaning time.

Further, in the above-mentioned conventional examples, the technical concept of superimposing and integrating the time failure factor on the arc occurrence frequency was not disclosed.

In view of the above-mentioned problems, the present invention integrates the integration signal based on arc discharge and stores it in a non-volatile manner, thereby preventing the generation of a time difference in the display time of cleaning timing between continuous use and intermittent use, thereby ensuring accurate cleaning. We have created an easy-to-use cleaning time detection device that can display the cleaning time and, by superimposing time-element signals, can always display the cleaning time after a predetermined time even if dust that is difficult to cause arc discharge accumulates. It is about providing.

To explain an embodiment, the electrodes of an electrostatic precipitator are composed of discharge electrodes 1 and 2 and a dust collection electrode 3, as shown in FIG. Since the dust collection electrodes 3 are arranged in large numbers, they have a stray capacitance and are used as one capacitor 3 of a voltage doubler circuit of a power supply as shown in FIG. This voltage doubler circuit is composed of diodes D1 and D2 and capacitors 3 and 4. 5 is a resistor that generates voltage during arc discharge, 6 is an operation indicator lamp, and 7 is its protective resistor. When electrode contamination progresses and arc discharge occurs in a part of the dust collection electrode, capacitor 3 is short-circuited in Figure 2, and current flows in the direction of the arrow, causing an arc signal to be generated in the form of voltage across resistor 5. S1 occurs. This signal S1 is synchronized with arc occurrence.

In FIG. 3, reference numeral 8 denotes an integration signal generation unit that receives the arc signal S1 and generates an integration signal, and internally generates one pulse-like arc integration signal S2 at the generation timing of the arc signal S1. It is equipped with a known pulse generating circuit 8a such as a mono-multivibrator, and an oscillator 8b that generates a pulsed time signal _S3 of a constant period during operation of the electrostatic precipitator. 8c and 8d are variable resistors that control the current value of the integrated signal.

Reference numeral 9 denotes an integration unit that receives the two types of integration signals and integrates these signals, and includes an electrolytic integration element 9a that integrates the quantity of electricity, a transistor 9b that controls current application to this element, and an integration element 9a. Thyristor 9 operates to generate the cleaning signal _S4 when the integration is completed.
d etc.

Reference numeral 10 denotes a driving section that receives the cleaning signal S4 and drives the display element 11.

Reference numeral 12 denotes a reset unit that returns the electrolytic integration element 9a to its initial state by pressing the RK key. 12a
is a variable resistor that controls the current at the time of setting.

The electrolytic integration element 9a utilizes the law of electroplating, and as shown in FIG. 4, consists of a center electrode M, a case electrode K, and an electrolytic solution filled between the two electrodes. When a current I ₁ is passed from the case electrode to the center electrode for a time T ₁ as shown in a of the figure, metal ions in the electrolyte move to the center electrode, and metal is accumulated (plated) on the center electrode as shown in b. Ru. In this state, the electrical resistance of both electrodes is small and the terminal voltage is several millivolts (this state is called the set state). Next, when a current I ₂ is applied in the opposite direction to both electrodes M and K as shown in c in the same figure, the metal on the center electrode M is transferred into the electrolyte in the form of ions, and after a time T ₂ the metal has completely transferred into the electrolyte. In the state d (integration completed state), the resistance of the voltage across the integration element 9a increases rapidly, and the voltage becomes 800 mV.
From this state, if a current is applied again as shown in FIG. 5A, it can be returned to the set state and can be used repeatedly as an integrating element.

The above I ₁ , T ₁ , I ₂ , and T ₂ have the relationship of I ₁ ×T ₁ =I ₂ ×T ₂ . Therefore, the time T ₂ , that is, the time from the start to the end of integration (cleaning time) can be arbitrarily selected by the set values of I ₁ , I ₂ , and T ₁ .

Next, the operation of the embodiment will be explained. It is assumed that the electrolytic integration element 9a is in a set state in advance. When arc discharge occurs at the dust collection electrode, an arc signal S1 is generated, and in synchronization with this, the pulse generation circuit 9
An arc integration signal S2 with a constant waveform is generated from a. Further, the oscillator 8b always generates a time measurement integration signal S3 with a constant period. As shown in FIG. 5, the signal S2 is a low level triangular wave, and the signal S3 is a low level square wave. Transistor 9b is always ON
When the signals S2 and S3 are generated, a current _I2 in which both signals are superimposed flows from 9b to 9a as shown by the solid line arrow, and the electrolytic integration element 9a starts integrating the current (Fig. 4). state of c]. During integration, the internal resistance of this element 9a is low, so the level at point P is maintained at a high level, and the thyristor 9d is
It remains OFF. When the integration of the electrolytic integration element 9a is completed [the state shown in FIG.
The potential at the point drops by that voltage. Due to this voltage drop, gate current flows through the thyristor 9d.
It turns ON and generates a cleaning signal S4 from its cathode. In response to the generation of the signal S4, the drive unit 10 drives the display element 11 to display that it is time to clean the dust collecting electrode.

Cleaning time t of electrostatic precipitator and electrolytic integration element 9a
The relationship between the integrated amount W is shown in FIG. 6 (WE indicates the end point of integration). In this figure, A is the characteristic when the cleaning period t is set long, and B is the characteristic when the cleaning period t is set short.

The above characteristics A and B are selected depending on the degree of contamination of the room to be purified by the electrostatic precipitator, the type of dust, and the dust collection ability of the precipitator. Adjustment of the cleaning timing is performed by variable resistors 8c, 8d, and 12a. For example, the integrated current by signals S ₂ and S ₃ can be adjusted by using 8c and 8d, and the electrolytic integration element 9 is controlled by 12a.
The set state (I ₁ ×T ₁ ) can be adjusted by changing the set current of a. In addition, the generation cycle of the time-counting integration signal S3 and the arc integration signal _S2 for one arc occurrence
It can be easily adjusted by the number of occurrences or the width of occurrence.

After the cleaning time is displayed, the dust collecting electrode is cleaned and the electrolytic integration element 9a is reset. The reset operation is performed by pressing the RK key of the reset section 12 shown in FIG. Transistor 9 is activated by pressing the RK key.
b is in the OFF state, and a reset current is generated for a fixed time in the direction opposite to the solid arrow indicated by the dotted line arrow in the electrolytic integrating element 9a.
IR is applied to bring this element 9a into the set state as shown in FIG. 4b.

In the above embodiment, shaped triangular waves and square waves are used as the integrated signals S2 and S3, but the present invention is not limited to this, and for example, the arc signal _S1 may be used as the signal _S2 , and the constant level signal _S3 may be used as the signal S3. A DC signal may also be used. In the case of DC signals, if the level is too low, it will easily pick up noise and the integration may not be performed accurately. Therefore, it is recommended to configure the system so that only high-level signals can be integrated, so that only high-level pulse signals can be integrated. It will be more accurate.

As explained above, according to this embodiment, the time to clean the electric precipitator is detected by simultaneously integrating the frequency of occurrence of spark discharge and the time element, so detection is more accurate than in the past. can. According to the present invention, the amplitude (current value), period, and
The cleaning timing can be easily adjusted depending on the number of particles generated, and the operating efficiency of the electrostatic precipitator can be improved without impairing the dust collection efficiency. Further, according to the present invention,
An electrolytic integration element is used in the integration section to superimpose and integrate the integration signal and a fixed-period pulsed time signal, and store it in a non-volatile manner.The integration is then completed by detecting the change in internal resistance of the electric field integration element at the end of integration. Since the configuration is configured to generate a cleaning signal to notify that it is time for cleaning, even if the power is turned off, the integrated value is stored non-volatilely as an internal resistance value, so it is easy to determine when it is time to clean during continuous use or intermittent use. We have created an easy-to-use cleaning time detection device that can prevent time lags in the display time, accurately display the cleaning time, and always display the cleaning time after a predetermined time even if dust that does not easily cause arc discharge accumulates. Obtainable.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of an electrode of an electrostatic precipitator, Fig. 2 is a structural diagram of an arc signal generation circuit according to an embodiment of the present invention,
Figure 3 is a circuit configuration diagram of the main parts of the embodiment, Figure 4 is a functional explanatory diagram of the electrolytic integrating element, Figure 5 is a signal waveform diagram accompanying the operation of each part in Figure 3, and Figure 6 is the electrostatic precipitator. FIG. 3 is a diagram showing the relationship between the cleaning timing and the integrated amount of the integrating element. 3; Dust collection electrode, 8; Integration unit, 8b; Time signal circuit, 9; Integration unit, 9a; Electrolytic integration element, 10;
Drive unit, 11; display element.

Claims (1)

[Claims] 1 Integration signal generation unit equipped with a pulse generation circuit that detects arc discharge of the dust collecting electrode and generates a pulse-like integration signal synchronized with the arc discharge, and integrates this integration signal and generates a cleaning signal at the end of integration. In the cleaning time detection device, the integration signal generating section includes a transmitter that generates a pulsed time signal of a fixed period, and the integration section is filled between a center electrode, a case electrode, and both poles. The electrolytic integrating element includes an electrolytic integrating element consisting of an electrolytic solution containing metal ions, a thyristor having a gate connected to the electrolytic integrating element, and a reset circuit for resetting the electrolytic integrating element, and the electrolytic integrating element is connected from a case electrode to a center electrode. The metal in the electrolyte is accumulated at the center electrode by the current flowing toward the center electrode, and in this state, when current is passed from the center electrode to the case electrode, the metal accumulated in the center electrode is ionized and moved into the electrolyte, increasing the amount of current flowing. is integrated and stored in a non-volatile manner as an internal resistance value, and the reset circuit includes a power source that flows a current from the case electrode to the center electrode, and a reset key and a variable resistor connected in series to the power source. is connected between the center electrode and the case electrode of the electrolytic integration element, and the electrolytic integration element superimposes and integrates a pulsed integration signal synchronized with the arc discharge and the fixed periodic pulsed time signal, 1. A cleaning time detection device, characterized in that the internal resistance value increases rapidly at the end of integration, turning on the thyristor and generating a cleaning signal.