JPS6135905B2 - - 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 collecting electrode. When the dust collection electrodes become partially narrowed due to the dust adhesion, spark (arc) discharge occurs between the dust collection electrodes. 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 the leakage current 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, changing the cleaning time is not easy and is inconvenient.

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 the cleaning time is not displayed during continuous use and intermittent use, there is a time difference in the time when the cleaning time is displayed between continuous use and intermittent use, making it difficult to accurately indicate the cleaning time. There was a problem that I couldn't do it.

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 occurrence of a time difference in the display time of the cleaning period between continuous use and intermittent use, thereby ensuring accurate cleaning. An object of the present invention is to provide a cleaning time detection device capable of displaying the time.

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 a large number of dust collection electrodes 3 are arranged, 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 a 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. A known pulse generating circuit 8a such as a mono-multivibrator is provided. 8C is a variable resistor that controls the current value of the integration signal.

Reference numeral 9 denotes an integrating unit which receives the integration signal and integrates the signal, which includes an electrolytic integrating element 9a which integrates the quantity of electricity, a transistor 9b which controls the current supply to this element, and an integration unit which integrates the integrated signal when the integrating element 9a completes the integration. It includes a thyristor 9d and the like that operate to generate a cleaning signal S4.

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 _I2 in the opposite direction is applied to both electrodes M and K as shown in c in the same figure, the metal on the center electrode M transfers into the electrolyte in the form of ions, and when the metal on the center electrode M is completely transferred after a time _T2 , the same figure 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. As shown in FIG. 5, the signal S2 is a low level triangular wave. Transistor 9b is always on, and when signal S2 is generated, current _I2 flows from 9b to 9a as shown by the solid arrow, and electrolytic integration element 9a starts integrating the current (see Figure 4c). situation〕. Since the internal resistance of this element 9a is low during the integration, the level at point P is maintained at a high level and the thyristor 9d remains OFF. When the integration of the electrolytic integration element 9a is completed (the state shown in FIG. 5d), its internal resistance increases rapidly and the voltage across both ends rises rapidly, so that the potential at point P drops by that voltage. Due to this voltage drop, a gate current flows through the thyristor 9d, turning it on, and generating 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.

The relationship between the cleaning time T of the electrostatic precipitator and the integration amount W of the integration element is shown in FIG. 6 (WE indicates the integration completion point). In this figure, A is the characteristic when the cleaning period is set to be long, and B is the characteristic when the cleaning period is set to be 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.

The cleaning timing can be easily adjusted by adjusting the variable resistors 8c and 12a, and when the set state of the electrolytic integration element 9a is the same, the integration signal S ₂
It can also be easily adjusted depending on the width of occurrence.

After the cleaning time is displayed, clean the dust collection electrode and reset the electrolytic integration element. 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 turned OFF, and a reset current IR is applied to the electrolytic integrating element 9a for a certain period of time in the direction shown by the dotted arrow, thereby bringing the element 9a into the set state as shown in FIG. 4b.

Although a shaped triangular wave is used as the integrated signal _S2 in the above embodiment, a square wave with a constant level may be used, or the arc signal may be amplified and used as it is.

According to this embodiment, the cleaning timing can be easily set based on the peak value and pulse width of the integrated signal, and the operating efficiency can be increased without impairing the dust collection efficiency of the electrostatic precipitator.

According to the present invention, an electrolytic integrating element is used in the integrating section to integrate the integrated signal and store it in a non-volatile manner, and at the same time detect a change in internal resistance of the electrolytic integrating element at the end of integration, and notify the arrival of cleaning time at the end of integration. Since the configuration is configured to generate a cleaning signal, the integrated value is non-volatilely stored as an internal resistance value even when the power is turned off, so there is a time difference in the display time of cleaning timing between continuous use and intermittent use. can be prevented,
A cleaning time detection device that can accurately display the cleaning time can be obtained.

[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 collecting electrode, 8; Integrating section, 9; Integrating section, 9
a; 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 integrating section includes an electrolytic integrating element comprising a center electrode, a case electrode, and an electrolytic solution containing metal ions filled between the electrodes, and a gate to the electrolytic integrating element. and a reset circuit for resetting the electrolytic integrating element, the electrolytic integrating element accumulates metal in the electrolyte at the center electrode due to current flowing from the case electrode to the center electrode, and in this state, the center electrode The reset circuit is configured such that by passing current through the case electrode, the metal accumulated in the center electrode is ionized and moved into the electrolyte, and the amount of current is integrated and stored in a non-volatile manner as an internal resistance value. The electrolytic integrating element is connected between the center electrode and the case electrode, and includes a power source that flows a current from the case electrode to the center electrode, and a reset key and a variable resistor that are connected in series to the power source. 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.