JPH02227152A - Dust collecting electrode hammering method - Google Patents

Abstract

PURPOSE:To heighten dust removing effect from a dust collecting electrode by hammering by a method wherein voltage application to a discharge electrode and a dust collecting electrode is suspended until the last hammer of a plurality of hammers hammers an optional rod to be hammered since a fist one of them hammers the rod. CONSTITUTION:A discharge electrode 16 is formed facing to a plurality of dust collecting electrodes 1, 17 installed in parallel each other. A rod 2 to be hammered is installed in the lower part of each dust collecting electrode, and a hammering shaft 3 is installed in the rectangular direction to the dust collecting electrodes. A plurality of hammers 4a-4c are installed in the hammering shaft 3 with divided angles against each rod 2 to be hammered. An impact sound generated when one of the hammer falls and hits each rod 2 to be hammered is detected by a microphone sensor 19 and recognized as a hammering sound. Then, until the last hammer of the plurality of hammers hits any rod 2 to be hammered since a first hammer hits the rod, voltage application between the discharge electrode 11 and the dust collecting electrode 17 is suspended.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a dust collecting hammering method applied to an electrostatic precipitator.

[Conventional technology]

Figure 6 shows the dust collecting pole hammering mechanism of a conventional electrostatic precipitator, in which there are a plurality of dust collecting poles 1 arranged in parallel and facing each other, and each of the lower ends of the dust collecting poles 1 has a covered part. A striking rod 28 is attached. A hammering shaft 3 is installed perpendicularly to the dust collecting pole 1, and hammers 29 are attached to the hammering shaft 3 at angles divided by the number of dust collecting poles 1. As the hammering shaft 3 rotates, the hammer 29 falls one after another and hits the covered driving rod 28 to remove dust from the dust collection pole 1.

On the other hand, as shown in FIG. 7, a discharge electrode 16 is arranged between each of the dust collection electrodes 1. This discharge electrode 16 is connected to a DC high-voltage power supply 18 that is connected to a commercial AC power supply 11 via an AC power regulator 12 having a thyristor 26, etc. A high voltage output is connected, so that a DC high voltage is applied between the discharge electrode 16 and the dust collecting electrode 1.

A DC corona discharge occurs between the discharge electrode 16 and the dust collecting electrode 1 due to the DC high voltage, and the dust that flows between the two electrodes is charged.
It is drawn toward the dust collection pole by the electric field, and is collected and deposited on the dust collection pole surface. The accumulated dust on the surface of the dust collection electrode is peeled off and dropped by the impact when the dust collection pole 1 is hammered by the hammer 29 by the dust collection pole hammering device, and is collected in the lower hopper. When dust is removed from the surface of the dust collection electrode by hammering the dust collection electrode, the dust is scattered again. In order to reduce the amount of dust flowing out from the electrostatic precipitator due to this re-scattering, the hammer 2 is attached to the hammer shaft 3 as described above.
A method is used in which the dust collection poles are hammered one by one by dividing the dust collection poles into angles and attaching them. Further, intermittent hammering is performed in which the electric motor 5 with a reduction gear that drives the hammering shaft 3 is operated for a preset operating time T1 and a preset rest time Tt.

The following method has been used as a countermeasure in cases where the electrical resistivity of the dust collected by the electrostatic precipitator is high (or the electrical adhesion of the dust to the dust collecting electrode is large).

(1) In the intermittent hammering, the interval between hammerings is shortened, and the frequency of hammering the dust collector is increased.

(2) Increase the force of one hammering by increasing the weight of the hammer.

(3) The application of high DC voltage to the discharge electrode and the dust collection electrode is stopped by the start signal (operation signal) of the electric motor with a speed reducer to reduce the electrical adhesion of dust to the dust collection electrode during hammering. lower.

[Problem to be solved by the invention]

The conventional device described above has the following problems.

(1) When the frequency of hammering increases, dust re-scattering increases, resulting in a decrease in dust collection performance.

(2) An increase in hammering force results in a decrease in the mechanical life of the dust collection electrode.

(3) Since the activation signal and the timing at which the dust collection pole is actually hammered are not synchronized, the application of the DC high voltage is stopped for a certain period of time, resulting in a decrease in dust collection performance during that time.

[Means to solve the problem]

The present invention takes the following measures to solve the above problems.

That is, as a method of hammering the dust collecting electrodes, (1) a plurality of dust collecting electrodes are provided in parallel, a discharge electrode is provided facing each of the dust collecting electrodes, and a discharge electrode is placed at the lower end of each of the same dust collecting electrodes. The attached hitting rod, a hammering shaft arranged perpendicular to the same collecting rod, and a plurality of hammering hammers each attached to the same hammering shaft at angles divided with respect to the said hitting rod. In the electrostatic precipitator, the impact sound generated when the above-mentioned hammer falls and hits each of the hit rods is detected by a microphone sensor, recognized as a hammering sound, and the impact sound generated when the above-mentioned hammer falls and hits each of the hit sticks is detected, and is recognized as a hammering sound, The application of voltage to the discharge electrode and the dust collector is stopped from the time when the first hammer among the plurality of hammers strikes until the last hammer strikes. .

(2) A plurality of dust collection electrodes provided in parallel, a discharge electrode provided opposite each of the dust collection electrodes, a power source for charging the same dust collection electrodes and the discharge electrode, and a lower end of each of the same dust collection electrodes. A hammering rod attached to the part, a hammering shaft arranged perpendicular to the collected dust, an electric motor rotating the hammering shaft, and an angle divided into the hammering shaft with respect to the hammering rod. In an electrostatic precipitator having a plurality of electrostatic precipitator chambers each equipped with a plurality of hammers installed in Detected by a sensor and recognized as a hammering sound, the period from the first hammering of the plurality of hammering hammers of any of the above-mentioned hitting rods to the last hammering. The voltage application to the discharge electrode and the dust collection electrode of the electric dust collection chamber to which the hammer belongs is stopped only when the electric motor for the hammer is operating.

[Effect]

(1) With the above means, the impact sound generated when the first hammer hits the hitting rod is detected by the microphone sensor, recognized as hammering sound, and the voltage applied to the discharge electrode and the dust collection electrode is In the same way as described above, voltage application is resumed when the last hammer strikes.

In this way, the voltage application is stopped while the second to last hammer hits, and during that time the electrical adhesion of the dust to the dust collection electrode is reduced, so the dust is peeled off from the dust collection electrode. It is easier to remove dust (that is, the dust removal effect by hammering is higher).

(2) With the above means, the impact sound generated when the first hammer hits the shaft to be hammered is detected by the microphone sensor and recognized as a hammering sound, and the first hammer hits the hammer. The voltage application to the discharge electrode and the dust collection electrode of the electric dust collection chamber to which the first hammer belongs is stopped only when the driving electric motor is operating. When the hammer strikes, voltage application is restored only when the motor is operating.

In this way, the voltage application is stopped while the second to last hammer hits without being affected by the sound of the hammers on the dust collection poles of other dust collection chambers. Therefore, during this period, the electrical adhesion of the dust to the dust collecting electrode is reduced, so that the dust is more easily peeled off than the dust collecting electrode, which means that the dust removal effect by hammering is enhanced.

〔Example〕

An embodiment to which the method of the present invention is applied will be described with reference to FIGS. 1 to 4.

Figure 1 is a configuration diagram, Figure 2 is a perspective view of the hammer section,
FIG. 3 and FIG. 4 are action explanatory diagrams.

Note that the description of the portions described in the conventional example will be omitted to avoid redundancy, and the description will mainly focus on the portions related to the present invention.

In FIG. 2, a covering rod 2 is provided at the bottom of each dust collection pole 1. Three hammers 4a are attached to the hammer shaft 3 at angles for each of the hit rods 2.

4b+4c are provided. Further, as shown in FIG. 1, the electrostatic precipitator is provided with a microphone sensor 19,
The output is sent to a comparator 21 via a filter 20. The comparator 21 receives the output from the setter 22 and also sends its own output to the timer circuit 23 and the counter circuit 2.
Send to 4. Further, the timer circuit 23 receives the outputs of the counter circuit 24 and the setting device 25, and sends its own output to the AC power regulator 12.

In the above configuration, the analog signal Sa from the microphone sensor 19 attached to the electrostatic precipitator is inputted to the comparator 21 after noise is removed by the filter 20 . The comparator 21 compares the input signal SL with the sound pressure level Sc preset by the setter 22, and when the input signal Si exceeds the set sound pressure level Sc, the detected sound at this time is detected by the hammer 4a.

4b+4c is recognized as an impact sound (hammering sound) when the hit part hitting rod 2 is hammered, and the comparator 21 outputs a recognition signal.

The recognition signal Rd+ of the first (i-first) hammering sound is input to the timer circuit 23 and the counter circuit 24, respectively.

The timer circuit 23 receives the hammering signal Rd as shown in FIG.

A gate-off command signal G is output after a time Td preset by the setting device 25 has elapsed since the input of the gate-off command signal G, and this gate-off command signal G is reset (turned off) by the count-up signal C of the counter circuit 24. T
d is a time provided to optimally adjust the DC high voltage power supply output stop period. The counter circuit 24 is a hammering signal Rdt
, Rd*, Rds are counted manually, and when the third hammering signal Rd is input, the count-up signal C is outputted and the count is reset. The gate-off command signal G output from the timer circuit 23 is input to the gate 27 of the thyristor 26 of the AC power regulator 12,
While the signal G is on, the thyristor 26 is maintained in the off state, and during this period, the DC high voltage output from the DC high voltage power supply 18 is stopped.

In this way, while the second and third hammers 4b and 4c are in operation, charging of the discharge electrode and the dust collection electrode is stopped, thereby enhancing the dust removal effect as shown by the dotted line in FIG. 4.

There are various types of microphone sensors 19, but the hammers 4a, 4b, 4 (but not the hammer 2)
The microphone sensor 19 can be easily installed on the side wall of the electrostatic precipitator or on the door of an inspection manhole. Tokoro.

In addition, if the electrostatic precipitator is dust-proof, high-temperature resistant, etc., and can be installed inside the electrostatic precipitator, it can be installed on the side wall, inspection manhole door, etc., since it can be installed while the electrostatic precipitator is in operation. It is extremely easy to apply the dust collection hammering method of this embodiment to.

Another embodiment will be explained with reference to FIG.

In an electrostatic precipitator having a plurality of dust collection chambers, a microphone sensor 19 and a filter 20 are provided as in the above embodiment.
, comparator 21, timer circuit 23, counter circuit 2
4th class will be provided. The output of the timer circuit 23 is sent via an AND circuit 28 to each AC power regulator 12 (only one dust collection chamber is shown in the figure, and those of other dust collection chambers are omitted). Further, the AND circuit 28 inputs a starting signal M for each motor with a speed reducer that drives the hammer shaft.

The operation in the above configuration will be explained.

In an electrostatic precipitator that has multiple dust collection chambers and each dust collection chamber has a DC high-voltage power supply and a dust collection pole hammering mechanism, the hammering sound detected by the microphone sensor 19 indicates which dust collection chamber is collecting dust. It is necessary to distinguish whether it was due to the Gokutsuchi strike or not. Therefore, the AND result of the start signal (for example, the excitation signal for an electromagnetic contactor, etc.) of the motor with a speed reducer that hammers the relevant dust collection chamber and the gate-off command signal G of the timer circuit 23 is input to the gate 27 of the thyristor 26. do. In this way, it is possible to perform the hammering of the dust collecting pole only for the relevant dust collecting room in the same manner as in the above embodiment, without recognizing the hammering sound as being caused by the hammering of the dust collecting pole of other dust collecting rooms. .

〔Effect of the invention〕

As explained above, the present invention has the following effects.

(1) - Each hitting rod has a plurality of hammers, which fall one after another and hit one dust collection pole with a hammer.

Furthermore, when the second and subsequent hammers hammer the dust collecting electrode, the application of DC high voltage between the discharge electrode and the dust collecting electrode is stopped, which prevents the electricity of the collected dust from reaching the dust collecting electrode. Since the adhesion force to the target is significantly reduced, the dust collection and removal effect by hammering can be significantly enhanced without increasing the hammering force per hammer or increasing the frequency of hammering.

(2) The output of the DC high-voltage power supply is stopped by detecting the impact sound generated by the actual hammering, so there is no unnecessary output stop time, and the drop in dust collection during this time is minimized. It can be suppressed.

(3) A microphone sensor is used as a means of recognizing actual hammering, and since this sensor can be easily placed on the side wall of the electrostatic precipitator or on the manhole door for inspection, it is inexpensive and can be installed on existing steel. It is also extremely easy to add.

(4) It works effectively even in a dust collection device having a plurality of dust collection chambers, and the dust removal effect is improved.

[Brief explanation of the drawing]

Fig. 1 is a structural system diagram of an embodiment of the present invention, Fig. 2 is a perspective view of the structure of the hammering device section of the same embodiment, Figs. 3 and 4 are action explanatory diagrams of the embodiment, and Fig. 5 The figure is a structural diagram of another embodiment, FIG. 6 is a perspective view of a conventional dust collector hammering device, and FIG. 7 is a continuation of the structural system of the conventional example. 1.17... Dust collecting pole, 3 - Hammering shaft, 5 - Electric motor with reducer, 18 - DC high voltage power supply, 19, 20... Filter, 22.25... - Setting device, 24...Counter circuit, G...Gate off command signal, M...-Electric motor start signal with reduction gear. 2... Hitting rod, 4a, 4b, 4c- hammer, 16- discharge electrode, microphone sensor, 21-- comparator, 23-- timer circuit,

Claims (2)

[Claims] (1) A plurality of dust collection poles installed in parallel, a discharge electrode installed opposite to each dust collection pole, a hammering rod attached to the lower end of each dust collection pole, and a plurality of dust collection poles installed in parallel. In an electrostatic precipitator comprising a hammering shaft disposed perpendicularly to the pole, and a plurality of hammers each attached to the hammering shaft at angles divided relative to the rod to be hammered, the hammering A microphone sensor detects the impact sound generated when the hammer falls and hits each hammered bar, recognizes it as a hammering sound, and selects the first of the plurality of hammers of any of the hammered bars. A method for hammering a dust collecting electrode, characterized in that application of voltage to the discharge electrode and the dust collecting electrode is stopped from the time when the hammer hits until the last hammer hits. (2) A plurality of dust collection electrodes provided in parallel, a discharge electrode provided opposite each of the dust collection electrodes, a power source for charging the same dust collection electrodes and the discharge electrode, and a lower end of each of the same dust collection electrodes. A hammering rod attached to the part, a hammering shaft arranged perpendicular to the dust collecting pole, an electric motor rotating the hammering shaft, and an angle divided into the hammering shaft with respect to the hammering rod. In an electrostatic precipitator having a plurality of electrostatic precipitator chambers each equipped with a plurality of hammers installed in Detected by a sensor and recognized as a hammering sound, the period from the first hammering of the plurality of hammering hammers of any of the above-mentioned hammering bars until the last hammering hammer. , a hammer for a dust collection pole, characterized in that voltage application to the discharge electrode and the dust collection pole of the electric dust collection chamber to which the hammer belongs is stopped only when the electric motor for the hammer is operating. How to hit.