JPS5879561A - Electrostatic precipitator - Google Patents

Abstract

PURPOSE:To improve dust collecting performance and to reduce power consumption by performing charging and suspension of charging during charging cycle instantaneously within the limit of reverse ionization time constant and performing application and suspension of output voltage to the electrostatic precipitator at a short period. CONSTITUTION:In an electrostatic precipitator provided with a saturable reactor 4 as a charging electric power source, a phase controlling circuit 3 provided with a forcing circuit that performs charging cycle consisting of normal direction forcing charging of saturable reactor exciting circuit and reversing of charging polarity and suspension of charging is controlled by the signal of a current detecting device 2 as both side arms of a thyristor 1. By performing charging and suspension of charging during charging cycle instantaneously within the limit of reverse ioization time constant, application and suspension of output voltage to the electrostatic precipirator are made at a short period. Exciting current is decreased sharply before dust of high specific volume resistivity causes reverse ionization, and occurrence of reverse ionization phenomenon can be evaded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to fILgl and JKIIIl devices, and more particularly, to prevent as much as possible the occurrence of reverse ionization phenomena in collection and storage in 1 having a saturable reactor III switching circuit. The present invention also relates to an electrostatic precipitator that can improve the ability of cod to nest and reduce power consumption.

1, which has a discharge electrode for causing corona discharge and a dust collection electrode for attaching and collecting dust in the contaminated gas;
Conventionally, in order to maintain a high dust collection current, a spark discharge device is used to detect the spark discharge generated within the current, and the failure of the detected spark discharge is measured for a unit time. There is a voltage i#I control method based on the frequency of spark discharge, which controls the source voltage to the high voltage 1 of the dust collector fiM- so as to maintain the voltage i#I within a predetermined value. However, this type of electrostatic precipitator cannot handle contaminated gas containing dust (10 to 101j-51) with a high specific resistivity, such as sintering dust. In this case, the powder adhering to the curvature does not easily lose its charge, so 115+!
It strongly adheres to the nesting board due to the mirror image force, and the normal 14kJi
It was not possible to remove the powder sufficiently using the method of removing the powder from the layer with a lli plate.

In other words, if you try to continue collecting dust with the above-mentioned powder having a large magnetic volume TGI resistivity deposited on the SM plate, a certain dielectric breakdown will occur in the deposited layer, and a so-called reverse charge will occur. The phenomenon has a time constant of 1.0 to 20 times *
Because of the angle, there was a drawback that the total dust collection power was severely hampered compared to the power used.

By the way, when a thyristor path is adopted as the 0M power source of an electrostatic precipitator, the ionization phenomenon occurs due to the intermittent application of power by the S source control circuit because the IMWk is extremely high above the Is dormitory. However, due to the poor reverse current waveform, the contribution value as AC current is 1.5 to 2 times the average value, and it is difficult to convert high voltage transformer for the same DC output current rating. - and rectification - six major considerations had to be made. Similarly, if a saturable reactor circuit is adopted as the charge source, the articles of incorporation will be 0.4.
Since the degree of kickback is ~1°0, it is impossible to perform intermittent # range in a short period of time by using a control circuit in the case of the above-mentioned Iristor circuit. Even if this was adopted, it was inevitable that the dust collection performance would deteriorate.

The present invention has been made in view of the above-mentioned problems, and is intended to prevent as much as possible the occurrence of reverse electric phenomena that have a great influence on the physical appearance, and to reduce dust particles with a large specific electrical volume resistivity. It is an object of the present invention to provide a 4-fi dust collector that can perform effective dust collection even in the case of the present invention.

Hereinafter, an example of this book S1 will be explained based on the accompanying drawings.

Figure 1 shows uII in the Shirofi dust collector according to the present invention.
Figure 2 is an exciting current characteristic diagram corresponding to Figure 1, and Figure 6 is an output 11EE characteristic diagram.

That is, the 4-collection device according to the present invention has a predetermined charging cycle 1. Jin 411 synchronized mini, perform 7 orsing Wt electricity in the normal direction for 11 hours within the range of
The charged electrode i of the saturable reactor excitation circuit momentarily within the range of 1m#lt time-determined ridge! 1i inversion and t-seki m5r
T go, next call? ! The charged body is stopped for 11 hours until the 11th cycle of the I charge (see Figure 1111).
), as a result, the excitation current of the saturable reactor becomes the same as shown in Figure 2, and the output 1g pressure also becomes the same as shown in Figure 6. One! ip electrical volume resistivity is higher than that of inverted l
The excitation current is drastically reduced before K#11 occurs, thereby preventing the occurrence of the reverse electric phenomenon.

Note that if the charge polarity of the saturable reactor excitation circuit is not reversed, the result will be as shown by the broken line in Figure 0113 due to reverberation hysteresis.

Figure 44 shows an example of a charged 1g circuit in a current concentrator according to the present invention. The phase 1IlIl111 circuit with one single circuit, (4) is a saturable reactor, that is, the thyristor (1) is provided with a current output (2) as both arms, and based on the signal of this current detection device (2). A phase control circuit with a forcing circuit is controlled to apply a 7-ohing voltage to the saturable reactor (4), and perform the control. In other words, by phase control 1gl with phasinda IgIs (8), the -order m field applied to the town l1aiKJ reactor (4) is the first
By controlling the four times shown in the figure], as a charge @-, the town *
It is possible to avoid the occurrence of the back-smoking phenomenon even in a @collecting and feeding device having an n reactor.

As described above, according to the present invention, in an electrostatic precipitator having a saturable reactor region,
) A 1iII control circuit that regularly returns the charge 1iEv cycles consisting of normal charging, reversal of charge polarity, and charging suspension of the excitation circuit, and
By reversing the 1c polarity instantaneously within the range of the reverse current provisional articles of incorporation, the configuration allows the application and suspension of the output voltage applied to the P dust collector to be performed in a short W4'@, which greatly reduces the response time. Even in an electrostatic precipitator with a saturable reactor power supply circuit, it is possible to effectively collect dust from f8 dye gas containing electrical volume m;ii dust with large resistivity (1.1 m, 10 to 10 Ω.(111)). In addition, this invention can be carried out using only a small amount of electricity per 1F4, and has an extremely large effect in terms of energy saving policy.

By the way, the present invention 11v1. loss device and conventional electrical collector j with 10Ω/100″O exhaust gas containing sintered dust of Japan.
A comparison of the I11fM position and the S dust is shown in the table below.
It is shi.

Dust concentration (q/w/h) Power consumption (ImW) Conventional 60560 Main power supply 111 25 150 In this case, To: 1 to 2 decrease, Tz: 0-2 to 0-
4(8), Ding type: 0.1~0.2sec, Ts: Q
-7 to 1.4 mg.

[Brief explanation of the drawing]

FIG. 1 is a charging characteristic diagram of the excitation voltage of the saturable reactor in the electrostatic precipitator according to the present invention, FIG. 2 is a charging characteristic diagram of the excitation voltage corresponding to FIG. 1, and FIG. 11
The EE characteristic diagram, FIG. 4, is an explanatory diagram showing one embodiment of the charging circuit in the S dust collector according to the present invention. (3) is a phase system # circuit with a 7-o-cinder circuit, and (4) is an a-phase reactor. Patent applicant: Sumitomo Metal Industries, Ltd. Figure 4

Claims (1)

[Claims] (1) In an electrostatic precipitator having a source circuit of the ciJ saturation reactor 1, the reversal of the 7t-singing charge and the charge 1lCfi properties of the saturable actuator excitation circuit and the stoppage of the charged body result in #electrical The output applied to the collecting device is provided with a control circuit that repeats the cycle regularly, and performs charging and charging pauses intermittently within the range of the reverse IIE time interval during the charging cycle. '111
An electrostatic precipitator characterized in that it is configured to apply and stop the application of 11E in short cycles.