SU1570780A1 - Apparatus for controlling electric precipitator - Google Patents

Abstract

The invention relates to the electrical purification of gases, can be used in the energy and other sectors of the industry and allows an increase in the degree of purification of gases. The device for controlling the electrostatic precipitator contains two sources 6 and 7 of light emission, through power supply units 9 and 10 connected to synchronizer 11, light emission meter 8, through delay circuit 4 and subtraction unit 5 connected to the first input of control unit 12, which is connected to the outputs the power units 1 of the electrostatic precipitator sections and the shaking mechanisms 2, the second source 7 being installed normally relative to the first source 6 and the unit 1, the meter 8 is connected to the second inputs of the circuit 4 with its outputs ki, subtracting unit 5 and the control unit 12. 2 Il.

Description

figure 1

The invention relates to the electrical cleaning of gases and can be used in the energy, metallurgical and other industries.

The purpose of the invention is to increase the degree of gas cleaning from dust.

FIG. 1 shows a block diagram of the proposed device for controlling an electrostatic precipitator; in fig. 2 is a control block diagram.

The block diagram of the device contains (Fig. 1) the power units 1 of the sections of the electrostatic precipitator, the mechanisms 2 of the electrode electrodes being agitated, the dust line 3, the delay circuit 4, the subtraction unit 5, the first 6 and second 7 light sources, the light meter 8 radiation, power supply units 9 and 10 of light emission sources 6 and 7, connected respectively to the first and second outputs of synchronizer 1J, control unit 12, the inputs of which are connected to the output of light emission meter 8 of subtraction unit 5, and outputs to power supply units 1 sections u ektrofiltra mechanisms 2 and agitating precipitator electrodes. Control unit 12 (FIG. 2} contains adder 13, AND circuit 14 and switch 15, wherein the switch outputs are outputs of control unit 12} the input of adder 13 is the first input, and the first input of AND circuit 14 is the second input of control unit I2 .

The device for controlling the electrostatic precipitator operates as follows.

When burning solid fuel in the boiler box through the dust line 3 after the electrostatic precipitator, the flue gases flow with solid particles of combustion products not captured by electrostatic precipitators. The meter, containing the first 6 and second 7 sources and the light emission meter 8, provides information to the control unit 12 on the concentration (optical density) of solid particles and flue gases, which via the control unit 12 to the agitation mechanisms 2 and power units 1 A signal is received that corresponds to the necessary modes of cleaning (shaking) the electrodes and powering the electrostatic precipitators. In the case of partial replacement of solid fuel with liquid (fuel oil) or when, during parallel combustion of fuel oil,

when it is not burned, a significant amount of soot particles, the efficiency of the electrostatic precipitator decreases sharply.

During the operation of the rotary kiln on fuel oil, the electrostatic precipitator electrodes are covered with a dense, difficult-to-remove layer of magnesite dust. Analysis of dust from electrodes showed that it contains up to 6%. Sulfuric compounds, in a mortar in reaction with MgO, form a layer on the electrodes that is similar in properties to Soreil cement. To remove the obtained layer from the electrodes, it is necessary to use a special cleaning mode, for example, alternate the pulsed power supply and intensive (continuous) shaking of the electrodes. An additional (second) source of light 7 is used to obtain information on entering the measurement zone (i.e., electrostatic precipitators) of soot particles, which determine the inoperative mode of cleaning the electrodes. The light rays from the source 6, after passing through the controlled volume, carry information about the darkness of the latter (optical density), composed of dust and soot particles (from the combustion of fuel oil). The light rays from source 7 fall on the meter 8 after reflection from the clock.

Particles in the controlled volume of the dust pipe 3. The reflection of light rays comes from solid particles of ash, black particles, approaching in their characteristics to the black body, mainly absorb rays from source 7. Therefore, from the latter, the meter 8 reports only the amount of solid particles. ash type particles. The extraction of information on the presence of carbon black in a controlled volume is performed by supplying synchronous power pulses to sources 6 and 7 from synchronizer 11 through blocks 9 and 10 of power. The impulse supplied to the power supply of the first source 6 after passing through the controlled volume and conversion in the meter 8 is fed to the delay circuit 4, where it is delayed for a predetermined period of time before the second pulse arrives at the second source 7. This pulse is transformed at source 7 light, enters the meter 8 and carries information about the presence of solid particles, excluding sooty. On the emitter 5, a signal is delayed from the common signal from the circuit 4, proportional to the amount of ash. The resulting differential signal carries information on the presence of ash in the monitored volume and goes to control unit 12 to change the operating mode of the electrostatic filters. The pulse frequency depends on the characteristics of the fuel, electrostatic precipitators and can be selected within 10–20 s. The duration of the pulses is 1 s.

The unit 12 of the control of the electrostatic precipitator (figure 2) is made in the form of the scheme And

14, adder 13 and switch (relay)

15. The adder 13 provides the addition of information from two sources 6 and 7 further supply to the switch, the position of which in this case corresponds to the cleaning mode of the electrodes. Admission to one of the inputs of the circuit

And the 14th signal about the presence of soot, ensures its operation, since a constant voltage is applied to its second input. The operation of the circuit And 14 causes the switch to switch to the second position, corresponding to the non-working mode of electrode cleaning, for example, continuous shaking.

Sources 6 and 7 and radiation meter 8 are installed with a gap relative to the outer wall of the dust pipe, as in this case air is allowed to leak from the atmosphere into the cavity of the dust pipe, which clears the sensitive elements of the dust meter by its flow.

The synchronizer 11 also adjusts the delay time in circuit 4, since the duration of the first pulse is longer

1570780

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five

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five

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in scheme 4. The synchronizer 11 can be made of a mechanical type in the form of a drum with contacts and a synchronous motor, as well as an electronic one in the form of a generator and I.

Claims (1)

Invention Formula The device for controlling the electrostatic precipitator, maintaining the power units of the electrostatic precipitator sections, the shaking mechanisms of the electrodes with the dust conductor, the delay circuit, the subtraction unit, the first light source with the power supply unit and the light emission meter are different in order to increase the degree of cleaning gas from dust, it additionally contains a second light source with a power unit, a control unit and a synchronizer, while the second light source is: normal to the optical axis the first source and light meter, each light source is connected via the corresponding power supply unit to the first and second outputs of the synchronizer respectively, the third output of which is connected to the control input of the delay circuit, the light meter output is connected to the input of the delay circuit, the first inputs of the readout unit and the control unit, the output of the delay circuit is connected to the second input of the subtraction unit, the output of which is connected to the second input of the control unit, and the outputs of the control unit with dineny with power units and mechanisms shaking electrodes. Jl jl t t FIG. 2