SU1477476A1 - Control device for electrostatic precipitator consisting of n units - Google Patents

Abstract

The invention relates to the electrical cleaning of gases, can be used to remove dust from the combustion products emitted into the atmosphere, for example, thermal power plants, petrochemical and cement plants, and reduces atmospheric emissions by forcibly maintaining the voltage on the electrodes of subsequent sections of the electrostatic filter during removal marry with the previous one. A device for controlling an N-section, for example, a three-section, electrostatic precipitator in each section contains 6,9,12 power units, a master frequency generator 31-33, RS-TRigger 22-24 and a block 34-36 STANDARD SETTING TRIGGER, B of the FIRST Section Single ONE VIBRATOR 25, FORMER 28 and IMPLUSOV and ONE ELEMENT OR 37, in the second section and subsequent two single vibrators, respectively, 26.40 and 27.41, two elements, OR, 38.44 and 39.45, respectively, two pulse generators, respectively, 29.42 and 30.43. At the same time, in each section, the initial setup block of the trigger is 34-36 and the power unit, respectively, 6.9 and 12, respectively, through the corresponding element OR 37-39 CONNECTED To the R input of the corresponding trigger 22-24, the output of which is connected to the corresponding power unit 6.9 and 12 and through a serial connection of the corresponding pulse formers 28-30 and one-shot 25-27 connected to the power unit. The master frequency generator 31 in the first section is connected to R - trigger input 22. In each section, starting with the second one, the output of the second one-vibrator, respectively, 40.41, is connected to the inputs of the corresponding master frequency generator 32.33 and the second pulse driver 42-43, the outputs of which through the corresponding second element OR 44.45 with S - the input of the corresponding trigger 23,24, and the input of the second one-vibrator of each subsequent section, respectively 40,41, is connected to S - the entrance of the trigger of the previous section 22 and 23 respectively.

Description

one

The invention relates to the field of electrical gas cleaning and can be used in electrostatic precipitators for gas cleaning of thermal power plants, enterprises of the petrochemical and pulp and paper industries, ferrous metals and nonferrous metallurgy, as well as the building materials industry.

The aim of the invention is to reduce dust emissions into the atmosphere during the cleaning process of electrodes of different sections.

The drawing shows a block diagram of a device for controlling a p-section electrostatic precipitator (a case of controlling a three-section electrostatic precipitator is considered).

The block diagram contains three sections of an electrostatic precipitator, 1-3, respectively, with corona and collecting electrodes, each of which is connected to the high voltage terminals of its power supply unit. Section 1 conc. To the terminals 4 and 5 of the unit 6 pi / dzhi, section 2 - to the terminals 7 and 8 of the power unit 9, and section 3 to the terminals 10 and 11 of the power unit 12. Each power supply unit at the input is connected to an AC mains supply and contains phase shift blocks (BFS), respectively, 13-15, control pulse formers (BFIU), 16-18, respectively, and breakdown units (sensors), respectively, 19-21. The power unit of each section is connected to its own control circuit, with each circuit

control unit 6-12 power contains RS-flip-flop, respectively 22-24, one-shot respectively 25-27, pulse shaper, respectively 28-30, the master oscillator

5 frequencies, respectively, 31-33, the initial setup block of the trigger, respectively 34-36 and the scheme of the elements OR, respectively, 37-39. In addition, each unit control circuit

0 9 and 12 power supplies contain the second single-vibrator, respectively, 40 and 41s, and the second pulse shaper, respectively, 42 and 43, and the second element, OR, respectively, 44 and 45, and the geneoatoms 32 and 33 of the setting frequency are equipped with a control input. The outputs of blocks 19 and 34,, and 20. 35, 21 and 36, respectively, through the OR elements 37-39 are connected to the R-input of the flip-flops 22-24 of the respective control circuits, and the output of the master frequency generator 31 is connected to the S-input of the flip-flop 22 and to the input of the one-oscillator AO. The output of the one-vibrator 40 is connected to the inputs of the generator 32 of the driving frequency and the formation of the body 42 of pulses, which through the OR element 44 are connected to the S-input of the trigger 23 and to the input of the one-vibration 41. The output of the one-frequency 41 is connected to the inputs of the generator 33 of the driving frequency and the driver 43 of the pulses which are connected to the S-input of the trigger 24 via the element OR 45. The outputs of the triggers 22-24 are connected respectively to the BFS 13-15 and through the formers 28-30 and the single-oscillators 25-27 with the BFIU 16-18. In addition, the input of the second one-shot of each subsequent section, starting with the second, respectively 40 and 41, is connected to the input of the trigger of the previous section, respectively 22 and 23.

The device works as follows.

The power units 6, 9 and 12, controlled respectively by BFS 13-15, BFIU 16-18 and the corresponding breakdown blocks, convert the alternating voltage at the input to a high rectified voltage at the output (pins 4 and 5 for the first section 1, 7 and 8 for the second section 2 and 10 and P for the third section 3). Under the action of high voltage on the electrodes of the sections of the electrostatic precipitator, dust particles are trapped from the gas flow and deposited on the electrodes. To clean the latter from a layer of dust settled, the voltage from the electrodes is abruptly removed during their cleaning. For this, the master frequency generator, respectively 31–33, alternates with a next pulse the corresponding trigger 22–24 to the state in which a signal appears at its output, which leads to a decrease in the phase angle of the control pulses, and the voltage on the electrostatic precipitator electrodes begins to increase Electrostatic precipitator sample. In the case of breakdown, the voltage from the electrodes decreases sharply, at the output of the breakdown block, respectively, 19–21, a signal arises, which, via the corresponding element OR 37–39, switches the corresponding trigger 22–24 to the initial state. The signal at the trigger output will disappear. Rear

77476 4

the front of this signal starts i the corresponding driver 28-30 pulses and starts the corresponding one-shot 25-27. The impulse of the latter is blocked by the corresponding BFS 13-15. As a result, the voltage at the terminals of the power unit is not restored. During

10, the entire pulse duration of the indicated one-shot (1–20 s) voltage across the electrodes is absent and the collapse of the layer of settled dust from the electrodes occurs. After this time elapses, the voltage across the electrodes is restored and the gas cleaning process continues.

At the same time, during the specified time, gas cleaning in the corresponding section of the electrostatic precipitator, for example, the first, does not occur and the dust-laden gas enters the second section, where it should be cleaned. An indispensable condition for this is that the voltage on the electrodes of section 2 is high. This is ensured by the fact that the pulse that appears at the output of the frequency-setting generator 31 triggers the one-shot 40 on section 2. At the output of the one-shot, there is a pulse that blocks on the control input generator 32 of section 2, and the voltage across the electrodes of the latter is maintained. The next shaking of the electrodes of the second floor will occur when the pulse at the output of the one-shot 40 stops, and its back front starts the pulse shaper 42, which through the element OR 44 switches 40 trigger 23. The further process will occur as described.

In exactly the same way will be forced to maintain voltage

45 on the electrodes of section 1 during the cleaning of the electrodes of section 2, and so on, up to the n section.

So that the voltage on the electrodes of the next section cannot

50 disappear before the previous electrode cleaning process is completed; the pulse duration at the output of the second one-vibrator of the next section must be longer than

55 pulses at the output of the one-shot of the first previous section for the time of voltage rise from the initial level to the breakdown of interelectrode gaps. This time may be 0.02-10 s.

51

Claims (1)

Invention Formula A device for controlling a p-section electrostatic precipitator containing, in each section, a power unit with a phase displacement unit, a driver for controlling pulses and a probe, connected to the electrodes of this section, an RS trigger, a master frequency generator, an OR element, a single vibrator, a driver pulses and the initial setup of the trigger, while in each section the initial setup of the trigger and the probe sensor through the OR element are connected to the trigger trigger, the output of which is connected to the phase displacement unit and through pulse shaper and one-oscillator - with a pulse shaper The generator and the frequency adaccic generator in the first section are connected to the S-input of the trigger, characterized in that, in order to reduce dust emissions into the atmosphere during the cleaning of the electrodes of different sections, the second and subsequent sections additionally contain a second one-shot, the second pulse driver and the second element OR, in each section, starting with the second, the output of the second one-shot is connected to the inputs of the master frequency generator and the second pulse generator, the outputs of which are connected to the S-input through the second OR element trigger and the input of the second monostable each subsequent section is connected to the S-input of the flip-flop of the previous section.