Electrostatic precipitator power supply
AssigneeSiemens Aktiengesellschaft
InventorsRichard Dallhammer, Franz Neulinger, Walter Schmidt, Helmut Schummer
Life of this patent
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Abstract
An electrostatic precipitator is supplied with a d-c voltage of variable level upon which is superimposed a series of voltage pulses. For each voltage pulse, the difference between a positive current-time area and a negative current-time area beneath a current-voltage curve is determined and maximized by changing the pulse amplitude, pulse width, pulse repetition frequency and/or the rate of pulse rise. In addition, the d-c voltage is controlled to have a value at a point of maximum slope of the function of precipitator current with respect to the magnitude of the d-c voltage.
Claims19
A method for electrically energizing an electrostatic precipitator, comprising the steps of:
- generating a d-c voltage of amplitude variable in accordance with precipitator breakdown thresholds;
- transmitting said d-c voltage to said electrostatic precipitator;
- generating a series of voltage pulses characterized by a plurality of parameters including d-c potential level, pulse amplitude, pulse width, pulse repetition frequency and rate of voltage rise, at least one of said parameters being variable;
- transmitting said voltage pulses to said electrostatic precipitator over a primary winding and a second winding of a high-voltage transformer, thereby superimposing said voltage pulses on said d-c voltage;
- sensing a current of at least of said voltage pulses;
- generating an electrical signal indicative of said current;
- automatically determining from said electrical signal a difference between a positive area under a current-time curve for said sensed current and a negative area under such current-time curve;
- and
- automatically varying at least one of said plurality of parameters in response to said difference to increase the value of said difference.
An apparatus for electrically energizing an electrostatic precipitator, comprising:
- first voltage generating means for generating a d-c voltage of amplitude variable in accordance with precipitator breakdown thresholds, said first voltage generating means being operatively connected to said electrostatic precipitator, whereby said d-c voltage is transmitted to said electrostatic precipitator;
- second voltage generating means for generating a series of voltage pulses characterized by a plurality of parameters including d-c potential level, pulse amplitude, pulse width, pulse repetition frequency and rate of voltage rise, at least one of said parameters being variable, said second voltage generating means being operatively connected to said electrostatic precipitator over a primary winding and a second winding of a high-voltage transformer, whereby said voltage pulses are transmitted to said electrostatic precipitator and superimposed on said d-c voltage;
- current detector means operatively connected to said second voltage generating means for sensing a current of at least one of said voltage pulses and for generating an electrical signal indicative of said current;
- calculation means operatively connected to said current detector means for automatically determining from said electrical signal a difference between a positive area under a current-time curve for said detected current and a negative area under such current-time curve;
- and
- control means operatively coupled to said calculation means automatically varying at least one of said plurality of parameters in response to said difference to increase the value of said difference.
Dependencies are inferred from the claim text.