US 5,477,464 AGranted

Method for controlling the current pulse supply to an electrostatic precipitator

AssigneeABB Flakt AB

InventorHans Jacobsson

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Abstract

The present invention relates to a method for controlling, in an electrostatic precipitator unit comprising discharge electrodes and collecting electrodes between which a varying high voltage is maintained, a pulsating direct current supplied to these electrodes. In the method according to the invention the frequency, pulse charge and/or pulse duration of the pulsating direct current are caused to vary such that a plurality of combinations of frequency, charge and duration are obtained. For each of these combinations, the voltage U between discharge electrodes and collecting electrodes is measured, and for each of these combinations, a voltage level U.sub.ref is determined, measured or calculated. In a defined time interval, for each of these combinations, either the integral I.sub.k =.intg.U.multidot.(U-U.sub.ref).dt is measured and/or calculated during the time interval, or A.sub.i =U.multidot.(U-U.sub.ref) is measured at a number of points of time, whereupon I.sub.k or linear combinations of A.sub.i are used to select the combination of frequency, charge and duration of the pulsating direct current.

Claims20

Dependent claims

A method for controlling, in an electrostatic precipitator unit comprising discharge electrodes and collecting electrodes between which a varying high voltage is maintained, said method comprising the steps of:

supplying a pulsating direct current to said electrodes;
causing at least one of frequency, pulse charge and pulse duration of a pulsating direct current applied to said electrostatic precipitator to vary thereby obtaining a plurality of combinations of frequency, charge and duration;
measuring for each of said combinations a voltage U between said discharge electrodes and said collecting electrodes;
determining for each of said combinations a reference voltage level U.sub.ref ;
determining for each of said combinations one of an integral I.sub.k =.intg.U.multidot.(U-U.sub.ref).multidot.dt during a defined time interval, and a linear combination of A.sub.i =U.sub.i .multidot.(U.sub.i -U.sub.ref) at a number of points of time i in a defined time interval;
and
selecting an optimal combination of frequency, charge and duration of said pulsating direct current based on one of said integral I.sub.k and said linear combinations of A.sub.i to control the electrostatic precipitator.

4 more elements

Dependencies are inferred from the claim text.