Apparatus for electrode rapper control

Claim 1

An electrostatic precipitator having electrodes, rapping means therefor, and an electronic logic control for regulating the frequency and duration of rapper energization comprising: a clock pulse generator circuit for producing a series of clock pulses at a selected frequency having first and second logic levels; a ripple counting circuit operative in response to first and second logic levels of said clock pulses to produce monitoring sequence pulses having first and second logic levels; a load sensing circuit operable to sense the particle load magnitudes collected on different selected ones of said electrodes and produce in response to said sensing load pulses having first and second logic levels indicative of a desired rapping on-time and off-time respectively as defined within a maximum and minimum desired particle load magnitude for each of said different selected ones of electrodes; a decoding monitor circuit operable in response to said first and second logic levels of said monitoring sequence pulses and to said load pulses for sequentially monitoring said load pulses and selectively producing rapper driving pulses having first and second logic levels, said rapper driving pulses being produced in separate output channels corresponding in number to and respectively associated with each of said different selected ones of electrodes and being sequentially selected by said first and second logic levels of said monitoring sequence pulses when the on-time is indicated by said first and second logic levels of the respective one of said load pulses then being monitored; a rapping means driving circuit having associated channels for connecting said rapper driving pulses to respective ones of said rapping means respectively associated with said different selected ones of said electrodes for energization; means responsive to said first and second logic levels of said rapper driving pulses to interrupt the feed of said series of clock pulses to said ripple counting circuit during said rapping on-time and activate the feed of said series of clock pulses to said ripple counting circuit during said rapping offtime; and an on-timer circuit operable in response to said first and second logic levels of said rapper driving pulses for timing a maximum allowable duration of energization of any of said rapping means and reactivating the feed of said series of clock pulses to said ripple counting circuit in the event said maximum time is attained.