(19)
(11) EP 0 103 950 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
26.09.1984 Bulletin 1984/39

(43) Date of publication A2:
28.03.1984 Bulletin 1984/13

(21) Application number: 83304133

(22) Date of filing: 15.07.1983
(84) Designated Contracting States:
CH DE FR GB IT LI SE

(30) Priority: 28.07.1982 GB 8221806

(71) Applicant: F.L. Smidth & Co. A/S
 ()

(72) Inventors:
  • Henriksen, Henrik c/o Nea Lindberg A/S
     ()
  • Taarning, Claus Ebbe
     ()

   


(54) Method of protecting a thyristor switch of a pulse generator for an electrostatic precipitator


(57) To protect a thyristor switch in a pulse generator for an electrostatic precipitator it is desirable to control the spark-over rate in the precipitator. A first spark-over starts a measurement of the difference between the number of spark-overs and the number of times a pre-selected cooling period (pk) has passed after the first spark-over and the measurement is stopped when the difference becomes 0. The measurement is started again the next time a spark-over occurs and one or more relevant running parameters of the precipitator are influenced in such a way as to diminish the probability of a further spark-over when the difference exceeds a given value.






Search report