High-voltage pulse generating circuit and electrostatic recipitator containing it

• US 5,623,171 A
• Filed: 12/18/1995
• Issued: 04/22/1997
• Est. Priority Date: 09/14/1989
• Status: Expired due to Fees

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Nakajima, Shin
• Primary Examiner(s): Krishnan, Aditya
• Application Number:
  US08/573,863
• Time in Patent Office: 491 Days
• Field of Search: 323/247, 323/249, 323/259, 307/108, 307/110, 307/282, 307/106
• US Class Current: 307/106
• CPC Class Codes: B03C 3/68 Control systems therefor electricity supply or control systems for cleaning the electrodes B03C3/746, B03C3/763
• CPC Class Codes: H03K 17/80 using non-linear magnetic devices; using non-linear dielectric devices H03K17/95, H03K17/97 take precedence
• CPC Class Codes: H03K 3/55 the switching device being a gas-filled tube having a control electrode
• CPC Class Codes: H03K 3/57 the switching device being a semiconductor device

Abstract

A high-voltage pulse generating circuit of a charge transfer-type comprising a main capacitor for storing input energy and at least one magnetic pulse compression circuit comprising a saturable reactor, a saturable reactor on the side of a load comprising an energy recovery winding connected to the main capacitor via a rectifying element for returning unconsumed pulse energy from the load to the main capacitor. This circuit is suitable for an electrostatic precipitator.

Claims

1. A high-voltage pulse generating circuit of a charge transfer-type comprising:

a main capacitor for storing input energy,

a transformer, having a primary winding and a secondary winding, connected between said main capacitor and a load,

at least one magnetic pulse compression circuit comprising a saturable reactor, and an energy recovery circuit for returning unconsumed pulse energy from said load to said main capacitor,

said saturable reactor being connected to an output winding of said at least one magnetic pulse compression circuit, to said secondary winding of said transformer, and to an energy recovery winding, said energy recovery winding being connected in parallel to said main capacitor, and

a rectifying element inserted between said energy recovery winding and said main capacitor.

2. The high-voltage pulse generating circuit according to claim 1, wherein a reset circuit is provided for changing an operating magnetic flux density of said saturable reactor depending upon an input power supply voltage.

3. The high-voltage pulse generating circuit according to claim 1, wherein said load is an electrostatic precipitator.

4. The high-voltage pulse generating circuit according to claim 2, wherein said load is an electrostatic precipitator.

7. The high-voltage pulse generating circuit according to claim 2, wherein said high-voltage pulse generating circuit further comprises another saturable reactor connected to an output winding and to another reset winding of said reset circuit.

5. An electrostatic precipitator circuit comprising:

a high-voltage pulse generating circuit which includes a main capacitor for storing input energy,

a transformer, having a primary winding and a secondary winding, connected between said main capacitor and a load,

and at least one magnetic pulse compression circuit, connected to said secondary winding of said transformer, comprising a first saturable reactor, a second saturable reactor on the side of said load, said second saturable reactor comprising an energy recovery winding connected to said main capacitor via a rectifying element for returning unconsumed pulse energy from said load to said main capacitor, where the magnetic flux density of the saturable reactor is set such that the saturable reactor is saturated only during the period in which energy is supplied to the load, and not saturated when unconsumed energy is recovered from the load.

6. The electrostatic precipitator circuit according to claim 5, wherein said saturable reactor comprises a reset circuit for changing an operating magnetic flux density of said saturable reactor depending upon an input power supply voltage.