In a plasma air dust collector, the plasma air dust collector includes a first electrode fixing unit and a second electrode fixing unit respectively having a power terminal; at least two dust collecting electrodes; a discharge electrode arranged between the dust collecting electrodes; a terminal protrusion formed at the bottom end of each dust collecting electrode in the length direction; a terminal protrusion insertion hole formed at a side of the first electrode fixing unit; a combining protrusion formed at a side of the first electrode fixing unit and the second electrode fixing unit; and a combining groove formed at the both ends of each dust collecting electrode.

In an apparatus for the purification of a gas which apparatus includes a three section conduit with an ionization and cleaning section in which particles contained in water-saturated air are ionized and then conducted through a chamber with grounded walls so that part of the particles are deposited on these walls, an additional cleaning section which includes grounded tubes past which the gas is conducted to remove additional charged particles and a filter section in which dry remaining fine particles are removed from the gas stream, the deposited particles are flushed from all three sections and the flushing water including the particles is cleaned and recycled.

A discharge device for generating a streamer discharge includes a discharge electrode and a counter electrode. The discharge electrode is in a shape of a wire or rod and is disposed substantially parallel to the counter electrode. Thus, even when a tip of the discharge electrode becomes worn out, a shape of the tip of the discharge electrode remains unchanged and a distance between the discharge electrode and the counter electrode remains unchanged. As a result, even when the tip of the discharge electrode becomes worn out, the streamer discharge stability will not fall.

A gas treating device capable of electrically collecting dust and of decomposing odors and other matter by plasma includes a plasma generating device integrally incorporated into an ionization part in a casing. The ionization part has an ionization line and a columnar portion of a negative electrode member. The plasma generating device includes a discharge electrode which shares a counter electrode with the ionization line. During operation, dust of a relatively small size in room air is electrically charged by discharge between the ionization line and the counter electrode. An electrostatic filter entraps and collects the electrically charged dust. A plasma of low temperature is generated by streamer discharge between the discharge electrode and the counter electrode. Harmful substances and odorous substances in the room air are decomposed by an activated species contained in the generated low-temperature plasma.

A method of repairing an electrostatic precipitator, including building a temporary support truss assembly, supporting the temporary truss assembly at the level of the hot roof of the electrostatic precipitator, transfeffing the weight of the internal components of the electrostatic precipitator from the upper girders to the temporary truss assembly, repairing or replacing the upper girders of the electrostatic precipitator, and then transferring the weight of the internal components to the repaired or replaced upper girders.