An air-conditioning apparatus including an electrical precipitator part that has an electric discharge electrode having a body portion and corona discharge portions being for corona discharge and protruding from the body portion, and a collecting electrode that is provided opposite the electric discharge electrode, and an medium-efficiency particulate air filter part that is provided downstream of the electrical precipitator part , wherein the collecting electrode is a plate-shaped member, a plate surface thereof is provided parallel to a gas flow direction, and the corona discharge portion has a first corona discharge section that protrudes from the body portion at one side end of the body portion, upstream in the gas flow direction, and a second corona discharge section that protrudes from the body portion at the other side end of the body portion, downstream in the gas flow direction.

An electrostatic device, for example, an electrostatic air cleaner, may be provided with a corona discharge electrode; a collecting electrode; a power source connected to the corona discharge electrode and to the collecting electrode; an electrical parameter sensor; and a power supply system. The control system may receive a signal from the electrical sensor. The control system evaluates the electrical performance of the system and initiates appropriate or corrective action.

An electrostatic device, for example, an electrostatic air cleaner, may be provided with a corona discharge electrode; a collecting electrode; a power source connected to the corona discharge electrode and to the collecting electrode; an electrical parameter sensor; and a power supply system. The control system may receive a signal from the electrical sensor. The control system evaluates the electrical performance of the system and initiates appropriate or corrective action.

An electrostatic air cleaner may be operated according to a manner designed to achieve acceptable air quality while balancing power usage and corona electrode degradation levels. The voltage applied to the corona electrode(s) may be controlled as well as the voltage applied to repelling electrodes and air flow velocity. The air cleaner may also be operated to achieve desired particle separation.

An electrostatic air cleaner may be operated according to a manner designed to achieve acceptable air quality while balancing power usage and corona electrode degradation levels. The voltage applied to the corona electrode(s) may be controlled as well as the voltage applied to repelling electrodes and air flow velocity. The air cleaner may also be operated to achieve desired particle separation.

A wet-type electric dust collection device and low-concentration SO.sub.3 mist containing, in which the wet-type electric dust collection device has an electrical field formation part in which a plurality of discharge electrodes are provided on opposing surfaces of a first electrode and second electrodes for forming a DC electrical field. The discharge electrodes of the first electrode and the discharge electrodes of the second electrodes generate corona discharges that are reversed in polarity relative to each other. The gas containing the SO.sub.3 mist and the dust is guided to the electrical field formation part without electrically charging the SO.sub.3 mist and the dust or spraying a dielectric in the gas, and while the gas flows between the electrodes, the corona discharges impart electric charges of alternately reversed polarity to the SO.sub.3 mist and the dust. The first electrode and the second electrodes collect the charged SO.sub.3 mist and dust.

A wet-type electric dust collection device and low-concentration SO.sub.3 mist containing, in which the wet-type electric dust collection device has an electrical field formation part in which a plurality of discharge electrodes are provided on opposing surfaces of a first electrode and second electrodes for forming a DC electrical field. The discharge electrodes of the first electrode and the discharge electrodes of the second electrodes generate corona discharges that are reversed in polarity relative to each other. The gas containing the SO.sub.3 mist and the dust is guided to the electrical field formation part without electrically charging the SO.sub.3 mist and the dust or spraying a dielectric in the gas, and while the gas flows between the electrodes, the corona discharges impart electric charges of alternately reversed polarity to the SO.sub.3 mist and the dust. The first electrode and the second electrodes collect the charged SO.sub.3 mist and dust.

Provided is a solvent separation method and a solvent separation apparatus in which a vaporized solvent is collected at one internal side of a solvent separation unit by attracting the vaporized solvent based on electric field, while the vaporized solvent is prevented from coming into contact with electrodes, and the collected solvent is discharged from the solvent separation unit. Different electric fields are alternately applied to a pair of first electrodes and a pair of second electrodes present at predetermined locations inside a tetragonal tubular solvent separation unit to attract a vaporized solvent toward the second electrodes. Thus, the vaporized solvent is collected in a space between the second electrodes inside the solvent separation unit, and the collected solvent is discharged from the solvent separation unit, together with a portion of the exhaust atmosphere present around the collected solvent.

Provided is a solvent separation method and a solvent separation apparatus in which a vaporized solvent is collected at one internal side of a solvent separation unit by attracting the vaporized solvent based on electric field, while the vaporized solvent is prevented from coming into contact with electrodes, and the collected solvent is discharged from the solvent separation unit. Different electric fields are alternately applied to a pair of first electrodes and a pair of second electrodes present at predetermined locations inside a tetragonal tubular solvent separation unit to attract a vaporized solvent toward the second electrodes. Thus, the vaporized solvent is collected in a space between the second electrodes inside the solvent separation unit, and the collected solvent is discharged from the solvent separation unit, together with a portion of the exhaust atmosphere present around the collected solvent.

An electrostatic precipitation air cleaning system for removing mist, smoke or particles from an air stream. The electrostatic precipitation air cleaning system includes an ionizer, a collector, and an exhaust fan configured to draw the air stream through the ionizer and the collector. The electrostatic precipitation air cleaning system includes a high voltage power supply that provides an ionizer voltage to the ionizer and at least a first collector voltage and a second collector voltage. The electrostatic precipitation air cleaning system includes an electrostatic precipitator controller coupled to or integrated with the high voltage power supply and operable to select one of the at least the first collector voltage and the second collector voltage to provide to the collector.