The invention relates to a method for the selective purification of aerosols. The invention consists in electrostatically collecting all of the particles present in an aerosol, but with separation of the mechanisms on one hand for charging particles by unipolar ion diffusion in order to charge and then collect the finest particles, and on the other hand for charging particles by means of Corona discharge in order to charge and then collect the largest particles on a substrate different from the substrate for collecting the finest particles.

Disclosed herein is provide an electrostatic precipitator capable of allowing a charger to be thin while suppressing ozone generation. The electrostatic precipitator 1 includes a charger 10 provided with a high voltage electrode 11 receiving a high voltage from a high voltage generating circuit 40 and a counter electrode 12 facing the high voltage electrode 11 and receiving a reference voltage from the high voltage generating circuit 40, and configured to charge suspended particles by generating a discharge between the high voltage electrode 11 and the counter electrode 12; and a dust collector 20 disposed in the downstream side of an air flow direction of the charger 10 and configured to collect the suspended particles charged by the charger 10.

An electrostatic precipitator for removing particulates from boiler fine gas is provided. The electrostatic precipitator comprises discharge electrodes and collecting electrodes fitted in a gas passage, the electrodes being arranged in at least two electrical fields that are placed successively in relation to gas flow, and the electrical field establishing at least one electrical unit in transversal direction of said gas passage. The at least one electrical unit has the ability to be de-energised independently, separately from the other electrical units of the electrostatic precipitator. The first electrical field of the at least two electrical fields is also arranged first in the gas flow, and the first electrical field comprises more electrical units than a second field following the first field.

An apparatus and method of generating ozone and its incorporation into a system apparatus and method of cleaning exhaust gasses from fossil fuel burning boilers and/or furnaces are disclosed.

A flux recovery device recovers a vaporized flux being generated at a time of soldering an electronic circuit board on which electronic components are placed. The flux recovery device includes a first pipe, a dust collector, and a current controller. The first pipe causes gas including the vaporized flux to pass to the flux recovery device. The dust collector solidifies the vaporized flux passed through the first pipe and collects dust, by a plasma discharge. The current controller performs a constant current control of the plasma discharge.

The invention relates to a method and device for collecting nanoparticles which may be present in an aerosol. The invention consists of electrostatically collecting nanoparticles contained in an aerosol by a mechanism of particle charging by unipolar ion diffusion, followed by the application of a field without a corona effect, which makes it possible to deposit the particles in concentric rings on different parts of a single flat substrate oriented orthogonally to the aerosol circulation direction. The biggest particles are deposited towards the centre of the flat substrate and the finest particles towards the periphery of the flat substrate. The invention also relates to a method of operation and to the use of such a device for evaluating the exposure of workers or consumers to nanoparticles.

An electric dust collecting device according to the invention includes an electric charging unit for electrically charging dust in air, a first filter unit including a plurality of discharge electrode plates spaced apart from each other to define passages therebetween through which dust electrically charged by the electric charging unit passes, and a second filter unit disposed downstream of the plurality of discharge electrode plates in an air flow direction and connected to a ground to cause corona discharge between the plurality of discharge electrode plates and the second filter unit and to collect electrically charged dust. Dust particles electrically charged by the electric charging unit pass through the passages of the first filter unit and then are collected at the second filter unit, and dust particles electrically charged between the first filter unit and the second filter unit are electrically charged by the second filter unit, thus improving electric charging efficiency and dust collecting efficiency.

The subject of the invention is a procedure, a filter module, and an air cleaning device composed of such filter modules for the highly efficient cleaning of air containing small contaminating particles. In the course of the procedure, the principle of adhesion and repelling effect is exploited to capture the contaminating particles in the device composed of an appropriate number of filter modules (1). The air to be cleaned is moved like a quasi-electrodynamic linear engine in the device, so that the mass and/or size of the coagulated particles is increased by the powers of two as necessary while passing through two sequential filter modules (1), up to 2.sup.20 value. This way, the flow velocity of the fine grains with increased mass is decreasing gradually and they are separated or fall out from the flow space, meaning that particles with a starting size below 1 micrometre, in the nano-range, which are the most harmful to the human body, may also be captured. The essential part of the invention is the filter module (1) that is fitted with electrodes (7), composed of a collector (5) and a separator (6) located at a given distance, which are connected to a positive or negative high voltage (8, 9) and are surrounded by a cover consisting of a base plate, connected to zero potential (10), side plates, and a cover plate. Two electrodes (7) form an electrode pair, and two electrode pairs form a filter module (1), where the electrode pairs are placed so that there is one electrode (7) of the opposite potential installed between two electrodes (7) of the same potential. The solution according to the invention may be used in versatile ways, especially on the field of civil environmental protection, as stand-alone, pre-, or post-filter, such as for cleaning the air and exhaust gas in the chimney of industrial plants, for cleaning polluted urban air, for cleaning, de-germination, and filtering pollen from the air of closed premises, and for military purposes on the field of NBC safety as a pre-filter.

The present invention removes, by a preprocessing unit, harmful chemical materials and radioactive materials supplied to a positive pressure chamber and a negative pressure chamber and supplies same, removes contaminants discharged to the outside from the negative pressure chamber and sterilizes bacteria and floating viruses and discharges same, and adjusts, by a control circuit of a control panel, the rotating speed (RPM) of an air supply/discharge fan and adjusts the opening rate of an electric damper according to data that is measured in a pressure sensor provided in a space in which the positive pressure and the negative pressure are to be maintained and is transmitted in real time.

Particle measurement apparatus comprises an inlet for receiving a gas sample for analysis, a photoionisation chamber, at least one light source arranged to illuminate an interior of the photoionisation chamber, first and second electrodes coupled to a power source and configured to provide a DC potential difference across at least a portion of the photoionisation chamber, and an outlet, together defining a gas flow path from the inlet, through the photoionisation chamber, and towards the outlet.