Abstract: A sampler apparatus is disclosed. The sampler apparatus comprises an impactor assembly comprising a nozzle plate, an impaction plate, and a filter unit. The nozzle plate comprises a plurality of nozzles for channelling an air stream through the sampler apparatus. The impaction plate is adapted to collect particulate matter having size equal to or greater than a threshold size. The filter unit is adapted to collect particulate matter having size less than or equal to the threshold size. The sampler apparatus further comprises a control assembly coupled with the impactor assembly. The control assembly comprises one or more flow control devices to maintain a predetermined air-flow rate of the air stream within the sampler apparatus.

Abstract: A semi-dry type method for automatically sampling PM2.5 particles. The method collects an aerosol sample in a dry mode and extracts it in a wet mode to prevent sampling artifacts. In the dry mode, a first stage utilizes carbon brushes as discharge electrodes to charge aerosol particles which are then collected on a cylinder wall by an electric field setup between a high-voltage central metal rod and a grounded cylinder in a second stage. In the wet mode, deionized (DI) water is injected into an electrostatic particle-into-liquid sampler (EPILS) in a pulsation manner by opening and closing solenoid valves intermittently, which dislodges aerosol particles deposited on the cylinder wall effectively to become a liquid aerosol sample. The liquid aerosol sample is then analyzed for chemical compositions automatically.

Abstract: The present invention discloses a semi-dry type method for automatically sampling PM2.5 particles. The method an aerosol sample in a dry mode and extracts it in a wet mode to prevent sampling artifacts. In the dry mode, a first stage utilizes carbon brushes as discharge electrodes to charge aerosol particles which are then collected on the cylinder wall by the electric field setup between the high-voltage central metal rod and the grounded cylinder in the second stage. In the wet mode, DI water is injected into the EPILS in a pulsation manner by opening and closing solenoid valves intermittently, which dislodges aerosol particles deposited on the cylinder wall effectively to become a liquid aerosol sample. The liquid aerosol sample is then analyzed for chemical compositions automatically.

Abstract: The present invention discloses an efficient electrostatic particle-into-liquid sampler (EPILS). The EPILS collects an aerosol sample in the dry mode and extracts it in the wet mode to prevent sampling artifacts. In the dry mode, a first stage utilizes carbon brushes as discharge electrodes to charge aerosol particles which are then collected on the cylinder wall by the electric field setup between the high-voltage central metal rod and the grounded cylinder in the second stage. In the wet mode, DI water is injected into the EPILS in a pulsation manner by opening and closing solenoid valves intermittently, which dislodges aerosol particles deposited on the cylinder wall effectively to become a liquid aerosol sample. The liquid aerosol sample is then analyzed for chemical compositions manually or automatically.

Abstract: The present invention discloses an efficient electrostatic particle-into-liquid sampler (EPILS). The EPILS collects an aerosol sample in the dry mode and extracts it in the wet mode to prevent sampling artifacts. In the dry mode, a first stage utilizes carbon brushes as discharge electrodes to charge aerosol particles which are then collected on the cylinder wall by the electric field setup between the high-voltage central metal rod and the grounded cylinder in the second stage. In the wet mode, DI water is injected into the EPILS in a pulsation manner by opening and closing solenoid valves intermittently, which dislodges aerosol particles deposited on the cylinder wall effectively to become a liquid aerosol sample. The liquid aerosol sample is then analyzed for chemical compositions manually or automatically.

Abstract: A sampler apparatus is disclosed. The sampler apparatus comprises an impactor assembly comprising a nozzle plate, an impaction plate, and a filter unit. The nozzle plate comprises a plurality of nozzles for channelling an air stream through the sampler apparatus. The impaction plate is adapted to collect particulate matter having size equal to or greater than a threshold size. The filter unit is adapted to collect particulate matter having size less than or equal to the threshold size. The sampler apparatus further comprises a control assembly coupled with the impactor assembly. The control assembly comprises one or more flow control devices to maintain a predetermined air-flow rate of the air stream within the sampler apparatus.

Abstract: A semi-dry type electrostatic cyclone sampler includes a cyclone body, an insulate element, a discharge electrode, an air tube, an air introducing means, a discharging means and a flushing means. The insulate element is disposed at a top of the cyclone body and co-defines a cyclone chamber with the cyclone body. The discharging electrode is disposed on the insulate element. The air tube is disposed at a bottom of the cyclone body. The air introducing means is for introducing a particulate-containing air stream into the cyclone chamber. The discharging means is for charging the particulates so that the particulates can attach to an inside of the cyclone body. The flushing means is for flushing the inside of the cyclone body and collecting part of the particulates. When the discharging means activates, the air introducing means activates simultaneously. When the flushing means activates, the discharging means is deactivated.

Abstract: A semi-dry type electrostatic cyclone sampler includes a cyclone body, an insulate element, a discharge electrode, an air tube, an air introducing means, a discharging means and a flushing means. The insulate element is disposed at a top of the cyclone body and co-defines a cyclone chamber with the cyclone body. The discharging electrode is disposed on the insulate element. The air tube is disposed at a bottom of the cyclone body. The air introducing means is for introducing a particulate-containing air stream into the cyclone chamber. The discharging means is for charging the particulates so that the particulates can attach to an inside of the cyclone body. The flushing means is for flushing the inside of the cyclone body and collecting part of the particulates. When the discharging means activates, the air introducing means activates simultaneously. When the flushing means activates, the discharging means is deactivated.

Abstract: An electrostatic precipitator structure includes a dielectric plate arranged between two collecting electrode plates, which define an air flow channel. The dielectric plate divides the air flow channel into two sub-channels. A plurality of discharge wires are attached on in the upper and lower surfaces of the dielectric plate for generating corona discharge in the sub-channels. When a gas with particles passes through the sub-channels, the particles are charged by the ions produced by corona discharge and then migrate to the collecting electrode plates by electrostatic force. This electrostatic precipitator structure may avoid intensive particle contamination on the discharge wires, wherefore particle collection efficiency is enhanced. Further, due to the insulating dielectric plate immobilize the attached ions, the corona current and the ozone concentration is reduced, wherefore power efficiency is enhanced.

Abstract: A wet-film particle impactor includes a housing, a nozzle, an impact surface and at least one water inlet. The housing defines a chamber therein and has an air outlet and a water outlet. The nozzle is disposed on the housing and has a plurality of through holes in communication with an air inlet and the chamber. The water inlet is formed on the impact surface for introducing water into the chamber. Whereby, the wet-film particle impactor is adapted to introduce the particle-containing air stream into the chamber sequentially via the air inlet and the through holes. The particles in the air stream are collected by the impact surface. The water introduced from the water inlet flushes the impact surface, carries the particles collected by the impact surface, and then exits the chamber via the water outlet.

Abstract: A multi-filter PM 10-PM 2.5 sampler which enable the simultaneous collection of four PM 10 and four PM 2.5 samples is disclosed. The sampler is provided with a PM 10 impactor to remove coarse particles and operates at 33.4 L/min. After the PM 10 impactor, the aerosol flow is divided by half by a branch pipe. Half of the flow is directed into four PM 10 cassettes, while the other half is directed into four PM 2.5 cassettes after the aerosols are further classified by a PM 2.5 impactor. To ensure the aerosol flow uniformly passes through each of the four PM 10 or four PM 2.5 cassettes, an orifice plate is assembled behind each of the filter cassettes to increase the pressure drop, such that the flow rates of eight sampling lines are nearly equal.

Abstract: A portable nanoparticle sampler for collecting respirable particulate matters and nanoparticles is composed of a tangential flow cyclone, a multi-microorifice impactor and a filter cassette. The tangential flow cyclone can remove the microparticles with cutoff aerodynamic diameter (dpa) larger than 4 ?m and guide the airflow to the multi-microorifice impactor located below the cyclone. The multi-microorifice impactor includes a multi-orifice nozzle and a rotary impaction plate for enabling the microparticles with dpa from 100 nm to 4 ?m to be uniformly collected on a silicone-oil-coated impaction substrate. The remnant microparticles with dpa smaller than 100 nm are collected by the filter cassette. Therefore, compared with the prior art, the portable nanoparticle sampler is characterized by low pressure loss and accurate microparticle sizing to meet the requirement of nanoparticle sampling at workplaces.

Abstract: This invention relates to the reduction of charged particle loss by radially introducing sheath air from the porous wall. The corona-wire unipolar aerosol charger of the present invention includes a charging chamber, at least one aerosol inlet channel, a corona wire, an annular sheath air inlet opening, a porous tube defining a charging chamber, an annular sheath air outlet opening, and an aerosol outlet channel. The sheath air inlet opening is for radially introducing a sheath air flow into the charging chamber. The charged particles will not deposit on the wall surface of the charger if the radial velocity of the introduced sheath air at the wall is higher or comparable to the electrostatic velocity of charged particles. The dilution effect of charged particle due to the use of clean air can be further minimized by redirecting the excess clean air to the outside of the charger.

Abstract: A nozzle plate containing multiple micro-orifices for the cascade impactor and a method for manufacturing the same are disclosed. The nozzle plate is formed by a series of semiconductor processes, including lithography, etching and electroplating. The nozzle plate comprises a plate body and a plurality of micro-orifices formed on the plate body. The orifice has a diameter which gradually expands in the direction away from the bottom of the plate body to achieve a smooth inner surface, allowing particles to pass therethrough smoothly without being clogged in the nozzle plate.

Abstract: A portable nanoparticle sampler for collecting respirable particulate matters and nanoparticles is composed of a tangential flow cyclone, a multi-microorifice impactor and a filter cassette. The tangential flow cyclone can remove the microparticles with cutoff aerodynamic diameter (dpa) larger than 4 ?m and guide the airflow to the multi-microorifice impactor located below the cyclone. The multi-microorifice impactor includes a multi-orifice nozzle and a rotary impaction plate for enabling the microparticles with dpa from 100 nm to 4 ?m to be uniformly collected on a silicon-oil-coated impaction substrate. The remanent microparticles with dpa smaller than 100 nm are collected by the filter cassette. Therefore, compared with the prior art, the portable nanoparticle sampler is characterized by low pressure loss and accurate microparticle sizing to meet the requirement of nanoparticle sampling at workplaces.

Abstract: A nozzle plate containing multiple micro-orifices for the cascade impactor and a method for manufacturing the same are disclosed. The nozzle plate is formed by a series of semiconductor processes, including lithography, etching and electroplating. The nozzle plate comprises a plate body and a plurality of micro-orifices formed on the plate body. The orifice has a diameter which gradually expands in the direction away from the bottom of the plate body to achieve a smooth inner surface, allowing particles to pass therethrough smoothly without being clogged in the nozzle plate.

Abstract: A venturi scrubber which avoids clogging in the throat by dust particles is developed. The scrubber includes a venturi tube, two scrubbing fluid conduits and a storage tank. The venturi tube has a converging section, a diverging section and a throat section which is connected between the converging section and the diverging section. The scrubbing fluid conduit has a top end connected with the bottom end of the converging section of the venturi tube, and a bottom end extending into the storage tank. Thereby, scrubbing fluid can be guided directly into the storage tank without passing through the throat section. As a result, the clogging of dust particles on the converging section of the venturi throat can be minimized and the abnormal increase in the pressure drop of the air flow through the throat can also be avoided.

Abstract: A particle charger with sheath air flow for enhancing charging efficiency includes a housing and a discharge wire. The housing has a charging chamber for accommodating the discharge wire, a particle inlet, a sheath air inlet, an outlet and an accelerating channel. A clean sheath air is guided through the sheath air inlet into the charging chamber to surround charged particles, reducing deposition of charged particles on the inside wall of the housing. A relatively small annular gap of accelerating channel accelerates the charged particles to exit the particle charger, and therefore minimized the particle electrostatic loss due to depositing on the inner surface of the housing. Additionally, uncharged particles approach the discharge wire axially, and charged particles move away radially. It is helpful for the charged particles to diffuse rapidly and uniformly, thereby enhancing the charging efficiency.

Abstract: A multi-filter PM 10-PM 2.5 sampler which enable the simultaneous collection of four PM 10 and four PM 2.5 samples is disclosed. The sampler is provided with a PM 10 impactor to remove coarse particles and operates at 33.4 L/min. After the PM 10 impactor, the aerosol flow is divided by half by a branch pipe. Half of the flow is directed into four PM 10 cassettes, while the other half is directed into four PM 2.5 cassettes after the aerosols are further classified by a PM 2.5 impactor. To ensure the aerosol flow uniformly passes through each of the four PM 10 or four PM 2.5 cassettes, an orifice plate is assembled behind each of the filter cassettes to increase the pressure drop, such that the flow rates of eight sampling lines are nearly equal.

Abstract: A wet electrostatic precipitator (ESP) is disclosed to have a housing, several discharge wires, two roughened collection electrodes coated with TiO2 or SiO2 nanoparticles, two porous metallic plates, and two roughened glass plates coated with TiO2 or SiO2 nanoparticles. The porous metallic plates and the glass plates coated with TiO2 or SiO2 nanoparticles located above the collection electrodes are used to enhance the uniformity of the water film. When particles are introduced into the ESP, they are charged by gas ions generated by corona discharge, and then migrate to collection electrodes due to electrostatic force. Finally, particles are removed by uniform water film flowing downward along the collection electrodes. Furthermore, pulse jet passing through the small holes on the collection plates is used to clean discharge wires, maintaining electric corona strength and prolonging the operation life.