National Yang Ming Chiao Tung University

Institute of Occupational Safety and Health Council of Labor Affairs

Jusun Instruments Co., Ltd.

Industrial Technology Research Institute

Institute of Occupational Safety and Health

Institution of Occupational Safety and Health

Chuen-Jinn Tsai

Tung-Sheng Shih

Guan-Yu Lin

Chun-Nan Liu

Chih-Liang Chien

Cheng-Han Wu

Shou-Nan Li

Shih-Hsuan Huang

Sheng-Jen Yu

Chen Hui-Lin

Yu-Shan Yang

Shi-Nian Uang

Lin Guan-Yu

Tzu-Mimg Chen

Kang-Chieh Fan

Shao-Ming Hung

Da-Toung Tang

Shi-nian Uang

Cheng-Hsiung Huang

Cheng-Sheng Chang

Chao-Ting Hsu

Virat Wattanamekhinkul

Sheng-Chieh Chen

Jonathan Yang

Hong-Dar Chen

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.

Semi-dry type method for automatically sampling PM2.5 particles

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.

Efficient electrostatic particle-into-liquid sampler which prevents sampling artifacts

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.

Semi-dry type electrostatic cyclone sampler and method for sampling gas and/or water sample

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.

Multi-filter PM 10-PM 2.5 sampler

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 &#x3bc;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 &#x3bc;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.

Portable nanoparticle sampler

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.

Corona-wire unipolar aerosol charger

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.

Method for manufacturing a nozzle plate containing multiple micro-orifices for cascade impactor

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.

Wetted wall venturi scrubber with a 2-stage venturi throat

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.

Particle charger with sheath air flow for enhancing charging efficiency

A wet electrostatic precipitator (ESP) is disclosed to have a housing, several discharge wires, two roughened collection electrodes coated with TiOor SiOnanoparticles, two porous metallic plates, and two roughened glass plates coated with TiOor SiOnanoparticles. The porous metallic plates and the glass plates coated with TiOor SiOnanoparticles 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.

Wet electrostatic precipitator with pulse jet for cleaning discharge wires

A personal nanoparticle sampler is disclosed to include a pre-classifier, a nozzle, a connector and a final filter pack. The connector and the final filter pack respectively accommodate a particle-sizing filter and a final filter to collect nanoparticles smaller than a diameter. The pre-classifier removes large particles to avoid clogging of the connector. The nozzle raises the airflow velocity to reduce the cut-off diameter of the particle-sizing filter without increasing the total flowrate, allowing the personal nanoparticle sampler to be used with a personal sampling pump.

Personal nanoparticle sampler

This invention is a tube bundle heat exchanger for thermophoretic deposition of aerosol particles. It has a housing with an internal chamber, and several cold and hot tubes. The cold and hot tubes are arranged in a staggered manner in the internal chamber of the housing. Low and high temperature fluids flow inside the cold and hot tubes, respectively. When the exhaust gas passes through the chamber, temperature gradient between the cold and hot tubes causes aerosol particles suspended in the exhaust gas to deposit on the surface of cold tubes to achieve the treatment of exhaust gas. Staggered arrangement of cold and hot tubes can maintain nearly constant temperature gradient in the direction of the gas flow thereby enhances the overall removal efficiency of particles.

Tube bundle heat exchanger of constant temperature gradient for thermophoretic deposition of aerosol particles

A wet electrostatic precipitator is disclosed to include a condensation-growth chamber, a precipitation chamber connecting with the condensation-growth chamber, three dual-sleeve members mounted in the precipitation chamber, three discharge electrodes connecting with the dual-sleeve members, two insulating members covering on the inner surface of the precipitation chamber, and two ground electrodes mounted on the outside of the precipitation chamber. Thus, a uniform water film is formed on the surface of the insulating members to wash away the particles from waste gas. The condensation-growth chamber is provided for the particles to grow therein and thereby enhances the collection efficiency. The insulating member acts as a shield between the discharge electrodes and the ground electrodes and thereby avoids a short circuit or sparks.

Wet electrostatic precipitator with condensation-growth chamber

A porous metal denuder has a cascade impactor to collect aerosol particles of different diameters, two porous metal discs downstream to collect basic and acidic gases, respectively, and a final filter to collect particles smaller than the cut diameter of the last stage of the cascade impactor which will penetrate the two porous metal discs.

Porous metal denuder

A three-stage dust sampler makes use of a porous foam as the impactor substrates. The sampler includes an annular inlet which conforms to ISO/CEN/ACGIH inhalable sampling criteria, two impactor stages to classify thoracic and respirable particles and a final filter to collect respirable particles after the impactors. For 100 ppi polymer foam substrates, and a flow rate of 3.2 lpm, the collection efficiency curves of the thoracic and respirable dust matches ISO/CEN/ACGIH criteria when the jet-to-plate distance is 1.0. The cut-off aerodynamic diameter is 9.6 and 4.0 &#x3bc;m for the first and second impactor stages, respectively, and &#x221a;{square root over (stk)} is 0.39 for both stages. The collection efficiencies for solid particles is equal to that for liquid particles, indicating that there is no solid particle bouncing from the foam substrates.

Growing community of inventors

Hsinchu County, Taiwan

Chuen-Jinn Tsai