Abstract: A wet cyclone particle collector is disclosed. The wet cyclone particle collector includes a cyclone unit, a liquid delivery unit and a sample collection unit. The cyclone unit draws a gas sample into a cyclone chamber and creates a circular flow of the gas sample inside the cyclone chamber so that particles in the gas sample are separated from said gas sample by centrifugation force. The liquid delivery unit delivers a collection liquid into the cyclone in a non-continuous fashion. The sample collection unit harvests the collection liquid from the cyclone unit. The non-continuous delivery of the collection liquid significantly reduces consumption of collection liquid during operation of the particle collector.

Abstract: In an embodiment, a wetted wall cyclone comprises a cyclone body including an inlet end, an outlet end, an inner flow passage, and an inner surface defining an inner diameter. In addition, the wetted wall cyclone comprises a cyclone inlet tangentially coupled to the cyclone body. The cyclone inlet includes an inlet flow passage in fluid communication with the inner flow passage. Further, the wetted wall cyclone comprises a skimmer extending coaxially through the outlet end of the cyclone body. The skimmer comprises an upstream end disposed within the cyclone body, a downstream end distal the cyclone body, and an inner exhaust passage in fluid communication with the inner flow passage. Still further, the wetted wall cyclone comprises a first annulus positioned radially between the upstream end and the cyclone body having a radial width W1 between 3% and 15% of the inner diameter of the cyclone body.

Abstract: An inline virtual impactor comprising an outer housing having a housing inlet, a housing inner surface, a major flow outlet and a minor flow outlet; a flow accelerator member disposed in the upstream portion of the outer housing; and a flow stabilizer member disposed within the outer housing downstream of the flow accelerator member, wherein the disposition of the flow accelerator creates an annular flow passage between the flow accelerator and the outer housing, and wherein a flow divider that is at least partially downstream of the flow stabilizer member effects splitting of the flow stream entering the housing into major and minor flows. The minor flow comprises primarily particles having a size greater than a cutpoint size and the major flow comprises primarily particles smaller than the cutpoint size. The inline virtual impactor may further comprise an aspiration section located upstream of the flow accelerator member.

Abstract: A wetted wall cyclone system for sampling an aerosol. In an embodiment, the system comprises a cyclone body including an inlet end, an outlet end, and an inner flow passage extending therebetween. In addition, the system comprises a cyclone inlet tangentially coupled to the cyclone body proximal the inlet end. The cyclone inlet includes an inlet flow channel in fluid communication with the inner flow passage of the cyclone body. Further, the system comprises a skimmer coaxially coupled to the outlet end of the cyclone body. The skimmer comprises a separation end extending into the outlet end of the cyclone body, a free end distal the outlet end of the cyclone body, and an inner exhaust channel in fluid communication with the inner flow passage of the cyclone body. Still further, the system comprises means for reducing the temperature of at least a portion of the cyclone body.

Abstract: A wet cyclone particle collector is disclosed. The wet cyclone particle collector includes a cyclone unit, a liquid delivery unit and a sample collection unit. The cyclone unit draws a gas sample into a cyclone chamber and creates a circular flow of the gas sample inside the cyclone chamber so that particles in the gas sample are separated from said gas sample by centrifugation force. The liquid delivery unit delivers a collection liquid into the cyclone in a non-continuous fashion. The sample collection unit harvests the collection liquid from the cyclone unit. The non-continuous delivery of the collection liquid significantly reduces consumption of collection liquid during operation of the particle collector.

Abstract: An inline virtual impactor comprising an outer housing having a housing inlet, a housing inner surface, a major flow outlet and a minor flow outlet; a flow accelerator member disposed in the upstream portion of the outer housing; and a flow stabilizer member disposed within the outer housing downstream of the flow accelerator member, wherein the disposition of the flow accelerator creates an annular flow passage between the flow accelerator and the outer housing, and wherein a flow divider that is at least partially downstream of the flow stabilizer member effects splitting of the flow stream entering the housing into major and minor flows. The minor flow comprises primarily particles having a size greater than a cutpoint size and the major flow comprises primarily particles smaller than the cutpoint size. The inline virtual impactor may further comprise an aspiration section located upstream of the flow accelerator member.

Abstract: A wetted wall cyclone system for sampling an aerosol. In an embodiment, the system comprises a cyclone body including an inlet end, an outlet end, and an inner flow passage extending therebetween. In addition, the system comprises a cyclone inlet tangentially coupled to the cyclone body proximal the inlet end. The cyclone inlet includes an inlet flow channel in fluid communication with the inner flow passage of the cyclone body. Further, the system comprises a skimmer coaxially coupled to the outlet end of the cyclone body. The skimmer comprises a separation end extending into the outlet end of the cyclone body, a free end distal the outlet end of the cyclone body, and an inner exhaust channel in fluid communication with the inner flow passage of the cyclone body. Still further, the system comprises means for reducing the temperature of at least a portion of the cyclone body.

Abstract: In an embodiment, a wetted wall cyclone comprises a cyclone body including an inlet end, an outlet end, an inner flow passage, and an inner surface defining an inner diameter. In addition, the wetted wall cyclone comprises a cyclone inlet tangentially coupled to the cyclone body. The cyclone inlet includes an inlet flow passage in fluid communication with the inner flow passage. Further, the wetted wall cyclone comprises a skimmer extending coaxially through the outlet end of the cyclone body. The skimmer comprises an upstream end disposed within the cyclone body, a downstream end distal the cyclone body, and an inner exhaust passage in fluid communication with the inner flow passage. Still further, the wetted wall cyclone comprises a first annulus positioned radially between the upstream end and the cyclone body having a radial width W1 between 3% and 15% of the inner diameter of the cyclone body.

Abstract: A circumferential slot virtual impactor includes a disk-shaped housing with an endless circumferential slot for receiving aerosols. The slot forms an acceleration nozzle, and a receiver nozzle spaced apart radially inwardly from the acceleration nozzle exit. In an annular gap between the two nozzles, negative pressure is selectively applied to draw a major flow of the aerosol axially away from the nozzles, while a minor flow of the aerosol is drawn radially inward and enters the receiver nozzle. A portion of the larger particles leaves the major flow and merges with the minor flow due to particle momentum, thus increasing the large-particle concentration of the minor flow. The acceleration nozzle incorporates convex curvature along its opposed interior surfaces, for a smoother aerosol flow and reduced large-particle deposition.

Abstract: A transpirated wall aerosol collection system includes a collector operable to receive a gas flow containing particulate matter. The system also includes a porous wall having a first surface and a second surface. The porous wall is operable to transpire a liquid from the first surface to the second surface. Particulate matter contained in the gas flow is deposited in the liquid on the second surface of the porous wall. A virtual impactor may be used with the system for concentrating the particulate matter contained in the gas flow.

Abstract: The apparatus and method of the present invention extract samples of emissions within a stack or duct through the use of a probe. The sample is transported from the probe through a transport device into a mass-monitoring device in which the amount of particulate matter contained in the sample of the emissions is continuously analyzed. The apparatus of the present invention includes a transport device which has a porous inner tube completely sealed inside a solid outer tube. The outer tube of the transport device is supplied with gas through a transpiration port in the outer tube. The gas permeates from the outer tube through the porous inner tube in order to reduce deposition by keeping the particulate matter suspended within the porous inner tube.

Abstract: A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems.

Abstract: Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

Abstract: Apparatus having reduced background for measuring radiation activity in aerosol particles. A continuous air monitoring sampler is described for use in detecting the presence of alpha-emitting aerosol particles. An inlet fractionating screen has been demonstrated to remove about 95% of freshly formed radon progeny from the aerosol sample, and approximately 33% of partially aged progeny. Addition of an electrical condenser and a modified dichotomous virtual impactor are expected to produce considerable improvement in these numbers, the goal being to enrich the transuranic (TRU) fraction of the aerosols. This offers the possibility of improving the signal-to-noise ratio for the detected alpha-particle energy spectrum in the region of interest for detecting TRU materials associated with aerosols, thereby enhancing the performance of background-compensation algorithms for improving the quality of alarm signals intended to warn personnel of potentially harmful quantities of TRU materials in the ambient air.

Abstract: This invention relates to an aerosol sampling probe and method used for the collection of samples from moving fluid streams. A shroud surrounds the probe which enables the collection of more representative concentrations of aerosol particles in the fluid stream in many sampling applications.