Patent application number | Description | Published |
20090288475 | Skimmer for Concentrating an Aerosol - A skimmer device for concentrating an aerosol from a flowing gas stream, having an inlet with inlet aperture and inlet raceway, an outlet with virtual impact void and collector channel, and bulk flow divertors symmetrically disposed on either side of the long axis of flow, further characterized in that the downstream walls of the bulk flow divertors are concavedly curved and reverse the direction of bulk flow. In section, the four channels or passages of the “skimmer” thus form a “crossed tee” with concavedly contoured lateral arms curving back around. The lateral flow channels are for diverting the bulk flow into exhaust chimney spaces, and the chimney spaces are positioned proximate to the inlet element and anterior to the collection channel. In operation, the bulk flow streamlines are thereby folded more than 90 degrees away from the long axis of flow on the laterally disposed concave walls of the bulk flow channels. While counterintuitive, this was found using computational fluid dynamics (CFD) and experimentation to dramatically reduce wall separation and related instabilities and to improve particle recoveries. Large two-dimensional arrays of closely stacked inlet and skimmer elements are thus achieved by fitting the chimneys into spaces between parallel inlet elements. The interlinked problems of flow instability, manufacturability of arrays, and scale-up of chimney cross-sectional area to equalize pressure differentials in the bulk flow diverter exhaust ducts, particularly in two-dimensional arrays at high throughput, are uniquely solved with this geometry. | 11-26-2009 |
20100186524 | Aerosol Collection and Microdroplet Delivery for Analysis - An apparatus or device for collecting aerosol particles from a gas stream, having a collector body enclosing a collector channel, a particle trap in the collector channel, and an injection duct for injecting a discrete microdroplet of an elution reagent. The particle trap may be a centrifugal impactor, a bluff body impactor, or an electrostatic impactor. Aerosol particles are deposited on the surface during collection and are subsequently eluted with a microdroplet or a series of microdroplets as a concentrated liquid sample so that the sample can be analyzed in situ or conveyed to a detector for analysis. The collector serves as an aerosol-to-liquid conversion module as part of an apparatus for detecting and analyzing aerosol particles, and may be used in an integrated environmental threat assessment system, for example for characterization of aerosolized chemical and biological weapons, or for industrial or environmental monitoring. | 07-29-2010 |
20110072772 | Skimmer for Concentrating an Aerosol and Uses Thereof - Skimmer devices for concentrating an aerosol from a flowing gas stream, said skimmers having an inlet with inlet aperture and inlet raceway, an outlet with virtual impactor void and collector channel, and a bulk flow divertor positioned axisymmetrically on the long axis of flow, further characterized in that the downstream surface of the bulk flow divertor is curved for contactingly diverting the streamlines of the bulk flow by greater than 90 degrees away from the long axis of flow without wall separation or instability. Also described are combinations of slot-type and annular-type skimmers with upstream focusing elements such as aerodynamic lenses, and uses thereof. | 03-31-2011 |
20110132108 | Particle Interrogation Devices and Methods - Devices and methods are disclosed for non-contact pneumatic sampling of surfaces, persons, articles of clothing, buildings, furnishings, vehicles, baggage, packages, mail, and the like, for aerosols or vapor residues indicative of a hazard or a benefit, where the residues are chemical, radiological, biological, toxic, or infectious in character. A central orifice for pulling a vacuum is surrounded by an array of convergingly-directed gas jets, forming a “virtual sampling chamber”. The gas jets are configured to deliver millisecond pneumatic pulses that erode particles and vapors from solid surfaces at a distance. A curtain wall flow encloses the sampling area during pulse retrieval. | 06-09-2011 |
20110186436 | Particle Interrogation Devices and Methods - Devices, apparatus and methods are disclosed for non-contact pneumatic sampling and sampling of surfaces, persons, articles of clothing, buildings, furnishings, vehicles, baggage, packages, mail, and the like, for contaminating aerosols indicative of a hazard or a benefit, where the contaminating aerosols are chemical, radiological, biological, toxic, or infectious in character. In a first device, a central orifice for pulling a suction gas stream is surrounded by a peripheral array of convergingly-directed gas jets, forming a virtual sampling chamber. The gas jets are configured to deliver millisecond pneumatic pulses that erode particles from solid surfaces at a distance. In another aspect of the invention, a suction gas stream is split using an air-to-air concentrator so that a particle-enriched gas flow is directed to a particle trap and any particles immobilized in the particle trap (including any adsorbed vapors associated with the particles) are selectively analyzed to detect trace residues associated with explosives. | 08-04-2011 |
20110203931 | Particle Interrogation Devices and Methods - Devices, apparatus and methods are disclosed for non-contact pneumatic sampling and sampling of surfaces, persons, articles of clothing, buildings, furnishings, vehicles, baggage, packages, mail, and the like, for contaminating aerosols or vapors indicative of a hazard or a benefit, where the contaminating aerosols or vapors are chemical, radiological, biological, toxic, or infectious in character. In a first device, a central orifice for pulling a suction gas stream is surrounded by a peripheral array of convergingly-directed gas jets, forming a virtual sampling chamber. The gas jets are configured to deliver millisecond pneumatic pulses that erode particles and vapors from solid surfaces at a distance. In another aspect of the invention, a suction gas stream is split using an air-to-air concentrator so that a particle-enriched gas flow is directed to a particle trap and particles immobilized therein are selectively analyzed for explosives and explosives related materials under optimized conditions for analyzing particle-associated constituents and a bulk flow is directed to a vapor trap and free vapors immobilized therein are selectively analyzed for explosives and explosives related materials under optimized conditions for analyzing free vapors. Detection signals from the particle channel and the vapor channel are compared or integrated to detect trace residues associated with explosives. | 08-25-2011 |
20110232498 | Omnidirectional Aerosol Sampling Intake - An aerosol sampling intake configured to exclude particles generally greater than 20 microns AD and capture particles of less than about 10 microns AD with high efficiency, independent of weather conditions, through which air is sampled by suction. The intake combines an omnidirectional horizontal segment with diffuser and elbow, the elbow transitioning flow to a vertical segment, the vertical segment with overhanging lip, the centrifugal impactor for self-cleaning operation, thus relieving the dual problems of re-entrainment of particles bouncing from the impactor surface and fouling by particles sticking to the impactor surface. The device is adapted for use on moving vehicles, for sampling at increased windspeeds, or for sampling in rain. | 09-29-2011 |
20120105839 | Progressive Cut-Size Particle Trap and Aerosol Collection Apparatus - Improved centrifugal particle traps for aerosol particle collection and sampling characterized by a curved, progressively tapered impactor channel operable over a incompressible or compressible flow regime, or a flow regime transitioning from incompressible to compressible over the length of the particle trap. Mixtures of particles in a flowing gas stream are impactingly captured and separated by size. The particle traps can be operated to collect submicron particles without blockage, have lower pressure drops to reduce overall power requirements, and surprisingly, viability of biological particles captured in the particle traps of the invention is increased. Also disclosed are systems and methods combining these improved particle traps with in-line particle concentrators and with aerosol sample or liquid sample processing and analysis systems. | 05-03-2012 |
20120174650 | Aerosol Collection Apparatus and Methods - The lifetime of aerosol monitoring, concentration and collection equipment is extended by acoustic cleaning of accreted particle deposits from internal surfaces where fouling occurs by application of acoustic energy to the particle accretion surface, optionally in combination with a liquid wash or sampling volume. In one application, acoustic cleaning or sampling of particle deposits for analysis is triggered by a signal indicating changes in gas flow associated with particle loading. In another application, electro-acoustic transducers may be used to prevent particle buildup without interruption of particle monitoring. | 07-12-2012 |