Abstract: Apparatus and methods for selectively separating a volatile constituent of a particle from a gas stream for analysis. Particles are separated from bulk flow by inertia and impacted in a cavity containing a small but stable vortex or eddy. Heat is applied to volatilize constituents of the particles. The gas entrained within the vortex, which exchanges only slowly with the bulk flow, is withdrawn for analysis. In this way, a high volume flow containing particles of interest is reduced to a low volume flow containing a vapor concentrate. Advantageously, the apparatus may be operated at very low pressure drops in fully continuous, semi-continuous or batch mode according to the requirements of the downstream analytical unit. The apparatus finds use in active surveillance, such as in use of aerosols to detect explosives or chemical residues on persons, vehicles or luggage in real time.

Abstract: An imaging system with the ability to produce clear images of deposits inside operating high temperature process equipment such as kraft recovery boilers and power utility boilers uses a terahertz/mm-wave imaging system. This system allows direct inspection capability and the ability to directly measure deposit thickness on tubes and other interior surfaces at all locations within the boiler and precipitator. Terahertz and mm-wave imaging systems employ active imaging in which a beam of terahertz or mm-wave radiation generated within the imaging system is used to illuminate a region of the scene under investigation. The reflected radiation is collected by a lens or mirror system and focused onto a detector that converts the collected radiation into an electrical signal. Both the illuminating beam and the receiving optics are scanned across the scene in a raster fashion to produce a time-varying signal that is converted into an image of the scene.

Abstract: A device for detection of pluggage in an ash hopper of a coal fired boiler to identify when the opening in the bottom of the ash hopper becomes blocked by obstructions, so that timely and effective measures can be taken to remove the blockage without incurring economic loss in the operation of the boiler. At least one microwave or Terahertz transmitter unit configured to produce a microwave beam in either X or K band frequencies or at Terahertz frequencies (300 GHz to 3 THz), and at least one microwave receiver unit or beams that are interrupted by a blockage in the ash hopper, and produce an output to indicate obstruction of the beam or beams by the blockage. When the beam is interrupted, an output signal is produced to indicate obstruction of the beam by the blockage. The output signal is to notify process operators of the need to remove said blockage, and to control a blockage removal process.

Abstract: 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.

Abstract: A system for detection and control of deposition on pendant tubes in recovery and power boilers includes one or more deposit monitoring sensors operating in infrared regions of about 4 or 8.7 microns and directly producing images of the interior of the boiler, or producing feeding signals to a data processing system for information to enable a distributed control system by which the boilers are operated to operate said boilers more efficiently. The data processing system includes an image pre-processing circuit in which a 2-D image formed by the video data input is captured, and includes a low pass filter for performing noise filtering of said video input. It also includes an image compensation system for array compensation to correct for pixel variation and dead cells, etc., and for correcting geometric distortion. An image segmentation module receives a cleaned image from the image pre-processing circuit for separating the image of the recovery boiler interior into background, pendant tubes, and deposition.

Abstract: A sensing system simultaneously obtains images and surface temperatures of processing tubes inside process heaters using an imaging sensor operating in the visible or infrared regions of the spectrum and capable of detecting visible or infrared radiation emitted or reflected from surfaces within the process heater, and of providing an image signal to a display or to an image processor. One or more single element infrared detectors viewing specific regions within the aforesaid image accurately measure the intensity of radiation emitted by surfaces within those specific regions so as to allow the temperature of the surfaces within those specific regions to be inferred.

Abstract: Respirable particles with diameters on the order of 0.05 to 10 microns entrained in an air stream, are concentrated in an aerodynamic lens (FIG. 2) for separation from the air steam. The entire structure is made by microfabrication techniques, such as silicon micro-machining which enables arrays of precisely aligned slit lenses to be made on a silicon chip. At a Reynolds number of 800, a slit 25 microns wide by 1 mm tall will pass a flow of only 0.28 liters per minute, but arrays of lenses (FIG. 4), stacked in parallel banks, multiplies the available flow rate. Placing a skimmer (27) at the exit of each silicon micro-machined lens in the assembly and connecting the skimmer channels in chimneys (55), allows the bulk of the gas flow to be stripped off while allowing the concentrated particle stream to pass into a region of much lower flow rate, thereby producing a highly concentrated aerosol in the low velocity stream.

Abstract: 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.

Abstract: An acoustic pyrometer measures the average gas temperature across a space of known distance, especially turbulent, high temperature gas loaded with caustic particulates. It includes an acoustic signal generator that generates a high amplitude acoustic signal with a short rise time The acoustic signal generator includes an outer tank closed at top and bottom ends by top and bottom end walls and enclosing an outer chamber. A cylinder is supported within the tank and has top and bottom opposed ends. A mid-plate extends across the cylinder and defines the bottom end, and an axial opening in the mid-plate receives a shaft of a piston assembly having an upper piston and a lower piston at ends of the shaft. A throat is attached to the bottom end, and receives the lower piston. The lower piston seals the throat when received in the throat. The upper piston is slidable in the cylinder under influence of air pressure.