Abstract: An apparatus for supplying a controlled flow of pneumatically transported solid particles, in particular, pulverized coal, comprises a pulverizer or vessel for containing pneumatically suspended solid particles. A supply pipe is connected to the pulverizer or vessel for removing a mixture of pneumatic gas and solid particles from the vessel. A bend is provided in the supply pipe and an aspirator is connected to the supply pipe at a distance of from one to two pipe diameters from the bend. The aspirator is provided on the outer wall of the bend and is supplied with aspirating gas to draw off an amount of mixture from the supply pipe. This controls the amount of remaining flow of mixture through the pipe. The supply of the aspirator is connected to a bypass line which is connected to the mixture inlet of an injector which is supplied with injecting gas. The supply of the injector which carries the mixture is connected back into the vessel.

Abstract: A pressure transducer utilizes a diaphragm made, for example, of ceramic or the like having upper and lower surfaces. One surface of the diaphragm receives an elongated thick film resistor. Circuitry is connected to the resistor for measuring any changes in resistance due to strains or forces applied to the resistor. Pressures applied perpendicularly to the longitudinal direction of elongation of the resistor produces high outputs in the form of changes in resistance which can be used to calculate strains in the longitudinal and transverse directions as well.

Abstract: An accelerometer comprises a base and cover together defining a chamber which receives an inertial mass. The diaphragm carries the inertial mass and is bolted between the base and the cover. The inertial mass and the base have facing incorrugated surfaces with offset teeth in each of the corrugated surfaces. An optical fiber is clamped between the teeth and extends between the corrugated surfaces. The intensity of light passing through the fiber changes with movement of the inertial mass with respect to the base. The inertial mass moves through the resiliency of the diaphragm, when the base is subjected to accelerations, such as those caused by vibrations. A reference optical fiber may also extend through the chamber above the inertial mass. The same light is supplied to both fibers and the intensity of light from both fibers is subtracted to leave the variation in intensity due to bending of the sensing optical fiber.

Abstract: A fuse cover includes a transparent resilient cylindrical member, having a full length axially extending slot therein. Two pairs of recesses are provided in the slot for engaging a pair of fuse clips mounted to a circuit board and holding a fuse there between. The tubular member has opposite open ends for ventilation and can be installed over and removed from a fuse without tools and without disturbing the mounting of the fuse.

Abstract: An apparatus for controlling emissions of a coal fired boiler includes a hot catalytic baghouse for receiving flue gases along with injected ammonia and alkali. The alkali and ammonia react with SO.sub.x and NO.sub.x in the flue gas while particulates in the flue gas are trapped in the baghouse. The still hot but clean flue gases are supplied from the baghouse to a heat pipe air heater which also receives combustion air to be preheated before it is supplied to the boiler for combustion with coal to produce the flue gases.

Abstract: A self-tuning system and method for controlling a process based on a measured variable comprises modular parameter estimators, parameter converters and controllers which are used to control the process and receive input from the process. Self-tuning gain scheduling allows the calculated parameters to be updated by a second variable from the process. Regression analysis is used in conjunction with the conventional gain scheduling to more accurately refine the control action. A limiter is also used in conjunction with the regression analysis to avoid an overly high or low correction signal for the controller.

Abstract: An electro-hydraulic positioning system which has automatic calibration capabilities is disclosed. The system includes a microprocessor which accesses calibration parameters stored in a non-volatile memory unit. The microprocessor adjusts the position demand according to the stored calibration parameters. The system may be placed in an atuomatic calibration mode. In which case, update calibration parameters are automatically determined and stored. The system also includes a microcontroller which monitors system operating variables and reports deviations of the variables from expected values for same.

Abstract: A method of controlling the operation of a pulverizer includes detecting the type of fuel being supplied to the pulverizer. At least one characteristic of the fuel is determined by a combination of measurements and calculations. One characteristic is moisture content which distinguishes one type of fuel, in particular, one type of coal, from another. The feeding rate of the fuel to the pulverizer is selected from a curve which plots primary air flow against percentage of rating for the pulverizer. This curve is constant for the pulverizer despite the types of fuel used.

Abstract: An improved burner having a very particularly designed gas element for the combustion of coal, oil or gas places a plurality of retractable and rotatable gas elements in close proximity to the outlet end of a tubular burner nozzle of the burner which are shielded from combustion air provided around the tubular burner nozzle by a flame stabilizing ring having a plurality of openings adapted to closely receive each of the plurality of retractable and rotatable gas elements. Eddies produced by the flame stabilizing ring create a low oxygen/fuel rich flame resulting in reduced NO.sub.x formation.

Abstract: A remotely operable boiler tube wall cleaning and inspection system including a collapsible "H" frame capable of being inserted through the boiler manway access ports and being positioned at will over the full area of the tube wall.

Abstract: An apparatus and method for sampling gas containing a reactive particulate solid phase flowing through a duct and for communicating a representative sample to a gas analyzer. A sample probe sheath 32 with an angular opening 34 extends vertically into a sample gas duct 30. The angular opening 34 is opposite the gas flow. A gas sampling probe 36 concentrically located within sheath 32 along with calibration probe 40 partly extends in the sheath 32. Calibration probe 40 extends further in the sheath 32 than gas sampling probe 36 for purging the probe sheath area with a calibration gas during calibration.

Abstract: An apparatus and method for conducting optical spectroscopy in a hostile environment comprises a light source, e.g., a laser or an incandescent light connected to a multiplexer for supplying high intensity light to at least two optical fibers. One of the optical fibers extends to a material in the hostile environment to be analyzed. The second optical fiber is connected between the multiplexer and a standard sample for yielding known spectroscopic results. Either the same or additional optical fibers are used to return light from the material to be analyzed. Each optical fiber has an end portion covered by a sheath to shield the optical fiber from the hostile environment. The sheath has an open end covered by a transparent window which is preferably made of diamond, again, to seal and protect the optical fiber in the sheath.

Abstract: An ultrasonic transducer arrangement for inspecting a work piece at an elevated temperature through the use of ceramic delay lines is disclosed. The ceramic material utilized for the delay lines is comprised of a composition of silicon nitride and boron nitride which is hot pressed so that the boron nitride platelets are aligned substantially parallel to the propagation direction of the ultrasonic pulses thus minimizing pulse attenuation. The ceramic material is heat and wear resistant and can be machined so as to conform to the surface of the work piece being inspected.

Abstract: A proportional plus integral plus differential (PID) controller containing an algorithm option is disclosed. The option allows the selection of a classical interacting type of controller or a non-interacting type of controller. The classical interacting type of controller is characterized by the property that tuning any one of the proportional, integral or derivative terms changes the effective value of the other terms. In contrast, the non-interacting type of controller is characterized by the property that tuning any one of the proportional, integral or derivative terms has no effect on the other terms.

Abstract: A remotely operable boiler tube wall cleaning and inspection system including a collapsible "H" frame capable of being inserted through the boiler manway access ports and being positioned at will over the full area of the tube wall.

Abstract: An apparatus and method for supplying a controlled flow of fluid transported solid particles, in particular, pulverized coal by the controlled injection of a fluid, such as a gas like compressed air, into at least one feed pipe. The flow of coal in feed pipes is controlled by selectively reducing or increasing the flow of primary air to achieve a balanced burner operation.

Abstract: An improved method of chromizing the surface of a ferritic boiler component. An aqueous coating composition is applied to the surface to be chromized, which includes at least 10% by weight of chromium, at least 12% by weight alumina, a binder of ammonium alginate or methyl cellulose, and a halide activator, and in which the weight ratio of chromium to water is greater than 0.7. Alternative embodiments involve the application of a halide activator over the top of a previously applied and dried coating that is lacking said halide activator, as well as to the application of multiple layer single component slurry coatings.

Abstract: A surge control system (16) is provided for a compressor (14) which anticipates the actual surge condition and initiates anti-surge protection in proportion to the magnitude of the anticipated surge condition. This is done by providing a feed forward signal (20) to a summing station (48) along with a normally generated surge control line point (44) to offset this point (44) by an amount determined by the feed forward signal (20). This offset point (50) is used as an input to a controller for controlling the bypass valve (28) in a bypass loop (30) around the compressor (14).

Abstract: An apparatus and process for the chemical vapor deposition of a matrix into a preform having circumferentially wound ceramic fibers, comprises heating one surface of the preform while cooling the other surface thereof. The resulting product may have fibers that are wound on radial planes or at an angle from the radial planes. The fibers can also be precoated with pyrolytic carbon before application of the matrix. The matrix is applied by passing reactant gas through the preform thereof to the other side thereof for the initial deposition of matrix near such other surface of the preform. The matrix fills in the preform from the other side surface thereof to the surface of the side of application thereof until a desired amount of matrix has been deposited.

Abstract: An apparatus and method for measuring the tip location of a consumable electrode in an electric arc furnace employing an optical fiber with high temperature capability and an optical time domain reflectometer. The optical fiber is encased with a metal tube to prevent the optical fiber from slipping therein and to provide high temperature capability.