Abstract: A low NO.sub.x burner system for a furnace having spaced apart front and rear walls, comprises a double row of cell burners on each of the front and rear walls. Each cell burner is either of the inverted type with a secondary air nozzle spaced vertically below a coal nozzle, or the non-inverted type where the coal nozzle is below the secondary air port. The inverted and non-inverted cells alternate or are provided in other specified patterns at least in the lower row of cells. A small percentage of the total air can be also provided through the hopper or hopper throat forming the bottom of the furnace, or through the boiler hopper side walls. A shallow angle impeller design also advances the purpose of the invention which is to reduce CO and H.sub.2 S admissions while maintaining low NO.sub.x generation.

Abstract: A fluid flow circuit for a boiler having a combustion chamber and an exhaust passage. In one embodiment there is provided at least one upflow evaporative generating bank module in the exhaust passage and at least one downflow evaporative generating bank module in the exhaust passage, positioned downstream of the upflow module. One or more upper downcomers are connected to a steam drum and supply water to the lower header of the upflow module and to the upper header of the downflow module. If needed, the convection pass wall enclosures can also be fed by the upper downcomers to their upper inlet headers. One or more lower downcomers may be connected to each lower header of the downflow module (and to the lower outlet headers of the convection pass wall enclosures) for supplying the water to a plurality of furnace circuits which extend along the combustion chamber in the boiler. The opposite end of each furnace circuit is connected to one or more risers which, in turn, are connected to the steam drum.

Abstract: A burner for the combustion of a fuel plus air mixture comprises a central nozzle pipe having an inner surface with a portion which diverges outwardly. An axially moveable plug is positioned within the nozzle pipe and includes an outer wall with a diverging section extending within the diverging section of the nozzle pipe. By axially moving the plug, the cross sectional area of the space between the diverging surfaces increases and decreases for respectively decreasing and increasing the velocity of the fuel plus air mixture passing through the nozzle space. This reduces the formation of NO.sub.x and the length of the flame produced by the burner.

Abstract: A temperature compensated, self-referenced fiber optic microbend pressure transducer employs a fiber optic loop (90) to compensate for thermal offset of the microbend sensor output. In the preferred embThis invention was made with Government support under Contract No. NAS3-25796 awarded by the National Aeronautics and Space Administration. The Government has certain rights in this invention.

Abstract: An apparatus for supplying fluidized bed material to a circulating fluidized bed boiler having a primary zone with a fuel feed point and a furnace zone above the primary zone, a mixing chamber for receiving solid fuel and a portion of the total combustion air needed in the boiler. The combustion air and circulating fluidized bed solids are supplied tangentially into the chamber which is advantageously in the form of a horizontally extending cylinder. The combustion air and solids are intimately mixed with each other before they are discharged into the primary zone of the boiler. The primary zone of the boiler is shaped with an upwardly increasing cross sectional area so that the already mixed combustion air and solids diffuse evenly through the fluidized bed boiler.

Abstract: A vertical, co-current dry scrubber comprises a housing having a waste gas inlet and a treated gas outlet. A plurality of airfoil mounted atomizers extend across the interior of the housing for discharging slurry into the gas stream for treatment of the gas. The use of airfoil mounted atomizers reduces pressure drop across the chamber.

Abstract: An improved articulated sludge lance with a retractable movable extension nozzle for cleaning a steam generator. The extension nozzle includes a flexible conduit adapted to be moved with a wire cable to place the nozzle in close proximity to a support plate for effectively cleaning the broached holes therein. A bumper member fastened to the flexible conduit provides a side-to-side motion from impact with the tubes when the lance is moved therethrough.

Abstract: A method for manufacturing a sensor with an attached leadwire (10) fastened to an adaptor block (18) which is attached to a gage shim (24). The sensor is deposited on an insulated layer (28) placed on the gage shim (24) in electrical contact with the electrical leads (16) of the leadwire (10). One or more passivation layers (36) are applied over the upper surface of the entire sensor to provide a complete seal.

Abstract: An improved high energy density welding method for reducing input keyhole welding prepares the weld joint (8) between two edges (10, 14) of at least one member by separating the edges (10, 14) of the member (12, 16) with a controllable gap (22) by a projecting portion (24) selectively positioned on one edge (10, 14) of the member (12, 16). The projecting portion (24) closely abuts the other edge of the member for maintaining the controlled distance (d) of the controllable gap (22) to enhance the welding method.

Abstract: A fluid flow circuit for a boiler having a combustion chamber and an exhaust passage. In one embodiment there is provided at least one upflow evaporative generating bank module in the exhaust passage and at least one downflow evaporative generating bank module in the exhaust passage, positioned downstream of the upflow module. One or more upper downcomers are connected to a steam drum and supply water to the lower header of the upflow module and to the upper header of the downflow module. If needed, the convection pass wall enclosures can also be fed by the upper downcomers to their upper inlet headers. One or more lower downcomers may be connected to each lower header of the downflow module (and to the lower outlet headers of the convection pass wall enclosures) for supplying the water to a plurality of furnace circuits which extend along the combustion chamber in the boiler. The opposite end of each furnace circuit is connected to one or more risers which, in turn, are connected to the steam drum.

Abstract: A process and apparatus for simultaneously removing NO.sub.X and SO.sub.X from the exhaust of a furnace includes an injection of limestone into a region of the furnace having a temperature of about 2,000.degree.-2,400.degree. F., and an injection of ammonia into a region in the furnace having a temperature of about 1,600.degree.-2,000.degree. F. The limestone absorbs at least some of the SO.sub.X and the ammonia absorbs at least some of the NO.sub.X. The exhaust from the furnace which contains particulate and gases, is supplied to a dry scrubber where further reactions take place between unused ammonia and SO.sub.X, and calcium sorbent and SO.sub.X. Sorbent and ammonia regeneration can also be utilized to further improve the efficiency of the system.

Abstract: A neural network control based on a general multi-variable nonlinear dynamic model incorporating time delays is disclosed. The inverse dynamics of the process being controlled is learned represented by a multi-layer neural network which is used as a feedforward control to achieve a specified closed loop response under varying conditions. The weights between the layers in the neural network are adjusted during the learning process. The learning process is based on minimizing the combined error between the desired process value and the actual process output and the error between the desired process value and the inverse process neural network output.

Abstract: An apparatus and method for the measurement of low levels of carbon dioxide in a sample employing membrane separation and ion-exchange technology. The difference in acid strength of carbonic acid and other acids is exploited by first treating the sample with a weak base in a membrane separator and then with a strong base in the membrane separator. In this manner, the carbonic acid is distinguished from the stronger acids. By converting carbonic acid to sodium carbonate, the conductivity level is enhanced facilitating more precise measurements.

Abstract: An apparatus for determining the fluid velocity and direction of flow in a generating bank tube attached to a drum of a boiler provides fluid to a measurement area located within the drum. In one embodiment, static and dynamic pressures of the fluid within the measurement area are determined by a pitot tube assembly located in the measurement area and sent to a pressure measuring device such as a U-tube manometer or a Bourdon gage for a direct pressure reading, or to a pressure transmitter to produce signals for processing by a calculating device. The calculating devices processes the pressure transmitter signals representative of the pressures, uses the energy equation to calculate the fluid velocity based upon these pressures, and transmits same to a display device for reading by an operator. In another embodiment, a flowmeter is used on the measurement area directly and transmits the fluid velocity to a display device.

Abstract: A method and apparatus of scrubbing acid gas from flue gas comprises slats which define a moving bed of scrubbing material which is capable of reacting with the acid gas to form reaction products on particles of the scrubbing material. Flue gas from a boiler or other sources of flue gas is passed through the moving bed of scrubbing material. The scrubbing material is sprayed with water to the saturation point for increasing the rate of reaction between the reaction gas on the scrubbing material. The scrubbing material leaving the bottom of the moving bed is subjected to a separation step which removes the reaction products as fine dust which is disgarded, and returns the now regenerated particles of scrubbing material to the top of the moving bed.

Abstract: A method and apparatus for operating a limestone wet scrubbing flue gas desulfurization apparatus comprises first and second pH measuring devices connected respectively to a recirculation line in the scrubber and above the liquid holdup tray in the scrubber. The difference in the pH values measured at these two locations in the system is used to adjust the amount of air supplied to the sump or reaction tank of the scrubber to maximize oxidation in the scrubber and to avoid wasted airflow.

Abstract: A fiber optic microbend sensor employs a resilient coil (12) with an optical fiber (10) positioned therein. The coil (12) has a predetermined length and pitch. An optical signal is applied to the optical fiber (10) with the coil (12) interrogating a parameter. Any movement of the coil (12) modulates the optical signal transmitted along the optical fiber (10). Detecting means (32) measures the modulations of the optical signal for characterization of the parameter.

Abstract: A nozzle apparatus for producing flexible fibers of superconducting material receives melted material from a crucible for containing a charge of the superconducting material. The material is melted in the crucible and falls in a stream through a bottom hole in the crucible. The stream falls through a protecting collar which maintains the stream at high temperatures. The stream is then supplied through the downwardly directed nozzle where it is subjected to a high velocity air flow which breaks the melted superconducting material into ligaments which solidify into the flexible fibers. The fibers are collected by blowing them against a porous cloth.

Abstract: A plant loop communication system utilizing a plurality of Loop Interface Slave (LIS) modules, each of which being an intelligent slave module incorporating its own microprocessor, is described. The use of such a module permits off-load processing so that receiving, transmitting and message processing cam occur simultaneously. A Superloop Bus Module (SBM) contains a data base which allows the asynchronous operation of the system. A Superloop Storage Module (SSM) stores data for transmission onto the loop and/or incoming data for transmission to an operator console.

Abstract: An arrangement for providing radio frequency and electromagnetic interference protection to at least part of circuitry mounted on a circuit board comprises alternating slots and bridges which form a boundary between a protected area of the circuit board and an unprotected area of the circuit board. The circuit portions which require protection are mounted in the protected area and are covered by a top cover having fingers which extend through the slots. Connecting lines between the protected and unprotected portions of the circuit portions extend along the bridges between the slots. A bottom cover engages under the protected area and mates to the top cover for providing electromagnetic interference protection for the circuit portions within the protected area.