Abstract: In order to maintain the flue gas temperature from a steam generator up to the temperature required for a NO.sub.x catalytic reactor during low load operations, the flow of feedwater through the steam generator economizer is controlled to control the degree to which the flue gas is cooled as it passes over the economizer heat exchange surface. More specifically, an economizer bypass line is provided and the flow of feedwater during low load operations through the bypass line and the economizer is regulated to maintain a desired flue gas temperature to the catalytic reactor. As the flue gas temperature changes with load, the flow through the economizer and bypass line is modulated to maintain a proper temperature. At full or near full load, the bypass line is fully closed.

Abstract: A combined cycle system has a gas turbine connected to a heat recovery steam generator and the heat recovery steam generator contains a selective catalytic reactor section wherein nitrogen oxides (NO.sub.x) are reacted with reactant gas such as ammonia or urea to produce molecular nitrogen and water vapor. The expanding transition section contains an array of flow profile control pipes extending across the section in a pattern which distribute the flue gas uniformly over the large cross-section of the heat transfer section. The reactant gas is injected into the flue gas stream through a series of nozzles spaced across the flow control pipes so as to uniformly mix and distribute the reactant gas in the flue gas stream before it enters the selective catalytic reactor section.

Abstract: A coal fired power plant includes the catalytic reduction of NO.sub.x in the flue gas and the catalytic oxidation of SO.sub.2 to SO.sub.3 followed by the hydration of the SO.sub.3 to H.sub.2 SO.sub.4 vapor and then the condensation to H.sub.2 SO.sub.4 liquid. The condensation takes place in a wet sulfuric acid condenser by heat exchange with incoming combustion air. A portion of the heat picked up by that combustion air is used to provide a portion of the heat for the condensate from the steam turbine. The combustion air is then fed to an air preheater and to the steam generator as primary and secondary combustion air.

Abstract: A tank (18) forms a chamber having an upper and lower region. The tank (18) is in even elevation with a horizontal pipe (12) having a top region and a bottom region. An upper connecting pipe (14) fluidly connects the top region of the pipe (12) to the upper region of tank (18). A lower connecting pipe (16) fluidly connects the bottom region of pipe (12) to the lower region of the tank (18). Heat junction thermocouples (22) generate a signal indicative of water in the pipe (12). The signal is transmitted to a remote location by line (24).

Abstract: A plug which is inserted into the nozzle of nuclear reactor steam line is provided with a set of inflatable primary seals which resemble a pair of tires. A locking ring which features pads which can be hydraulically driven radially outward into engagement with the nozzle wall, is located adjacent the tire-like inflatable seals. The latter are inflated by a spring loaded piston. A tool which inserts the plug into the nozzle is adapted to tract the piston against the bias of the preloading springs, until such time as the plug is inserted into position. After insertion the piston is released and the seals are inflated.

Abstract: To improve and simply ultrasonic measurement of thin layers, an adaptive least-mean-square (LMS) implementation of a Wiener filter is used to deconvolve ultrasonic waveforms. This filter is structured as a finite-impulse-response (FIR) filter and solved using Widrow's adaptive linear combiner. The filter is implemented on a microcomputer with gating features for automated signal peak identification and measurement. The deconvolution process begins by assuming an impulse (the desired response) to a known input (the ultrasonic response). A transfer function is then determined that, when convolved with the response, results in the assumed impulse. The transfer function in this case is a long FIR filter typically requiring up to 128 taps to achieve acceptable results.

Abstract: In order to reduce the time and difficulty of disassembling a seal arrangement in a cramped radioactive environment, a nozzle assembly hub is provided with a step bore which receives a seal arrangement, a compression collar, and a retaining nut which presses the seal arrangement into engagement with an inner wall portion of the hub and an outer wall portion of an ICI (in-core instrument) seal plug assembly. The ICI units remain connected to the seal plug assembly during normal disassembly operations. In this manner, the nozzle assembly may be disassembled by merely removing the retaining nut, compression collar, and seal arrangement and lifting the reactor head, along with the nozzle assembly, over the ICI units. The compression collar extends outside the retaining nut such that the collar can be engaged and compressed by an hydraulic loading tool while threading the retaining nut onto the hub.

Abstract: A pulverizer for crushing coal for use in a combustion process includes a bowl shaped body, a roller dimensioned and configured for contact with at least a portion of the bowl shaped body, apparatus for causing relative movement between the bowl shaped body and the roller; and apparatus for biasing the roller against the bowl shaped body, the apparatus for biasing including a spring assemblyat includes a first spring and a second spring. The apparatus means for biasing including apparatus allowing initial compression of the first spring before the second spring is compressed. In some forms of the invention the first spring and the second spring are coil springs and the first and second springs are compressed simultaneously after initial compression of the first spring. In other forms of the invention the first and second springs are disposed in coaxial relationship with the second spring overlapping an axial part of the first spring.

Abstract: A mounting for an oil gun in an associated steam generation boiler which includes a stationary union block having first and second output ports for respective fluid streams; a removable block having first and second input ports dimensioned and configured for registration with the first and second output ports; apparatus for mounting the stationary union block which comprises a collar welded to the end of an associated guide pipe and apparatus coupling the collar and the stationary union block and allowing relative pivotal moment between the collar and the stationary union; and apparatus for forcing the removable union block against the stationary union block with the respective ports thereof in registered relationship. In some forms of the invention the apparatus coupling the collar and the stationary union comprises a pin, the pin extending through the stationary union block. The apparatus coupling the collar and the stationary union block may comprise first and second plates that are carried on the pin.

Abstract: A pulverized coal steam generator employing tangential, concentric firing with oxidizing conditions adjacent the furnace walls and using overfire air and low NO.sub.x firing methods is operated at very low excess air levels. This is possible because the unburned carbon in the flyash is measured and the pulverizers are adjusted to control the particles size of the pulverized coal and maintain a desired carbon level. The slagging and corrosion associated with deep staging is overcome by the concentric firing. Overall plant efficiency is obtained while still meeting performance objectives and emissions controls.

Abstract: In order to eliminate the need to weld, drill or otherwise machine a shroud structure which is used to surround a plurality of fuel assemblies in a nuclear reactor, a plurality of upper hanger rods interconnect a structure above the shroud to a support ring which is clamped about the upper periphery of the shroud. Lower hanger rods interconnect a lower edge or shoulder portion of the shroud with the support ring. Thus, through the upper and lower hanger rods and the support ring, the shroud can be supported within the RPV. The upper support ring is arranged to clamp the lower ends of the upper hanger rods against the upper outer peripheral portion of the shroud while the lower ends of the lower hanger rods are clamped against the lower peripheral wall portion of the shroud by a lower support ring.

Abstract: A furnace apparatus which includes a plurality of water walls. Each includes a plurality of tubes and the water walls collectively enclose a combustion chamber. The apparatus includes a plurality of windboxes, each of the windboxes is disposed intermediate adjacent water walls. A pulverizer and ducting to direct the flow of pulverized coal to the windboxes is also a part of the apparatus in accordance with the invention as is a bisector regenerative air heater having a rotor a housing having a generally cylindrical cavity in which a drum shaped rotor having heat transfer surfaces thereon is mounted for rotation on a shaft. The heater includes ducting for directing flue gas and forced draft air respectively into first and second angular sectors of the cavity which at any one instant will flow over respective angular sectors of the rotor. The rotor is heated during the travel of any portion thereof in the first angular sector and is cooled in the second angular sector.

Abstract: An improved gas turbine combined cycle system having a diffuser duct between the gas turbine and steam generator. The diffuser duct has boundary layer suction to prevent gas jet separation, thereby reducing pressure loss and improving gas velocity profiles in the duct, while eliminating the need for internal flow controls. The gas turbine combined cycle system can be vertically oriented to reduce the plan area of the system and provide for convenient use of a symmetrical diffuser duct and the use of forced circulation on the water side of the steam generator.

Abstract: The final reheater in a circulating fluidized bed combustion system which is located in a separate fluidized bed heat exchanger and which would be subjected to hot solids without any cooling after a blackout or turbine is cooled by bleeding a portion of the steam from the superheater outlet through a normally closed high pressure drop valve and into the final reheater. A valve downstream from the final reheater is also opened to permit flow.

Abstract: A nuclear fuel rod spacer grid is formed of slottedly interlocked sets of flat strips. One set of strips is formed with integral coplanar tab portions which have one or more edge portions bent at angles to form integral mixing vanes.

Abstract: Apparatus for cooperation with an associated furnace having the capability of burning either coal or oil wherein the improvement includes a coutant having an opening in the bottom thereof. An extended ash hopper is disposed under the coutant. The hopper includes a portion that extends beyond the coutant and a furnace sidewall that abuts an end of the coutant. The ash hopper is generally registered with respect to the opening and the apparatus includes apparatus for conducting gases to be recirculated including a recirculation fan, a duct coupling the apparatus for conducting to the ash hopper; and apparatus for sealing the portion with respect to the duct. In some forms of the invention the duct enters the laterally extending portion through the top thereof. The apparatus for sealing may include first apparatus for receiving a liquid and apparatus for sealing includes at least a first plate fixed to and depending form the coutant.

Abstract: A coal nozzle apparatus which includes a generally cylindrical main body and a generally cylindrical tip section disposed in generally coaxial relationship with the main body. The apparatus includes apparatus for mounting the tip section in relation to the body section, including two coaxial pins which, each have an axial portion cooperating with the main body and another axial portion connected to the tip section; each of the pins has a head, each of which is disposed proximate to the geometric center line of the body portion. Each of the pins has an axis that is generally coincident with a diameter of the main body. In some forms, the head of each pin is generally cylindrical in shape and the apparatus for mounting includes respective counterbores dimensioned and configured for cooperation therewith. The apparatus for pivoting may include a generally cylindrical nozzle front that is fixed to the main body and has an inner face, with the tip section disposed in side abutting relation to the nozzle front.

Abstract: Disclosed is a method for reducing embrittlement of certain materials of pressurized water reactor vessels caused by neutron flux. According to this method, "shadow shielding" is placed within the core support barrel in areas having a more benign flow environment than that of the downcomer area. This shadow shielding provides an increased neutron scattering cross section. In one example, the shadow shielding replaces segments of the core shroud plate in a manner which does not interfere with coolant flow in the vessel. The segments of the shroud plate which are replaced are those near critical regions of the vessel, typically welds. The size and shape of the shielding is determined according to plant specific requirements.

Abstract: A wear resistant coating (50) for a component of a nuclear reactor fuel assembly or control assembly comprising a ceramic material (52) which is premixed with a glass (54). The coating is applied to components of the nuclear reactor vessel, or portions thereof, which are subject to the greatest wear due to friction or fretting. Also disclosed herein is a method for enhancing the wear resistance of a portion of a metal component of a nuclear reactor by coating a surface of the component with a wear-resistant coating formed from diamond, metal nitride, or a composite of a ceramic material and a glass.

Abstract: A permanent annular ring seal and refueling deck assembly providing an effective water barrier over the annular space between a nuclear reactor vessel flange and a surrounding annular ledge includes annular platform, a support and a joint seal. The joint seal has an upper cylindrical section and a lower flexible corrugated or arcuate shaped section which accommodates radial, axial and rotational movements of the vessel, and reduces joint stress.