Abstract: A scoop is used to collect a liquid slurry upstream of an internal collection tank. The scoop is in fluid communication with a downcomer, which receives at least part of the collected slurry, thereby maintaining a continuous flow of liquid slurry through the scoop to prevent plugging. Collected slurry can be removed for treatment from the scoop or the downcomer. In an application to a wet flue gas desulfurization (FGD) scrubber, the scoop collects an effluent slurry of partially reacted liquid scrubbing reagent and scrubbing byproducts before they drain into an internal reaction tank. Partially reacted liquid scrubbing reagent and scrubbing byproducts can therefore be withdrawn for treatment before the addition of fresh reagent alters the pH of the treatment stream.

Abstract: A stepped, perforated tray is provided for increasing the available gas-slurry contact area in a flue gas desulfurization chamber. The tray redirects the horizontal flow upwardly through the tray for increased surface area and contact time with slurry for removing SOx or other contaminants from a fossil fuel combustion flue gas before releasing the flue gas to the atmosphere. The tray is adaptable for use in vertical tower systems as well.

Abstract: An improved diaphragm for use with a gasket to prevent leakage of a pressurized fluid. The diaphragm has an internal groove which uses strong spring back and the pressure of the fluid to increase the gasket seating load, thereby providing a self-energizing seal which can accommodate changes in gasket load due to changes in fluid pressure. In one embodiment, a ring is shrink-fit or press-fit about the outer side edge of the diaphragm which improves strength and reduces the material cost.

Abstract: A device for channeling boiler flue gas flow and injecting controlled amounts of ammonia upstream of a selective catalytic reduction (SCR) NOx removal system. A perforated plate and/or damper can be located within one or more channels to provide volumetric control through a channel. Flow conditioning devices such as static mixing tabs and/or flow straightening tube bundles can optionally be included in each channel to improve mixing and velocity profiles. Gas flow rate measurements made, for example via pressure taps, within one or more channels can be used to measure flow and provide feedback for improved ammonia-to-NOx mole ratio control.

Abstract: A circulating fluidized bed (CFB) unit utilizing a mechanical dust collector located in a vertical flue above at least one heat exchange surface, and at least partially underneath the floor of a non-vertical flue, includes a plurality of individual collection elements each having a downward bottom outlet for a flow of cleaned gas conveyed through the collection elements.

Abstract: A method of welding together the parts of a boiler tube wall panel includes placing at least two parts of the panel to be welded together along a weld line and adjacent each other, and forming a weld along the weld line using a laser beam. The method can advantageously be used to weld boiler tube wall panels solely from one side of the panel. A GMAW process can also be used in combination with the laser beam to form the weld. Where the boiler tube wall panel includes a membrane between tubes, the membrane may be beveled.

Abstract: A support plate for retaining tube array spacing within a heat exchanger tube and shell structure. The support plate having a plurality of individual tube receiving aperture formed therein. Each apertures has at least three inwardly protruding members and bights are formed therebetween when the tube associated therewith is lodged in place to establish secondary fluid flow through the support plate. The inwardly protruding members terminate in flat lands that restrain but do not all contact the outer surface of the respective tube. These flat lands minimize fretting wear and eliminate potential gouging of the outer wall of the tube. The plate wall forming each aperture has an hourglass configuration which, inter alia, reduces pressure drop, turbulence and local deposition of magnetite and other particulates on the support plates.

Abstract: A support bar for tubes in a heat exchanger, such as the U-bend tubes in the U-bend region of a recirculating, nuclear steam generator, provides positive restraint in both the in-plane direction of the tube planes and the out-of-plane direction. The bar has pairs of parallel surfaces aligned with first and second axes such that the bar may be positioned with either axis arranged parallel to the tube planes. The bar can be used in place of other types of tube support bars, and can also be used as an auxiliary bar for installation into a fully assembled heat exchanger to provide additional support to supplement other tube support arrangements.

Abstract: A chilling sleeve is provided for insertion into a hollow cylinder, such as a control rod driving mechanism guide tube, for adjusting the temperature and therefore the diameter of the cylinder. The chilling sleeve has external inlet and outlet ports, regulated by a pump. The pump injects high pressure liquid coolant, such as liquid nitrogen into the inlet port and through channels in the body of the sleeve out to a high pressure chamber. The liquid coolant escapes the high pressure chamber via escapes holes and enters a low pressure chamber, bordered by the outer wall of the hollow cylinder. In the lower pressure chamber, the liquid coolant evaporates, which chills the adjacent outer wall of the hollow cylinder, thereby shrinking the outer wall so that the hollow cylinder can be fitted into or removed from a cylindrical hole, for example a closure head hole in a vessel head of a nuclear reactor.

Abstract: A method for forming a chromium-rich layer on the surface of a nickel alloy workpiece containing chromium includes heating the workpiece to a stable temperature of about 1100° C., and then exposing the workpiece to a gaseous mixture containing water vapor and one or more non-oxidizing gases for a short period of time. The process conditions are compatible with high temperature annealing and can be performed simultaneously with, or in conjunction with, high temperature annealing.

Abstract: A compact, low-profile, in-line beveling tool suitable for use in a confined space, such as a tightly packed array of tubes. The tool is inserted within a workpiece via a feeding mechanism, such as a worm gear arrangement, and is secured to the workpiece via an internal expanding mandrel assembly. A motor drives cutting inserts, mounted on a beveling head, in rotational motion to bevel the workpiece. The motor and beveling head with cutter inserts all share the same axis. A gear reduction box, located between and operatively connected with the motor and beveling head, provides the low RPM and high torque needed to make practical use of carbide insert technology. In one embodiment, the motor is a hollow core air motor having vanes symmetrically arranged about the axis.

Abstract: A method of reducing the pressure drop in a downflow/upflow wet flue gas desulfurization (WFGD) system and of improving overall sulfur dioxide collection efficiency by converting the downflow/upflow WFGD system to an upflow single-loop WFGD system. The method includes the replacing of the downflow quencher and related duct work with a bypass for connecting the incoming flue gas duct with the upflow absorber, and the adding of a quenching zone in the absorber comprised of spray headers.

Abstract: A convection pass enclosure for a boiler comprising a front wall having a gas inlet for receiving gases from the boiler; right and left side walls connected to the front wall; a rear wall having a gas outlet, the rear wall being connected between the right and left side walls; and a roof, at least one of the front wall, right side wall, left side wall and rear side wall having a heat exchanger surface in the form of a horizontal spiral tube assembly.

Abstract: An apparatus for supplying relatively cool feedwater to a heated pressure vessel, while moderating the thermal gradients within the apparatus and the pressure vessel. The feedwater apparatus is generally comprised of a feedwater inlet nozzle, thermal sleeve and sparger assembly which is structured to provide a thermal barrier and to lengthen the path of heat conduction through the feedwater inlet nozzle; to insure adequate support for the thermal sleeve and the sparger; to improve feedwater flow through the thermal sleeve and the sparger; and to facilitate the inspection and repair of the welds used to structure the feedwater apparatus.

Abstract: A scoop is used to collect a liquid slurry upstream of an internal collection tank. The scoop is in fluid communication with a downcomer, which receives at least part of the collected slurry, thereby maintaining a continuous flow of liquid slurry through the scoop to prevent plugging. Collected slurry can be removed for treatment from the scoop or the downcomer. In an application to a wet flue gas desulfurization (FGD) scrubber, the scoop collects an effluent slurry of partially reacted liquid scrubbing reagent and scrubbing byproducts before they drain into an internal reaction tank. Partially reacted liquid scrubbing reagent and scrubbing byproducts can therefore be withdrawn for treatment before the addition of fresh reagent alters the pH of the treatment stream.

Abstract: An improved support for a tube bundle of a nuclear steam generator has a pair of plates separated by spacers and holding slotted disc springs used to mount tubes through tube holes of the pair of plates. The slotted disc springs deform upon installation and substantially eliminate tube vibration during use, thereby extending the useful life of the tubes. At the same time, the springs limit the pressure drop between sides of the support and enhance the heat transfer from the tubes.

Abstract: An internally threaded, segmented nut and conical bore for a pressure vessel are used to make removal of studs securing covers over openings through the pressure vessel wall. The segmented nut has a conical upper surface to mate with a corresponding surface of the conical bore when the stud is threaded through the internal thread of the nut and a load is applied. The segmented nut is easily replaced and the stud is easily removable due to the shape of the nut and bore. The segmented nut eliminates drilling and rethreading the bore to repair damaged threads.

Abstract: A forming or re-rounding machine has opposed inner and outer hydraulic ram sets each carried in a housing with rollers. The ram set housings are movably mounted onto an I-beam frame connected by hydraulic cylinders. The frame supports a can or shell for rotation of the surface to position a region for forming or reforming between the hydraulic ram sets. Each ram set has a hydraulic cylinder for advancing a re-forming tool on either the inside or outside of the can or shell to reform the selected region. The I-beam hydraulic cylinders are allowed to compress when the can or shell is positioned for forming or reforming and help prevent flexing of the can or shell outside the selected region.

Abstract: An hydraulic loading assembly for ball and ring coal pulverizers has a plurality of compression assemblies connected to a common hydraulic controller for exerting equal pressure simultaneously on each of the compression assemblies. The compression assemblies each have a hydraulic cylinder and piston located above and connected to a non-threaded rod which is in turn located above and connected to a compression spring exerting force on the top grinding ring of the pulverizer.

Abstract: A system for maintaining an optimal flue gas inlet to a boiler mounted SCR assembly in the flue of the boiler is accomplished by mixing the normal inlet feedwater to an economizer of the boiler with near saturation water from downcomers of the boiler to thereby raise the temperature of the flue gas passing across the economizer and raising the SCR inlet to the desired optimal SCR operation temperature.