Abstract: A method of reducing vibration in a bank of tubes due to fluid crossflow, the tubes having substantially parallel longitudinal axes. The method includes the steps of selecting a plurality of tubes from the bank of tubes and interconnecting the selected tubes so as to restrain motion of the selected tubes relative to one another in at least one direction, transverse to the longitudinal axes of the tubes, while permitting each of the selected tubes to rotate on its longitudinal axis and expand and contract in a region adjacent to the interconnection. Also disclosed are various apparatus for reducing vibration in a bank of tubes due to fluid crossflow.

Abstract: Piping systems adapted for handling fluids such as steam and various process and hydrocarbon gases through a pressure-reducing device at high pressure and velocity conditions can produce severe acoustic vibration and metal fatigue in the system. It has been determined that such vibrations and fatigue are minimized by relating the acoustic power level (PWL) generated in the piping system to being a function of the ratio of downstream pipe inside diameter D.sub.2 to its wall thickness t.sub.2. Additionally, such vibration and metal fatigue can be further minimized by relating the fluid pressure drop .DELTA.p and downstream Mach number M.sub.2 to being a function of the ratio of downstream piping inside diameter D.sub.2 to the pipe wall thickness t.sub.2, as expressed by M.sub.2 .DELTA.p=f (D.sub.2 /t.sub.2). Pressure-reducing piping systems designed according to these criteria exhibit minimal vibrations and metal fatigue failures and have long operating life.

Abstract: A solids pulverizing mill for producing fine particles such as coal dust, which includes a housing having a centrally located coal feed chute and enclosing an annular-shaped air port ring containing multiple nozzles located around a rotatable grinding table. Multiple grinding rollers press down and rotate upon the coal on the rotatable grinding table so as to pulverize the coal, which is then entrained by multiple intersecting and strongly interacting air jet streams upwardly from the grinding table through a classifier section to an exit conduit. The air port nozzle ring is fitted with multiple angled flow passages from which adjacent air jet streams intersect and interact strongly with the adjacent streams to product intense turbulence, which prevents undesirable acoustic vibration of the upflowing air/coal material within the mill housing. The centerlines of adjacent air jet nozzles intersect at an included angle of at least 20.degree. and not exceeding 90.degree.

Abstract: An acoustically pulsating burner assembly which includes an elongated outer tube, a fuel supply means located within the tube, and utilizes one or more integral axially adjustable Sondhauss thermoacoustic tubular elements to generate pulsations within the burner. The acoustic pulsations are generated inside the axially movable closed end tube element provided within the burner, and these vibrations promote more efficient combustion of the fuel so as to reduce undesired emissions in the combustion products. If desired, multiple thermoacoustic tubular elements of different lengths can be advantageously used to generate pulsations of different frequencies within the burner assembly. The burner assembly is located in a furnace windbox, and can be adapted for combusting gas, oil or particulate fuels such as coal.

Abstract: A rapping hammer system adapted for periodically rapping and cleaning tubes of a heat exchanger unit to remove undesired deposits from outside the tubes. A plurality of rapping hammers are each pivotably attached to a radial arm extending outwardly from and spaced apart along a rotatable shaft. A spring device is attached to each radial arm and arranged to contact the rapping hammer with sufficient force so as to substantially restrain repeated striking movements of the rapping hammer against an impact stem of the heat exchange unit following an initial impact of the hammer. A method is also disclosed for operating the rapping hammer system for periodically rapping and cleaning the outside surface of heat exchanger tubes such as boiler tubes of accumulated ash and soot deposits.

Abstract: A system and method for resisting thermoacoustic oscillations in systems comprised of hot and cold components is disclosed. More particularly, a combined cycle power generation system 32 having a gas turbine 40, a gas turbine discharge duct 34, and a gas turbine recuperator 36 and 38 is disclosed. The system 32 is designed to resist severe thermoacoustic oscillations over its entire load range by providing for an asymmetrical arrangement of the hot section L-l, including the gas discharge duct 34 and the plenum 36 of the recuperator, and the cold section L-l, including the heat exchange tubes 38 of the recuperator. Also disclosed is a steam generation system 42 having a plenum 46, a burner 48, and a furnace 44. The steam generation system 42 is also designed to resist severe thermoacoustic oscillations by providing for an appropriate burner length L and by providing for an asymmetrical arrangement of a hot burner section L-l and a cold burner section l within the burner 48.

Abstract: A system and method for resisting thermoacoustic oscillations in systems comprised of hot and cold components is disclosed. More particularly, a combined cycle power generation system 32 having a gas turbine 40, a gas turbine discharge duct 34, and a gas turbine recuperator 36 and 38 is disclosed. The system 32 is designed to resist severe thermoacoustic oscillations over its entire load range by providing for an asymmetrical arrangement of the hot section L-l, including the gas discharge duct 34 and the plenum 36 of the recuperator, and the cold section l, including the heat exchange tubes 38 of the recuperator. Also disclosed is a steam generation system 42 having a plenum 46, a burner 48, and a furnace 44. The steam generation system 42 is also designed to resist severe thermoacoustic oscillations by providing for an appropriate burner length L and by providing for an asymmetrical arrangement of a hot burner section L-l and a cold burner section l within the burner 48.

Abstract: A rotary cutoff device for reducing noise generated by the impeller blading of rotating centrifugal fans. The rotary device includes a casing partially enclosing a rotor mounted near the centrifugal fan discharge opening. The rotor containing a plurality of resonator cavities consisting either of quarter wave length resonators or of Helmholtz type resonators, each cavity being oriented preferably transverse to the rotor axis and having a length/diameter ratio in the range of 8/1-16/1. The rotor can be rotatably adjustable relative to the fan impeller, or it can be driven by a motor at a surface speed 30-100% that of the fan impeller surface speed, so that the rotor resonator cavities act as either quarter wave length or Helmholtz resonators to absorb effectively the acoustic pulsations generated by the centrifugal fan blade pass frequency of the fan and its harmonics, and reduce substantially the noise generated by centrifugal fans.

Abstract: A pulverizing mill for particulate material such as coal, containing a plurality of roller units each pivotably attached to the mill casing. The roller units are each biased downwardly against a rotatable table and annular track by dual loading arms which are pressed downwardly by spring means located outside the casing. The spring means are provided either by coil type springs contacting the loading arms, or are provided by the loading arms being fixed at their outer ends to the casing so as to act as curved torsional spring arms to provide a downwardly force on the roller units. The roller unit pivot shaft is advantageously attached to the casing at a level below the roller axis.

Abstract: A corrugated-shaped acoustic baffle unit for insertion into a tube bundle of a tubular-type heat exchanger having parallel staggered tubes to prevent flow-induced vibrations in the heat exchanger. The baffle unit is formed of at least two helical-shaped spacer members each rotatably attached to a flexible connecting barrier member, such as a fabric or metal mesh material or formed by multiple adjacent bars or tubes each attached to the rotatable spacer members. The flexible corrugated-shaped baffle unit can be inserted between adjacent parallel tubes of a heat exchanger by rotating simultaneously the helical-shaped spacer members. After insertion of the baffle unit, the ends of the helical-shaped spacer members are connected together so as to prevent their further rotation and thereby secure the baffle unit firmly in place between adjacent tubes of the heat exchanger.

Abstract: A heat exchange apparatus in which a plurality of heat exchange tubes are disposed in a enclosure and are supported relative to two opposed upright walls of the enclosure. Each tube is formed in a serpentine manner with adjacent tube sections extending in a vertically spaced parallel relationship between the upright walls. Adjacent tube sections are connected at a distance from each of the walls of between one-fourth and one-third the distance between the two walls.

Abstract: A disc roller mechanism and method for forming helical-shaped structures from a feed wire or rod, wherein the feed wire is drawn through a plurality of staggered disc-shaped forming rollers by rotation of the rollers, while the wire is also being rotated about its own axis so as to form the desired helical-shaped product. The roller mechanism includes a support frame and a first set of at least two fixed position driven disc-shaped rollers and a second set of at least one idler disc-shaped rollers, said idler rollers being transversely adjustable positions relative to the first driven roller set rotatably mounted in the frame. The driven roller set usually has a roughened outer perimeter surface to facilitate drawing the feed wire through the intersecting forming rollers. If desired, the feed wire can be pulled off a rotatable supply spool such as by a pair of guiding rollers and then passed through the staggered disc-shaped forming rollers to provide the desired helical-shaped product.

Abstract: A roller mechanism and method for forming helical shaped structures from a feed wire or rod, wherein the feed wire is drawn through a plurality of staggered forming rollers by rotation of the rollers, while the wire is also being rotated about its own axis so as to form the desired helical shaped product. The mechanism includes a support frame and at least four lower fixed position driven rollers and at least five upper idler rollers having adjustable positions relative to the lower rollers rotatably mounted in the frame. The lower rollers usually have a roughened or grooved surface to facilitate drawing the feed wire through the staggered forming rollers. If desired, the feed wire can be pulled off a rotating supply reel by a pair of guiding rollers and then passed through the forming rollers to provide the desired helical shaped product.

Abstract: An apparatus and method are provided for top-supporting a steam generator from a frame which is connected to a base. A plurality of dampers are connected between upstanding frame members and the steam generator, acting to absorb a portion of the energy resulting from dynamic loads imparted between the frame and the steam generator.

Abstract: There is disclosed an adjustable buckstay system for use in association with the walls of vapor generators or the like and whereby the magnitude of necessary clearances in various connecting elements of the system may be adjusted to reduce or eliminate vibration in the system.

Abstract: A method of suppressing formation of heat exchange fluid particles into standing waves is provided. Pursuant to the method a plurality of metal fins attached to a plurality of tube sections extending within a shell are disposed within a heat exchanger shell such that the fins extend parallel to the tube sections and parallel to the direction of flow of fluid through the shell. The fins define with the tube sections a barrier adapted to interrupt movement of columns of fluid particles in a direction perpendicular to the direction of flow of fluid through the shell.

Abstract: A tube spacer is provided for use in a tube bundle including a plurality of spaced apart rows of tube sections. The spacer comprises an elongated member having a contour defining a helix, is adapted to extend through the spaces defined between adjacent tube sections of the rows of tube sections and to contact the outside surfaces of the tube sections, and is adapted to be removed from the tube bundle in the direction in which it extends into the tube bundle.