Abstract: An apparatus is disclosed for aligning brushes of a dynamoelectric machine such as a dc generator or motor to minimize arcing of the brushes. The alignment monitor processes electrical signals from brushes of a dynamoelectric machine during tests in which various levels of buck or boost current are superimposed on a preselected level of excitation current applied to the machine; the monitor produces output signals which, together with the levels of applied buck or boost currents, are indicative of the brushholder rigging adjustment which is required to achieve the optimum rigging position for a wide range of arc-free machine operation. Included in the brush alignment monitor are, respectively, a high-pass filter, a clipping network, rectification means, a second high-pass filter, a discriminator, an rf amplifier and a peak integrator with alignment indicating means. Also included is an rf generator network which is used to test the operation of the alignment apparatus.

Abstract: An electronic control system to automatically determine the validity of an apparent overheating signal from an overheat monitor of a gas-cooled dynamoelectric machine and reduce machine load or indicate a monitor malfunction. Upon receipt of an apparent overheat signal by the control system, filtration of the monitored cooling gas is automatically initiated to remove pyrolysates released into the gas by overheated elements within the machine. A normal monitor response is thereby effected, provided the overheat signal is valid. If filtration of the monitored cooling gas fails to elicit a normal response within a preselected time period a monitor malfunction is indicated. The control system initiates a scheduled reduction in machine load either subsequent to validation of overheating or as verification is initiated, and if a valid indication of overloading persists, trips the excitation and remaining load from the machine.

Abstract: A stator for a dynamoelectric machine preferably comprises a stack of modular sections, each modular section comprising an outer metallic cylinder formed from a plurality of metallic laminations arranged in a plurality of layers. Furthermore, the stator module comprises an inner nonmetallic cylinder formed from nonmetallic laminations having inwardly projecting teeth so as to define a plurality of slots along the inner circumference of the modular sections, the nonmetallic laminations being adhesively bonded to the outer metallic laminations. The stator modules of the present invention may be incorporated either in a conventional air-gap winding generator or employed in a superconducting rotor generator exhibiting high magnetic flux in the air-gap region between the rotor and the stator.

Abstract: Brushholder apparatus is disclosed for supporting electrically conductive brushes of a dynamoelectric machine in a manner facilitating improved cooling of the brushes and adjacent collector ring. The apparatus includes a brushholder assembly with a pair of legs to internally support a brush and may also include a casing arranged to retain several brushholder assemblies, provide an enclosure for properly directing cooling gas circulated by a fan, and furnish a common electrical link between brushholder assemblies and a source of electric current. An insulated handle is described which can be inserted into the brushholder assembly and manipulated to lock handle, brushholder assembly, and brush together as a unit to permit safe removal of the brushholder assembly and associated brush from the casing and installation of a new brush during operation of the machine.

Abstract: A calibration signal source for instruments to measure power and negative sequence current of a multi-phase electric power generator. Separate signals are provided to represent load current for each phase of the generator ultimately to be tested, and to represent the instantaneous differences in voltage between each phase and a reference phase. The calibration signals are derived from a single sine wave by providing a plurality of phase shift and voltage difference networks. Means are provided for amplitude control and elimination of harmonic distortion of the single sine wave, and therefore the output calibration signals share these characteristics.

Abstract: Improved method and apparatus for controlling thermal stress on component parts of a steam turbine while providing maximum loading and unloading rates during startup, shutdown, and other periods of load change. From monitored and derived quantities, a loading rate is calculated for each of a plurality of preselected turbine component parts and the lowest rate is selected for control. Simultaneously, and in concert with load change calculation and execution, the steam admission mode of the turbine is automatically directed to either the partial arc mode or the full arc mode as necessary to reduce stress as compared with a preselected and adaptive stress reference value.

Abstract: An apparatus for continuously monitoring the alignment condition of a thrust bearing based on a pair of temperature differences is adapted to utilize either analog or digital means. The monitor is particularly applicable for use in large turbines, particularly those coupled to generators for the production of electric power. Bearing misalignment and other variables are determined from temperature measurements of the oil feed temperature and from two temperature measurements made on diametrically opposite portions of the bearing surface. The apparatus of the present invention is made possible by observed predetermined relations between certain computed temperature differences which relate bearing thrust and misalignment moment and which also relate minimum oil film thickness and actual misalignment slope.

Abstract: A monitor for logic circuits detects loss of redundancy within the monitored circuit and designates that portion thereof which is out of service. Loss of redundancy is detected by sensing the passage of normal load current, or a portion thereof, through shunt current paths; the occurrence of such current flow coupled with the direction of flow uniquely determining the portion of the logic circuit which is out of service. In a preferred form of the invention, a low ohmic valued resistor is connected in each shunt current path. Upon loss of redundancy, a voltage signal generated across at least one such resistor, is applied to one or more parallel connected amplifiers responsive to the signal to activate corresponding switching circuits and audio/visual indicators.

Abstract: An improvement in torsional vibration monitors wherein a frequency shift is applied to the torsional vibration signal to achieve improved stability and increased confidence in the measurement. The torsional vibration signal is applied to parallel frequency shifters to produce a lower frequency measuring signal and a lower frequency reference signal. The two lower frequency signals are applied to parallel connected filters to obtain spectral content of the signals. Once the spectral content is obtained, each lower frequency measuring signal and each lower frequency reference signal is shifted back to the original frequency range to produce filtered reference signals and filtered measuring signals. These signals are then correspondingly summed to provide a set of torsional vibration signals segregated with respect to the frequency spectrum and meaningful with respect to a time base.

Abstract: Terminal boxes for large dynamoelectric machines provide a housing for high voltage terminal bushings which connect the dynamoelectric machine with a power grid. The stray flux from the terminal bushings induces eddy and circulating currents in the terminal box walls and consequent heating of the walls. To limit wall temperatures water is circulated through sealed flow channels fabricated to the terminal box walls and in series with the terminal bushings flow circuit. A preferred wall construction comprises an outer wall of stainless steel clad carbon steel and an inner wall of stainless steel.

Abstract: Method and apparatus to limit and control rotational loss heating such as occurs in a large steam turbine in the bypass mode of operation under no-load and low-load operating conditions. According to the invention, a portion of the high pressure bypass steam is admitted to the lower pressure sections of the turbine to provide motive fluid for driving the turbine while, simultaneously, a second portion of the high-pressure bypass steam is admitted to the high-pressure section of the turbine in a reverse-flow direction to pass backwards therethrough and limit the rotational loss heating. The two flows may be proportioned to control rotational loss heating in both the high-pressure and lower pressure sections of the turbine. A reverse-flow valve and a ventilator valve are provided for routing the reverse-flow of steam.

Abstract: Apparatus and method for monitoring torsional vibration in the rotor of a dynamoelectric machine by detecting electrical quantities available at the output terminals of the machine. For at least one phase of the machine, output voltage and current are detected and a composite signal is formed therefrom in signal processing circuitry. The composite signal is in synchronous phase with the mechanical angle of the rotor and may be demodulated to obtain the torsional vibration information.

Abstract: A thrust bearing wear detector is mounted on a positioning apparatus which is capable of moving the sensor a predetermined fixed distance toward and away from a rotating collar fixed to a turbine shaft. The positioning apparatus comprises a fixed piston, a movable piston, and a movable casing in which the pistons are slidable. Additionally, bias means, such as springs, position the pistons and the sensor in a predetermined, fixed position until working fluid is delivered under pressure through channels in the fixed piston. The positioning apparatus of the present invention readily facilitates verification of the proper operation of the wear detector.

Abstract: A moisture separator reheater combination includes specially located perforated baffles which function to reduce components of steam fluid velocity flow which are substantially parallel to the cylindrical axis of the moisture separator vessel. These baffles counteract the effects of transverse vortices which produce local pressure variations and adversely affect the efficiency of the moisture separator elements. The use of the baffles of the present invention improves the uniformity of steam flow through the moisture separator elements.

Abstract: Shell and tube heat exchangers achieve greater efficiency and substantially eliminate instabilities due to condensate subcooling by the location of flow restricting orifices at the outlet ends of heat exchanger tubes adjacent to the outlet header. Outlet orificing preferentially passes liquid condensate so as to prevent accumulation of condensate within the tubes and permits a higher tubeside temperature, even in the most heavily loaded tubes. In a two-pass configuration all tubes are outlet orificed. In a four-pass system, the most heavily loaded tubes (second pass) are orificed, although all tubes may be outlet orificed. Outlet orificing may be used in conjunction with inlet orificing which is used to provide greatest mass flow of tubeside steam to most heavily loaded tubes. Outlet orificing may be used in connection with vertical or horizontal U tube configurations. Preferred embodiment is utilized in a moisture separator reheater for use with steam turbines to reheat steam for later turbine stages.

Abstract: A manway handling apparatus for handling heavy sealing manways in large shells without damaging sealing surface means therefor is provided which includes a support arm pivotally mountable on equipment having elliptical manway access openings. The support arm when mounted is swingable toward and away from an access opening and carries a bearing block supporting bracket which is longitudinal adjustably positionable on the arm. A bearing block is vertically adjustably positionable in the bracket and slidably supports a shaft which is attachable to an elliptical cover. Structure is provided for longitudinally actuating and rotating the shaft to position and rotate the cover to facilitate installation and removal of the cover through the elliptical opening. The shaft carries structure means which when actuated by turning of a crank handle is effective for tilting the cover also to facilitate its installation and removal.

Abstract: Phosphosilicate compositions are disclosed for treating foundry molds and like products to enhance mold strength and refractoriness. The phosphosilicates, characterized more specifically as silicyl metaphosphates, may be used in combination with select refractory aggregates and other additives to form mold surface treating compositions, or may be combined directly with foundry sand or other comminuted refractory material for compacting into a mold form.

Abstract: A dedicated supervisory control system for a steam turbine-generator comprising a hierarchy of microcomputer subsystems interactive with a conventional analog electrohydraulic control system to provide control and monitoring capabilities during all operating phases of the turbine-generator. The separate microcomputer subsystems are programmed for coordinated interaction and communication through shared, dual-port read/write memory units and each microcomputer subsystem is programmed and configured to handle a separate group of control responsibilities in a distributed control system.

Abstract: The disclosure relates to the construction of large fluid conduits and particularly to steam conduits used in large power plants. In some power plants, steam is transferred from the exhaust of a higher pressure turbine section into the inlet of a lower pressure turbine section through a steam conduit sometimes referred to as a cross-over which may include several bellows type joints. If the turbine rotor speed exceeds rated speed, then it is desirable to limit the maximum speed to be attained by the turbine rotor. The present invention provides a reliable and advantageous construction which will decrease the maximum speed of a turbine rotor over designs now available in the prior art.

Abstract: An improved air gap baffle is disclosed for a dynamoelectric machine of the type having an air-tight casing filled with a cooling gas, a stator core, a rotor defining an air gap with the stator core, and a means for recirculating the cooling gas through the stator core and the rotor. The baffle is an annular member which is disposed in the air gap between the stator core and the rotor for defining air gap zones having different cooling gas pressures and/or gas flow in opposing directions. The baffle comprises a flexible abradable member having a serrated tip in sealing relationship with the rotor. The baffle improves sealing between adjacent air gap zones by minimizing running clearances and by providing a labyrinth seal. The flexible nature of the baffle reduces the possibility of damage to either the baffle or the rotor during assembly and thereby allows the dynamoelectric machine to be assembled with minimal running clearances between the baffle and the rotor.