Abstract: A positioning system for a steam turbine element includes a plurality of flex plates which support an inner cylinder of a steam turbine element with the rotating blades of a rotor and the stationary blades of the inner cylinder at a predetermined position. Sensors detect shifting of the rotor within the inner cylinder and provide control signals to a motor which drives the inner cylinder in an axial direction to account for shifting of the rotor.

Abstract: In a method and apparatus for detecting the presence of contaminants in a liquid stream which may also contain gas bubbles, the gas bubbles are detected by mechanically generating an alternating hydraulic pressure in the liquid stream, and monitoring the response of gas bubbles in the stream to the alternating hydraulic pressure.

Abstract: The movement of a rotating part of a machine is monitored by deriving a signal representing the motion of the rotating part, at least temporarily storing the derived signal, and analyzing the stored signal, with temporary storage being performed only on portions of the signal derived during spaced time intervals during each revolution of the rotating part.

Abstract: The present invention is a monitor that detects generator core 12 hot spots where the insulation between ferromagnetic sheets is breaking down by monitoring rotor 10 shaft voltage. The difference between the differential shaft voltage at each end of the rotor 14 produces a voltage signal that changes as the core 12 malfunctions. By comparing signal samples over time, core failure can be detected. Spring loaded rotor shaft brushes 20 and 22 connected to differential isolation amplifiers 24 and 26 obtain the voltage between ends 16 and 18 of the rotating shaft and nearby frame, and a differential amplifier 28 produces the difference between the shaft end differential voltages which is the shaft dissymmetry voltage. An analog-to-digital converter 30 produces digital values of the dissymmetry voltage which can be converted into a voltage frequency spectrum by a Fourier Transform routine executed by a computer 32 or analyzed directly.

Abstract: A shaft torsion monitor comprises a plurality of sensors for sensing the angular position of various portions of the shaft under dynamic conditions and for producing sets of data representative of the sensed angular positions. A memory is provided for periodically storing one of the sets of data representative of the angular position of the various portions of the shaft in the absence of torsion. Circuitry is provided for subtracting the stored set of data from each of the other sets of data to eliminate the effects of noise. The resulting data is analyzed to determine the torsion experienced by the shaft.

Abstract: A system for monitoring the clearance between a plurality of turbine blade shroud segments connected to form a turbine blade shroud and the stationary portion of the turbine comprises a sensor responsive to eddy currents generated in each of the shroud segments for producing input signals representative of the clearance between each shroud segment and the stationary portion of the turbine. Indicia are carried by the turbine blade shroud for causing the sensor to produce a known displacement signal. A processor is responsive to the input signals and the displacement signal for producing output signals indicative of the clearance between each shroud segment and the stationary portion of the turbine. The output signals have a predetermined relationship to the known displacement signal.

Abstract: A system for monitoring the temperature of a plurality of turbine blade shroud segments includes indicia carried by each shroud segment. A sensor produces input signals in response to the indicia. A temperature sensor measures the temperature of the sensor producing the input signals. A first circuit, responsive to the temperature sensor, corrects the input signals to compensate for the effects of temperature on the sensor. A second circuit determines the temperature of each shroud segment based on the corrected input signals.

Abstract: A method of determining the untwist of turbine blades under dynamic conditions is comprised of the steps of producing a first pair of blade passing event signals in response to a blade tip's movement past a pair of fixed sensors. The signals comprising the first signal pair are compared to one another to establish a first differential value. Another data point containing blade vibrational information is produced. The first differential value and the other data point are evaluated to discriminate between blade untwist and synchronous vibration. Based on the magnitude of the blade untwist, inferences can be drawn regarding the status of the turbine blade lashing wires.

Abstract: A flow sensor includes a strap-on heater attached to a fluid conduit downstream of a drain valve and two differential temperature measuring thermocouples attached to the fluid conduit downstream of the heater. A monitoring system employing at least one of the flow sensors further includes a controller which receives the differential temperature signal produced by the two thermocouples, a signal indicative of a selected valve position, and a signal indicative of steam turbine operating condition, i.e., hot or cold. The controller includes a logic circuit for correlating the differential temperature value signal, the valve position signal and the steam turbine condition signal to a diagnosis of the drain valve condition.

Abstract: Instrumentation and monitoring systems utilize, as differential temperature sensors, heated, split-well thermowells of duplex design, mounted to the sidewall of a pressure vessel and communicating through a penetration in the sidewall with the fluid state within the vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the presence of steam versus water. The systems monitor the differential temperature outputs of plural such sensors to produce alarm indications and perform verification and error checking of the sensor output indications.

Abstract: A vibration sensor 24 is disclosed which uses a piezoelectric crystal 26 to electrically modulate the phase of a laser beam using a phase modulator 28 producing a linearly phase modulated light beam. A DC bias can be provided by a battery 60 while a photocell 64 can provide the DC bias along with a calibration signal. The sensitivity of the sensor 24 can be doubled by passing the light beam through the sensor 24 twice using a reflector 74. By routing optical fibers 20, 22 and 31 carrying a reference beam and a sensing beam along the same physical path mechanical stress effect noise can be removed.

Abstract: An improved tracer gas leak detection system and method for air inleakage testing of a turbine-condenser system quantified leak testing with two new elements: one, by providing discharge of a fixed, reproducible amount of tracer gas at a possible leak site, which is accomplished by controlling the flow rate, pressure and time interval of the discharge. Secondly, the total amount of tracer gas subsequently detected within the turbine-condenser is determined by integrating the detector response.

Abstract: A light beam altering grid (20), having a graded slit density pattern (22), is mounted on a temperature responsive support structure (23) to traverse a light beam (28). The slit density (slit per unit length) of the grid (20) is greater at one end of the grid (20) and gradually reduces towards the opposite end of the grid (20). The grid (20) is disposed on a thermally responsive support (23) such as a bimetallic cantilever (23). The thermally responsive support (23) operates to bend by an amount dependent upon the temperature of the environment in which it operates. In this manner, the grid (20) disposed on the thermally responsive support (23) is positioned in dependence upon the environmental temperature.

Abstract: A method and apparatus for controlling the operation of a normally open bypass valve in a steam turbine air inleakage exhaust vent pipe. The valve is used to bypass a flowmeter connected in a bypass pipe parallel with the valve. The flowmeter provides signals indicative of bypassed flow. The method and apparatus compares the signals from the flowmeter to a reference signal corresponding to a first predetermined flow rate and generates a valve closure signal if the flow through the flowmeter is less than the predetermined flow rate. If the valve is closed, the signals from the flowmeter are used to display the actual air inleakage exhaust rate. If the flow exceeds a second predetermined value, a signal is generated to open the valve for bypassing the exhaust through the valve around the flowmeter. During the second mode of operation, the flowmeter indicates only approximate inleakage exhaust flow rate.

Abstract: A heated, split thermowell comprises a cylindrical shank and integral, axially extending, part-cylindrical probes spaced by at least a first gap defined by a bilateral plane. The thermowell is mounted to the sidewall of a pressure vessel for communicating through a penetration in the sidewall with the fluid state in the pressure vessel. Each probe has at least one parallel axial bore therein, a related, selected pair of probes receiving respective heater and temperature sensing elements in the associated bores, and together functioning as a differential temperature sensor producing distinguishable, differential temperature outputs representative of the fluid condition of steam versus water. Duplex sensor embodiments permit toggling between different, selected such pairs of probes for on-line testing and verification of monitored conditions and operability of the elements and supporting circuits, with automatic substitution of complementary elements in the event of element failure.

Abstract: In an active shaft ground system for maintaining a rotating shaft (4) of a machine substantially at ground potential, which system includes a circuit coupled to the shaft (4) for monitoring the voltage on the shaft (4) relative to ground and a brush (6) coupled to the circuit and contacting the shaft (4) for conducting to the shaft (4) a compensating current having an amplitude and polarity adjusted for maintaining the shaft voltage substantially at ground potential, there is provided shaft condition detection circuitry (18,20,24,26,28,34,36) coupled to the circuit for monitoring the voltage on the shaft (4) relative to ground and the current flowing between the brush (6) and the shaft (4) and for producing a fault indication when the voltage on the shaft (4) relative to ground is outside of a selected range at the same time that the current flowing through the brush (6) is substantially equal to zero.

Abstract: A normally closed valve system for sealing off low pressure gas flow through a pipe. The valve system comprises an inflatable bladder which blocks relatively low pressure flow through the pipe and permits relatively high pressure flow through the pipe. In one form, the invention comprises a fail-safe bypass monitor and method for measuring air inleakage in a steam turbine. The monitor selectably bypasses low volumetric flow rates from a pipe for measurement and admits flow through the pipe whenever the flow rate exceeds a predetermined value.

Abstract: A thermally self-adjusting mount for a proximity sensor for detecting movement of a turbine blade tip within a turbine housing includes an elongated chamber in an interior wall of the turbine housing adjacent the path of travel of the turbine blade tip. The chamber is configured to receive a blade tip sensor therein and accommodate relative movement of the sensor toward and away from the path of travel of the blade tip. A thermally expansive element is operable coupled with the sensor for moving the latter in the chamber toward the path of travel of the blade tip upon heating of the sensor. A spring is provided for maintaining the sensor in contact with the thermally expansive element during both expansion and contraction of the latter.

Abstract: Apparatus for monitoring displacement of a translational member in a pressurized vessel. In one form, the apparatus comprises first and second fluid containing compressible bellows each coupled to a differential pressure gauge in order to measure pressure fluctuations between the bellows. An end portion of the first bellows is coupled to the translational member in order to receive a variable compressive force as the member is displaced. The displacement of the translational member is determined as a function of the pressure variation between the first and second bellows.

Abstract: A method and device for monitoring the operation of a component which is located in a sealed enclosure and is movable into a selected operating position in response to an activating signal uses the steps of: generating a short-duration acoustic signal in the enclosure in response to the movement of the component into the selected operating position; sensing the acoustic signal at the exterior of the sealed enclosure; and determining the time relationship between the activating signal and the acoustic signal. The acoustic signal is generated by an element which is carried by or moveable with the component and which generates the acoustic signal by striking an interior surface of the enclosure when the component moves into the selected operating position.