Abstract: A flowmeter of the vortex type in which an obstacle assembly mounted in a flow tube causes vortices to be shed at a frequency that is a function of flow rate. The assembly includes a block fixedly mounted across the flow tube at right angles to the direction of flow, the block having a substantially square cross-section to present a flat face to the incoming fluid. The width of the block has its maximum value at the mid-point thereof and diminishes gradually toward either end where the width assumes its minimum value such that the upper and lower faces of the block are bellied and the front face has a double-convex contour. The maximum width value affords an efficient shedding action, the mean width value of the block being significantly smaller than the maximum value to substantially reduce the pressure drop produced by the meter.

Abstract: An evaporator adapted to convert a liquified gas, such as chlorine, into a gas, the evaporator including an enclosed vapor chamber functioning as a pressure vessel. The vapor chamber is suspended within a water chamber having a heater serving to raise the temperature of the water to a level at which heat transfer through the wall of the vapor chamber causes the liquified gas fed therein through an inlet pipe to evaporate and produce a superheated gas that is discharged through an outlet pipe. The vapor chamber is fabricated of a steel tank whose outer surface is coated with a film of tetrafluoroethylene having a thickness just sufficient to render the film impermeable to water, thereby inhibiting corrosion of the steel surface and the formation of scale thereon, the thickness of the film being insufficient to materially reduce the heat transfer characteristics of the vapor chamber.

Abstract: A highly compact electromagnetic flowmeter unit interposable between the flanged ends of upstream and downstream line pipes for metering fluid passing through the line. The flowmeter is constituted by a ferromagnetic ring within which a pair of electromagnet coils is supported at opposed positions along a diametrical axis normal to the longitudinal axis of the ring, the longitudinal axis passing through the central flow passage of an annular pressure vessel. The vessel, which is formed of high-strength insulating material, is molded within the ring and encapsulates the coils as well as a pair of electrodes disposed at diametrically-opposed positions with respect to the flow passage along a transverse axis at right angles to the coil axis to define a unitary structure. The unit is compressible between the end flanges of the pipes by bridging bolts that pass through bore holes in the pressure vessel or lie outside the ring to encage the unit.

Abstract: A two-wire transmitter operating in conjunction with a meter whose output signal varies in frequency as a function of the metered variable. The meter signal is changed into an analog voltage that is converted by the transmitter into a corresponding output current and conveyed to a receiving station over a two-wire line which also supplies operating voltage to the transmitter. In the transmitter, the analog voltage is applied to a differential amplifier which converts the voltage into an output current via a transistor acting as a variable impedance across the line to make up the difference between the operating current drawn by the transmitter and the output current. This make-up current is stored to provide an energy source for operating a totalizing counter coupled to the meter to determine the total amount of the variable passing through the meter.

Abstract: An acceleration-proof vortex-type flowmeter in which fluid to be measured is conducted through a flow tube having an obstacle assembly mounted therein capable of generating periodic vortices, causing a deflectable tail section of the assembly to vibrate at a corresponding rate. The vibrations are externally sensed to produce an output signal whose frequency is proportional to the fluid flow rate. The tail section is cantilevered by a flexible beam from a fixed section mounted across the flow tube, the vibrations of the tail section being transmitted to an external coupling head by a rod extending though the beam and connected at an immediate junction of a bar disposed within a longitudinal bore in the fixed section. The upper end of the bar is pivotally supported by a diaphragm covering the bore and is linked to the coupling head which is engageable by a force sensor.

Abstract: A multi-channel, common-line transmission system linking a plurality of flowmeter primaries installed at different points in a process to a remote receiving station. Each primary includes a flowmeter adapted to measure the flow rate of fluid passing through the flow conduit in which it is interposed by generating physical variations as a function of flow rate, these variations being sensed by a resonator element included in a channel oscillator whose carrier is modulated accordingly. The channel oscillators of the flowmeter primaries are assigned different frequencies within a predetermined spectrum. The modulated-carrier signals from the channel oscillators are fed over the common line to the remote station where each signal is demodulated.

Abstract: A displacement detector yielding an electrical output signal that is linearly proportional to the extent of input motion. The input motion to be monitored is applied to the shiftable armature of a differential reluctance transducer constituted by a pair of transformers, each having a primary, a main secondary and an auxiliary secondary. Fed to the primaries is a high-frequency drive voltage generated by an oscillator whose amplitude is regulated by a feedback loop in which a feedback voltage taken from the auxiliary secondaries is compared with a reference voltage to provide a control voltage that so regulates the drive voltage oscillator as to cancel out the effect of temperature on the output signal derived from the main secondaries.

Abstract: A flowmeter including a conduit-forming a passage for the liquid to be measured and an obstacle assembly mounted therein capable of generating strong, stabilized fluidic oscillations which cause a deflectable non-streamlined section of the assembly to vibrate at a corresponding rate, the vibrations being sensed to produce a signal whose frequency is proportional to the flow rate of the fluid passing through the conduit. The non-streamlined section is cantilevered from a front section to define a gap therebetween and is provided with a downstream tail whose geometry is such as to reinforce the fluidic oscillations trapped within said gap to thereby improve the signal-to-noise ratio of the signal.

Abstract: An override process control system for regulating a process with a single final control element, such as a valve, from two or more process variables that are interdependent and must not exceed acceptable minimum and maximum limits. The system includes a like number of electronic controllers each acting to compare a respective process variable with a set point to produce an output signal reflecting the deviation of the process variable from the set point. The primary controller responsive to the process variable directly influenced by the setting of the final control element has its output signal applied thereto to regulate this element, whereas the other controllers which are responsive to secondary process variables operate on a standby basis.

Abstract: An angle-to-current converter for generating an electrical current output in direct proportion to the degree of angular displacement of an input shaft. The converter includes a differential-inductance transducer constituted by a variable reluctance disc mounted on the input shaft, the profiled edge of the disc passing through diametrically-opposed air gaps defined by the cores of a pair of inductors. The profile of the disc edge is so contoured that as the disc rotates, the region of the edge lying within one gap increases while that lying within the other gap decreases, thereby varying the inductance ratio of the pair as a function of input angle. The transducer inductors are connected to the input of an astable multivibrator in a transmitter wherein the multivibrator generates a square wave whose duty cycle is varied in accordance with the varying inductance ratio and the square wave is integrated to produce a voltage whose magnitude is proportional to the input angle.

Abstract: A flowmeter of the vortex type in which an obstacle assembly mounted in a flow tube of relatively small diameter causes vortices to be shed at a frequency which is a function of flow rate. The assembly includes a block fixedly mounted across the flow tube at right angles to the direction of flow, the block having a substantially square cross-section to present a flat face to the incoming fluid. The upper and lower rear corners of the block are bevelled to define a flat rear face of reduced area, the resultant block configuration acting to enhance the shedding characteristics of the assembly and to produce substantially linear flow rate measurements at low Reynolds numbers.

Abstract: A flowmeter capable of accurately measuring and transmitting extremely low flow rates, the meter including a vertically-positioned flow tube having a ferromagnetic ball therein which is subjected to the force of gravity as well as to the drag force imposed by the upward flow of fluid to be metered. Associated with the flow tube is a position sensor which yields a control signal when the ball lies in a detection zone. The ball is also subjected to a magnetic force produced by an electromagnet energized by a current controller governed by the control signal, which force seeks to displace the ball away from the detection zone. The control signal causes the magnet current to pulse and the ball to oscillate in said tube at a frequency which is a function of flow rate, the frequency of the current being indicated to provide a flow rate reading.

Abstract: A system for metering a fluid stream constituted by a mixture of oil and water to determine the volumetric ratio of oil-to-water in the stream. The system includes a vortex meter through which the stream is conducted to produce a meter signal whose frequency depends on the volumetric flow and whose amplitude depends on the mass flow of the stream. Derived from the meter signal is a volumetric signal that is solely a function of frequency and a mass flow signal that is solely a function of amplitude, the volumetric signal being divided by the mass flow signal to produce a density signal. The volumetric and density signals are fed to a computer to which is also applied a temperature signal that depends on the temperature of the metered stream. The computer has stored therein the relationship between water density and temperature and that between oil density and temperature, and it functions in response to the signals applied thereto to determine the respective volumes of oil and water in the mixture.

Abstract: An ejector assembly adapted to intermingle a gas, such as chlorine, with process liquid or water to form a solution which is discharged from the assembly. Included in the assembly is an ejector body within which is disposed a nozzle whose output is spaced from the inlet of a throat to define an interaction zone which communicates with a gas supply. Liquid under pressure is fed into the nozzle and is forced thereby at high velocity into the interaction zone to create a vacuum acting to draw gas from the gas supply. The gas interacts with the liquid to form a solution that is discharged via the throat through suitable piping to a point of application.

Abstract: A flowmeter capable of accurately measuring and transmitting extremely low flow rates, the meter including a vertically-positioned flow tube having a ferromagnetic ball therein which is subjected to the force of gravity as well as to the drag force imposed by the flow of fluid to be metered. Associated with the flow tube is a position sensor typically constituted by a light source projecting a beam across the translucent tube that is intercepted by a photosensor yielding a control signal when the beam is obscured by the ball. The ball is also subjected to a magnetic force produced by an electromagnet energized by a current controller governed by the control signal, which force seeks to displace the ball away from the light beam. Thus the ball acts as a force summing junction and is caused to assume a position depending on the vector resultant of the co-acting drag, gravitational and magnetic forces.

Abstract: An electromagnetic flowmeter having a flow tube interposed in a normally less-than-full fluid line. A pair of arcuate electrodes are mounted in the flow tube at opposed positions spanning a substantial portion of the total circumference of the inner wall of the tube, whereby the electrodes are operative with respect to fluid in the tube in a range extending from a level close to empty to completely full. The electrodes which are in direct contact with the fluid have an inverted T formation, whose vertical leg conforms to the inner circumference of the tube, and whose horizontal base extends along the bottom of the tube, thereby maintaining a large portion of the electrode area in contact with the fluid at all times. Associated with the flow tube is an electromagnet that is excited by a periodically interrupted direct current to establish a magnetic field in the tube which is intercepted by the fluid passing therethrough to induce a signal in the electrodes.

Abstract: A vortex-type flowmeter having a flow tube forming a conduit for the fluid to be metered and an obstacle assembly mounted therein capable of generating fluidic oscillations. These oscillations cause a deflectable section of the assembly which is cantilevered by a flexible beam from a fixed section mounted across the tube to vibrate at a corresponding frequency proportional to flow rate. These vibrations are mechanically transmitted to a coupling point outside the flow tube, whereby the flow rate may be read by means of an external force sensor engaging the coupling point. Vibration transmission is effected by a rod secured at one end to the deflectable section and passing through a bore in the flexible beam to join a probe which extends at right angles thereto. The probe is disposed within a bore in the fixed section and projects through an opening in the flow tube wall to terminate in the outside coupling point.

Abstract: An electronic data processing system for a vortex-type flowmeter wherein the fluid to be measured is directed past a vortex-producing element to induce fluidic variations whose frequency is a function of flow rate. These variations are detected by a sensor yielding a signal having an A-C component whose frequency represents the uncorrected flow rate and a D-C component whose magnitude represents the temperature of the fluid. In order to correct for the effect of temperature on the accuracy of the reading, the signal components are separated from each other and converted into corresponding digital values which are fed into the data processing system to which are also applied digital values representing the fluid characteristics, the system producing an output signal representing the true flow rate.

Abstract: A pressure transmitter for sensing fluidic pressure to produce an indication that is converted into a signal for transmission to a remote station. The transmitter includes a sensor constituted by a diaphragm which seals a chamber in a meter body subject to fluid pressure, the diaphragm being axially dilated in accordance with the applied pressure. Anchored on the diaphragm is an upstanding force beam which is pushed thereby in the axial direction. A range spring which is offset with respect to the axis of the beam is connected between an intermediate point on the beam and the meter body. The spring acts to constrain axial motion of the beam, whereby when the diaphragm is dilated by fluidic pressure, the beam is caused to deflect to an extent determined thereby. A motion detector is operatively coupled to the upper end of the beam to convert the deflection thereof into a corresponding signal for transmission.

Abstract: A flowmeter including a flow tube forming a conduit for the fluid to be measured and an obstacle assembly mounted therein capable of generating strong, stabilized fluidic oscillations which are sensed to produce a signal whose frequency is accurately proportional to the flow rate of the fluid passing through the tube, regardless of fluid turbulence or other disturbing factors. The obstacle assembly is formed by a vortex-shedding front section which is mounted across the flow tube, and a vortex-stabilizing rear section supported behind the front section to define a gap therebetween. The rear section has a central opening therein to permit the passage of fluid therethrough to smooth out turbulence and thereby create an orderly trail of vortices.