Abstract: An electromagnetic flowmeter system in which the flow rate signal yielded by the flowmeter primary is applied as an input to a secondary which acts to measure the ratio of the input signal to a reference voltage proportional to the magnetic flux established in the primary, the reference voltage reflecting variations in this flux. Ratio measurement is effected in the secondary by means of a feedback loop in which the reference voltage is pulse-modulated by pulses having a constant width and a frequency which varies in accordance with the flow rate, the pulses having a duty cycle sufficient to cancel the input signal at the input of a summing amplifier. When the variable frequency pulse output from the secondary accurately represents the flow rate, the pulse-modulated reference voltage will then be equal in magnitude and opposite in phase to the input signal.

Abstract: An electronic totalizer having a non-destructive readout indicative of the time-integrated total of a process variable such as flow rate, metered by a transducer whose output signal lies within a predetermined current range. In the totalizer, the transducer signal is converted into a proportional voltage signal that is applied to a voltage-to-frequency converter yielding pulses at a rate which varies with the magnitude of the voltage signal, the pulse frequency being high at the upper limit of the range. The converter pulses are fed to an adjustable scaler yielding output pulses at a scaled-down rate appropriate to the desired unit of measurement, these being applied to a counter which gives a totalized reading. By setting the scaler, one may establish a reading in useful increments of process flow, such as gallons or liters.

Abstract: An apparatus for injection-molding an insulating liner onto the surface of a metal spool to be included in an electromagnetic flowmeter in which the fluid to be metered is conducted through the lined spool. The spool is composed of a cylindrical body having end flanges and a pair of diametrically-opposed circular bosses disposed midway between the flanges to receive the meter electrodes. To carry out injection molding, the spool is supported within a mold which defines a liner cavity conforming to the inner surface of the cylindrical body and to the faces of the end flanges, the liner cavity communicating with cavities conforming to the inner surface of the electrode bosses. The molding material is injected into a sprue in the mold which runs along the longitudinal axis of the spool toward the hub of a runner extending radially toward an axisymmetric ring gate opening into the liner cavity at a point adjacent the boss cavities.

Abstract: An ultrasonic flow rate measuring system in which a pulse of ultrasonic energy is emitted by a transducer placed on a pipe conducting the fluid to be metered, the energy being propagated through the fluid and being picked up by a second transducer at a different pipe position. The received signal burst includes a first pulsatory swing whose amplitude differs from subsequent swings, the signal burst being applied to the input of an amplifier having automatic-gain control. A clamp circuit coupled to the amplifier input is rendered operative immediately after the first swing is yielded in the amplifier output, the clamp acting to ground the input whereby the operative control level and the resultant gain of the amplifier is determined solely by the first swing.

Abstract: An ultrasonic flowmeter including a pair of alternately-excited upstream and downstream transducers, an acoustic pulse emitted by one transducer and propagated through the fluid being received by the other. The time delay difference between the upstream and downstream transit times is measured to determine the flow rate of the fluid. A single pulse power generating device is employed to excite both transducers, the device being coupled to the transducers through respective gates, each activated by an associated gate driver. Also included are logic means to periodically activate the device to produce power pulses and to alternately activate the gate drivers to cause the pulses to pass through alternate gates to excite one transducer and then the other.

Abstract: An ultrasonic flowmeter for measuring the flow rate of fluid conducted through a pipe, the meter including a pair of alternately-excited transducers, one being placed at an upstream and the other at a downstream pipe position. An acoustic pulse transmitted by one transducer and propagated through the fluid at an angle to the longitudinal flow axis is received by the other transducer. The time delay difference between the upstream and downstream transit times which depends on flow velocity is determined to provide a flow rate reading. Since the geometry of the pipe is a major factor in flow rate measurement, to factor-in this geometry, a third transducer or one of the pair is arranged to produce an auxiliary acoustic pulse that is propagated in a direction normal to the flow axis to produce a first echo at the interface of the inner pipe surface and the fluid on the transducer side, and to produce a second echo at the diametrically opposed side of the pipe, these echoes being received by the same transducer.

Abstract: A Doppler-type ultrasonic flowmeter whose transmitting transducer is excited by an oscillator to project into the meter pipe a diverging beam of ultrasonic energy. The projected beam is reflected by contaminants carried by the fluid lying within the zone in which the projected beam intersects a reception beam converging toward a receiving transducer which picks up the reflected energy. The transmitted signal is mixed with the Doppler signal yielded by the receiving transducer to yield positive and negative beats which are applied to a low-pass filter from which is extracted a band of negative beat frequencies representing the disparate flow velocities of the contaminants within the zone dictated by the prevailing velocity profile of the fluid. This band is subjected to spectral analysis to determine the velocities of the contaminants and their relative percentages, from which the flow profile of the fluid being metered is calculated to ascertain the mean flow velocity thereof.

Abstract: A gas-extraction arrangement for a settling tank included in a wastewater treatment system, the tank having an outlet zone defined by an effluent trough at least one side of which has a weir to permit clarified water from the tank to spill therein. The trough is covered by a hood which acts to confine the atmosphere thereabove to the hood region, at least one side of the hood protruding into the tank water at a point spaced from the weir to create a scum baffle preventing grease and other floating matter from being discharged into the trough. The hood is coupled to a suction pump which acts to draw noxious gases emitted as the water spills over the weir into a gas-control system or other means for deactivating the gases.

Abstract: An electromagnetic flowmeter which includes a pair of electrodes molded of electrically-conductive synthetic plastic material disposed at diametrically-opposed points in a flow tube through which the fluid being metered passes to intercept a magnetic field, thereby inducing a voltage in the electrodes that is a function of flow rate. The inner wall of the tube is protectively covered by an insulating liner molded of a synthetic plastic material having an affinity for the electrode material and fused to the periphery thereof to define a monolithic conduit which is leak-proof.

Abstract: An electromagnetic flowmeter wherein a liquid to be metered is conducted through the flow tube of a primary to intersect a transverse magnetic field produced by an electromagnet. The resultant signal induced in the liquid is transferred to a pair of electrodes mounted at diametrically-opposed points on the tube. To avoid spurious signal components arising from stray couplings between the electromagnet and the loop constituted by the electrodes and the liquid bridging the electrodes, the coil of the electromagnet is energized by a low-frequency wave whose frequency is well below that of the standard a-c power line.

Abstract: A compact electromagnetic flowmeter unit interposable between the flanged ends of upstream and downstream line pipes for metering fluid passing through the line, the unit being subject to compression by the flanged pipe ends to effect a fluid seal. The flowmeter is constituted by a non-magnetic metal spool of high strength whose inner surface is protectively covered by an insulating liner to provide a flow conduit for the fluid. Surrounding the spool and concentric therewith is a cylindrical housing fabricated of ferromagnetic material, the housing being formed by complementary half-pieces which include end plates that join the corresponding ends of the spool to define an annular inner chamber. Mounted adjacent the inner surface of the half-pieces at diametrically-opposed positions along a coil axis normal to the longitudinal flow axis are relatively thin coils which are shaped to conform to this surface to define electromagnets.

Abstract: A camming device for centering a meter or other instrument having a cylindrical body with respect to the upstream and downstream pipes of a flow line in which the meter is interposed. Each pipe is provided with an end flange having a circle of bolt holes, the pipe flanges being bridged by clamping bolts which pass through the holes to encage and compress the meter, the holes having clearances allowing limited bolt play. Rotatably mounted on the meter body is a camming device provided with a symmetrical array of camming edges that tangentially engage the bolts. When the device is turned on the meter body, it acts to force the bolts to their extreme hole positions, as a result of which the meter body is caused to assume a position concentric with the bolt circle that is centered with respect to the pipes.

Abstract: A vortex-shedding flowmeter capable of accurately measuring the flow rate of a liquid or gas even under extreme operating conditions. The fluid to be metered is conducted through a flow pipe having a shedder/sensor unit torsionally supported therein on a pivot axis normal to the flow axis of the pipe, said unit being caused to oscillate about said axis at a rate proportional to the flow rate of the fluid. The torsional support included a torque tube whose base is received within a bore in the pipe and is welded thereto and whose tip is welded to one end of the shedder/sensor unit to provide a closed structure preventing leakage of fluid from the pipe. These oscillations are converted into corresponding electrical signals by an external torque transducer operatively coupled to the unit by a sensor link assembly including a rod which extends into the torque tube and is welded to the tip thereof.

Abstract: An analog-to-digital converter for an electromagnetic flowmeter in which the fluid being metered passes through a flow tube to intersect a magnetic field, the voltage induced in the fluid being transferred to a pair of electrodes. The magnetic field is established by an electromagnet supplied with excitation current that is alternately turned "on" and "off" at a low frequency rate. The resultant flow-induced electrode signal is sampled for a predetermined interval in each "on" and "off" field state, successive differences therebetween serving to develop an analog signal representing the flow rate. Conversion is effected by integrating each sample to produce a sloped voltage whose polarity corresponds to that of the sample and whose peak level relative to a base level is determined by the amplitude of the sample, the sloped voltage being then de-integrated back to base level in a time slot whose duration is directly proportional to the average level of the sample.

Abstract: An in-line contactor adapted to bring about intimate contact between a disinfectant and a wastewater stream to produce a reaction between the disinfectant and pathogens effecting kills in a manner minimizing unwanted side effects. The wastewater stream is pumped through the successive stages of the contactor, the first of which is an input section having a converging nozzle that projects the stream at high velocity into a throat. The throat feeds the stream in a highly turbulent state through a mixing section, the resultant vacuum created within the throat acting to draw a disinfectant such as aqueous or gaseous chlorine from a disinfectant supply into the mixing section where it is thoroughly intermingled with the turbulent stream before the stream is discharged from the contactor through a diverging pressure-recovery output section.

Abstract: A vortex-shedding flowmeter capable of accurately measuring the flow rate of a liquid or gas even under extreme operating conditions. The fluid to be metered is conducted though a flow pipe having a shedder fixedly mounted therein. A sensor which is caused to oscillate at a rate proportionate to the flow rate of the fluid is torsionally supported downstream behind the shedder on a pivot axis normal to the flow axis of the pipe, the torsional support including a torque tube whose base is received within a bore in the pipe and is welded thereto and whose tip is welded to one end of the sensor to provide a closed structure preventing leakage of fluid from the pipe. The sensor oscillations are converted into corresponding electrical signals by an external torque transducer operatively coupled to the sensor by a sensor link assembly including a rod which extends coaxially into the torque tube and is welded to the tip thereof.

Abstract: An electromagnetic flowmeter which includes a flow tube through which the fluid to be metered is conducted, the fluid intercepting a magnetic field to induce a voltage therein which is transferred to a pair of electrodes mounted at diametrically opposed positions on the tube. The inside surface of the meter tube is protectively lined with a stable liner assembly constituted by a three-dimensional stiffening structure embedded in an insulating layer which conforms to the surface.

Abstract: A method and systems based thereon for conducting a multiple velocity traverse of a flow stream cross section of known shape and area to determine flow therethrough. The technique employs any one of the known methods of numeral integration to place the traverse chords and weight the chord average velocities, the technique being applicable to flow streams of any known cross-sectional shape and area without requiring that the chords be parallel.

Abstract: A disinfectant system for intermingling a disinfectant with an effluent to be treated, such as wastewater, to kill pathogens therein, the system enhancing contact between the effluent and the disinfectant to effect a rapid and efficient disinfection action. The system includes an ejector through which a minor portion of the effluent is pumped to produce a motive fluid which induces a disinfectant therein to produce a concentrated disinfectant fluid. Th ejector terminates in a cylindrical diffuser section having a closed end and at least two circumferential series of orifices whereby the disinfectant fluid is discharged therefrom as high velocity jets which project radially with respect to the longitudinal axis of the section.

Abstract: A flowmeter of the variable area type capable of measuring corrosive liquids and gases and including a metal metering tube having a corrosion-resistant PTFE liner. To match the corrosion-resistance properties of the lined metering tube, the float assembly operating within the tube is mainly of FEP construction, the float head of the assembly which engages the inner wall of the metering tube being constructed of tantalum.