Showing papers on "Thermal mass flow meter published in 2002"

Mass flow ratio system and method

Abstract: A system for dividing a single mass flow, including an inlet adapted to receive the single mass flow and at least two flow lines connected to the inlet. Each flow line includes a flow meter and a valve. The system also includes a controller programmed to receive a desired ratio of flow through a user interface, receive signals indicative of measured flow from the flow meters, calculate an actual ratio of flow through the flow lines based upon the measured flows, and compare the actual ratio to the desired ratio. The controller is also programmed to calculate the desired flow through at least one of the flow lines if the actual ratio is unequal to the desired ratio, and provide a signal indicative of the desired flow to at least one of the valves.

Compact flow meter

Abstract: Apparatus for measuring the composition and flow rate of a fluid (1) comprising a mixture of e.g. oil and water in a pipe (2), wherein an integrated mechanical structure (3) serves as a microwave resonator sensor for providing permittivity measurements and where the mechanical structure also functions as a differential pressure element for providing flow rate measurements.

Apparatus and method for self-calibration of mass flow controller

Abstract: A mass flow sensor calibrator employs a variable-flow fluid source, a receptacle of known volume, and a pressure differentiator. The variable-flow fluid source supplies gas at varying rates to the mass flow sensor being calibrated and at proportional rates to a receptacle of known volume. A pressure differentiator computes the time derivative of gas flow into the receptacle of known volume and, from that, the actual flow into the receptacle. Given the actual flow, the proportionate flow into the mass flow sensor may be determined and the flow signal from the mass flow sensor correlated to the actual flow.

Fan for combustion air

Abstract: A method and device for adjusting the air ratio of a gaseous fuel/air mixture for operating a burner (18) comprises measuring the mass flow (7) and the Wobbe (viscosity) index of the fuel (5), measuring the mass flow of the air (13) and controlling a mass flow on the basis of these values to give the predetermined value of lambda. An Independent claim is also included for a device for the above method having flow sensors and a data unit to regulate the fuel flow though a dosing valve.

Method and apparatus for flow control of NH3

Abstract: The present invention provides an apparatus and method for accurately controlling the amount of NH3 to be applied to a field by measuring the NH3 flow rate without condensing or cooling the NH3. The system includes a control station 12 on the vehicle with a tachometer 12A or a GPS system for providing a vehicle speed signal to a control panel 13. The control panel includes a toggle switch 17 for adjusting the opening or closing of a valve 52 in the flow line to regulate the flow through the system, although the control panel alternatively may automatically control the valve 52. The vehicle transports a tank 20 containing liquid NH3 and a tool bar 30 for distributing the NH3 to the soil. After flowing through the flow meter 40, 60, 130, the NH3 is conducted to the soil through a series of hoses, fittings, a distributor, and tubing. The flow meter transmits a signal to the control panel, which is converted to a corrected flow rate signal in response to a fixed value vaporization correction factor. The temperature of the NH3 is also measured to correct for density variations. An improved variable area meter 60, 130 uses a hall effect sensor 72 and a magnet 68 mounted on a rotatable vane shaft 70 to overcome problems with prior flow meters. The improved meter 60, 130 is ideally suited for measuring the fluid flow of a low temperature vaporization liquid, such as anhydrous ammonia, propane and butane.

Flow conditioners design and their effects in reducing flow metering errors

Abstract: The sensitivity of differential‐pressure flow meters to the quality of the approaching flow continues to be a cause for concern to flow meter manufacturers and users. Distortions to the approaching velocity profiles generated by pipe fittings and installations located upstream of a flow meter, can lead to considerable errors in flow metering. This cannot be ignored because of the likely cost and process efficiency implications. This paper describes the effects of various entrance flow velocity profiles on the performance of an orifice flow meter with and without flow conditioning. Asymmetric swirling velocity profiles were generated by a ball valve. These caused significant shifts to the meter’s calibration. The use of a vaned‐plate flow conditioner, consisting of six vanes attached to a 70 per cent porosity plate, greatly improved the performance of the meter. Thus, the device can be used as part of a flow metering package that will have considerably reduced installation lengths. The less‐sophisticated NEL plate proved to be a good flow straightener, i.e. a good swirl remover, but was not an efficient flow conditioner.

Method and device for measuring a temperature variable in a mass flow pipe

Abstract: A method and an arrangement are suggested for determining a temperature quantity in a mass flow line which includes a throttle position and to which an additional gas mass flow is supplied after the throttle position. The temperature ahead of the throttle position is determined on the basis of the portion of the additional gas mass flow in the total flow in dependence upon the temperature of the mixture of the two gas mass flows as well as the temperature of the introduced gas mass flow.

Experimental and Numerical Investigation of Gravity-Driven Pipe Flow With Cavitation

Abstract: Gravity driven pipe flows contain no risk of pump failure and are considered to be reliable even under accident conditions However, accurate prediction methods are only available for single phase flow In case of the occurrence of two-phase flow (caused eg by boiling or cavitation), a considerable reduction in mass flux can be observed In this study, an experimental and numerical investigation of gravity driven two-phase pipe flow was performed in order to understand and model such flows An experiment was conducted to analyse gravity driven flow of water near saturation temperature in a complex pipe consisting of several vertical and horizontal sections The diameter was 100 mm with a driving height of 13 m between an elevated tank and the pipe outlet The experiment shows that cavitation leads to formation of steam The two-phase character of the flow causes a significant reduction of mass flux in comparison to a single phase flow case The experimental flow rate was reproduced by one dimensional single and two phase flow analysis based on standard one dimensional methods including models for steam formation The main part of this study consists of a three dimensional CFD analysis of the two phase flow A three dimensional model for cavitation and recondensation phenomena based on thermal transport processes was developed, implemented and validated against our experimental data Due to the fact that beside bubbly flow, also the stratified and droplet flow regimes occur, a new approach to model phase interaction terms of the Two-Fluid Model for mass, momentum and energy is presented Thereby, the transition from one flow regime to another is taken into account The experimental mass flow rate can be predicted with an accuracy of 10% The three dimensional analysis of the flow situation demonstrates the influence of pipe elements such as horizontal and vertical sections, bends and valves of the pipe on the mass flux and the steam distribution The analysis of secondary flows in bends emphases their importance for the steam distribution within the pipe, for the pressure loss and the average mass fluxCopyright © 2002 by ASME

A Universal, Nonintrusive Method for Correcting the Reading of a Flow Meter in Pipe Flow Disturbed by Installation Effects

Abstract: A method is described that allows the correction of the reading of a flow meter that is exposed to pipe flow disturbed by installations upstream of the meter. The method is aimed at minimizing the distance between installation and meter and is based on characterizing the flow by fundamental disturbances, physically interpretable as vortical structures, and on the detection of these disturbances by a measuring device located slightly upstream of the meter. A functional relationship between fundamental disturbances and error shift of the meter is postulated, and its existence is demonstrated by a number of experiments. It is concluded that the correction method is applicable to any type of installation and flow meter

Positive flow meter

Abstract: A flow meter and electrically operable valve assembly having integral flow meters provide detection of very low water flows, along with ease of installation and compact packaging for a water supply control system. The flow detection is particularly useful for systems that control household water supplies to prevent flooding, but is also useful in other applications such as agricultural and industrial systems where low water flow rates must be determined. All of the controls and features are integrable within a compact package that occupies essentially the same volume and piping space as a conventional electrically operable valve.

Flow measurement sensor

Abstract: To provide a flow measurement sensor which accurately outputs signals even when pulsation flow is generated at high engine speed and also when pulsation flow accompanying reverse flow is generated. In a flow measurement sensor comprising a flow measurement element which has a heater resistance pattern on one side of a plate-shaped member, and a bypass passage in which the flow measurement element is disposed, a first outlet through which fluid flowing along the surface of said flow measurement element flows out, and a second outlet through which fluid flowing along the back side of said flow measurement element flows out are provided, and said second outlet is positioned at a different location from said first outlet.

Thermal-type flow meter with bypass passage

Abstract: A flow measurement sensor accurately outputs signals even when pulsation flow is generated at high engine speed and also when pulsation flow accompanying reverse flow is generated. The flow measurement sensor has a flow measurement element which has a heater resistance pattern on one side of a plate-shaped member, and a bypass passage in which the flow measurement element is disposed, a first outlet through which fluid flowing along the surface of the flow measurement element flows out, and a second outlet through which fluid flowing along the back side of the flow measurement element flows out. The second outlet is positioned at a different location from the first outlet.

Apparatus for measuring the flow velocity and/or flow throughput of fluids

Abstract: A flow meter, such as a gas meter, for measuring the flow velocity and/or the volumetric through-flow of fluids. The flow meter has a body with connecting flanges for connecting the meter to a pipeline for the fluids. The meter has a tubular center piece that, on its exterior, has at least two receptacles, each of which receives a measuring device. The measuring devices are coupled to a signal processing unit. Electrical cabling between the measuring devices (probes) and the signal processing unit is completely covered against damage from the exterior by partially guiding the cables through bores in walls of the center piece of the flow meter and by covering portions of the cable and protruding sections of the probes with a cap.

Coriolis mass flow meter with swirl mixer

Abstract: Method for measuring a fluid flow physical variable, especially the mass flow, density or viscosity, for a fluid flowing in a pipe. Method uses a Coriolis flowmeter and has the following steps: generation of a helical flow relative to the flow axis at the inlet to the flowmeter; excitation of the fluid in the flowmeter measurement pipe; and measurement of the reaction to the excitation to generate a measurement signal that is proportional to a flow physical variable. The invention also relates to a corresponding measurement sensor and a measurement instrument. Said measurement sensor has an eddy generator at the inlet to the measurement pipe for generation of helical flow.

Turbine stage mass flow evaluation in a compression tube facility

Abstract: This paper describes a procedure to determine the mass flow of a cooled turbine stage tested in a compression tube facility. In this type of test rig, high-pressure air pushes a lightweight piston inside a closed cylinder. A quasi-isentropic compression is performed. Then, a shutter valve is opened, the flow enters the settling chamber, chokes the downstream throat and fills up the downstream vacuum tank. Thanks to mass flow and energy balances, pressure and temperature history can be predicted in all the elements of the facility and the mass flow can be evaluated in key locations. The model is validated against a large number of test data and is able to determine the mass flow for each single test. Two different turbine configurations are investigated and single test uncertainties of 0.88 % and 1.6 % are achieved, depending on the test condition. NOMENCLATURE

Thermal mass flow meter with air-cooled support member

Abstract: Support member (7) where flow amount detection element (9) including a heating resistor and electronic circuit parts (8) is cooled from both the direction of the main flow of main passage (2) and the direction of a reverse flow (the opposite direction to the direction of the main flow).

Method for driving a magneto-inductive flow meter

Abstract: The flowmeter comprises a flow sensor (1) with a measuring tube (11), two electrodes (12, 13) and two field coils (14, 15) in each of which an excitation current (I1 or I2) flows, as well as an operating and evaluation -Electronics. The method is used to generate an error signal when the uniform turbulence is disturbed in the liquid to be measured. During the period (V1), the excitation currents (I1, I2) equal to each other, have the constant value (Ik) and flowing in the same direction. During the period (V2), the excitation current (I1) to the constant value (Ik) and flows in the opposite direction (G) and the excitation current (I2) is smaller by a constant amount, and flows in the flow direction (R). During the period (V3) the exciting currents (I1, I2) have the constant value (Ik) and flow in the opposite direction (G). During the period (V4), the exciting current (I1) has the constant value (Ik) and flows in the flow direction (R) and the excitation current (12) is smaller by a constant amount, and flows in the opposite direction (G). During each period, a voltage (U1, U2, U3, U4) derived from the electrodes and from two voltage differences; (= Q U24 / U31) is formed and the quotient (U31 = U3 - - U1 U2 U42 = U4). This is determined during a calibration with uniformly turbulent flow and stored. During operation of the quotient values ​​are constantly formed and compared with the stored quotients; in case of deviations an alarm is triggered and / or the volume flow signal derived from the voltage difference (U31) is represented corrected.

Method for determining fluid mass flow rate by measurement of a temperature profile in a pipe and measuring the time of travel until the same profile is detected at a downstream point, so that calibration is not required

Abstract: Method for determination of fluid mass flow velocities, in which the temperature profile in a pipe or conduit is measured at a first measurement point and the time measured until the same temperature profile occurs at a downstream measurement point. As the separation of the two points is fixed the mass flow rate can be determined. An Independent claim is made for a system for determining fluid mass flow rate using two measurement arrays for determining the temperature profile of fluid flowing in a pipe at intervals to each other, means for recording the time elapsed between a certain measured profile moving downstream from the first array to the second and calculation means for determining a corresponding mass flow rate. Typically a temperature sensor will be placed at or near the center of a pipe.

Acoustic flow meter in the form of a valve key

Abstract: An acoustic flow meter in the form of a valve key has an acoustic sensor for measuring the peak sound level which occurs when the key is used to close a valve in a fluid pipeline. The peak sound level can be used to accurately calculate the flow through the valve and provide the flow information on a display unit. Parameters for the upstream supply pressure, pipe diameter and valve characteristics can be entered to ensure the accuracy of the flow calculations. The key therefore provides a way of determining fluid flow in a pipeline to a reasonable level of accuracy without having to install in-line flow meters.

Thermal gas flow measuring device with gas quality indicator

Abstract: Method for measuring gas consumption using a gas meter, especially for measuring gas energy consumption, whereby the meter is suitable for measuring both a gas mass flow and energy consumption in that the meter determines the gas type and if it is incombustible calculates a mass flow in weight or volume units, liters per minute (l/min), while if it is combustible calculates consumption in energy units, kWh. An independent claim is made for a gas meter that functions as both a mass flowmeter and an energy meter, having a gas quality sensor with means for determining a gas parameter that is indicative of whether the gas is combustible or not. To determine the gas type its heat conductivity, heat capacity, diffusivity or viscosity are calculated, from which the gas mixture can be determined.

Water spout device with flow meter, changeover cock with flow meter, flexible water spout pipe with flow meter, flow meter for water purifying-activating instrument, cock with flow meter for under-sink type water purifying-activating instrument, and flow meter unit

Abstract: PROBLEM TO BE SOLVED: To enable simply and posteriorly install to various water purifiers having different specifications such as a cartridge lifetime and to correspond to approximately all water purifying-activating instruments while accurately displaying the residual lifetimes of the cartridges corresponding to specifications by precisely measuring the integral flow rates or the like of the water purifying-activating instruments. SOLUTION: The changeover cock with the flow meter has a purifying-activating water inflow port 111, a purified-activated water discharge opening 112, a body case 110 with a purified-activated water passage 113 and a flow meter unit 120 being arranged in the passage 113 for the case 110 and measuring the integrated flow rate of purified-activated water passed through the passage 113. The total filtering flow rate of the cartridge for the water purifying-activating instrument is set by a micro computer 151 and an operating section 152, and the micro computer 151 is constituted so that the residual lifetime of the cartridge for the purifying-activating instrument is operated arithmetically in response to the rate of the integrated flow rate to the set total filtering flow rate and the residual lifetime of the cartridge for the instrument is displayed to a liquid-crystal display section 154. COPYRIGHT: (C)2004,JPO&NCIPI

Method and apparatus for testing fluid flow through transmission cooling systems

Abstract: Method and apparatus provided to accurately test fluid flow through cooling systems including pressurizing a fluid to create a fluid flow into the cooling system, measuring a fluid flow rate, and determining when the fluid flow rate is acceptable.

Thermal flowmeter and smoking apparatus

Abstract: PROBLEM TO BE SOLVED: To provide a thermal flowmeter which reliably prevents aerosol from easily adhering onto the surface of a thermal flow sensor. SOLUTION: The thermal flow sensor 1 has a pair of temperature sensors (temperature-sensing sections) Tu, Rd provided in the conducting direction of fluid at a specific interval while a heater element Rh is sandwiched. In the thermal flow sensor 1, a drive voltage or a drive current is increased for allowing the temperature-sensing sections to generate heat. Or, a heater 1a provided near the temperature-sensing section is driven to generate heat for allowing thermal migration in the fluid to occur near the surface of the thermal flow sensor 1. The thermal migration prevents particles contained in the fluid from adhering to the thermal flow sensor (a temperature control means). COPYRIGHT: (C)2004,JPO&NCIPI

Thermal mass flow meter with particle protection

Abstract: The invention relates to a flow rate measuring device (1) which comprises a means for introducing a backward flow (21) of the main passage (17) into the sub-passage (18) through the outlet (32) of the sub-passage of the flow rate measuring device is provided near the outlet of the sub-passage (18), in order to keep the flow rate measuring element from being destroyed under the presence of dust and water in an intake manifold and which has high reliability for a long period of use and an excellent pulsation characteristic.

Bubble ultrasonic flow meter

Abstract: A method and apparatus for preventing flow rate errors derived from an ultrasonic flow meter utilized in semiconductor fabrication operations. The ultrasonic flow meter is generally configured to include an extension chamber connected to a thin branch tube of the ultrasonic flow meter. A venturi tube can be positioned at an outflow location of the ultrasonic flow meter, such that the thin branch tube is broached into the venturi tube, wherein bubbles contained in a slurry flow are forced directly into the outflow location to thereby prevent inaccurate flow measurements derived from the ultrasonic flow meter. The extension chamber may be configured to reduce an inflow velocity associated with the slurry slow and ensure that the bubbles with not drift with the slurry flow. Additionally, a diameter of the branch tube may be configured such that the diameter is much smaller than a diameter associated with an inflow and/or outflow tube of the ultrasonic flow meter.