Showing papers on "Thermal mass flow meter published in 1984"

Thermal air flow meter

Abstract: A thermal air flow meter is equipped with a flow rate detector utilizing the phenomenon that heat is carried away in proportion to flow rate. The flow rate detector comprises a support, a heat-sensitive resistor formed on the support and leads attached to both ends of the support. To make the temperature distribution uniform, the heat-sensitive resistor is formed in such a manner that the resistance per unit length of the heat-sensitive resistor at either end of the support is greater than the resistance per unit length of the heat-sensitive resistor at the center of the support. This arrangement can provide a thermal air flow meter which has a rapid response to changes in flow rate.

Fast responsive flowmeter transducer

Abstract: A split flow mass flowmeter transducer in which measuring the rate of fluid flow through the meter is obtained via a thermal signal from a locally heated sensor tube that affords a parallel fluid flow path about the primary flow path through the main meter body. Enabling the measurement signal to respond more rapidly to changes in flow rate is a thermal shunt bridging the heated portion of the sensor tube for substantially equalizing tube temperature at predetermined locations upstream and downstream thereof.

Electrostatic flow meter

Abstract: The mass flow rate of particles conveyed by a gaseous medium through a conduit is measured by an electrostatic flow meter comprising a grounded electrical conductor in contact with a semiconductive static charge-generating element exposed to the moving particles. As the particles pass the semi-conductive, static charge-generating element, they impart a static charge to the element which is transferred by the conductor to ground. The resulting current, which can be measured by any suitable current measuring means, is proportional to the mass flow rate of the particles.

Pipeline flow measurement proving system

Abstract: A pipeline flow measurement proving system has a custody transfer insertion turbine meter mounted at a first location on a fluid pipeline. A proving insertion turbine flow meter is mounted at a second location on the pipeline upstream from the custody meter at a distance of approximately ten diameters of the pipeline. This offset spacing reduces the fluid turbulence which may be produced by the turbine head of the proving meter. The proving meter is calibrated against a standard at the National Bureau of Standards. Each of the flow meters produces a pulse signal which is proportional to the rotation of the corresponding turbine head. The calibration is carried out by counting the number of pulses produced by the two meters during a selected time period. The ratio of the counts of the pulses comprises a calibration constant which is utilized by a custody transfer flow computer for producing a flow measurement. The proving insertion turbine flow meter can be utilized to calibrate a plurality of custrody meters or can be utilized as a backup for the custody meter.

Enhanced pneumatic regenerator flow control

Abstract: Pneumatic control of flow patterns in regenerators is improved by the use of flow amplifier nozzles.

Average mass flow rate meter using self-heated thermistors

Abstract: A thermal type flow meter for measuring the mass flow rate of a fluid medium especially that of a gas in a duct, said meter comprising a plurality of thermistors operated electrically in the "self-heated" mode located on the trailing edge of rigid, rectangular members oriented with the long axis perpendicular to the primary direction of flow. The thermistors are located strategically throughout transverse plan of the duct. Each sensor (thermistor) is located substantially at the center of the downstream end of a right circular cylinder. The voltage drops through all of the thermistors located in a two-dimensional array oriented normal to the flow direction are summed electrically using an operational amplifier. Due to both the geometrical location of the sensors and the characteristics of thermistors in the self-heated mode, the voltage drop across each sensor is linearly proportional to the local mass flow velocity. This allows the summed output from all of the flow dependent sensors to represent a true average of the flow in a duct providing a sufficient number of sensors exist to reveal the overall flow patterns in the duct.

A thermal mass flow meter

Abstract: A thermal mass flow meter has a channel (21) defined in a substrate (10). Small elements (16a, 16b, 16c) bridge the channel (21) carrying heater or temperature sensor elements (17) of low thermal mass in direct contact with fluid in the channel (21). The temperature differential between the sensor elements (17), when the device is in operation, is indicative of the thermal mass flow rate.

Method of flow measurement and flow meter

Abstract: A method of urine flow measurement where liquid in the form of a free-fall jet is collected in a collecting vessel and the vertical force produced by the collecting vessel on a measuring device, for example a scale or the like, is sensed, and the change in time of said force is utilized for obtaining a measure of the flow corresponding to the jet. The method is especially characterized in that the effect of the impulse of the jet on the sensed force is eliminated by deflecting the vertical flow constituted by the jet to a substantially horizontal flow by a rotating device before the liquid is caused to contact the vessel. The invention also relates to a flow meter.

Fluid density and mass flow measurement

Abstract: The mass flow rate of fuel pumped in a conduit (16) to a gas turbine engine (12) is controlled by use of a throttling valve (18) driven from the outputof a comparator of a set mass flow signal (38) with a measured mass flow signal (36) derived from a processor (24) for multiplying a volumetric flow rate signal (34) from a volumetric flow meter (22) by a density signal (32) from density sensing apparatus (20). The density sensing apparatus (20) includes a fluidic oscillator (40) using as the working fluid in its power nozzle (58) a part of the fuel bled off at (28) and returned to the conduit (16) upstream of a fuel pump (14). The pressure drop across the power nozzle (58) is controlled by a regulator (42) to be at a preset constant pressure difference so that the frequency of the oscillator output is a measure of the density of the fuel regardless of variations in temperature, pressure or viscosity of a particular fuel.

Thermischer Massendurchflußmesser für korrosive Gase / Thermal mass flow meter for corrosive gases

Abstract: Schnellanzeigende Massendurchflußmesser, die hohen Temperaturen (Τ > 400 Κ) und korrosiven Gasen (Säuredämpfen, Cl2, H2S usw.) ausgesetzt werden können, existieren nur in Form von Schwebekörperdurchflußmeßgeräten [1]. Diese Art der Durchflußmessung liefert allerdings keine durchflußproportionale, elektrische Signale, wie sie in der modernen Prozeßkontrolle notwendig sind. Thermische Massendurchflußmesser [2; 3], die sich fur hohe Temperaturen und korrosive Gase eignen, haben im allgemeinen den Nachteil, daß sie nicht schnellanzeigend sind, da die Meßwiderstände außerhalb des Strömungsrohres liegen und dadurch eine Zeitverzögerung eintritt. Durchflußmessungen, die nach dem Dopplerprinzip (optisch oder akustisch) arbeiten, haben in der Regel einen recht hohen Aufwand zu verzeichnen und sind demzufolge auch sehr teuer. Flügelradanemometer sind, abgesehen von der mechanischen Anfälligkeit, auch nicht für hohe Temperaturen und korrosive Gase geeignet.

New Micro Motion mass flow meters

Abstract: A detailed case-history study of the application of special mass flow meters in coal-liquefaction facilities is presented.

Counting mechanism for flow as a function of temperature in central heating systems

Abstract: The counting mechanism in accordance with the invention is used, in particular, in central heating systems for generating hot water for sanitation purposes, for heating spaces or the like, the aim being to measure the effective consumption for each hot water consumer. The mechanism divides the incoming hot water into two component flows, of which one flows via a volumetric meter, while the other is united in a manifold immediately downstream of the meter with the component flow running through the meter. In this way, the component flow measured by the meter is proportional to the temperature of the hot water. A maximum temperature is fixed at which, for example, the entire flow runs via the meter, and a minimum temperature at which the entire flow is redirected without flowing via the meter.