Showing papers on "Volumetric flow rate published in 1979"

Air flow rate measuring apparatus

Abstract: An apparatus for measuring the flow rate of suction air in an internal combustion engine in which the heat radiation characteristic of a heat generator disposed in the suction air passage, which characteristic varies with the lapse of time due to dust and like foreign matters depositing on the heat generator, is calibrated on the basis of the air flow rate value measured by an air flow rate measuring device of differential pressure type so as to insure accurate measurement of the suction air flow rate.

Reactive ion etching of silicon

Abstract: Reactive ion etching of silicon substrates in a plasma containing chlorinated species does not result in undercut of a permanent mask. When the silicon is very highly doped it behaves as a different material and undercut has been observed. This phenomenon will be discussed. For use in chlorinated plasmas, there is a choice of nonerodible masks that sputter slowly but will not be redeposited on the substrate surface. Both CCl4/Ar and Cl2/Ar plasmas will be described. The variation in etch rate of silicon with rf power, frequency, reactant concentration, reactant flow rate, gas presure, crystal orientation, and batch size will be presented. The possibilities of polymer formation and surface roughening will be discussed.

Method and apparatus for effecting subsurface, controlled, accelerated chemical reactions.

Abstract: The problem of conducting chemical reactions at elevated temperatures and pressures, such as in the wet oxidation of a waste stream, without excessive expenditures of energy is solved by the method and apparatus for effecting accelerated chemical reactions utilizing a reactor (15) extending into a vertical hole (16) in the earth and having an outer flow passage (21) receiving influent fluid from a supply (38) and supply lines (31 and 33) pumped with air by a pressure pump (29). The fluid undergoes an accelerated oxidation in the hole giving off the products of reaction, heat, and an effluent fluid which flows up an inner flow passage (22) to a settling tank (41) and/or other discharge lines (44, 42). Apparatus for control of temperature, pressure and flow rate are also provided to maximize reaction rates and minimize power requirements.

Hydrogen peroxide production in trickle-bed electrochemical reactors

Abstract: A trickle bed electrochemical reactor has been developed for the production of dilute alkaline peroxide solutions by reduction of oxygen. Oxygen gas and sodium hydroxide flow concurrently downward through a cell which consists of a thin packed cathode bed of graphite particles separated from the anode plate by a porous diphragm. Current flows perpendicular to the flow of electrolyte. The effects of current density, oxygen pressure and flow rate, electrolyte concentration and flow rate, graphite particle size, bed thickness and length were investigated. In 2 M NaOH peroxide solutions of 0.8 M have been produced at 60% efficiency with current densities of 1200 A m−2 and cell voltages of 1.8 V. A bipolar cell stack consisting of five cells has been tested.

Method for detecting and controlling flow rates of the droplet forming stream of an electrostatic particle sorting apparatus

Abstract: A novel method is disclosed for detecting and controlling the flow rate of a perturbed, droplet-forming stream in an electrostatic particle sorting apparatus. Detection apparatus is located at two points along the stream, at a first particle sensing point for sensing the presence of particles within a core portion of the stream, and at a second downstream point, preferably the stream breakpoint, for sensing light scatter and extinction characteristics which are proportional to the surface characteristics of the sheath portion of the stream. Changes in phase shift, pulse width, duty cycle, pulse area, or breakpoint location are detected by analyzing these sheath surface-related characteristics. An error signal is produced in response to such changes which drives an electromechanical fluid flow regulator to increase or decrease the fluid flow rate in a direction which tends to minimize the error signal. The flow rate is thus maintained at a reference flow rate setting.

Apparatus for treating fluent materials

Abstract: An apparatus for heating fluids to a relatively high temperature, such as sterilization temperature, in which the fluid, such as a liquid, is heated by direct contact with steam while it is in the form of a very thin, free-falling film or a continuous falling stream so that heating of the fluid is accomplished without the fluid coming into contact with any surface and particularly metal surfaces which are hotter than the fluid product being heated and with minimum agitation and turbulence of the fluid product. This procedure enables maximum and uniform heat penetration in a minimum time interval with the film or stream being maintained as thin as possible and unbroken by introducing steam at a relatively low velocity in a large volume vessel. A flow control is incorporated into the apparatus to maintain a constant flow rate of fluid and to maintain a constant and critical fluid level in the bottom portion of the large volume vessel with the flow characteristics of the apparatus and the internal forces produced by the apparatus serving to counterbalance each other to provide a relatively simple but yet accurate flow rate and liquid level controls for the fluid being heated.

Flow rate measurement

Abstract: A method is presented for measuring fluid flow rate in a system having a conduit through which the fluid flows. The method is particularly useful for measuring blood flow rate in a cardiovascular system. A substance which provides a plurality of microbubbles is added to the fluid flow system upstream of the measurement position in the conduit. An ultrasonic pulse is generated from a position opposite and spaced from the conduit as the microbubbles pass therethrough. A reflected ultrasonic image, created by reflection of the pulse from at least the wall of the conduit which is distal from said position, is measured. The fluid flow rate within the conduit is determined from these ultrasonic images using dye dilution techniques. In a living being, the pulse is preferably generated adjacent the rib cage or in the esophagus and the conduit is preferably the heart or the pulmonary artery, whereby, the blood flow rate determined is equal to the volumetric cardiac output rate.

Constant flow rate fluid supply device, particularly for a spray gun

Abstract: Device for supplying at a constant rate a fluid utilizing apparatus with at least one fluid of variable viscosity, comprising a fluid source delivering said variable viscosity fluid, a first fluid circuit connecting said fluid source to the fluid utilizing apparatus, a second fluid circuit in which flows a constant viscosity fluid, two volumetric pumps mechanically coupled so that their flow rates are in a fixed relationship, a first one of the two pumps being inserted in the first fluid circuit, whereas the second pump is inserted in the second fluid circuit, and adjusting means inserted in the second fluid circuit, downstream of the second pump, for adjusting the flow rate of the constant viscosity fluid. The supply device is particularly suitable for supplying a spray gun with paint.

The kinetics of the reduction of chromium oxide by hydrogen

Abstract: The reduction kinetics has been studied as function of hydrogen partial pressures,pH2O/pH2 ratio, gas flow rate, and temperature. The reduction follows a linear time law and is dependent on the gas flow rate below a value of approximately 10 cm · s-1, since the rate is determined by the removal of the water vapor being formed. In this range the reduction rate may be calculated from gas dynamical data. At sufficiently high flow rates the phase boundary reaction is rate determining. The activation energy is 123 kJ · mol-1. The reduction rate is proportional to the square root of hydrogen pressure and decreases with increasing water vapor content.

Model experiments on the effect of bifurcations on capillary blood flow and oxygen transport.

Abstract: O2-delivery by a single capillary is a function of the flow rate and thefraction of flow made up of red blood cells. Capillary flow rate in turn depends upon flow resistance which is determined by thefraction of capillary volume occupied by red blood cells. Experiments were carried out to study the relationship between these parameters in an in vitro model consisting of glass capillaries (I.D. 3.3–11.0 μm) branching from a large bore feeding channel which was perfused at variable flow rates with suspensions of human red cells with different hematocrits. Capillary flow rates ranged from 0–10−4 mm3 s−1. The results indicate that the red cell flow fraction increases with increasing capillary flow rate and with decreasing feeding vessel flow rate. Capillary volume fraction occupied by red cells similarly depends on these two parameters, but is consistently lower than the red cell flow fraction. Capillary flow resistance increases with flow rate due to increasing volume fraction of cells. If the results obtained with the model system are applicable to in vivo capillaries it must be concluded that O2-delivery by a single capillary is not linearly related to flow rate but increases more than proportionately with flow rate. Due to alteration of resistance with flow rate another type of “autoregulation” of capillary flow is proposed which tends to keep flow rate constant despite changes of driving pressure.

Method of injectivity profile logging for two phase flow

Abstract: Fluid injectivity within an interval in a well bore is determined by injecting into the well two fluid streams, one of which flows down the tubing and one of which flows down the annulus, one of said fluid streams containing a radioactive tracer. The sum of the two fluid flow rates is held constant while each flow rate is varied against the other. At each different pair of flow rates, a stable interface is formed between the fluid containing the radioactive tracer and the fluid without it. The position of this stable interface at each different set of fluid flow rates is measured by a conventional gamma ray well logging tool, and from the series of such measurements an injectivity log over the measured interval can be determined. The injectivity profiles for the two components of a two phase fluid flow system are determined by conducting the survey with a radioactive tracer soluble in the gas phase and repeating the survey with a radioactive tracer soluble in the liquid phase.

Method and device for feeding a fuel cell with fluid reactants

Abstract: A method for feeding with the same fluid different chambers of a fuel cell block, each of these chambers being connected to a fluid feed pipe and to a fluid discharge pipe, the fluid flow rate admitted into each chamber being limited by flow rate control means, this method comprising the step of scavenging with fluid at least one chamber, once or periodically during the operation of the pipe, by passing during a limited time interval, the flow regulation means associated to this chamber.

Theoretical study of hydraulically fractured penny‐shaped cracks in hot, dry rocks

Abstract: A simple and analytical method of solving the problem of heat extraction from a penny-shaped crack having both inlet and outlet holes is developed by using a two-dimensional flow model when fluid is injected at a constant flow rate. Temperature distributions in both rock and fluid are obtained by taking into account the hydraulic and thermal growth of the crack. The outlet fluid temperature and energy extraction rate versus time are shown by some illustrative examples. Although the effect of thermal, contraction of rock upon the crack width is large, its influence upon flow rate and crack tip stress intensity factor is sufficiently small within the first several years so that the crack radius can be determined mainly by the mechanical deformation of, the rock.

Method and apparatus for determining fluid flow

Abstract: A method and apparatus for determining volumetric fluid flow rate in an arbitrarily shaped fluid conveyance are disclosed. A plurality of functions, fj (p,mk) (where p is a position in the conveyance and mk depends upon the Reynolds number of the fluid flow), each function being approximately representative of the fluid flow velocity across the conveyance, are linearly combined to approximate the velocity, P(p), of the fluid flow at any point in a plane normal to fluid flow. The scalar constants Aj,k, of the linear combination ##EQU1## are estimated by solving a system of linear equations, ##EQU2## in which acoustical measurements along the paths yi through the conveyance provide an estimate, vmeas(i), of the actual average velocity vi at paths yi. The average fluid velocity and hence volumetric flow across the conveyance can then be determined by taking an area integral of the linear combination ##EQU3##

Fluid flow measuring apparatus

Abstract: A Karman vortex type flow rate measuring apparatus is provided with a plurality of vortex shedding members each having a different effective width, and a plurality of vortex detecting elements The distance between the vortex detecting elements is so selected that it coincides with the distance between the vortices of some one of the vortex trains induced by respective vortex shedding members The apparatus enables a positive and accurate detection of the vortices, and a compensation for drop out of the vortex shedding

Flowmeter method and apparatus

Abstract: A flowmeter determines the density of a fluid stream by periodically shifting a carrier sonic signal at a carrier modulation frequency and detecting the peak received energy after the carrier sonic signal traverses the stream. The flowmeter may additionally determine the temperature, volumetric flow, and mass flow of the fluid stream.

Validity of cubic law for fluid flow in a deformable rock fracture. Technical information report No. 23

Abstract: The validity of the cubic law for laminar flow of fluids through open fractures consisting of parallel planar plates has been established by others over a wide range of conditions with apertures ranging down to a minimum of 0.2 ..mu..m. The law may be given in simplified form by Q/..delta..h = C(2b)/sup 3/, where Q is the flow rate, ..delta..h is the difference in hydraulic head, C is a constant that depends on the flow geometry and fluid properties, and 2b is the fracture aperture. The validity of this law for flow in a closed fracture where the surfaces are in contact and the aperture is being decreased under stress has been investigated at room temperature using homogeneous samples of granite, basalt, and marble. Tension fractures were artifically induced and the laboratory setup used radial as well as straight flow geometries. Apertures ranged from 250 ..mu..m down to 4 ..mu..m. The cubic law was found to be valid whether the fracture surfaces were held open or were being closed under stress, and the results are not dependent on rock type. Permeability was uniquely defined by fracture aperture and was independent of the stress history used in these investigations. The effects of deviations from the ideal parallel plate concept only cause an apparent reduction in flow and may be incorporated into the cubic law by replacing C by C/f. The factor f varied from 1.04 to 1.65 in these investigations. The model of a fracture that is being closed under normal stress is visualized as being controlled by the strength of the asperities that are in contact. These contact areas are able to withstand significant stresses while maintaining space for fluids to continue to flow as the fracture aperture decreases. The controlling factor is the magnitude of the aperture and since flow depends on (2b)/sup 3/, a slight change in aperture evidently can easily dominate any other change in the geometry of the flow field.

Flowmeter of hot wire type

Abstract: The flow rate is determined from the heat transferred from an electrically heated wire stretched in a fluid flow to the fluid. The wire is placed not on a plane normal to the flow but within a section of the fluid passage bounded by two spaced planes normal to the flow. Preferably the wire is composed of series of line segments which are distributed evenly not only around the central axis of the passage but also in the direction of the flow so that the heat release from the wire in its entirety corresponds to the mean value of fluid velocities at various points.

Liquid volumetric flowmeter

Abstract: A liquid volumetric flow measuring apparatus is disclosed wherein a turbine or vane, flow straighteners therefor, and a rotating shaft mounted therewith, and a magnetic sender are all mounted as an integral unit in a U-shaped pipe trap, and a volumetric calculator is mounted in conjunction therewith. By a specific mounting of the turbine in the trap there is a dampening action causing the calculator to cease recording the flow immediately upon this stopping of the motion of the liquid through the trap. This construction provides a guard against any air which is pumped through the pipe being recorded as liquid in contradistinction to a gaseous fluid. The magnetic sender has a reed switch and a magnet which are specifically mounted so as to provide low angular momentum and reliability, at both high and low flow rates. The present invention is particularly useful in fuel delivery, wherein the liquid volumetric flowmeter is mounted within the system of the party to whom the fuel is delivered, and permits the party to accurately record the liquid fuel actually delivered, and to guard against being charged for air flow from the fuel supplier's pump.

Method and apparatus for measuring porosity

Abstract: A practice for measuring porosity wherein a plurality of medium flows of different volumetric flow rates are provided to a predetermined area of a material under test in dependence upon the pressure difference thereacross and wherein certain measured pressure /differences and their corresponding flow rates are employed to determine the material porosity

Water treatment device

Abstract: PURPOSE:To treat water efficiently by controlling the flow rate and displaying the treating ability according to the comparison of the amount of remained ions at the outlet of treating tank with the total quantity of ions obtained from the ionic concentration and flow rate at the inlet of tank every time. CONSTITUTION:The ionic concentration and flow rate are measured by the ionic concentration detector 6 and flow meter 3 of the original water pipe 4 respectively and are transfered to the arithmetic unit 8. Also the concentration of remained ions is measured by the remained ion concentration detector 9 of the treated water pipe 5, a signal is sent to the exchange detector 10 when the concentration reaches a specified value. The total quantity of ions is computed and integrated with respect to time by the arithmetic unit 8 to obtain the amount of ions in the adsorber 1. At this time, the integral is controlled by the integrating time at the exchange detector 10. The data is transfered to the data processor 14, the treating ability, exchange time and complement are determined by the memory and arithmetic display.

Fluid property detection system

Abstract: A differential pressure Δp is detected across an orifice plate in a pipe section. The same differential pressure is also allowed to drive a turbine meter. The turbine meter is conventional and produces electrical output pulses at a frequency f 1 proportional to the volume flow rate therethrough. It then has been found that the properties of a fluid in the pipe section and in the turbine meter may be found automatically by electronic computation of first and second ratios Δp/f.sub.1 and Δp/f.sub.1.sup.2 respectively, where the first and second ratios are proportional to mass flow rate of the fluid in the pipe section or total mass flow when the mass flow rate is integrated with respect to real time, and the density of the fluid respectively.

Optimization of continuous wave nuclear magnetic resonance to determine in situ volume fractions and individual flow rates in two component mixtures.

Abstract: In this paper, the optimization of continuous wave nuclear magnetic resonance in two component flowing mixtures to determine the in situ volume fractions and the individual component flow rates is described from both an analytical and an experimental point of view. A simple and accurate measuring system is discussed and the analytical and experimental results are compared for oil–water mixes. The use of a relatively long polarizing magnet prior to the highly homogeneous detector magnet has been shown to improve the flow‐rate range considerably and makes feasible a relatively inexpensive, accurate, and genuine two‐phase or two component flow meter. By measuring the optimum value of H1, or the rf level required to produce that optimum value, and by simultaneously measuring the magnitude of the signal at that time, both the in situ volume fraction and the flow rate can be determined. This is provided that there is no chemical reaction between the two components and that they travel at the same average veloci...

Intake air flow rate detector

Abstract: An intake air flow rate detector of an internal engine using a Karman vortex sensor, wherein the mass flow rate is obtained by detecting a volumetric flow rate by the Karman vortex sensor and a dynamic pressure or differential pressure at upstream and downstream of the sensor by a strain gage mounted on a partition in a closed chamber. Density compensation of the flow of air is effected only taking said measurement values at a standard range in which the Karman vortex is stable and the differential pressure has a large value.

Mass flow sensor

Abstract: A mass flow sensor comprising a Karman flow detector in a fluid passage including a vortex generator and a vortex detector for detecting periods of generated vortices, and an air density detector including a reference pressure chamber enclosing a standard gas and a comparison pressure chamber into which a fluid in the passage is introduced and detecting means whose output varies proportionally to pressures and temperatures of the fluid introduced in the comparison pressure chamber, thereby compensating a volume flow obtained from the flow detector to obtain a mass flow dependent upon a density of the fluid with high accuracy.