Showing papers on "Volumetric flow rate published in 1971"

Separation of nitrogen and methane via periodic adsorption

Abstract: The periodic process utilizes a rapid pressure swing cycle in an adsorbent bed to effect the separation of gas mixtures. During the first portion of a cycle the compressed gas mixture flows into the adsorbent-filled column. Next, while the feed gas is restrained, an exhaust orifice is opened at the feed end of the column providing depressurization. The product stream is enriched in the component exhibiting the lowest coefficient of adsorption. A mathematical model based upon the assumption of instantaneous equilibrium between the gas phase and the adsorbed gas was formulated and solved to simulate the periodic, adsorption process. The measured nitrogen content of the product gas stream was found to correlate with the ratio of the product gas rate to the feed gas rate. At 24°C. the calculated pressure response, feed gas flow rate, and product gas composition correspond favorably with related experimental measurements for all values of the feed gas pressure, cycling frequency, and product gas flow rate within the ranges investigated.

Stratified laminar flow of two immiscible fluids

Abstract: We consider the steady co-current flow of two immiscible viscous liquids in a horizontal pipe, the fluid interface being ripple-free and plane. It is shown that if the cross-section of the duct is symmetric with respect to the interface, the velocity distribution may be expressed in terms of two separate pipe-flow solutions. One corresponds to the flow of a single fluid occupying the whole of the pipe, and the second to a similar flow in a pipe whose cross-section coincides with that of the region occupied by one fluid in the two-phase motion. Flow rates and other quantities of engineering interest are evaluated, and several particular flows are discussed.

Measurement of fluid flow rates

Abstract: Apparatus and a method for measuring the flow rate of a fluid in which a beam of ultrasonic ≮, electromagnetic, optical or other radiant.]. energy is transmitted across the flow at each of two positions spaced apart in the direction of flow, the noise amplitude, frequency or phase modulation on each beam due to disturbances in the flow is detected, and the two resultant signals are cross correlated to determine the time delay therebetween producing maximum correlation, i.e. the mean fluid transport time between the beams, and thus the mean fluid flow rate.

Study on Distribution of Flow Rates and Flow Stabilities in Parallel Long Evaporators

Abstract: Distributions of flow rates and flow stabilities in parallel evaporator tube systems have been experimentally investigated. The evaporator is composed of three parallel copper tubes of 4mm inside diameter and 40 m long. Experiments were carried out by using refrigerant R-113 as the fluid in pressure range from atmospheric pressure to supercritical pressure, in order to simulate phenomena in steam generators. It has been shown that distributions of flow rates, their hysterisis and onset of excursion phenomena can be estimated from pressure drop versus flow rate curves for single tubes. Moreover, description is made of behaviors of thermal oscillative instability which are observed at relatively low flow rate. In addition to the experimental results, by a theoretical analysis of a simple model, stability criteria in parallel tube system have been described.

Wave-flow theory for a thin viscous liquid layer

Abstract: On the basis of a simplified system of equations we study the process of development and stability of wave flows in a thin layer of a viscous liquid. Any unstable disturbance of the laminar flow grows and leads to the establishment of the wave regime. The time to establish the flow changes little for large flow rates, but increases sharply with reduction of the flow rate. Given the same amplitudes of the initial disturbances, the optimum regimes which provide the greatest flow rate in a layer of given average thickness develop more rapidly than the other regimes. All the wave regimes are unstable to disturbances in the form of traveling waves. With moderate flow rates, the optimum regimes will be most stable to near-by disturbances. Strictly periodic wave flows in a thin layer of a viscous liquid under the influence of the gravity force were calculated in [1], Various flow wave regimes which differ in wavelength can theoretically be established for a given liquid flow rate. In particular, there is a wavelength for which the flowing layer exhibits minimum average thickness (and maximum flow rate for a given average thickness). These optimum regimes correspond closely to the experimental data [2]; however, with regard to calculation technique these regimes are no different from the others. In the following we make a comparison of the wave regimes on the basis of the nature of their development and stability.

Improved parametric characterization of flow geometries

Abstract: An improved parametric method is presented for characterization of the flow geometry in the rectilinear flow of non-Newtonian fluids in open and closed conduits of arbitrary crosssection and in purely viscous, inelastic flow of non-Newtonian fluids through packed beds and porous media. In the new formulation, an infinite number of geometric parameters characterize the flow geometry. The actual number required in a particular application is shown to be determined by the fluid model equation representing the rheological behavior of the fluid. For Ostwald-de-Waele and Ellis fluids with flow behavior indices s = 1/n and α integers, the number of geometric parameters required to represent the relationship between flow rate and pressure drop is given by s + 1 and α + 1, respectively. The efficacy of the present method is demonstrated by comparisons with available results for various fluid models and flow geometries.

Thermal Creep Flow of Rarefied Gas between Two Parallel Plates

Abstract: The thermal creep flow of a rarefied gas between two parallel plates is investigated on the basis of a relaxation model of the Boltzmann equation for all range of the Knudsen number. The velocity profile as well as the volume flow rate is calculated

Smokeless flare pit burner and method

Abstract: This invention involves a method and apparatus for smokeless combustion of a combustible gas, which is supplied at a flow rate which varies widely from a low to a high value. It involves dividing the total flow rate through a manifold into a plurality of flow lines with each flow line providing gas to a plurality of burners. The pressure of the gas in the manifold is measured and valves in each of the flow lines are controlled as a function of the manifold pressure, so that they open, one at a time, as the flow increases, thereby supplying gas to each flow line and to its burners at a much narrower range in flow rate. Thus the velocity of the gas is always high enough to get proper air mixing and smokeless combustion.

Ultrasonic acceleration of liquid flow through porous media

Abstract: This investigation included a study of the effects of ultrasonic radiation upon the flow rate of crude oil through sandstone and also the effect on both water and oil flow through a porous stainless steel filter. When ultrasonic energy having a frequency of 20 kHz was introduced, there was a substantial increase in the rate of liquid flow through all the porous mediums tested. An increase in temperature of the system during ultrasonic radiation was found to increase the oil flow rate several times beyond that which could be accounted for by the decrease in the viscosity of the oil. A plausible explanation is conjectured to be the fact that under the influence of ultrasonic radiation, a progressive change in the Poiseuille type of flow occurs in the micro channels of the media as the temperature increased. An equation stipulating the conditions for this departure from Poiseuille flow by ultrasonics was formulated. It was found that the application of pressure on the insonated system increased the maximum rate of oil flow. However, an increase in ultrasonic power was required to attain this maximum oil flow rate. The ultrasonic power increase needed was proportionately less than the resultant increase in themore » oil flow rate.« less

The cross-beam electric-discharge convection laser

Abstract: An experimental investigation of a 60-cm-wide × 2.5-cm-high N 2 -CO 2 cross-beam electric-discharge convection laser (EDCL) is described. In the cross-beam EDCL, the discharge is maintained along the flow in a rectangular cross-section channel and optical power is extracted transverse to the discharge and flow. High mass flow rates are employed to achieve high volumetric power densities. Experiments relating to the achievement of uniform and stable discharges at high-power levels in the rectangular laser channel, and measurements of the small-signal gain characteristics, amplifier performance, and optical quality are described. Using an 11-pass optical scheme, a CW optical output power of 2 kW has been extracted from the amplifier at an electrical efficiency of 9.6 percent.

Linear readout flowmeter

Abstract: A flow meter for determing the rate of flow of fluid through a conduit and indicating the flow rate on a linear scale. A signal having a magnitude inversely proportional to the time elapsed for a substance carried by the fluid to travel a fixed distance is produced and converted into a flow rate indication.

Chemical tracer method of and structure for determination of instantaneous and total fluid flow mass and volume

Abstract: Total mass flow of a fluid component is determined by structure for and the method of inserting a chemical tracer into a flowing fluid at a known mass flow rate, removing a mixed sample of the flowing fluid and tracer, analyzing the concentration of tracer and the concentration of a component of the flowing fluid, the total mass of which is to be determined, determining the ratio of tracer to component of interest, integrating the ratio over a predetermined time and multiplying the result by the mass flow rate of the tracer inserted into the main fluid flow. The total particulate mass flow and total volume flow as well as instantaneous mass, particulate mass and volume flows are determined by similar structures and methods. A method of expressing tracer concentrations in analyzers rather than in main fluid flow tubes and a method of taking into account tracer components present in the main flow tube before insertion of the tracer into the main fluid flow are provided. Cancellation of tracer components in the main fluid flow upstream of the point of injection of tracer is also disclosed.

Volumetric flow rate measurement of a flowing stream

Abstract: The specification discloses a technique for determining the volumetric flow rate of a flowing stream wherein a predetermined quantity of material which will alter the electrical conductivity of the stream is selectively introduced into the stream. A conductance probe is disposed downstream from the point at which the material is deposited in order to continuously detect the electrical conductivity of the stream. An enforced linearity electrical bridge is responsive to the output of the probe for detecting the change in conductance of the stream which is caused by the added material. Integrating circuitry integrates the change in conductance determined by the bridge. A nonlinear meter is responsive to the integrating circuit, along with an indication of the electrolyte equivalents of the deposited material, in order to directly indicate the volumetric flow rate of the stream. Circuitry is provided to prevent the polarization of the conductance probe. A reset circuit enables the integrating circuitry to be set to zero for additional measuring cycles.

Portable high volume gas supply system

Abstract: There is provided a mobile system for dispensing a gas generated as a consequence of vaporization of a cryogenic fluid at high volumetric flow rates and at temperatures approaching ambient The system consists of a cart-mounted container for a cryogenic fluid and a gas dispensing system having, as a part thereof, a contained and protected primary heat transfer coil secured to a secondary heat transfer surface which is a part of the cart

Flow control system

Abstract: The present invention deals with an improved method and apparatus for measuring flow in fluid flow systems characterized by low flow rate. The invention utilizes the transit time or oscillatory frequency of a ball or float which moves along the direction of fluid flow and is returned to its original position by actuating a magnetic return system as it breaks a light beam or other sensing system. The cycle is repeated, with the transit time or oscillatory frequency being related to rate of fluid flow, and thus serving to indicate same for control purposes. The flow tube-ball measuring unit may take the form of a disposable insert into the flow measuring system.

Effect regulator for constant and variable volume-flow pumps

Abstract: Means for regulating the flow of fluid from two or more pumps in a hydraulic system, according to the instantaneous demand for energy.

Method and apparatus for distributing fluids

Abstract: A method and apparatus are disclosed for discharging fluid in a sheetlike flow made up of contiguous flow zones extending across the width of the sheetlike flow. The fluid flow rate in each flow zone is individually controllable and is virtually unaffected by the fluid flow in the adjacent flow zones. The method consists of expanding the widths of a plurality of spaced-apart, individually flow-rate-controlled streams until all streams are contiguous and thus form an uninterrupted sheetlike flow, while maintaining substantially uniform flow rate distribution profile across the width of each stream. The apparatus consists of a plurality of diffusion chambers arranged in a line and with the flow direction of each chamber parallel to each other. The widths of the chambers widen downstream in the chambers until all chambers adjoin each other. Fluid enters the upstream end of each chamber from its individual, valve-controlled conduit. The invention has particular value in applying fluid to a wide surface where the amount of fluid desired to be applied varies for different areas across the width of the surface. A particular use for the invention is to aid uniform drying of a wet paper web on a papermaking machine by controlling the flow rate distribution profile across the width of a sheetlike flow of steam discharged against the paper web.

Monopropellant Thruster Exhaust Effects upon Spacecraft

Abstract: a = ion engine exhaust opening radius A = cross-sectional area Ann = Einstein coefficient B = absorption coefficient c = speed of light D = thruster exhaust diameter at the thruster exhaust plane e = electron charge E = energy f = absorption oscillator strength (Landenburg/value) h = Planck constant / = photon intensity J = inner quantum number k = Boltzmann constant m = atom mass n = ion arrival rate per unit area per unit time n}n = excitation level n0 = neutral atom density N = charge exchange ion production rate JV = atom density N" = number of adsorbed atoms per unit area N(r,x) = charge exchange ion arrival rate per unit area r = distance from thruster exhaust opening Pa = absorption probability P = pressure Pv = vapor pressure Q = charge exchange cross section t = time T = temperature x = distance measured perpendicular to exhaust plume centerline x',y,z = dimension as in Fig. 5 a,/3 = angles (see Fig. 5) F = evaporation rate F(r,0) = atom flow rate Fa = atom arrival rate A = line width AL = incremental length 0 = angle from plume centerline X = wavelength Ho' — rate per unit area at which neutral atoms leave engine exhaust plane v — frequency T = mean life w = statistical weight

Synthesis of Gallium Phosphide

Abstract: An open‐flow synthesis system for the production of polycrystalline , using flowing over Ga in a temperature gradient, has been investigated with regard to purity of the product and yield of in terms of the elements Ga and P. This material is suitable as starting material for single‐crystal growth by the liquid‐encapsulated Czochralski technique. Optimization of the synthesis time, flow rate, and temperature gradient resulted in a P reaction efficiency of 50–55% and a yield of 35–38g per 50g of Ga. A mechanism involving the formation of a reaction barrier over the Ga was used to explain the increase in P reaction efficiency and yield with decreasing flow rate. Both an increased reaction efficiency and yield were observed with increasing temperature gradients, indicating a diffusion‐controlled reaction. It was found that Si atoms cm−3 were incorporated in the when pyrolytic boron nitride boats and silica liners were used. When He was substituted for H2 as the carrier gas, the Si contamination dropped to about cm−3. Silicon contamination of about atoms cm−3 was observed using an all silica system. When water vapor was introduced in small amounts to He in the pyrolytic boron system, the yield was reduced by about 10% but the material produced was found to have an optically active Si content of about 1016 cm−3. These results indicate the dominance of the vapor transport mechanism for Si contamination of . Material grown in an all‐pyrolytic boron nitride system, where the boats were physically separated from hot silica, had a Si contamination of less than cm−3.

Fuel management system

Abstract: An aircraft fuel management system providing accurate and comparable measurement and display of on-board fuel quantity, fuel rate and flight time remaining. This system utilizes capacitance method of fuel gaging and fuel mass flow rate derived from both volumetric flow measurement and capacitance density compensation. These separate measurements - fuel gaging and mass flow rate - are combined electronically to obtain ''''flight time remaining'''' under prevailing flight conditions.

Through flow fluid treatment apparatus

Abstract: This invention relates to a through flow heat exchanger or other fluid treatment apparatus. The treatment apparatus has a battery of treatment tubes in a treatment compartment. The treatment apparatus also has an inlet and an outlet and flow control means so that fluid can normally flow through the tubes in one flow pattern. The flow control means can be changed for temporary operation to produce a different flow pattern. The volumetric flow rate through the apparatus varies but the linear flow rate through the tubes is constant. The apparatus may be incorporated in trains so that one train can be spared for maintenance leaving the other train or trains to process all the fluid.

Method and means for magnetohydrodynamically controlling the flow rate of a current-conducting liquid

Abstract: A method and means is provided for controlling the flow rate of a current-conducting liquid. In the flow of a current-conducting liquid flowing between the poles of a magnetic system there are provided regions extending along the flow wherein there arise different conditions of electric current induction. Such regions having different conditions of electric current induction are established by varying magnetic density along the flow, for example, by forming the magnetic system poles shaped as a number of alternating protrusions and recesses.

Drag Reduction by a Polymeric Aluminium Soap

Abstract: THE pressure drop per unit length of pipe during the turbulent flow of liquids is reduced by certain additives. Most such “drag-reducing” or “friction-reducing” agents are polymers of very high molecular weight1–3. In water, poly(ethylene oxide) at a concentration of ten parts per million can reduce the pressure for a given flow rate to a fifth of that required for water alone1,4. Suspensions may show drag reduction. Some soap or soap-complex solutions also show the phenomenon2,3.

Heterogeneous combustion of boron-containing polymers.

Abstract: The hybrid regression rate for boron-containing polymers having B-O and B-C linkages has been measured at different oxygen flow rates and at different time intervals* The regression rate varies with the oxidizer flow rate according to the equation r-Z)0-2 = a-(ro n, where a depends strongly on the time of combustion. A siihilar dependence on t6tal mass flow rate is also observed. The regression rate calculated from the equation of Marxman et al. does not agree with the experimental values when the mixture ratio and the stoichiometric ratio differ. It has beeil concluded that the regression rate decreases with time on account of transfer of heat to unreacted oxidizer* This becomes an increasingly important factor as the diameter of the duct increases. Thermal degradation of boron-containing polymers also has been studied. The data are found to satisfy first-order kinetics and an Arrhenius equation. Good correlation with the hybrid regression rate data is obtained by using Houser's equation. For this purpose thermal conductivity, specific heat, density, and surface temperature of the polymers have also been measured.

Process and apparatus for determining the weight per unit volume of liquids of variable density

Abstract: A method of determining the weight per unit volume of liquids of variable density is carried out by taking a volumetric measurement and a density measurement The density measurement is converted from analog-to-digital and is fed to the first input of a counter Because the density measurement converted to digital has an order of magnitude greater than the volumetric measurement, the volumetric measurement is fed to a second input of the counter which increases the order of magnitude of the volumetric measurement On the counter, the two measurements are added to provide an indication of the weight per unit volume

A process for cooling hot gas/solids suspensions

Abstract: A hot gas/solids suspension, of the kind formed during the reaction between gaseous metal halides and gases containing oxygen, is cooled by introduction of cold gas either radially or annularly. The suspension, flowing through a pipe at about 10 to 100 meters per minute, passes into a cylindrical chamber where its direction of flow is changed abruptly to produce turbulence and its flow rate is reduced to less than one-half its previous level. The direction of flow of the suspension is then abruptly changed again, the chamber discharging into a pipe so that the flow rate is increased. Means are provided to scrape away any solids which may deposit in the chamber. In this manner the cooling is controlled which, in turn, controls the form of the solids.