Venturi meter concept in hindi explain venturi meter. To find the coefficient of discharge for orifice meter. The meter consists of a pipe with a narrowing throat that expands back to its original diameter on the other side of the choke point. There are many different meters used to measure fluid flow. Fm 308 flow measurement by venturi and orifice meter objectives. Pdf experimental investigation of the installation. Venturimeter principle, construction and working with. The venturi meter precisely calculates the volumetric flow rate of a fluid using a complete formula. It consists of an inlet section followed by convergent section a cylindrical throat and a gradually divergent cone. The converging part is made shorter by employing large cone angle 19 21 while diverging section is longer with lower cone angle 5 15. A venturi meter is also called a venturi flowmeter.
Implications of robert venturis theory of architecture 359 was a tendency in his own work. Inserttype venturi flow meter installation and operation manual designs, materials, weights and performance ratings are approximate and subject to change without notice. Venturi meters represent one of the oldest and most reliable of the. Another method of measurement, known as a venturi meter, is to constrict the flow in some fashion, and measure the differential pressure using a.
Venturi meter is a device or component which is used for measuring the rate of. The venturi meter is an obstruction meter named in honor of giovanni venturi 17461822, an italian physicist who first tested conical expansions and contractions. Venturi meters are flow measurement instruments which use a converging section of pipe to give an increase in the flow velocity and a corresponding pressure drop from which the flowrate can be deduced. As the fluid from the entry section of venturi meter flows into the converging section, its pressure keeps on reducing and attains a minimum value p2 when it enters the throat. Two vertical tubes, open to the atmosphere, rise from two points. Energy losses through venturi, orifice, and rotameter. Venturi meter design equations formulas calculator. It may be noted that in the usual form of venturi meter intended for flow measurement, pressure tappings are made only at the entrance and at the throat, as these two readings suffice to measure the discharge. A schematic of the venturi meter is shown on the diagram at the end of the procedure. A venturi meter is used to measure the flow rate through a tube. Pdf when venturi meters are used in wet gas, the measured differential. The venturi flow meter obtains a pressure differential by constricting the flow area and therefore increasing the velocity at the constriction, which creates a. It is a cheaper device as compared to venturimeter.
A venturi tube can also be used to mix a liquid with a gas and siphon into the venturi flow. A constriction of crosssectional area a2 is put in a pipe of normal crosssectional area a1. By measuring the difference in the pressures at an axial station upstream of the convergent section and at the throat, the volumetric flow rate can be estimated. Pdf venturi meter constructions for plastic irrigation pipelines. What are some industrial uses of venturi and orifice. Definition, parts, working principle, derivation, applications with pdf. References international standard iso51671 2003, measurement of fluid flow by means of pressure differential devices part 1. Energy losses through venturi, orifice, and rotameter flowmeters. In practise the venturi tube is used in planes to measure the flight velocity. Venturi meter is a device in which pressure energy is converted into kinetic energy and it used for measuring the flow rate discharge of the system. The illustration shows that you can express the fluid velocity v 1 at the inlet of the device in terms of the difference in pressure measured by the manometer. A venturi meter, or venturi flow meter, is a device used to measure the velocity, or flow rate, of fluid flowing through a pipeline. As the liquid flows through the pipeline, the device measures the pressure of the liquid before it enters the venturi tube and as it exits the constricted area. Flow through venturi meter background and theory introduction flow meters are used in the industry to measure the volumetric flow rate of fluids.
A venturi is a convergingdiverging nozzle of circular. Theory venturi flow measurement fluid dynamics scribd. A simple, inexpensive venturi experiment applying the. Venturi meter and orifice plate effects are two main and very important phenomenas in fuild mechanics sub field of mechanical engineering. The measured alteration is then related to the flow. Experimental investigation of the installation effects on the venturi flow meter performance conference paper pdf available june 2000 with 2,477 reads how we measure reads. The equation is based on the bernoulli equation, conservation of energy, and the continuity equation. However, it has many more pressure tappings, connecting to water manometers, which allow full study of the pressure distribution along the convergentdivergent passage.
Cross sectional area of throat in venturi meter s 2 1. Venturimeter is the most widely used device to measure the discharge through the pipe. The original, or classical, venturi was invented by a u. If a pump forces the liquid through a tube connected to a system consisting of a venturi to increase the liquid speed the. Vbs and vcw gas venturi meters installation manual gas venturi meters e bulletin pn 80157 ed. Venturi meter posted on march 15, 2011 april 4, 2012 by mrsoltys a venturi meter is a device that allows flow rates through pipes to be calculated by measuring the difference in pressure created by a contraction in a pipe. With the introduction of new measurement technologies and the myriad of performance claims from sale literature, its easy to lose sight of the important elements that an effective flow meter offers no matter what technology is used. When a venturi flow meter is placed in a pipe carrying the fluid whose flow rate is to be measured, a pressure drop occurs between the entrance and throat of the venturi meter this pressure drop is measured using a differential pressure sensor and when calibrated this pressure drop becomes a measure of flow rate. Applications of the bernoulli equation the bernoulli equation can be applied to a great many situations not just the pipe flow we have been considering up to now. The venturi meter device measures the flow rate or velocity of a fluid through a pipe. Note that it presumes that the density of the flowing gas is constant, which will not necessarily. The pressure along the meter is obtained using the 11 pressure taps at the locations shown on the diagram. In this post the effect of venturi meter and orifice plate on the fluid flow will be disciussed and complete work will be presented in the form of report. Both are used to measure the flow rate of gases and liquids.
Experiment 1 report flow through a venturi meter group members. It provides more exact measurement than for example the common pitot tube but it is intended rather for smaller flight velocities the speed of sound is reached in the thinner part at small velocities. Venturi flow equation and calculator engineers edge. Differential pressure type flow meters head flow metersmeasure flow rate by introducing a constriction in. A major disadvantage of the venturi nozzle is that it is more difficult to replace than the orifice unless it can be removed as part of a spool section. By attaching manometers to three sections of the tube, the pressure drop can be measured and the flow rate through the throat calculated. The principle of venturimeter is that when a fluid flows through the venturimeter, it accelerates in the convergent section and decelerates in the divergent section, resulting in a drop in the static pressure followed by a pressure recovery in the flow direction. There are basically two applications for a venturi. The venturi meter is a device for measuring discharge in a pipe. Discharge coefficient performance of venturi, standard concentric orifice plate, vcone, and wedge flow meters at small reynolds numbers colter l. Venturi tube exit 2 venturi 3 venturi system venturi entrance 2 water level in pail 4. Inserttype venturi flow meter installation and operation. Definition, parts, working, derivation, applications. Here the velocity of the fluid increases and pressure decreases.
The simplest apparatus is a tubular setup known as a venturi tube or simply a venturi plural. There are pressure gauges at the entrance and at the throat, which is 300mm above the entrance. To find the coefficient of discharge for venturi meter. A venturi is a convergingdiverging nozzle of circular crosssection. The inlet diameter equals d 26 mm and the throat diameter d 16 mm. Experimental and cfd analysis of flow through venturimeter. The orifice meter consists of a flat orifice plate with a circular hole drilled in it. They have been in common use for many years, especially in the water supply industry. Fm 308 flow measurement by venturi and orifice meter. A wide variety of venturi meter options are available to you, there are 302 suppliers who sells venturi meter on, mainly located in asia. A venturimeter is essentially a short pipe consisting of two conical parts with a short portion of uniform crosssection in between. The iso reference has a more complete discussion of venturi tubes than the asme reference.
The venturi meter constricts the flow using a herschel venturi tube. The restriction diameter should not be less than 0. The venturi flow meter consists of a streamlined contraction and a streamline expansion as shown the diagram. The flow nozzle, like the venturi meter, has a greater flow capacity than the orifice plate and requires a lower initial investment than a venturi tube, but also provides less pressure recovery.
A venturi meter is used to measure the flow rate through a tube or volumetric flow rate, q. The principle of the orifice meter is identical with that of the venturi meter. Above fig shows the general dimensions of a herschel standers type venturi meter. Pdf venturi wet gas flow modeling based on homogeneous and. Venturi meter is usually made of cast iron, bronze or steel.
A dp diagnostics venturi flow meter under a customers fat. An intelligent flow measuring technique using venturi. Venturi meterconstruction, working, equation, application. More commonly, a venturi can use this negative pressure to draw a. Various coefficient are added to compensate for the viscosity of.
Tecquipments bernoullis theorem is typical of meters used throughout industry. Each meter works by its ability to alter a certain physical property of the flowing fluid and then allows this alteration to be measured. The classical venturi meter, whose use is described in iso. Converging cone or diameter the area is decreasing throat diameter the area is constant. The fluid whose flow rate is to be measured enters the entry section of the venturi meter with a pressure p1. It is used to calculate the velocity of fluids in running through a pipeline. This also work on the same principle as that of venturimeter. Flow through a venturi meter from maae 2300 at carleton university. It consists of flat circular plate which has a circular hole, in concentric with the pipe. To avoid undue aerodynamic drag, a venturi tube typically has an entry cone of 30 degrees and an exit cone of 5 degrees. In 3 calibration of flow meter is done with the help of microcontrollers. A venturi tube contains a throat which is smaller in a diameter to the pipeline, into which it fits.
Discharge coefficient performance of venturi, standard. There is a pressure tap upstream from the orifice plate and another just downstream. Pvc fittings to produce constructed venturi meters as a lowcost option for. To find the coefficient of discharge of an orifice meter. Department of mechanical engineering venturi meter.
The water flow rate can be adjusted using the valves on the hydraulics bench. Venturimeter it is a device, which is used for measuring the rate of flow of fluid through a pipe. Pdf venturi tubes or meters, represent one of the oldest and most reliable flow meters that can readily pass the debris frequently. The bernoulli balance was applied to the inlet line i. Fluid flows through a length of pipe of varying diameter. The venturi meter has a converging conical inlet, a cylindrical throat and a diverging. Differential pressure type flow meters head flow meters measure flow rate by introducing a constriction in the flow. The whole assembly of venturi meter, manometer tubes, scale and manifold is supported on a base mounted on adjustable screwed feet. Dp diagnostics supplies a unique, powerful, industrially proven, patent pending diagnostics system.1078 407 1280 1616 1483 551 626 1008 918 1516 228 637 1603 23 1594 1632 1022 181 1441 960 1398 363 1052 1334 638 1114 1113 687 1321 729 1393 582 1123 651 753 176 220