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Combustion Research Associates manufactures differential producer type flow
meters for gas and liquid flow measurement.
WORKING PRINCIPLE OF FLOWMETER
The flow-meter offered is differential producing flow-meter and is
most widely used in industry for flow measurement applications.
The meter consists of three separate major devices that act on
combination to measure the flowrate. The first device is differential
producer, a PRIMARY device called VENTURI or ORIFICE PLATE which
generates differential pressure proportional to flowrate. The second
device is DIFFERENTIAL PRESSURE TRANSMITTER, which measures this
pressure and generates signal, which is proportional to the flowrate.
The third device is the rate indicator and recorder (optional) which
gives the flowrate and totalised flow in desired engineering unit.
BASIC PRINCIPLE
The underlying principle of all differential -producing flowmeters
is Bernaulli's streamline energy equation. When the flow is contracted,
either gradually or abruptly, kinetic energy increases increases at the
expense of available potential energy (static pressure). tHe pressure
diffence between the taps located at the full pipe section and and in
the vicinity of contraction is related to the square of the velocity
at section 2, fluid properties and to the abruptness of contraction.
Since the velocity times the pipe area is volumetric flowrate, the
basic flow equation may be written as a squre-root relation ship among
measured differential pressure hw, density p and flowrate Q as
Q = Fmc [ hw /p]1/2
The meter constant Fmc adjusts for dimensional units and includes
a discharge coefficient that corrects for contraction characteristics,
pressure tap location, and velocity profile [Reynolds number].
Combustion Research Associates manufactures orifice plate,
venture, flow limiting nozzles as per approved international standards.
Materials chosen are compatible to the medium of flow.
FEATURES
- As per international design
- Venturi are energy saving due to pressure recovery
- Economic and cost
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