Flow measurement

FLOW MEASUREMENT

• Dennis C. Porlaje

TERMINOLOGIES

• FLOW – the amount of fluid past a given point.
• FLOW RATE – the amount of fluid past a given point at any given instant.
• TOTAL FLOW – the amount of fluid past a given point during a specific period of time.

UNITS OF FLOW

• MASS-BASED – e.g. g/s, kg/s, kg/min, kg/hr, oz/s, lb/hr, tons/hr, etc.
• VOLUME-BASED – e.g. cc/s, m³/hr, cc/min, gal/s, gal/min, ft³/s, ft³/min, etc.

OPEN-CHANNEL FLOW MEASUREMENT

• The "open channel" refers to any conduit in which liquid flows with a free surface. Included are tunnels, non-pressurized sewers, partially filled pipes, canals, streams, and rivers.

OPEN-CHANNEL FLOW MEASUREMENT

• Weir
• Flume
• Flow Nozzle

WEIR

• Weirs operate on the principle that an obstruction in a channel will cause water to back up, creating a high level (head) behind the barrier. The head is a function of flow velocity, and, therefore, the flow rate through the device.

WEIR

• Rectangular
• Triangular (V-Notched)
• Trapezoidal (Cipolleti)

RECTANGULAR WEIR

RECTANGULAR WEIR

V-NOTCHED

V-NOTCHED

CIPOLLETI

CIPOLLETI

FLOW NOZZLE

• Kennison Nozzle

KENNISON NOZZLE

KENNISON NOZZLE

KENNISON NOZZLE

PARSHALL FLUME

PARSHALL FLUME

PARSHALL FLUME

PALMER-BOWLUS

PALMER-BOWLUS

PALMER-BOWLUS

CLOSED-PIPE FLOW MEASUREMENT

• Differential Pressure (Head)
• Variable Area
• Positive Displacement
• Velocity
• Mass

Differential Pressure (Head)

HEAD FLOW ELEMENTS

• Orifice Plate
• Venturi Tube
• Flow Nozzle
• Pitot Tube
• Elbow
• Target Meter

Orifice Plate

Types of Orifice Plates

Venturi Tube

Typical Venturi Tube

Flow Nozzle

Pitot Tube

Pitot Tube

Elbow

Target Meter

Target Meter

VARIABLE AREA

• Rotameter

Rotameter

Typical Rotameters

Rotameter

POSITIVE DISPLACEMENT

• Nutating Disc
• Reciprocating Piston
• Oval Gear
• Rotary Vane
• Bellows Gas Meter

Nutating Disc

Nutating Disc

Reciprocating Piston

Oval Gear

Rotary Vane

Bellows Gas Meter

VELOCITY FLOW METER

• Turbine Meter
• Vortex
• Electro-Magnetic
• Ultra-Sonic

Turbine Meter

Turbine Meter

Turbine Meter

Vortex Flow Meter

Vortex Flow Meter

Electro-Magnetic Flow Meter

Electro-Magnetic Flow Meter

Electro-Magnetic Flow Meter

Ultra-Sonic Flow Meter (Doppler)

Ultra-Sonic Flow Meter (Transit-Time)

• Reflection Mode

• Diagonal Mode

MASS FLOW METER

• Coriolis

Coriolis Mass Meter

Coriolis Mass Meter