17 – Measurement of Flows in Piping Systems 2 March 19, 2013 Professor Doran CEE 410

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type

Variable area-type flowmeters generate predictable response to rate of flow: ufm/index.cfm?task=variable_ area

Variable area-type flowmeters generate predictable response to rate of flow: Inexpensive Small flow rates ½ - 2” Pipe <200 gpm Clean water/gas Available in difference accuracy classes

Variable area-type flowmeters generate predictable response to rate of flow: Manufacturing tolerances; readout scale detail and precision; electronic readout-recording

Propeller-type flowmeters generate predictable response to rate of flow: Q = f (ω)

Propeller-type flowmeters generate predictable response to rate of flow: Clean Fluid +/- 2% Accuracy Available in 2-in to 96- in pipe sizes Wide range of capacities Inexpensive in small to medium sizes Expensive in large sizes

Nutating disc-type flowmeters have ‘wobble’ proportionate to volume metered

Each wobble passes a known volume. Shaft moves in circular motion, used to count. Inexpensive 5/8 – 2” Diameter <160 gpm Clean water +/- 1.5% Accuracy

Gear meters trap and deliver known volume with each rotation.

Inexpensive Small flows (< 65 gpm) +/- 0.3% Accuracy Clean water

Geared lobe meters trap and deliver (larger) known volume with each rotation. _displacement

Geared lobe meters trap and deliver (larger) known volume with each rotation. ¼ - 16-in line sizes Inexpensive in smaller sizes Flow rates up to 5,000 gpm +/- 0.1 – 0.5% Accuracy Clean water

Geared lobe meters trap and deliver (larger) known volume with each rotation.

Vane-type meters trap and deliver known volume with each rotation.

Wide range of flows (up to 18,000 gpm) Can tolerate some solids in larger sizes +/- 0.1% accuracy

Vortex-type meters create vortices that oscillate at a rate proportionate to flow

Normally available in ½-in to 12-in pipe sizes Accuracy of % at high Re (> 30,000) Lower accuracy at lower Re (~10% at <10,000) Can tolerate fine SS (not stringy material) Moderate cost

Magnetic-type meters generate voltage proportionate to velocity (flow)

Clean or dirty fluid Moderate cost (high in larger sizes) Normally available in 4, 6, 8 and 10-in sizes Up to 0.5% accuracy

Magnetic-type meters generate voltage proportionate to velocity (flow)

Ultrasonic-type meters compute flow based on transit times of sound wave

Large range of pipe sizes (1”- >60” Requires bubbles or suspended matter Pipe materials and lining can interfere Low to medium cost +/- 1% of full scale accuracy

Mass flow meters use physics and properties of fluid to compute mass flow rate Coriolis-type meter iki/Mass_flow_meter

Mass flow meters use physics and properties of fluid to compute mass flow rate Coriolis-type meter High Accuracy High Cost Limited capacity Special Applications

Mass flow meters use physics and properties of fluid to compute mass flow rate Hot wire-type meter

Mass flow meters use physics and properties of fluid to compute mass flow rate Biogas or airflow

Mass flow meters use physics and properties of fluid to compute mass flow rate

Compound meters can provide improved accuracy over extended range

Metering Systems Most Commonly Used FluidMeter TypeNotes Water – Point of UseDisplacementAccuracy, Value Water - ProductionFlow Tube, MagAccuracy, Value Air or BiogasFlowtube, Displacement, Hot Wire Biogas corrosivity Wastewater – PipelinePump Runtimes, Mag, Ultrasonic, Flowtube Handle Solids Wastewater – Open Channel Weir, FlumeHandle Solids Wastewater - SewerInsert Flume or Weir, Insert Magnetic Portability, Handle Solids

Learning goals for today are to improve understanding of: Variable area-type flowmeters Propeller-type flowmeters Displacement-type flowmeters Vortex-type flowmeters Magnetic flowmeters Ultrasonic flowmeters Mass flowmeters Summary and Selection of Metering Type