Coriolis Flow Meter

Coriolis mass flow meters measure the mass flow of liquids, such as water, acids, caustic, chemicals, and gases/vapors. Because mass flow is measured, the measurement is not affected by fluid density changes.

The mass flow meter does not measure the volume per unit time (e.g., cubic meters per second) passing through the device; it measures the mass per unit time (e.g., kilograms per second) flowing through the device. Volumetric flow rate is the mass flow rate divided by the fluid density. If the density is constant, then the relationship is simple. If the fluid has varying density, then the relationship is not simple. The density of the fluid may change with temperature, pressure, or composition, for example

Rheonik Messgeräte GmbH has more than twenty years of experience in the field of Coriolis Mass Flow meter design and development. Beginning in 1984, Karl Küppers began the design of a mass flow meter based upon the Coriolis effect that later became the patented Omega tube Coriolis Mass Flow meter manufactured by Rheonik today. 

All Rheonik coriolis mass flow meters are based on a patented Omega tube design with increased signal-to-noise ratio, for excellent performance and reliability. The combination of a patented torsion rod swinger with the Omega shape and support bars results in high accuracy measurement independent of pressure, even at very low flow velocities.

RHM coriolis flow sensors offer direct mass flow rate for liquids, sludge, and gases, all with high accuracies. These sensors are extremely resistant to gas bubbles entrained in the process stream, and are unaffected by viscosity, density, extreme temperatures, and pressure changes.There’s a Rheonik RHM flowmeter for nearly any flow application range :

RHM Sensors Overview from Rheonik Messtechnik GmbH :

Model

Qmin

Qmax

Qnom

pmax @ 120°C

typical size of process connection

kg/min

kg/min

kg/min

bar(g)

thread

flange

RHM 015

0.002

0.6

0.6

700

1/4″

DN15, 1/2″

0.038

5.0

5.0

870

1/4″

DN15, 1/2″

0.05

10

10

870

1/4″

DN15, 1/2″

0.15

20

20

510

1/2″

DN25, 1″

RHM 08

0.30

50

50

1,185

1/2″

DN25, 1″

RHM 12

0.75

100

75

960

3/4″

DN25, 1″

RHM 15

1.00

200

150

815

3/4″

DN40, 1 1/2″

RHM 20

2.25

300

300

700

1″

DN50, 2″

RHM 30

5.0

750

600

700

—

DN80, 3″

RHM 40

12.5

1,500

1,250

290

—

DN80, 3″

RHM 60

45

3,000

2,500

430

—

DN100, 4″

RHM 80

130

8,000

5,000

215

—

DN150, 6″

RHM 100

200

12,000

10,000

150

—

DN200, 8″

RHM 160

600

30,000

23,000

50

—

DN300, 12″

Our Technology 

The typical Omega shaped Rheonik Coriolis mass flowmeter. All Rheonik meters are principally based on the design shown beside. No other design offers this degree of versatility and rangeability:

  • Measurement of liquid and gaseous fluids

  • Flow rates from 0.002 to 30,000 kg/min (0.004 to 66,000 lbs/min)
  • Diameters up to 12 inch / DN 300
  •  Pressure over 1,000 bar (14,500 psi)
  • Temperature from -196°C to +395°C (-320°F to +743°F)
  • Hazardous area certified versions available (ATEX, CSA etc.)
  • Available in stainless steel, Alloy C22, Duplex, Tantalum and others
 The Advantages Summary
 Omega design is the basis for one of the most advanced Coriolis meters available:
  • No change of accuracy with changing pressures – active measurement section is half round and maintains its exact shape at any pressure
  • Active measurement section of the Omega is de-coupled from process connections via mass bars. Vibrations have less influence on measurement than with conventional Coriolis meters
  • Tensions from the process side cannot disturb active measurement section of Omega since it is de-coupled (straight tube shaped meters are very vulnerable in this regard)
  • Mass bar and torsion rods (rods work as a spring) form a harmonically oscillating system, resulting in great stability and little energy needed (therefore intrinsically safe)
  • Mass bar – torsion rod system provides very big amplitudes, hence excellent signal to noise ratio. Even smallest rates can be measured reliably.
  • Straight tubes have low signal to noise ratio
  • Torsion oscillator allows bigger wall thickness, hence higher pressure ratings, increased safety, and extreme temperature possible
  • Torsion movement instead of bending creates less stress in tubes – longer life time
  • Torsion movement is less affected by pipe vibrations since the vibrations are horizontal or vertical. Operational movement (torsion) is not in the same plane as the vibration movements – less cross talk
  • Compact form. Shorter face-to-face length than straight tube shaped meters
  • Separate transmitter for flexibility – easy to integrate into systems
  • Extreme applications
  • Sensor models rated over 1,000 bar are available
  • Temperatures from -196°C to +395°C
  • Highest accuracy under real-life conditions
  • Units available for fiscal duties
  • Low energy usage
  • EEx ia IIC sensors available (ATEX and CSA)
  • Flexible configuration
  • Diameters from ½” to 12″
  • Wetted parts materials available: stainless steel, Alloy C22, (Super) Duplex, Tantalum and others