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The Uses of Coriolis Technology with Flow Instruments are Enormous

Wednesday, June 28, 2023

The use of Coriolis Technology for Flow Instruments are increasing in popularity due to the flexible nature of these Instruments.

Mass Flow Controllers are used to control the flow rate of a liquid or a gas. However traditionally that device is not flexible that you can switch between a gas and a liquid on the same device. Coriolis technology has led to a universal mass flow instrument, where either a gas or a liquid can be used on the same device.

Setting up and taring your Coriolis instrument

The Fluid doesn’t need to be known for the Coriolis technology to work, simply fill the pipe with the required fluid (liquid or gas) at the normal operating pressure, then ensure there is a no flow situation ideally with shut off valves and tare the device.

This is now a calibrated condition to measure the fluid. The tare is a simple push of a tare button on the device itself or via the free software, of course you can wire this yourself and perform the same tare. The tare takes a matter of seconds to perform. Instructions are clear with the operation manual - which can be found on this page.

Alicat Coriolis Mass Flow Controller via a Micro Gear Pump
Alicat Coriolis Mass Flow Controller via a Micro Gear Pump.

There are 2 ways to control the flow typically with a Coriolis mass flow instrument:

  1. A valve to control the flow by opening to a position to meet the desired flow rate selected by the user.
  2. Incorporating a pump for liquid applications is a common method of Liquid Flow Control. The Pump is required when the liquid has insufficient pressure to allow for accurate flow control with a valve. The pump sucks the liquid and passes it through the process system pipes and delivers it to a Coriolis flow meter, the meter measures the flow and signals the pump to rotate faster or slower to meet the changing needs of the flow rate setpoint.

Thus, the uses of Coriolis technology with flow instruments are enormous, a device that can cover the most demanding needs for the process engineer.

Alicat Coriolis Mass Flow Meter (MFM) with SAE threaded connections.

Alicat Coriolis Mass Flow Controller (MFV) with control valve and VCR Connections.

Understanding the Process details

Depending on what you want to achieve Premier Control Technologies can support you through the selection process. We can calculate the accuracy and pressure drop calculations based on your process conditions. These are available via a graphic chart illustration for the model selected.

The Process details must be supplied for accurate selection of the most suitable model.

Knowing the process details is crucial for our engineers to size the Coriolis instrument: Start with the phase of the fluid, is it a liquid or a gas?

What is the fluid this is the specific name such as gas: Hydrogen or liquid: Water.

  1. The Fluid is purely needed for:
    1. Sizing the device for the specific fluid
    2. Materials selection

    It is not needed for the measurement principle.

  2. The desired flow rate that you need to control. Including the maximum is the most common way to inform an application engineer, here a turn down ratio is used to calculate the minimum flow that can accurately be met.
  3. The supply pressure must be provided or the outlet pressure from the device must be known. Where only the outlet pressure is known, we can calculate the supply pressure required to meet this at the maximum flow of the desired range. Thus giving you all the details you need to ensure a perfect system is built. These are the most important details we need to size an instrument.

Caveats are if the fluid is unknown or a secrete formulae. Here it is acceptable to provide the viscosity and density of the fluid and we can therefore calculate the model needed.

Note: Customer input would be needed for the materials of construction selection as the user will know what is the best materials for construction for their secret fluid.

Aggressive Fluids: The Alicat Coda has a default construction of stainless steel when the fluid is aggressive a high Nickel alloy may be selected.

Similarly Seals are selected based on the fluid being used. Seals are made from elastomeric materials FKM, FFKM, EPDM or metals seals are also available in stainless steel or Nickel alloy.

Taking some details such as water with a maximum required flow rate of 1 LPM (Litre Per Minute) and an inlet pressure of 30 Bar (Gauge) and an outlet pressure of atmospheric we can see some details on the below graph.

Water Inlet Outlet Pressure Graph

Below is a typical graph of a Alicat Coda controller for water:

Two graphs showing Flow Rate against Pressure drop and Accuracy for water
Two graphs showing Flow Rate against Pressure drop and Accuracy for water.

The left-hand side graph shows the pressure required for a meter or a controller for flowing 1 LPM maximum of water. The pressure drop would be 2 barG for a meter and 2.25 BarG for a controller at full flow (1 LPM).

The right-hand side graph shows the accuracy. The accuracy at the full scale (Full flow of 1 LPM) is 0.2%, this continues at this high accuracy all the way to around 0.1 LPM.

Final thoughts on sizing up the application

Every process requires a sizing calculation which PCT may perform for you and share the data as per the above with you.

There are options available for the optimum Instrument specification. These include:

  • Standard pressure or high-pressure Coriolis. Exactly the same specs however high-pressure models are rated to 4000PSIA (275BARG).
  • Ingress protection by default is to IP40 however where needed this may be upgraded to IP67.
  • Process connections to the pipe, there are many options here from SAE, NPT, VCR and the ever-popular Compression fittings.
  • The final selection is what signals would be needed? How is the Coriolis controller going to be controlled? Would it be Python, Alicat’s Free software FlowVision 2.0 or a custom software and HMI.
  • Numerous signal options are available from Analog to Digital including a host of Bus options including: EtherNet/ Ip, EtherCAT, ProfiNET.

Put Premier Control Technologies to the Test!

Premier Control Technologies a leader in Flow and Pressure Instrumentation are the UK Distributor for Alicat Scientific.

Alicat Scientific Inc is a USA company (Arizona) Global HQ, European HQ (Netherlands) which specialises in scientific instrumentation based on low flow and Pressure.

Alicat Scientific Inc is part of UK’s Halma Group a FTSE 100 Company owning many Scientific Companies around the Globe.

Get in touch

Contact Premier Control Technologies for a consultation with one of our experts by calling 01953 609930 or email sales@pctflow.com.

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