Bronkhorst

New flow technologies using integrated sensor functionality

March 20, 2018 Egbert van der Wouden

Customers over the world are searching for simplication and integration of their gas, liquid or vapour flow processes. They prefer integrated platforms that are compact, robust and reliable, and even containing different type of sensors.

In this blog I provide a sneak-preview of the ‘toolbox’ which is under development at Bronkhorst High-Tech B.V. One of the components which we are working on, a micro Coriolis mass flow sensor, is already shared with you in our previous blog ‘Miniaturization to the extreme’.

Example future state sensor

Why do we develop a next-generation toolbox?

On a daily base, our customers tell us their need for miniaturization and the need to control a complex of different parameters to meet the stringent demands of their customers. These types of customers include the life-science market, analytical device manufactures but also markets in which online gas-concentration levels are measured.

MEMS based technology

These types of requests triggered us to work on the next level of sensor development which can support the future need of our customers. This new development includes MEMS based technology (Micro Electro Mechanical System) which gives you the possibility to measure more than just flow alone on one customized system that can consist of one or a combination of sensors.
 

Example of parameters which could be determined by combining several parameters
Example of parameters which could be determined by combining several parameters

For instance, a measured physical property can be used to identify the type of medium, if that property is unique for that medium. Or, in case the medium consist of a mixture of 2 gases, a property can be used to analyse the fraction of this binairy mixture.

Other parameters which can be thought of are the sugar content of a fluid, also referred to as the Brix number, or heat capacity that can be used to measure oil/water mixtures.

In short, these new concepts are under development to support our customers to solve their next generation technology challenges. 

Multi-parameter sensor chip

An example of how a program was started to minimize the footprint;
Bronkhorst received the request to measure fysical gas properties in combination with several partners. The fysical properties included the:

  • heat capacity (cp)
  • density (ρ)
  • thermal conductivity (λ) and
  • viscosity (η)
 
To analyze these properties several individual sensors like a Coriolis-, Thermal-, Pressure- and Density sensor where needed. To proof  that the combination of several sensors in combination with electronics  could meet the needs of the customer, a demonstation model was developed. This demonstration model contained commercially available products which where combined in one system. 
 

Demonstration model
Demonstration model

The learnings from the demonstration model support the project team to define the exact scope for the multiparameter chip alternative. 

One important aspect of sensor performance is the stability, espacially when multiple sensors are combined to determine information about the medium in the system. In figure on the right it is shown that we can measure the viscosity with a combination of the massflow, density and differential pressure.
With the demonstration model shown above we have tested if the viscosity of a medium can be measured accurately over longer periods independend room temperature changes.  The measurement of viscosity can be interesting for some applications, for instance with natural gas  where viscicosity and calorific value are strongly correlated.  The test results shown are for a test period of 84 hours, the histogram shows that all measurements values for the viscosity fall within a band of 0.5 %.
  

Future state sensor

The next level will be to combine the same functionalities on a much smaller footprint. The concept below shows the possibities to combine the required parameter on chip level.
 

Test results of the sensor performance stability for a test period of 84 hours
Test results of the sensor performance stability for a test period of 84 hours
Example future state
Example future state: combination of parameters on chip level

Bronkhorst® Flow Solutions

For machine builders all over the world who are searching for simplification and integration of their gas, liquid or vapour flow processes, Bronkhorst can already help in developing and supplying 100% customized flow solutions that fully meet the customer’s needs.

For information about our future toolbox concepts please contact our office [email protected].

In several earlier blogs the results of this co-creation process has been addressed: