As a researcher at the PC2A laboratory, I deal with low flows on a daily base. The PC2A laboratory (PhysicoChimie des Processus de Combustion et de l’Atmosphère) is a multidisciplinary public research unit (CNRS/University of Lille), whose activities concern the characterization of the atmosphere and combustion physico-chemistry. Physico-chemistry in general is chemistry that deals with the physicochemical properties of substances. Bronkhorst instruments play an essential role in our researches, for measuring and controlling these substances in various researches. In this blog I will provide an explanation of our research and why we need mass flow control.
Research activities of the PC2A laboratory
Research activities of the PC2A laboratory are related to energy and environment and are conducted by approximately sixty people divided into three research teams with their own disciplines:
1. Physical Chemistry of Combustion
Our first research team is working on the physico-chemistry of combustion. The initial goal of this research is to understand combustion chemistry, for instance how are formed pollutants such as Nitrogen Oxides ( NOx) and soot in flames. We develop detailed kinetic mechanisms of the oxidation and auto-ignition of substances, such as: biofuels, hydrogen, synthetic fuels, biomass or coal. All thanks to our large experimental platform containing flames, rapid compression machine and laser diagnostics techniques.
2. Physical Chemistry of Atmosphere
In the research team ‘Physical chemistry of the atmosphere’, we study chemical kinetics of reactions of atmospheric interest. The two main topics for us within this discipline are:
- Homogeneous and heterogeneous reactivity in the atmosphere to understand the transformation of pollutant gases and particles (pollens, soot) in the atmosphere;
- Air quality with experimental characterization and numerical simulation of indoor and outdoor environments, pollution sources and impacts on health and climate.
For these experiments we develop laboratory instruments to characterize the reactivity of important species that are involved in the atmospheric chemistry processes, especially reactive species (radicals). To perform our experiments it is essential to know precisely the amount of gas that is offered to our laboratory reactors and then the concentration of the reactants in the chemical system. For this application we use Bronkhorst mass flow controllers. El-Flow Select (link product page). These instruments allow us to easily perform parametric studies because of their fast response and high repeatability. Moreover, consistency in flow is crucial for accurate measurement.
3. Nuclear Safety: Chemical kinetics, Combustion, Reactivity
Our third team is a collaborative team between the PC2A and the Pôle de Sûreté Nucléaire (PSN) of IRSN (Institut de Radioprotection et de Sûreté Nucléaire), working on issues in relation to thermodynamic and chemical reactivity of fission products. The main objective of this research is to validate the estimations of radio-contaminant products emissions in case of nuclear accident by modeling development and experimental studies.
Mass flow controllers for physico-chemistry
The PC2A laboratory uses multiple mass flow controllers of Bronkhorst. And this is not only for their specifications like a fast response and high repeatability. Also because of the easy operation of these mass flow controllers with the Labview software these instruments are ready to hand. The possibility to export data and moreover the flexibility with switching between different flow controllers, make Bronkhorst a perfect match for us. The flow instruments we use in the lab are the thermal mass flow controllers ( EL-FLOW Select series) and the flow controllers with a low pressure drop ( LOW DeltaP-FLOW instruments).
LOW DeltaP-FLOW instrument
Watch the video of the working principle of EL-FLOW select.
To learn more about the LOW DeltaP-FLOW, please consult the product page.
The Tour de France has started this weekend, and all cyclists have prepared for this particular event for months. But, did you ever thought about how flow measurement could be of influence on the cyclists’ performance? Here’s how…
A while ago I had the chance to visit Relitech in Nijkerk. A company that is specialized in the development and design of reliable healthcare solutions. I talked to both Directors Ivar Donker and Henk van Middendorp about the activities of Relitech in the medical industry and their Metabolic Simulator. With all their enthusiasm and dedication in their line of work, I came to new insights regarding their matter and the importance of a company like Relitech.
In sports it’s all about optimal performance. Athletes are forced to push boundaries and the devil is in the details, more than ever. A few hundreds of a second can make a huge difference in - for example - a gold medal race. So testing the athletes’ condition and endurance is an important part in the bigger picture of their performances. This can help them to train more efficiently and it provides information that can be used for maybe a change in, for example, the athlete’s diet. For metabolic measuring, a lung function device could be used and these systems often easily interfaced with ECG’s, bikes and other external devices for complete, integrated cardiopulmonary exercise testing.
The big question is how to get the best performance by meeting legal regulations? Validation is the magic word. And for that, Relitech developed a metabolic simulator. Let’s take a look at some of the technical details of a device like that.
Metabolic simulator: quality control for respiratory products
In order to keep a high performance of respiratory products like lung function devices, they need to be validated, to meet the demands of legal regulations as well. The current situation in quality control regarding devices like these, is that it’s limited due to the fact that each sensor (O2, CO2 and flow) is calibrated separately, disregarding the critical dynamic interaction between each sensor. Relitech therefore came up with an in-field solution for their customers by developing this metabolic simulator.
Thermal mass flow controller
As we’re getting closer to the answer on the question I asked at the very beginning of this blog, we need to dig a little deeper into the Relitech simulator. First of all it’s fully mobile, which means it’s easy to transport and secondly it is ideal for on-site testing (in for example a lung function device used for athletes). The simulator mixes pure nitrogen and carbon dioxide by using two Bronkhorst thermal mass flow controllers. By mixing those two gases you can generate breathing gas exchange patterns, real-time and extremely close to authentic human breathing patterns. The results are so-called capnographs that resemble the ones of, for example, athletes. On the readout display of the Metabolic Simulator the capnograph values are visible. V’CO2 represents the exhaled amount of carbon dioxide and V’O2 is the amount of oxygen inhaled. BF is simply an abbreviation for breathing frequency.
“Using mass flow controllers is not new to me…” Van Middendorp explains, “…as I was already involved in designing lung function systems long before I joined Relitech in 2002.”
“As we started developing the metabolic simulator here at Relitech, we were looking for compact and highly accurate mass flow controllers and that’s where Bronkhorst and I crossed paths. So partly by using these compact thermal flow controllers we were able to develop an even more compact simulator design.”
Relitech, reliable technology
With dedication and passion Relitech develops reliable technology by focusing on electronics, software and embedded software. In combination with consultancy regarding measurement technology, their core competence lies within the medical sector, such as lung function measurement, anaesthesia and hyperthermia applications. For this, the company is ISO13485 certified. By working closely with various universities and academical institutes, multinationals and small businesses they have built an impressive and very diverse customer portfolio.
Ready for the Tour de France
So, for all the athletes out there, it’s time to put on the finishing touches and get ready for 2018. Who do you will win the Tour?
Check out the application story of quality control for respiratory products.
Let me start with explaining what demineralised water is. Demineralised water, also known as demi water, is purified water and is often used in laboratory applications for industrial and scientific purposes. However, also in your everyday life you will encounter applications with demi water.
For example for ironing your clothes with a steam iron, demi water can be used to avoid lime scale in your iron. But it is also used in car wash installations. A thin layer of demi water is sprayed over the car at the end of the car wash program to avoid dried up drops on your car. At the end of this document a few examples of the use of suitable Bronkhorst instruments are given.
Demineralised water versus distilled water
Demineralised water is water that has been purified in such a way that (most of) its mineral and salt ions, such as Calcium, Chloride, Sulphate, Magnesium and Sodium are removed. Demineralised water is also known as demi water or deionised water. Demineralised water is generally considered different from distilled water. Distilled water is purified by boiling and re-condensing. In this way salt ions are being removed.
The major difference between demineralised water and distilled water is that distilled water usually has less organic contaminants; deionisation does not remove uncharged molecules such as viruses or bacteria. Demineralised water most times has less mineral ions; this is dependent on the way it is produced. Deionisation has a cleaner production and it leaves behind less scale in the installations it is used in.
A point of attention when using this demineralised water is the material of your instruments. Not all material is suited to serve as a piping material for demi-water; this also depends on temperatures that are used.
How is it made?
Demineralised water is produced via three main routes:
Via Ion-exchange process using Ion exchange resins: Positive ions are replaced by hydrogen ions and negative ions are replaced by hydroxide ions.
Via Electro-Deionisation also an Ion-exchange process takes place: An electric current is sent through the resins to keep them regenerated. The unwanted ions move away from the reaction surface to the electrodes.
- Via Membrane filtration: most times in multiple steps
To get the right quality of demi-water several stages of demineralization are necessary. The use of membrane filtration in this case has the advantage that in general no chemicals are needed to produce the demi-water (except perhaps for cleaning); the disadvantage is the amount of (electrical) energy consumed by the process.
Demineralised water – common uses
Demineralised water is used for industrial and scientific purposes. You can think of the following applications:
- Laboratory applications and testing
- Wash water for computer chip manufacture
- Automotive uses eg. lead-acid batteries and cooling systems
- Boiler feed
- Laser cutting
- Optimisation of fuel cells
- Steam irons and steam raising applications
- Pharmaceutical manufacturing
- Fire extinguishers
Health Risks of demineralized water
Demineralised water, which is completely filtered of minerals via (electro) ion-exchange, distillation, membrane filtration or other production methods, you would think that it could be used as drinking water.
However, as with all things, there are advantages and disadvantages to drinking demineralised water. The advantage is that the minerals that are bad for us have been taken out. There is a lot of documentation available about bad influences of certain minerals on our bodies. The big disadvantage of drinking demineralised water, however, is that demi water takes out also the good minerals from our body and causes a shortage so our health system cannot function properly anymore.
Summarised: demi-water should not be used for drinking water as it removes minerals that are needed for a good health.
Some examples of instruments which can be used for demi water
There is a huge vatiation in candy available on the market, each brand with its own taste, texture and appearance. These features are often part of the branding of the major confectionery manufacturers and therefore important that is done properly.
One of the machine builders who is specialised in equipment for the food industry, escpecially in aerating, depositing, forming and mixing of fat creams, chocolate and other masses, is Haas-Mondomix. I had the opportunity to visit them in Almere (NL) and work with them on a solution, containing ultrasonic volume flow meters, for adding additives into the main stream of the production process of candy.
Important topics when dosing additives
The equipment Haas-Mondomix designs for the confectionery industry has to meet strict requirements. Important topics here are:
- High-quality confectionery products; As confectionery products, such as candy, represent a specific brand it is important that the colour, texture and taste are always the same. So reproducibility in this process is essential. Good reproducibility will result in high-quality confectionery products.
- Efficient use of raw materials (colourings, acid and flavourings); Coulouring and flavourings are very costly agents, especially the natural variant. Therefore, a controlled and efficient use of these substances is very much desired. You will save on raw materials and it will also add to a better quality as well.
- Sanitary design, suitable for food applications; for devices in food applications it is important that they have hygienic design meaning a surface roughness ≤ 0.8 µm and no dead volume.
Application at Haas Mondomix
Solution for dosing additives with an ultrasonic volume flow meter
In the old days, if something went wrong in the candy manufacturing process, poor quality was observed by looking at the candy at a rather late stage, resulting in entire batches of candy that had to be defined as 'second choice'.
In close cooperation with Haas-Mondomix and our Bronkhorst Nederland office, we succeeded in finding a solution which can help Haas-Mondomix to manufacture even more efficient equipment.
During a test we used multiple ultrasonic volume flow meters (Bronkhorst’s new ES-FLOW series) to measure the amount of additieves - flavourings, colourings and acids - that were added to the main stream of the production process.
As these fluids are highly concentrated, only small amounts have to be added. These small amounts can be measured with the ultrasonic flow meter, as the measurement range is within 4 to 1500 ml/min with a precision of +/- 1% Rd.
ES-FLOW, ultrasonic volume flow meter
Depending on the type of candy to be produced, the amounts and types of colourings, flavourings and acids will vary. For one type of candy - a red wine gum, for example - these amounts have to be constant for the entire batch. However, the setup with the ultrasonic volume flow meter is sufficiently flexible to be used for another type of candy - take a green wine gum - after rinsing in between.
In the current process, the ultrasonic flow meter is used for measuring, and sends the measurement values to the PLC. Currently, this procedure is standardised within Haas Mondomix, so that Bronkhorst’s ES-FLOW devices are incorporated as standard option in Haas Mondomix equipment for confectionery manufacturing.
How does this ultrasonic volume flow meter work?
Bronkhorst’s ES-FLOW ultrasonic volume flow meters uses Ultrasonic Wave Technology to measure the volume flow rates of liquids. This technology has been developed in close collaboration with TNO (Netherlands organization for applied scientific research).
Read more about how a ultrasonic volume flow meter works in our previous blog: How to measure low flow rates fo liquids using ultrasonic wave?
See the application note.
Read more about our the ES-FLOW ultrasonic volume flow meter and it’s possibilities.
For most people the classic summer treat is ice cream. Around 7 billion gallons of ice cream and other related frozen desserts are produced every year worldwide, with production peaking (as you might expect) in the summer months, according to the International Dairy Foods Association. Yet, the moment you consume an ice cream, you will probably not wonder how this delicacy is being made. To get that perfect ice cream, a mass flow controller is often used.
What does ice cream have to do with mass flow meters?
Ice cream contains many different ingredients, such as fat, sugar, milk solids, an emulsifying agent, flavoring and sometimes coloring agents. But there is one main ingredient that you may not have thought about, probably because you can’t see it—air. Ice cream is made by freezing and simultaneously blending air into the ingredients. So why is air so important?
If you have ever had a bowl of ice cream melt, and then refroze it and tried to eat it later, it probably did not taste very good. Moreover, if you leave a carton of ice cream out in the hot sun and let it melt, the volume of the ice cream would simply go down. Air makes up anywhere from 30% to 50% of the total volume of ice cream, therefore aeration in the production process is crucial.
The amount of air in ice cream (often called overrun) affects the taste, texture and appearance of the finished product. Higher aeration will produce a tastier and smoother ice cream. A side effect of adding air to ice cream is that it tends to melt more quickly . Thus, for attaining an optimal structure of the ice cream, it is important to have a stable inlet air flow in the production process with a constant cream/air ratio. This can be achieved by using a mass flow controller.
To get an idea of the effect of air on ice cream, think of whipped cream...Whipped cream - cream with air - has a different texture and taste than plain cream. To learn more about this process, please read the story of our guest blogger Hans-Georg Fenzel, where he explains how air is used to create whipped cream.
The process of whipping ice cream into shape
To guarantee the right consistency and structure which ensures a full flavored ice cream, the cream must contain the correct proportion and composition of air bubbles. Hence, aeration mixer manufacturers use a mass flow controller to dose an exact amount of air into the cooled mixer. Such a mass flow controller will ensure a continuous air delivery, proportional to the cream flow . The mass flow controller must be capable of maintaining its performance regardless of any possible back pressure variation. Occasionally, a check valve is mounted at the mass flow controller’s downstream. If inlet pressure drops, such a valve will avoid ice cream back stream into the instrument. A pressure meter is also used with the purpose of monitoring the inlet pressure.
Flow scheme of whipping ice cream process
The SEM (Scanning Electron Microscope) picture below shows the ice cream microstructure. Air bubbles are a critical ingredient. Experts claim its optimal size, distribution and quantity are one of the secrets for having a creamy texture recipe. Hence, according to meet such demands, Bronkhorst has provided efficient solutions for enhancing continuous aeration processes.
Ice cream microstructure
So, the next time you head to the ice cream parlor with your friends, be sure to keep in mind the importance of Bronkhorst when it comes to that delicious refreshment.
Bronkhorst EL-FLOW Select flow meter
In our daily life we use plastics or polymers in many different forms whether as a disposable product such as packaging film or as a long-lasting component in the automotive industry, in construction or in sports equipment and toys.
Nowadays, plastics are tailor-made for the respective application, depending on the properties desired. In this way, properties such as hardness, mold ability (or formability), elasticity, tensile strength, temperature, radiation and heat resistance can be adjusted as well as the chemical and physical resistance can be adapted to the desired function.
This large variety can be modified within wide limits by the choice of the basic building blocks (macro molecules), the production process and additives. The respective macromolecules are polymers of regularly repeating molecular units. The type of crosslinking and the used additives determine the final properties of the material. Last year, the world-wide production of plastics for bulk materials and films was over 300 million tons (source: BMBF) of which almost one third was produced in China. Europe and North America follow with slightly less than 20 percent each.
Precise dosing for operational efficiency and minimization of unnecessary waste
Typical additives in the plastics industry are antistatic agents, dyes, flame retardants, fillers, lubricants, colorants, stabilizers and plasticizers. Many of these additives are liquid. Precise dosing of the additives leads to operational efficiency and the minimization of unnecessary waste.
Additives are frequently added by use of needle valves, which is inexpensive, but always has a risk on malfunction because of fluctuation within the process (e.g., pressure and temperature). In particular the use of plasticizers is increasingly critical since some of these substances are directly absorbed by human beings or accumulate in the food chain.
With the proven CORI-FILL dosing technology, Bronkhorst offers an easy-to-use setup to ensure the required accuracy and reproducibility. By combining a mini CORI -FLOW with a pump or a suitable valve, fluids can be dosed continuously or as a batch into the reactor with high reproducibility. These systems can be integrated or used as an add-on in already existing processes and production lines.
5 Reasons why additive dosing with a Coriolis instrument supports process efficiency for plastic manufacturers
- No need for (re)calibration in the field – fluid independent flow measurement and control
- Gas and liquid can be measured with the same sensor
- Ability to measure undefined or variable mixture
- Multi parameters
- The CORI-FILL™ technology features an integrated batch counter function and enables direct control shut-off valves or pumps
Watch the principle of operation of the Coriolis Mass Flow Meter with dosing pump.
Want to learn more about improving dosing and metering pump performance? Please read the blog of James Walton where he discusses dosing pumps in combination with Coriolis mass flow controllers.
Visit Bronkhorst at the Compounding World Expo 2018
Stand number: 602