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, flavouring and sometimes colouring 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.
The process of whipping ice cream into shape
To guarantee the right consistency and structure which ensures a full flavoured 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 downstream of the mass flow controller. If inlet pressure drops, such valve will avoid ice back stream into the instrument. A pressure meter is also used with the purpose of monitoring the inlet pressure.
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.
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.
- Watch the video about the EL-FLOW Select to learn more about the thermal mass flow instrument which can help you create ice cream.
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When you install a mass flow meter or mass flow controller it is important that you get the best performance from the moment you install and turn it on. To help you, I have listed a few simple things you can check focusing on thermal mass flow meters and controllers for gases.
1) Mounting position of flow meter
The mounting position is important. For flow meters the preferred position is horizontal, and at high pressures ( > 10 bar for by-pass instruments) all meters should be mounted in this position. Avoid installation in close proximity to mechanic vibration and heat sources.
2) Avoid interruptions
Avoid abrupt angles – or any objects in the flow path which can cause turbulence - directly on inlet and outlet of your flow instrument, especially for high flow rates. We recommend at least 10x the pipe diameter as the distance between the angle and the inlet of the flow instrument.
If you are interested in why the choice of piping is important for thermal mass flow meters, please read our previous blog for more tips.
3) Name plate (serial number label)
Read the instrument’s name plate before installation and check the electrical connection, flow range, media to be measured, inlet and outlet pressure, operating temperature, ATEX classification (when applicable), as well as input and output signals. Also check the sealing material for compatibility with the process gas.
4) Electrostatic discharge (ESD)
The flow instrument contains electronic components which are sensitive to electrostatic discharges (ESD) – a sudden flow of electricity between two electrically charged objects caused by contact. Contact with electronically charged persons or objects could possibly endanger these components or even result in their failure.
Do not apply pressure until electrical connections are made. When applying pressure to the system, take care to avoid pressure shocks and increase pressure gradually.
6) Check the piping
Ensure that the piping of the system is clean (before installing the instrument). For absolute cleanliness always install filters to ensure a moisture and oil-free gas stream. It is recommended to install an in-line filter upstream of the mass flow meter or controller, and if back flow can occur, a downstream filter or check valve is recommended too.
7) In line installing
Install the mass flow meter or controller in the line and tighten the fittings according to the instructions of the supplier of the fittings.
8) Piping diameter
Avoid small diameter piping on high flow rates, because the inlet jet flow will affect the accuracy and may cause too high pressure drops over the piping and adaptors. Choosing the right piping diameter is also of importance to minimize the effect of turbulence as much as possible. Our previous blog describes the effect of turbulent flow and what to do about this.
9) Leak testing
Always check your system for leaks, before applying fluid pressure. Especially if toxic, explosive or other dangerous fluids are used.
10) Power up
Apply power to the flow meter or controller and allow for approx. 30 minutes to warm-up and stabilize. This may be done with or without fluid pressure, applied to the system.
I hope that this list is of use. Please feel free to use it as a reference for the next time you need to install a mass flow meter or controller. If you have further questions or if you think I have left anything out then please let me know. At Bronkhorst, we are happy to learn from your experience.
Check the frequently asked questions (FAQs) on our website.
Or download the manual or quick installation guide of the flow instrument.
Each industrial process starts on laboratory scale to define the important parameters efficiently. These parameters might be pressure, temperature, flow but also cost efficiency and standing times. The process with the highest yield is not automatically the most efficient one. For example in catalysis or exhaust/raw gas purification it is very important to find the economically best materials and parameters. From the laboratory beaker to bulk is the process which starts at a microscale and ends with a fully operating industrial process. In between often a pilot stage is included.
Biogas Purification Testing
In Pressure Swing Adsorption systems (PSA), adsorption processes are used for the purification of bio- or natural gas. Thereby, the preferred adsorption of CO2 by zeolites or carbon-based sorbents is used to generate highly pure methane. This methane can be used for heat and power generation, offering an alternative to fossil fuels. Particularly in case of pressure swing adsorption systems, new materials are continuously being developed and evaluated, promising optimized efficiency caused by better sorptive separation properties.
Laboratory scale studies are of special interest as the potential of new materials as well as the associated economics of corresponding industrial processes can be assessed in advance.
Breakthrough Measurements on Laboratory Scale
The Rubolab GmbH has been a spin-off from Rubotherm GmbH, Germany and the Ruhr-University in Bochum, Germany. Rubolab offers a broad versified portfolio of different adsorption measurement instruments. As Managing Director of Rubolab, I developed the worldwide first manometric high pressure adsorption screening instrument in 2012. During the last years, dynamic adsorption measurement instruments, so called Breakthough Analyzers, have gained increasing importance. In this context, Rubolab offers costumized instruments for the evaluation of novel sorbents in smallest amounts (MiniBTC series).
High pressure resistant vessels are filled with the materials which have to be analyzed. Afterwards this adsorber bed is pressurized using defined gas flows. A corresponding flow sheet of the instrument is shown in the following figure.
In the example above, the sorptive separation of CO2 and CH4 is investigated. In this case, CO2 is adsorbed by the material while the gas is flowing through the fixed bed. A high-purity methane stream is recovered at the top end of the adsorber column.
Three temperature sensors are positioned at different heights within the adsorber column. Due to the exothermic adsorption process, a temperature change within the adsorber bed can be detected, indicating the so-called Mass Transfer Zone (MTZ) going through the fixed bed. When this zone reaches the adsorber head, a corresponding breakthrough can be observed by using downstream gas analysis. Thereby the measured CO2 concentration in the product stream approaches the CO2 concentration of the feed stream. In larger industrial systems the adsorber should be regenerated at this time. This kind of experimental data provides information about adsorption capacities of the substances being investigated.
Mass Flow Controller and pressure regulation valves
For the highly accurate controlling of mass flows and downstream pressures these instruments are equipped with Bronkhorst mass flow controller and pressure regulation valves. In particular devices of the newest generation of mass flow controllers, the Bronkhorst EL-FLOW Prestige series, are used in corresponding laboratory instruments for high end accuracy and versatility. In other devices where the size is of high importance, the Bronkhorst IQ+FLOW series is used to take advantage of it’s very compact size and the possibility to set up small manifolds.
Mass Flow Controller of the EL-FLOW Prestige Series
EL-FLOW Prestige mass flow controllers and meters are highly versatile instruments with their onboard database for gases and mixtures. So it is easy to react on changing customer needs without the necessity to purchase another instrument, when the test gas changes. The Prestige guarantees highly accurate and reproducible gas flow due to an automatic temperature correction, newly designed sensor and valve technology.
Mass Flow Controller of the IQ+FLOW Series
The IQ+FLOW series consists of ultra compact mass flow meters, controllers and also pressure controllers, which are designed for analytical instruments with limited space. The integrated chip technology enables fast measurement and control down to smallest ammounts. 3-Channel devices designed for customer’s application are also available.
To get familiar with this mass flow controller series, please download the white paper for more in-depth information.
You will receive the white paper when you fill out your email in the form above.
Check our instruments used in this application: