Important tasks in the water production are the gas-liquid applications. For example, aeration to remove iron or subsequent carbonation with CO2. Important in these processes is to achieve optimum mass transfer through intimate contact between gaseous and liquid phase. Higher shear forces generate small bubbles and mass transfer is therefore quick.
Adding colors, syrup or flavors to water is another application where static mixers are installed.
Excellent blending abilities at low pressure drops are the major advantages in such applications.
Often drinks are deaerated before the carbonization stage. Stripping of oxygen with nitrogen is a well known process which takes place in tanks normally.
This exchange takes place in the interfacial area of the gas bubbles. As static mixers provide a bigger area and always renew the exchange layer, the process is much faster and a lot of expensive N2 can be saved.
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SMV® mixer for gas-liquid applications |
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In a SMV® mixer, gas bubbles are evenly spread over the cross section with a narrow bubble size distribution |
Fruit juice
Typical duties for static mixers in the processing of fruit juices are blending different juice concentrates, restitution of evaporated and condensed aromatic substances after concentration, admixing of sugar solution to mother liquor or lowering pH of vegetable juice by adding citric acid.
Re-dilution of fruit concentrates demands low temperatures and pressures in order to preserve color and flavor of the juice.
Dillution of concentrate by adding water to the required content can easily be done by relying upon static mixers.
Effective dilution without heating up, low pressure drop and excellent cleaning abilities are only a few advantages of static mixers in these applications.
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Using static mixers saves additives due to fast and effective mixing |
Coffee
The two main applications are admixing of aromatic substances to coffee extract and dispersing inert gases prior to the spray dryer.
Sulzer gas mixers are also able to equalize the temperature profile in the roasting gas stream.
Burning can be avoided and coffee is uniformly dried.
Another application is mixing different dried coffee blends together. Adding the different additives on the top, they fall through a mixer by gravity and are continuously mixed by guiding vanes.
A static mixer is highly efficient and provides an excellent homogeneity even with small additive amounts. The mixing takes only a few seconds so that production time is very short.
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SMF DN80 mixer for blending coffee or milk powder. |
Beer
Beer aeration is a major task in a brewery. Although sinter candles are widely spread in this industry, static mixers have important advantages.
The mass transfer is for both systems about the same but mixers create less foaming at about the same flotation, air consumption is lower and they are perfectly CIP cleanable.
A pay back time estimation made by users came to only about ½ year.
CO2 provides a fresh taste and acts as a preservative to beer.
Experiences with many plants have shown that reaching the required CO2 content is easy to fulfill when using static mixers shortly upstream of the filling machine.
Owing to large transfer area created by static mixers, the residence time can dramatically be reduced from the one typically encountered in gasification tanks.
Other applications are mixing beer batches with different alcohol contents or adding invert sugar to weak beer to bring it up to required strength.
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CompaXTM mixer to standardize beer or other drinks |
Wine
A possible use of static mixers is the admixing of casein solution to flocculate phenols or impregnating wine with CO2 to make it sparkling.
Another possibility is the aging of wine with air. SMVTM mixers are used to contact air with wine in a gentle way. |