Pressure and vacuum resistant reactors are required when vacuum drying is to be carried out. Then the wet or moist product must also be heated. This is usually done by giving the mixer a double jacket. A heat transfer medium circulates in the double jacket. This is steam, water, thermal oil or a molten salt (at particularly high temperatures). It is often advantageous if the mixing tools are also fully tempered. Either steam, water or thermal oil also circulates in the mixing tools. Basically, two efficient reactor designs are available in vertical construction. Shown on the left, the flat-bottom reactor and on the right the conical reactor.
A drying process can be fast and effective even at low temperatures. One lowers the system pressure by applying a vacuum. amixon® apparatuses are manufactured gas-tight. They can be operated with a vacuum of less than 50 mbar or even less than 5 mbar. If the pressure in the mixer-dryer is only 50 mbar, water will boil at a temperature of 33°C already. If the pressure in the mixer-dryer is only 10 mbar, water boils already at 10°C. Contact drying in the amixon® mixer dryer is a particularly gentle and low-emission drying method. The result is a dry, pure powder.
Vacuum mixer dryers and synthesis reactors play a subordinate role in connection with the preparation of animal feed. They are only used occasionally in the field of gluten drying and the preparation of starch derivatives. In addition, they are also used for fermentation tasks in connection with feed production, if vacuum drying should also to be carried out in the same apparatus.
Sometimes, pressed compound feeds or agglomerated powders should be supplemented with high liquid/fat contents. Here, impregnation can be conveniently applied by heating and vacuuming the powders/ pressed pellets before adding the fat. Then the capillaries are free of gas and the grease can penetrate there. Then the system pressure in the mixer/reactor is increased. This allows the grease to penetrate into the pores of the compacts.
We must answer your question with a clear yes. Horizontal paddle dryers and the vertical dryers shown above achieve comparable drying results.
In special cases, vertical mix dryers can even have far more square meters of heat exchanging surface per cubic meter of mix. A high degree of specific heat exchanger surface means shorter process times.
There are also interesting distinguishing features when comparing horizontal and vertical apparatus. This concerns the type of flowing and mixing.
Such detailed questions are quickly clarified when drying trials are demonstrated in the technical center. amixon GmbH would be pleased to invite you to this. In this context, many other questions can also be answered on topics such as