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application /advantages
The feed-and-turn drier, originally developed for drying very moist maize, is a proven and universal drier used a thousand times. For more
than 30 years, it is included in the manufacturing programme of STELA, who introduced this drying principle in Germany. The basic principle of the feed-and-turn drier has been known for
decades and such plants are built meanwhile by numerous manufacturers.
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stationary feed-and-turn drier

grass - pellets |

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STELA developed a special paddle and drive mechanism for the drying of foliage plants, herbs, grass, pellets, granulates, wood chips, marc and many
similar products. The feed-and-turn drier with the new paddle and drive mechanism is an excellent alternative for the belt drier in the medium range of capacity from approx. 1 000 kg/24 h up to
approx. 15 000 kg/24 h.
Advantages at first sight:
• evaporation capacities up to
15 t water/hour
• high throughput capacities with
constant final moisture, also with
varying initial product moistures
• wide control range of the drying
temperature (150 – 1000 °C),
so that the suitable drying temperature
can be adjusted for all products
• direct or indirect heating
• low fault liability – high operating safety
• low energy consumption |

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The drier
• is very robust and long-lived
• is reasonable concerning investment and operation
• is uncomplicated in operation
• is flexible – also a lot of other products can be dried
• works very energy-saving
• both continuous and discontinuous (batch) drying is possible
• very variable bed depths from 40 to 500 mm are possible
• can also be delivered "ready to plug in" in mobile design
• the product is turned automatically without the use of movable belts
This means:
• longer operating life (no belt wear possible)
• also very fine products can be dried on fine-meshed gratings
• 100 % safe against leak air
Drying principle
Hot air is blown through a double bottom – a latticed bottom – through the product. A mobile paddle mechanism mixes and conveys the product during the
whole drying time. This simple principle guarantees an almost maintenance- and trouble-free drying process.
A travelling mechanism moves the paddle wheel across the drier for several time during the whole drying process. The direction is changed by final switches and the respective automatic
control system.
This combination guarantees an optimum mixing of the product and consequently a constant and homogeneous drying. This system avoids the risk of agglomeration even for heavily polluted or
moist products.
The feed-and-turn drier can be optimally used for both small and medium-sized product quantities. This is achieved by 2 different modes of operation: batch drying or continuous drying.
Select batch drying for small quantities, i. e. the drier is filled, then the drying programme starts. If necessary, the product can be cooled after having reached the respective drying
degree, then the drier is emptied automatically.
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Batch drying
the product (yellow) is dried in batches

Continuous drying
yellow: dry product, green: pre-sweating zone, red: hot air, blue: cooling air |
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Continuous drying is used for large quantities. The product is fed and discharged permanently. At the end of the drier, fresh air is blown in, if
necessary, to bring the product to storage temperature. If cooling is not necessary, this zone can be used as an additional drying zone.
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