Hengyang Intelligent Control in the Application of a Rotary Dryer
for Reduction in the Over-Drying of Cut Tobacco
It is well-known that rotary dryers are the main dehydration
equipment used for many different types of processing such as food
industry, agriculture, and tobacco production. The rotary dryers
can remove water from the material through heat exchange; the
greatest advantage of rotary dryers is that they can process more
material in a more efficient way than other kinds of dryers.
At present, the application of automation control technology to the
industrial rotary dryer is a highly effective way to improve
operation, safety, and efficiency.
Cut Tobacco Rotary Dryer Principles of Operation
In its simplest form, the Rotary Dryer consists of a slightly
inclined rotating cylinder, fitted with a series of peripheral
flights arranged to lift, distribute and transport the material.
The flights are designed to suit the particular handling
characteristics of the material, which may vary with increasing
dryness. The principle of operation is based on showering, or
cascading the wet material through a hot gas stream, flowing either
co-current or counter-current to the solids. The hot gas induces
the evaporation of the moisture. The heat lost to the material and
evaporation of water vapor reduces the gas temperature rapidly,
such that it leaves the dryer at a comparatively low temperature.
The efficiency of the dryer is largely dependent on the
differential between the inlet and exhaust gas temperatures,
although the heat transfer rate is also influenced by the
relationship between the design of flights and the speed of
rotation. However, irrespective of the gas and material
temperatures the drying (or residence) time may be critical, as
this is governed by the rate of diffusion of water from the core to
the surface of the material. For special applications, the rotary
cascade design is adapted to provide a shortfall, or ‘Cruciform’,
lifter configuration.
Cut Tobacco Rotary Dryer Technical Details
| Specification | Length(m) | heat transfer surface(m2) | Speed (r/min) | Slope (%) |
| HYQ1200 | 9~14 | 90~140 | 0.5~5 | 1.5~3.5 |
| HYQ1600 | 12~18 | 200~330 |
| HYQ1800 | 14~20 | 250~480 |
| HYQ2200 | 16~24 | 530~800 |
| HYQ2600 | 18~28 | 840~1300 |
| HYQ3000 | 24~30 | 1450~1800 |
| HYQ3600 | 30~40 | 2000~2600 |
| HYQ4000 | 35~45 | 2700~3000 |
| HYQ4200 | 40~50 | 3200~3500 |
