Process Improvements

Ceramic Welding Backing | Ceramic Backing Welding| Ceramic Backing Taps

The most obvious form of such a device is a rotary furnace. In such a furnace, reactants are introduced
into one end of a rotating tube, and are conveyed at a set rate through a thermal profile by means of
tube rotation and an incline applied to the tube. As the reactant bed moves through the tube, it is
constantly stirred by the tube rotation.

The stirring action enhances thermal transfer to the bed, improves removal of product gases and
increases solid/gas exchange in cases where the furnace gas is also a reactant. Because of these
enhancements, the product material often exhibits an improved uniformity compared to static bedprocessed materials. In addition, because only the reactant powder is heated and cooled, the thermal
efficiency is significantly improved compared to pusher-style furnaces.
In practice, rotary furnaces provide the anticipated values of throughput and efficiency over a wide
range of materials, as long as the materials behave properly during the process. In some cases, the
nature of the reactant material can cause problems with the flow of material through the tube. Material
adhesion to the tube can change bed mixing behavior, flow through the furnace and, in extreme cases,
cause wide swings in material residence time. In other cases, material entrainment in the exhaust gas
can affect throughput and material flow.
These problems can sometimes be overcome by changing the physical form of the reactants. For
instance, fine powders might be granulated into pellets or aggregates. Alternately, the use of internal
features within the process tube can occasionally promote the desired bed behavior. At other times,
the nature of the material does not allow for granulation, or the granules are not sufficiently strong to
retain their shape throughout the process. In such cases, other means of high throughput and high
efficiency processing are needed for more challenging feedstock. 

Date: 2023-04-10     hits: 529    Return