Biomedical Engineering Reference
In-Depth Information
(A) Incorrect
(B) Correct
Minimum
width
Stagnant material
Inlet
height
Rotor
FIGURE 12.10 A small vertical section above a rotary feeder as shown on the right gives bet-
ter flow.
interface. The capacity increase along the feeder length is achieved by the
increase in height and width of the interface above the belt.
Poor design of a feeder is a common cause of flow problems, as it pre-
vents smooth withdrawal of solids. If the discharge rate of the chute is lower
than the maximum designed feeding rate of the feeder, the feeder can be
starved of solids and its flow control will be affected.
12.3.3 Conveying
There are several options for conveying biomass from one point to the other.
Some of the popular ones include:
1. Belt conveyor
2. Chain conveyor
3. Pneumatic conveyor
A belt conveyor is less expensive but have a larger footprint due to its rela-
tively low slope angle. The belt speed should be kept low below 2 m/s (Janze
2010). It allows a magnet hanging from the top to remove magnetic materials
and other devices to remove scrap materials and oversize feed as the biomass
moves along the belt. A chain conveyor, however, requires lower space as it
can operate at a steeper slope, but the chain conveyor is more costly.
Pneumatic conveying is the least costly option, but it has a high power
requirement. The fuel should necessarily be small for pneumatic conveying.
One could use dilute phase conveying. Installations also use dense phase
conveying.
Search WWH ::




Custom Search