This is a question related to research in food technology. I want to
know references and related work from people who have done anything
similar. Even if you can not provide exact information, I will
appreciate your effort to provide any related information that can
help. Any intuitive but feasible ideas are welcome.
We have a technology that can produce very small and uniform-size
particles. For this specific topic, we make very uniform particles of
sugars (sucrose, glucose, maltose, etc.) of size 300 to 800
micrometers (i.e. any size in between but all the particles will be
almost that size). The problem we face is how to dry those particles
and remove the water to a minimal level (20% or lower water
content)where they do not agglomerate. Note that sugars have very good
affinity to water.
We use initial solution of 40% (weight/volume) of sugar in water.
Generally, the problem is solved if you could reduce the water content
to 20% or low. From our work so far, we know that at appreciably high
temperatures (150-200 degree Celcius or so), drying up to 8-10 seconds
can give reasonably dry particles. The problem with achieving this
residence time in any system is that it is hard to keep the particles
stay up in air without touching anything for this long. We have not
done any modelling but we have tried several drying mechanisms
including a spray dryer of length 30 feet. We were never able to
achieve residence time above 2 seconds. (Most of our work has been on
intuitive designs and the only proven method that we tried is the
There are several intuitive ideas to help levitate the particles in
air. For example, a ping pong ball can stay in air for long time if
you precisely put it over an air orifice. But it is very hard to
achieve that with a large number of particles in continuous random
motion. This random motion leads to several problems: sticking to
walls, disappearance from the system, agglomeration, etc.
We feel there might be industrial processes already available that can
help us solve the problems. For example, spray dryers and fluidized
beds. There might be horizontal dryers that can keep particles in air
for long. But none are known to us so far. You are welcome to provide
details about their use, feasibility, past experiments, producer
I can provide more details if necessary.
Request for Question Clarification by
17 May 2006 15:40 PDT
Visualize a "cyclonic silo" of sorts, with a hot air flow.
The "cyclonic" part would be similar to that of a Dyson vacuum cleaner.
The sugar particles would be dropped down a vertical tube (a "silo"),
perhaps a few feet in diameter, with ducts introducing hot air to the
silo so as to introduce a circular flow of heated air.
This circular flow could be designed to provide a general upward flow
of hot air as well so as to increase "hang" time.
In addition there would be holes on the sides of the silo through
which heated air would also flow, so as to create an "air curtain"
to prevent the impact of the particles on the sides of the silo.
The silo shouldn't have to be very high to accomplish the task, maybe
20 to 30 feet depending on the flow of particles.
Looking Forward, denco-ga - Google Answers Researcher