The formal mechanisms for monitoring or even
controlling greenhouse gases (GHGs) in the United States have not been defined.
The EPA and the government have not yet implemented any meaningful legislation. But now is the time to start preparing, nonetheless.
by Darren A.Traub | October 1, 2008 | Comments (0)
Protection of the environment is a reality that we are going to have to deal with. We can run but we cannot hide: the United States houses approximately 5 percent of the world population, yet we are responsible for more than 25 percent of the world's pollution.
Plastic processing is a major part of the process heating world. Among the process methods for plastics are thermoforming, compression molding and roto-molding.
by Darren A.Traub | February 1, 2005 | Comments (0)
In injection-molding, plastic pellets are introduced -- with or without
other additives such as color, mold release agents and lubricants --
from a hopper into the molding machine. This feeding system is common
to most plastic-forming processes.
by Darren A.Traub | January 1, 2005 | Comments (0)
By special request, the "What's That Process?" file is being extended
to include other process heating topics that do not specifically relate
to drying. This month, I’ll begin a look at extrusion.
by Darren A.Traub | October 1, 2004 | Comments (0)
Distillation involves the separation of components of a mixture, most
commonly a liquid, by producing a gas or a vapor and then condensing
the so-formed vapor. Distillation is used extensively in the
fractionation of volatiles and other organic compounds. Multistage
distillation is common to achieve the final or various intermediate
fractions. How is this different than dehumidification?
by Darren A.Traub | September 1, 2004 | Comments (0)
Drying is just one of a myriad of industrial heat and mass transfer
operations. I am frequently asked questions such as "What is the
difference between drying and evaporating?", or "drying and curing," or "What is roasting and what is calcining?" These processes are related
but distinct enough to be characterized.
Condensation problems frequently occur during or soon after a plant
shutdown. This is because exhaust air is allowed to cool down inside
the dust collector, which permits moisture to condense, forming
moisture droplets on the surfaces. To avoid this potential
trouble spot, be sure that the dryer goes through a shutdown cycle that
will stop the feed, purge the moisture-laden process gas and allow the
gas to slowly cool under atmospheric humidity conditions.
Implicitly, exhaust streams in dryers contain moisture. If this
moisture is permitted to condense, it will create a "sticky situation"
and lead to blinding, buildup and bridging. So, how do you deal with
these evils?
Many drying systems employ reverse-pulsing dust collectors to control the solid particulate
emission and recover the final product. The physical action of reverse
pulsing releases a volume of compressed air at a substantially higher
pressure than the operating or atmospheric pressures. On expanding, the
air "shocks" the bag, effectively shaking the media and, together with
certain inducing devices, forces air in the opposite direction, the
reverse of the exhaust airflow.
