Chemical Engineering June 2010 - 19

SPX Cooling Technologies
Figure 2. Instead of having an air-cooled heat exchanger on top of the wet tower and
sharing the same fan, the ClearSky system has an air-to-air heat exchanger above the wet
section. It takes warm air from the wet section and pulls outside air across the other side
of the heat exchanger and warms it up before it goes into the tower, which reduces the
amount of relative humidity in the air leaving the tower so it doesn't make a visible plume
ability to provide a large amount of
cooling quickly, with lower upfront
costs than installing a new mechanical
system and more flexibility for the
future. While this " bolt-on " method
won't work efficiently for large refrigeration
capacities, it is a solid, economic
solution for smaller processes
such as reaction cooling or size reduction
(Figure 1). For example in reaction
cooling, a water cooled system or
heat transfer fluid might traditionally
be used, but liquid nitrogen can be incorporated
to provide necessary cooling
and temperature control for lower
temperature operations, greater flexcooling,
Niagara Blower offers a Wet
Surface Air Cooler (WSAC) technology
(Figure 3) that may help reduce the
amount of water required in a plant
due to the ability to use low-quality
water as spray makeup. Commonly
used for adding capacity in " thermally
challenged " plants, WSAC coolers and
condensers offer additional direct cooling
without having additional tower
capacity or makeup water.
The basic principle of WSAC technology
is that heat is rejected by
means of latent (evaporative) heat
transfer. Warm process fluids or vapors
are cooled in a closed-loop tube
bundle. Open-loop water is sprayed,
and air is induced over the tube bundle,
resulting in the cooling effect.
The process fluid being cooled never
comes in contact with the environment.
Due to the closed-loop design,
spray water never contaminates the
process stream, and higher cycles of
concentration can be achieved.
Industrial gas tactics
As more facilities are looking to increase
cooling capacity without complete replacement
of a process cooling system
or major capital costs, industrial gases
may provide a competitive solution.
" For processors who are looking to
boost capacity of mechanical refrigeration
systems, or overcome refrigeration
shortfalls, liquid cooling-nitrogen
systems can be used either by introducing
the nitrogen in direct contact
with a refrigerant or through a secondary
heat-transfer fluid, heat exchanger
and circulating pump, " says
Marna Schmidt, industry manager of
industrial cryogenics, with Air Products
(Allentown, Pa.).
The benefit here, she says, is the
LIST DRY PROCESSING saves
resources, energy, time and money.
Switch to a new, truly innovative
approach to running your process in
the concentrated phase. Get ready.
Lower operating costs
Less solvents
Environmentally friendly
Visit us at
K 2010
October 27 - Novemver 3
in Düsseldorf, Germany
Booth 9C24
www.list.ch | www.list.us | www.list.sg
Circle 12 on p. 62 or go to adlinks.che.com/29251-12
ChemiCal engineering www.Che.Com June 2010 19
Unique
www.loeweloewe.com

http://www.loeweloewe.com http://www.list.ch http://www.list.us http://www.list.sg http://adlinks.che.com/29251-12 http://www.Che.Com

Chemical Engineering June 2010

Table of Contents for the Digital Edition of Chemical Engineering June 2010