Chemical Engineering May 2013 - 6

Letters
Lessons learned
Your Editor's Page in today's Chemical Engineering
[March 2013, p.5] intrigued me because I too served
as a TA in a physical chemistry lab but long before
1980 and we did not have the luxury of a Fouriertransform
infrared spectrometer. But you certainly
have the experience to comment on the following:
The earth, according to Weil's law at an average temperature
of 15°C, radiates heat at 10 µm, which Planck
teaches is a 3-30 µm band centered around 10 µm. The
principal CO2 absorption bands are at 14.99 and 4.26 µm.
But spectroscopic studies indicate that atmospheric
transmittance of infrared radiation is about 80% from 8
to 12 µm. That is the so called " longwave window " where
the earth is said to vent off excess energy.
It appears that the importance of CO2 as a greenhouse
gas may be overstated. . .
Gerald McDonald
SEE US AT MD&M BOOTH #3132
Circle 18 on p. 72 or go to adlinks.che.com/45772-18
Turn Pipe Dreams
Into Hard Facts.
ABRESIST®
wear resistant basalt
linings help reduce costly
main te nance repairs and
pro duc tion downtime.
Doc u ment ed cas es show
Abresist linings perform at
optimum levels more than
25-30 years af ter in stal la tion.
Abresist Kalenborn offers 75
years of experience and:
■ other protective
linings include
alumina and
zirconium corundum
■ linings custom
designed for any
industrial application
■ field survey service
■ installation assistance
KALOCER®
-
alumina for extreme abrasion.
In your article in the March issue, you indicated that
both CO2 and water vapor have similar IR absorption
bands. I am curious, as perhaps are other readers, as
to their relative percentages of the atmosphere. Since
their IR absorptions are similar, would their percentage
numbers be a factor in their contribution to any
warming effect? Thanks for any insight you can shed
on this.
Rick Smith, P.E.
Applied Thermal Engineering, Inc.
Your Editor's Page piece in the March 2013 magazine
was / is good. If I were your editor, I would have
moved the last two paragraphs to the top, thus leading
with " Words like 'myth', 'hoax' . . . " . I see this as
grabbing the reader more effectively. Indeed, we need
all the " grab " we can get on a critical issue like this.
Nicholas Sheble
Engineering writer / Technical editor
KALCOR®
-
zirconium
corundum for
applications
up to 1830°F.
Highly resistant to sliding
abrasion, ABRESIST®
improves material flow,
and eliminates periodic
pipe rotation.
Editor's response:
A good article that addresses queries of the first two
letters is " Infrared radiation and planetary temperature, "
Raymond T. Pierrehumbert, Physics Today, January
2011, pp. 33-38. This author points out that CO2
accounts for about a third of the greenhouse gas effect.
The Wear Protection People
Abresist Kalenborn Corporation
5541 North State Road 13, Urbana, IN 46990
Toll Free: 800-348-0717 * Fax: 888-348-0717
www.abresist.com * E-mail: info@abresist.com
Postscripts, corrections
April, Nano-engineering infuses growing coatings
market, on pp. 17-22, requires a clarification. On
page 22, the article discusses the liquid repellent
coating from Ultratech International Inc. The highly
textured coating reduces the surface energy such that
liquids are prevented from wetting the surface. Liquids
are not actually prevented from contacting the
surface, as the article states.
April, in Focus on Seals & Gaskets, on p. 30, the correct
company name and location for the second item
is A.W. Chesterton Co., Woburn, Mass. Revised versions
of both articles can be found at www.che.com.
Circle 4 on p. 72 or go to adlinks.che.com/45772-4
6 ChemiCal engineering www.Che.Com may 2013
kalenborn
http://adlinks.che.com/45772-18 http://www.abresist.com http://www.che.com http://adlinks.che.com/45772-4 http://www.Che.Com
Chemical Engineering May 2013

Table of Contents for the Digital Edition of Chemical Engineering May 2013
