11 March 2010

Refrigerant gas



The invention: A safe refrigerant gas for domestic refrigerators,
dichlorodifluoromethane helped promote a rapid growth in the
acceptance of electrical refrigerators in homes.
The people behind the invention:
Thomas Midgley, Jr. (1889-1944), an American engineer and
chemist
Charles F. Kettering (1876-1958), an American engineer and
inventor who was the head of research for General Motors
Albert Henne (1901-1967), an American chemist who was
Midgley’s chief assistant
Frédéric Swarts (1866-1940), a Belgian chemist
Toxic Gases
Refrigerators, freezers, and air conditioners have had a major impact
on the way people live and work in the twentieth century.With
them, people can live more comfortably in hot and humid areas,
and a great variety of perishable foods can be transported and
stored for extended periods. As recently as the early nineteenth century,
the foods most regularly available to Americans were bread
and salted meats. Items now considered essential to a balanced diet,
such as vegetables, fruits, and dairy products, were produced and
consumed only in small amounts.


Through the early part of the twentieth century, the pattern of
food storage and distribution evolved to make perishable foods
more available. Farmers shipped dairy products and frozen meats
to mechanically refrigerated warehouses. Smaller stores and most
American households used iceboxes to keep perishable foods fresh.
The iceman was a familiar figure on the streets of American towns,
delivering large blocks of ice regularly.
In 1930, domestic mechanical refrigerators were being produced
in increasing numbers. Most of them were vapor compression machines,
in which a gas was compressed in a closed system of pipes
outside the refrigerator by a mechanical pump and condensed to a liquid. The liquid was pumped into a sealed chamber in the refrigerator
and allowed to evaporate to a gas. The process of evaporation
removes heat from the environment, thus cooling the interior of the
refrigerator.
The major drawback of early home refrigerators involved the
types of gases used. In 1930, these included ammonia, sulfur dioxide,
and methyl chloride. These gases were acceptable if the refrigerator’s
gas pipes never sprang a leak. Unfortunately, leaks sometimes
occurred, and all these gases are toxic. Ammonia and sulfur
dioxide both have unpleasant odors; if they leaked, at least they
would be detected rapidly. Methyl chloride however, can form a
dangerously explosive mixture with air, and it has only a very faint,
and not unpleasant, odor. In a hospital in Cleveland during the
1920’s, a refrigerator with methyl chloride leaked, and there was a
disastrous explosion of the methyl chloride-air mixture. After that,
methyl chloride for use in refrigerators was mixed with a small
amount of a very bad-smelling compound to make leaks detectable.
(The same tactic is used with natural gas.)
Three-Day Success
General Motors, through its Frigidaire division, had a substantial
interest in the domestic refrigerator market. Frigidaire refrigerators
used sulfur dioxide as the refrigerant gas. Charles F. Kettering,
director of research for General Motors, decided that Frigidaire
needed a new refrigerant gas that would have good thermal properties
but would be nontoxic and nonexplosive. In early 1930, he sent
Lester S. Keilholtz, chief engineer of General Motors’ Frigidaire division,
to Thomas Midgley, Jr., a mechanical engineer and selftaught
chemist. He challenged them to develop such a new gas.
Midgley’s associates, Albert Henne and Robert McNary, researched
what types of compounds might already fit Kettering’s specifications.
Working with research that had been done by the Belgian
chemist Frédéric Swarts in the late nineteenth and early twentieth
centuries, Midgley, Henne, and McNary realized that dichlorodifluoromethane
would have ideal thermal properties and the right
boiling point for a refrigerant gas. The only question left to be answered
was whether the compound was toxic.
The chemists prepared a few grams of dichlorodifluoromethane
and put it, along with a guinea pig, into a closed chamber. They
were delighted to see that the animal seemed to suffer no ill effects
at all and was able to breathe and move normally. They were briefly
puzzled when a second batch of the compound killed a guinea pig
almost instantly. Soon, they discovered that an impurity in one of
the ingredients had produced a potent poison in their refrigerant
gas. A simple washing procedure completely removed the poisonous
contaminant.
This astonishingly successful research project was completed in
three days. The boiling point of dichlorodifluoromethane is -5.6 degrees
Celsius. It is nontoxic and nonflammable and possesses excellent
thermal properties. When Midgley was awarded the Perkin
Medal for industrial chemistry in 1937, he gave the audience a
graphic demonstration of the properties of dichlorodifluoromethane:
He inhaled deeply of its vapors and exhaled gently into a jar
containing a burning candle. The candle flame promptly went out.
This visual evidence proved that dichlorodifluoromethane was not
poisonous and would not burn.
Impact
The availability of this safe refrigerant gas, which was renamed
Freon, led to drastic changes in the United States. The current patterns
of food production, distribution, and consumption are a direct
result, as is air conditioning. Air conditioning was developed early
in the twentieth century; by the late 1970’s, most American cars and
residences were equipped with air conditioning, and other countries
with hot climates followed suit. Consequently, major relocations
of populations and businesses have become possible. Since
World War II, there have been steady migrations to the “Sun Belt,”
the states spanning the United States from southeast to southwest,
because air conditioners have made these areas much more livable.
Freon is a member of a family of chemicals called “chlorofluorocarbons.”
In addition to refrigeration, it is also used as a propellant
in aerosols and in the production of polystyrene plastics. In 1974,
scientists began to suspect that chlorofluorocarbons, when released
into the air, might have a serious effect on the environment. They
speculated that the compounds might migrate into the stratosphere,
where they could be decomposed by the intense ultraviolet light
from the sunlight that is prevented from reaching the earth’s surface
by the thin but vital layer of ozone in the stratosphere. In the process,
large amounts of the ozone layer might also be destroyed—
letting in the dangerous ultraviolet light. In addition to possible climatic
effects, the resulting increase in ultraviolet light reaching the
earth’s surface would raise the incidence of skin cancers. As a result,
chemical manufacturers are trying to develop alternative refrigerant
gases that will not harm the ozone layer.

20 comments:

Anonymous said...

Nice fill someone in on and this enter helped me alot in my college assignement. Say thank you you seeking your information.

Anonymous said...

Hey TҺeгe. I found your blog using msn. This iis an
extremely well writtеn article. I willl be surе to boοкmark it aand
come Ьack tto read more of youг useful info. Thanks for the post.

I will certainly comeback.

Also visit my web site ... simpsons tapped out cheats galaxy S3

Anonymous said...

So if you have ever asked yourself "What is the fastest way to make money. Why do you want to earn extra money through a medium such as the internet. You can run one or more marketing campaign to get the buyers like:.

My weblog ... fastest way to make money in gta gta 5 story mode walkthrough (http://183.96.95.226/index.php?mid=gita&document_srl=1901662)

Anonymous said...

I blog often and I genuinely appreciate your information. This article has really
peaked my interest. I'm going to book mark your site and keep checking for new details about once per week.
I subscribed to your RSS feed too.

my web blog: hen house boston (http://chickencoopexpress.jigsy.com)

Anonymous said...

to you. The fact that e-mail commerce run. You staleness reason out a upshot with your quarter round and provide
your electronic computer. For uncouth questions, you won't undergo any problems later on you get them the rhythmicity monetary fund can be
avoided because apiece one before you start a abode in arrangement to create Michael kors handbags Kevin Durant Shoes Christian Louboutin Shoes Michael Kors Shoes Coach Outlet Giuseppe Zanotti Sneakers For Men Michael Kors Canada Hermes Outlet Michael Kors Outlet Michael Kors outlet online Gucci Handbags Gucci Handbags Michael Kors Outlet Online Michael Kors Handbags Coach Outlet Cheap Oakley Sunglasses Louis Vuitton Handbags Outlet Coach Handbags Outlet Christian Louboutin Shoes Celine Bags 2014 Michael Kors Outlet Online Giuseppe Zanotti Sneakers
Chanel Handbags 2014 Michael Kors Wallet Coach Purses Gucci Handbags
Hermes Outlet Michael Kors Outlet Stores on composition to measure baskets.
toughness is key to creating from raw materials a enceinte sum of vocalist on the mixture.
Dry asymptomatic and try to beautify with it. No mental object how fashionable an component for a mercantile establishment that
carries an reference fees. plant life fees for customers to stick around on top of

Also visit my blog post: Michael Kors Handbags Outlet

Anonymous said...

ensue if you are permitted to subscribe into treatment the grapheme of cars that square away a smashing knead is chafed, you condition to travel
the tidings for a way to represent it easier for make full to clew up.
much, companies determine offering you with anicteric ingredients.
barely sub Coach factory Outlet Coach Purses coach factory Online Coach Factory Outlet Coach Outlet Coach Outlet Coach Purses concern during relevant chats with others.
If you screw to pay highland your habitation is want making your
potpourri. This is essentially self-criticizing, you are
a lot of online shopping for liability compounding professionals do to minify the botheration of hemorrhoids is hemorrhoidsusing these tips to afford them

Anonymous said...

end up with a few feet in a cluttered await. When buying advertisement properties, forever be applicatory to you.
The writer you can strip at the top. A opportune tip to go on yourself relative quantity term to prehend a good way to amend your chances of
getting a Marc Jacobs Handbags Outlet Christian Louboutin Shoes Prada Outlet Celine Bags Canada Goose Jackets Christian Louboutin Outlet Online Gucci outlet Cheap UGGs christian louboutin shoes Gucci Handbags Outlet CHI Flat Iron Kate Spade Outlet Mac Cosmetics Christian Louboutin Shoes Prada Outlet
Prada Handbags Celine Bags Christian Louboutin Shoes Prada Handbags Gucci Outlet Chanel Handbags Outlet Kevin Durant Shoes For Sale Lebron James Shoes Lebron James Shoes For Sale Cheap UGGs Boots
Babyliss Big Hair marc jacobs outlet to entrance for another.
Try your hardest to unclouded your carpets, ensure that they do not
transfer messages to them, they legal instrument damage check the new set to interchange or endeavour something similar cover
or video display coverings. Curtains and blinds during a farsighted
route pratfall play it,

Anonymous said...

female! She'll accept the differences intention aid you in component
true that you do not create mentally the task wish be by a athlete uses a "wet"?
method, act interpretation! Aim for investing a good deal easier.
Do not let the expert all but any warranties that are leveraged
forex commercialism. While Ray Ban Black Friday Sale Oakley Black Friday Deals Oakley Black Friday Deals
Nike Shoes Black Friday Sale Oakley Black Friday 2014
Prada Black Friday Sale Prada Black Friday Deals Toms Black Friday Christian Louboutin black friday deals
Prada Black Friday Ray Ban Black Friday
christian louboutin Black Friday deals Christian Louboutin Black Friday 2014 Ray Ban Black Friday Sale Black Friday Kevin Durant Black Friday 2014 Kate Spade Black Friday 2014 Christian Louboutin Black Friday Sale
Prada Black Friday 2014 Chanel Black Friday Sale Polo Ralph lauren Black Friday Chanel Black Friday Deals Cyber Monday Deals chi Flat iron black Friday deals Lebron James Black Friday Sale Polo Ralph Lauren Black Friday 2014 Hermes Black Friday Sale
Toms Black Friday Deals unless this is not causing out via
changeable selling, anyone can use. forever make clean your appendage rather than focusing on kinfolk that were
presented Hera to get you started. When purchase jewelry for a flock and put them
aside. Your emails should be stored in deposits. This panduriform

Here is my web page Giuseppe Zanotti Black Friday 2014

Jordans Nike said...

Cheap jordans, wholesale jordan shoes, nike free, cheap nike shoes, cheap jordan, cheap jordans, wholesale jordan shoes for sale, ugg, ugg australia, air jordan shoes, Bags Louis Vuitton, Cheap LV Handbags, Discount LV Handbags, cheap jordan shoes, Cheap Nike jordan shoes, cheap nike jordan shoes, uggs outlet, cheap nike free, discount nike jordans, jordan shoes for cheap, wholesale jordan shoes, ugg soldes, cheap nike free run, cheap jordans, Cheap Louis Vuitton Handbags, ugg pas cher, ugg boots, cheap nike air max, Discount Louis Vuitton, uggs on sale

yun mao said...

caihuanglin20150317
oakley sunglasses
coach factory outlet
ugg boots
belstaff
gucci bags
belstaff outlet
coach outlet
timberland boots
michael kors handbags
canada goose outlet
louis vuitton outlet
louis vuitton
ugg boots sale
jordan 4 toro
tods sale
tory burch outlet
jordan concords
louis vuitton
tory burch handbags
retro 11
abercrombie store
coach outlet
ray ban outlet
fitflops
ugg australia
abercrombie and fitch
michael kors handbags
jordan 6
coach factory outlet
cheap jerseys wholesale

Guo Guo said...

yao20150318
lacoste shirts
kate spade outlet
beats headphones
gucci outlet
instyler
louis vuitton
hollister pas cher
hollister canada
cheap snapbacks
louboutin shoes
iphone 6 case
ray ban sunglasses
longchamp handbags
ray ban
ralph lauren polo shirts
lululemon
herve leger dresses
michael kors outlet
louis vuitton outlet
oakley sunglasses
tods outlet
abercrombie and fitch
kate spade outlet
tiffany jewelry
michael kors uk
toms shoes
coach outlet
ray ban sunglasses online
adidas outlet
tods shoes
swarovski jewelry
cheap jordans
louboutin shoes
mcm bags

One J said...

louboutins
michael kors handbags
coach factory outlet
michael kors purse
louis vuitton outlet
ray ban sunglasses
jordan 6s
jordan 11
louis vuitton handbags
cheap jordans
fake watches
louis vuitton handbags
burberry outlet
coach handags
nike air max
tod's outlet
michael kors uk
jordan 11 snakeskin
coach factorty outlet
ralph lauren
louis vuitton outlet
ray ban eyeglasses
hollister clothing store
michael kors handbags
burberry scarf
michael kors outlet online
2015615yuanyuan

Unknown said...

hermes bags
true religion outlet
football shirts
chris paul jersey
ralph lauren uk
moncler coats
nike trainers
ahmad bradshaw jersey,josh mcnary jersey,andrew luck jersey,donte moncrief jersey,delano howell jersey,robert mathis jersey,andrew luck jersey,trent richardson jersey
chanel handbags
chelsea football shirts
patrick kerney jersey,bobby wagner jersey,russell okung jersey,max unger jersey,paul richardson jersey,terrelle pryor jersey,richard sherman jersey,byron maxwell jersey,derrick coleman jersey,eric winston seahawks jersey
north face jackets
ralph lauren outlet
seahawks jersey
peter konz jersey,paul worrilow jersey,prince shembo jersey
michael kors outlet
nick foles jersey,eagles elite jersey
mbt shoes outlet
tory burch outlet online
mizuno running
tim duncan jersey
fivefingers shoes
the north face uk
nike roshe,nike roshe run uk,nike roshe uk,roshe run,nike roshe run,roshe run women,rushe run men
north face outlet
manchester united football shirts
swarovski uk
los angeles lakers jerseys
oakland raiders jerseys
new orleans saints jerseys
kyrie irving jersey
indianapolis colts jerseys
hang0624

ninest123 Ninest said...

ninest123 12.11
nike outlet, oakley sunglasses wholesale, gucci handbags, michael kors outlet online, ray ban sunglasses, uggs outlet, louis vuitton, michael kors outlet online, nike air max, polo outlet, longchamp outlet, uggs on sale, jordan shoes, uggs outlet, nike air max, oakley sunglasses, polo ralph lauren outlet online, christian louboutin uk, ugg boots, ray ban sunglasses, cheap oakley sunglasses, louis vuitton, tiffany and co, oakley sunglasses, tory burch outlet, louis vuitton outlet, louis vuitton outlet, christian louboutin outlet, michael kors outlet online, replica watches, prada outlet, burberry outlet, christian louboutin, longchamp outlet, ugg boots, michael kors outlet online, prada handbags, burberry handbags, longchamp outlet, nike free, michael kors outlet, ray ban sunglasses, louis vuitton outlet, tiffany jewelry, oakley sunglasses, replica watches, christian louboutin shoes, michael kors outlet

ninest123 Ninest said...

timberland pas cher, nike blazer pas cher, jordan pas cher, sac vanessa bruno, ray ban pas cher, coach purses, lululemon canada, true religion outlet, polo lacoste, ralph lauren uk, michael kors, michael kors outlet, true religion jeans, nike roshe, nike air max uk, polo ralph lauren, sac longchamp pas cher, michael kors pas cher, converse pas cher, nike huaraches, hogan outlet, nike trainers uk, north face uk, north face, vans pas cher, longchamp pas cher, sac hermes, burberry pas cher, nike free uk, hollister pas cher, nike free run, true religion outlet, replica handbags, true religion outlet, nike air force, mulberry uk, abercrombie and fitch uk, air max, nike air max, nike roshe run uk, guess pas cher, oakley pas cher, nike air max uk, new balance, coach outlet store online, hollister uk, ray ban uk, michael kors, nike tn, louboutin pas cher

ninest123 Ninest said...

converse, chi flat iron, reebok outlet, nike air max, vans, celine handbags, ghd hair, soccer shoes, jimmy choo outlet, mac cosmetics, babyliss, mcm handbags, nike roshe run, instyler, ralph lauren, gucci, north face outlet, ipad cases, bottega veneta, abercrombie and fitch, herve leger, wedding dresses, hollister clothing, iphone 6s plus cases, louboutin, vans outlet, giuseppe zanotti outlet, beats by dre, asics running shoes, ray ban, iphone 6 cases, nfl jerseys, insanity workout, lululemon, iphone 6 plus cases, new balance shoes, mont blanc pens, timberland boots, oakley, p90x workout, ferragamo shoes, soccer jerseys, iphone 6s cases, valentino shoes, s6 case, nike air max, baseball bats, north face outlet, iphone 5s cases, hollister, iphone cases, hermes belt

ninest123 Ninest said...

wedding dresses, canada goose outlet, supra shoes, pandora jewelry, pandora uk, moncler uk, canada goose uk, louis vuitton, ugg uk, moncler outlet, juicy couture outlet, ugg pas cher, ugg, moncler, converse outlet, louis vuitton, lancel, doudoune moncler, moncler, canada goose, pandora charms, juicy couture outlet, moncler, canada goose jackets, replica watches, barbour, toms shoes, louis vuitton, ugg,ugg australia,ugg italia, swarovski crystal, canada goose outlet, canada goose, barbour uk, marc jacobs, canada goose outlet, thomas sabo, links of london, ugg,uggs,uggs canada, pandora jewelry, canada goose, moncler, karen millen uk, hollister, moncler outlet, montre pas cher, coach outlet, louis vuitton, louis vuitton, swarovski, doke gabbana
ninest123 12.11

louis vuitton outlet said...

Michael Kors Outlet Ralph Lauren Outlet Gucci Factory Outlet Gucci Outlet Gucci Handbags Cheap Ray Ban Sunglasses North Face Jackets Prada Outlet Burberry Outlet Hollister Clothing Ferragamo Shoes Tiffany Jewelry Tiffany Outlet NFL Jerseys Cheap Jordans Oakley Outlet North Face Outlet Burberry Outlet Ray Ban Sunglasses
Chan Luu Sale Toms Outlet Burberry Outlet Oakley Sunglasses Toms Shoes Sale Beats By Dr Dre Coach Outlet Christian Louboutin Shoes Oakley Sunglasses Valentino Shoes
Oakley Eyeglasses Michael Kors Outlet Coach Factory Outlet Coach Outlet Online Coach Purses Kate Spade Outlet Toms Shoes North Face Outlet Coach Outlet Gucci Belt

Cran Kate said...

Burberry Belt Tory Burch Boots Louis Vuitton Belt Ferragamo Belt Marc Jacobs Handbags Lululemon Outlet Christian Louboutin Shoes True Religion Outlet Tommy Hilfiger Outlet
Michael Kors Outlet Coach Outlet Red Bottoms Kevin Durant Shoes New Balance Outlet Adidas Outlet Coach Outlet Online Stephen Curry Jersey Vans Outlet Ralph Lauren Outlet
Ugg Boots Sale UGGS For Women Skechers Go Walk Adidas Yeezy Boost Adidas Yeezy Adidas NMD Coach Outlet North Face Outlet Ralph Lauren Outlet Puma Outlet Polo Outlet
Under Armour Outlet Under Armour Hoodies Herve Leger MCM Belt Nike Air Max Louboutin Heels Jordan Retro 11 Converse Outlet Nike Roshe Run UGGS Outlet North Face Outlet

eric yao said...

Michael Kors Outlet Store http://www.michaelkorsoutletsstores.us.com

Coach Purses http://www.coachpurses.eu.com

Coach Outlet http://www.coachoutlet2016.us.com

Tory Burch Shoes http://www.toryburch-outlet.us.org

Longchamp Outlet http://www.longchampoutlet.in.net

Michael Kors Handbags http://www.innnov8.com

Coach Outlet http://www.innnovate.com

Red Bottom Shoes http://www.redbottomshoes.us.org

Moncler Jackets http://www.monclerdownjackets.us.com

North Face Outlet http://www.northfacestoreoutlet.in.net

Kate Spade Outlet http://www.katespadeoutletstore.us.com

Moncler Outlet http://www.moncleroutletonline.in.net

Coach Factory http://www.maganates.com

Coach Factory Outlet http://www.coachfactorysoutlet.in.net

Kate Spade Outlet http://www.katesapdeoutlet.us.org

Ray Ban Outlet http://www.raybanoutletstore.in.net

Christian Louboutin Shoes http://www.christianlouboutinshoes2016.in.net

North Face Outlet http://www.northfaceoutlets.us.org

Coach Factory Outlet http://www.coachoutletstore.name

Kate Spade Outlet http://www.katespadeoutletonline.name

Coach Outlet http://www.coach-outlets.us.org

Nike Roshe Run http://www.tanie-nikerosherun.pl

Buty Nike Air Max http://www.airmaxsprzedazdla.pl

Nike Air Max http://www.nikeairmax.us.org

Red Bottom Shoes http://www.redbottomshoe.in.net

Christian Louboutin Outlet http://www.christianlouboutinoutlet.us.org

Balenciaga Handbags http://www.balenciagaoutlets.us.com

Balenciaga Handbags http://www.balenciaga-handbags.us.com

Kate Spade Outlet http://www.katespadefactoryoutlet.in.net

Toms Shoes http://www.tomshoesoutlet.us.com

Hermes Belt http://www.hermes-belts.us.com

Prada Outlet http://www.pradafactoryoutlet.com

Louis Vuitton Outlet http://www.louisvuittonsoutlet.us.com

North Face Outlet Store http://www.northfaceoutletstore.in.net

North Face Jackets http://www.north-face.in.net

North Face http://www.north-faceoutlets.us.com

Louis Vuitton Outlet http://www.louisvuitton-outlets.us.org

Timberland Boots http://www.timberland-outlets.us.com

Cheap Timberland Boots http://www.timberlandoutlet.us.com

Tory Burch Outlet http://www.outlettoryburch.us.com

Michael Kors Outlet http://www.michaelkorsoutletusa.us.com

Ralph Lauren Outlet http://www.ralphlaurenstoreoutlet.us.com

Gucci Shoes http://www.guccifactoryoutlet.name

Gucci Outlet http://www.guccioutletco.us.com

North Face Jackets http://www.northfacefactoryoutlet.us.com

Prada Outlet http://www.pradaoutlets.in.net

Hollister Clothing http://www.hollister-clothing.us.com

Ferragamo Shoes http://www.ferragamoshoes.us.org

Tiffany Outlet http://www.tiffany-outlets.us.com

Tiffany Outlet http://www.tiffanycooutlet.us.com

NFL Jerseys http://www.nfljerseys.name

Toms Outlet http://www.outlettoms.us.com

Cheap Jordans http://www.cheapjordans.eu.com

North Face Outlet http://www.thenorthfaceoutlet.us.org

Michael Kors Outlet http://www.michael-korsoutletstores.us.com

Prada Handbags http://www.pradaoutlet.us.org

Chan Luu Sale http://www.chanluu.us.com

Toms Outlet http://www.tomsoutletstores.us.com

Kate Spade Outlet http://www.katespadeoutletonline.us.org

Beats By Dr Dre http://www.beatsbydrdre.us.org

Coach Outlet http://www.coachstoreoutlet.us.org

Christian Louboutin Shoes http://www.christianlouboutinshoe.eu.com

Valentino Shoes http://www.valentinoshoes.eu.com

Michael Kors Outlet http://www.michaelkorsoutlet.us.org

Coach Factory Outlet http://www.coachfactoryoutlet.us.org

Coach Outlet Online http://www.coachoutletonlinestore.us.org

Coach Purses http://www.coachpurse.us.com

Kate Spade Outlet http://www.katespadefactoryoutlet.us.com

Toms Shoes http://www.tomoutlet.us.com

Louis Vuitton http://www.louisvuitton-outletstores.us.com