Cooling with steam

[Jim Baber]

I have heard or read of a means of refrigeration that uses steam
directed thru a venturi to directly cool with the reduction of pressure
at the venturi. It sounds feasible, but I can't recall where I read
about the concept.

Has anyone out in the newsgroup any knowledge of this. I seem to recall
this principal was used to make ice before electrical refrigeration came
into the forefront. It seems to me that steam created in the cooling of
the high temperature solar PV cells in solar concentrators could
actually be used to refrigerate an house or building directly from the
surplus heat that is typically dissipated with the water cooling
commonly used in this style of concentrator. This would increase the
efficiency of these concentrator style devices as far as useful work,
but would it not create more electricity. But, considering that the
temperature here at my house has exceeded 100 degrees for 31 days since
June 14th any cooling would be appreciated.

Just an idea, any comebacks?

 

[Dale Farmer]

I have heard or read of a means of refrigeration that uses steam
directed thru a venturi to directly cool with the reduction of pressure
at the venturi. It sounds feasible, but I can't recall where I read
about the concept.

Only two times have I ever read about cooling with steam. The
first was in fighting fires aboard ships, where you put the fire out by
sealing the space and flooding it with steam. The other was in a
steel mill where the rollers carrying the white hot steel slabs from
the slab caster were cooled by steam piped through them.

--Dale

 

[John W. Hall]

I have heard or read of a means of refrigeration that uses steam
directed thru a venturi to directly cool with the reduction of pressure
at the venturi. It sounds feasible, but I can't recall where I read
about the concept.

Are you perhaps thinking of the Hilsch Vortex Tube?

This is a T-junction with a helical chamber at the joint and an
annulus (i.e. the hole in a washer). Blow compressed air in the 'leg'
of the 'T', cold air exits through the side with the annulus, hot air
through the other side.

http://www.exair.com/vortextube/vt_page.htm?source=google&group=vortextube
http://www.visi.com/~darus/hilsch/

 

[Gordon Reeder]

I have heard or read of a means of refrigeration that uses steam
directed thru a venturi to directly cool with the reduction of pressure
at the venturi. It sounds feasible, but I can't recall where I read
about the concept.

Has anyone out in the newsgroup any knowledge of this. I seem to recall
this principal was used to make ice before electrical refrigeration came
into the forefront. It seems to me that steam created in the cooling of
the high temperature solar PV cells in solar concentrators could
actually be used to refrigerate an house or building directly from the
surplus heat that is typically dissipated with the water cooling
commonly used in this style of concentrator. This would increase the
efficiency of these concentrator style devices as far as useful work,
but would it not create more electricity. But, considering that the
temperature here at my house has exceeded 100 degrees for 31 days since
June 14th any cooling would be appreciated.

Just an idea, any comebacks?

Over on the misc.transport.rail.americas group we just had
a disscussion about this. The AT&SF railroad used steam
opperated A/C for cooling passenger cars. I can't remember
the details of how it opperated. But, I recall steam was injected
via a steam injector, which created a low pressure at the
injector point. The chamber beyond the injector widened to
enhance the vacuume. The low pressure condensed the steam
and cooled the chamber.

A google of steam injector A/C or simular will bring a
much better description.

--
Just my $0.02 worth. Hope it helps
Gordon Reeder
greeder
at: myself.com

Hey EVERYBODY!
Unity means let's try to meet each other halfway

 

[[email protected]]

Newsgroups: alt.energy.homepower

Are you perhaps thinking of the Hilsch Vortex Tube?
This is a T-junction with a helical chamber at the joint and an
annulus (i.e. the hole in a washer). Blow compressed air in the
'leg' of the 'T', cold air exits through the side with the annulus,
hot air through the other side.
http://www.exair.com/vortextube/vt_page.
htm?source=google&group=vortextube http://www.visi.
com/~darus/hilsch/

In the '50's, American Instrument Co., Silver Spring, MD, built a
device for measuring the freezing-point depression of an aqueous
solution, using a small, compressed-air powered vortex chamber for
the cooler.




Tom Willmon
near Mountainair, (mid) New Mexico, USA

Net-Tamer V 1.12.0 - Registered

 

[Derek Broughton]

Absorption refrigerator. I have a "Consul". It better work, coz' I don't
have any electricity to cool it with

 

[daestrom]

I have heard or read of a means of refrigeration that uses steam
directed thru a venturi to directly cool with the reduction of pressure
at the venturi. It sounds feasible, but I can't recall where I read
about the concept.

Has anyone out in the newsgroup any knowledge of this. I seem to recall
this principal was used to make ice before electrical refrigeration came
into the forefront. It seems to me that steam created in the cooling of
the high temperature solar PV cells in solar concentrators could
actually be used to refrigerate an house or building directly from the
surplus heat that is typically dissipated with the water cooling
commonly used in this style of concentrator. This would increase the
efficiency of these concentrator style devices as far as useful work,
but would it not create more electricity. But, considering that the
temperature here at my house has exceeded 100 degrees for 31 days since
June 14th any cooling would be appreciated.

I've seen two types in my travels.

One, is a Lithium-Bromide Absorption chiller. Using a complex cycle with
Lithium-Bromide, it is able to achieve such a low vacum that water 'boils'
at around 38F. In order to regenerate the Lithium-Bromide solution, it has
to be heated to around 220-240F and the units I worked with used
low-pressure steam. Always thought it would be interesting to try and run
one from a solar-collector ;-) These are similar to the ammonia-hydrogen
absorption cycle used in some propane refrigerators, but on a larger scale.
These units are often used in large office buildings and can range from 80
to 250 ton.

The other type used several steam-jet ejectors in parallel to draw a vacumn
on a tank of water. This 'boiled' the water until it cooled to about 40F.
This water was circulated through the building. For a steam-jet ejector to
work, the ratio of inlet pressure to throat pressure has be higher than a
critical ratio (about 56%), and the outlet nozzle has to be a
'convergent-divergent' design. It first narrows, and then widens. The
result is the suction can be a near perfect vacumn (okay, only gets down to
about 28 inhg) while the outlet is at atmospheric pressure. The discharge
is directed towards an atmospheric condenser to condense the steam. This
style A/C isn't particularly efficient, it takes a *lot* of steam to drive
them, and the steam needs to be upwards of 120-170 psig. They also require
a lot of cooling water if you're going to condense the steam for re-use as
feed into the boiler. But it is reliable, small, and has few moving parts.

daestrom

 

[EXT]

I used to work for a local gas utility that sold gas powered refrigerators.
They also had an auditorium that was cooled in summer by steam from a
central boiler.

 

[Phil]

I have heard or read of a means of refrigeration that uses steam
directed thru a venturi to directly cool with the reduction of pressure
at the venturi. It sounds feasible, but I can't recall where I read

Way back around 1976 or 77 there was an article in Popular science that
used a venture effect to cool air , it used high pressure air though , not
steam. The article suggested using it to cool the air in Hazmat type suits
or something .

Phil

 

[Arnold Walker]

Way back around 1976 or 77 there was an article in Popular science that
used a venture effect to cool air , it used high pressure air though , not
steam. The article suggested using it to cool the air in Hazmat type suits
or something .

Phil

You can look at a company like Fox Valves (one of the eductor manufacturers)
and find that they work with gas(air),steam,and liquid.
And that there are low pressure versions also ,since many processing plants
like Campbell Soup will use medium pressure steam to run the steam kettles.
And the waste steam to drive the vaccuum eductor.Chilling the soup before it
spoils.(The soup itself is put in a vaccuum and flash cooled at
2000gallon/hr rate-- soup processed not the steam rate).

The cooling coil on what you are talking about is where the vaccum is and an
expansion valve is controling how low of a vaccuum.opening and closing as
needed.(boil rate in other words)
At 15in.....water boils at room temp........29in water boils at -60.

 

[Herb]

Way back around 1976 or 77 there was an article in Popular science
that used a venture effect to cool air , it used high pressure air
though , not steam. The article suggested using it to cool the air in
Hazmat type suits or something .
Phil

Sounds like you're talking about an "air fed oven suit" or steam
suit, least that's what I'm familiar with. Used 100 psig air to keep
the guy inside cool and breathing while in an extremely hot or steam
filled atmosphere.

Herb

 

[daestrom]

Sounds like you're talking about an "air fed oven suit" or steam
suit, least that's what I'm familiar with. Used 100 psig air to keep
the guy inside cool and breathing while in an extremely hot or steam
filled atmosphere.

I remember those. LMAO one time when the sailor getting into it tucked the
hot end of the vortex tube inside the suit pants. These things provide nice
cool air out one end, but the other end gets *HOT*.

daestrom

 

[daestrom]

You can look at a company like Fox Valves (one of the eductor
manufacturers)
and find that they work with gas(air),steam,and liquid.
And that there are low pressure versions also ,since many processing
plants
like Campbell Soup will use medium pressure steam to run the steam
kettles.
And the waste steam to drive the vaccuum eductor.Chilling the soup before
it
spoils.(The soup itself is put in a vaccuum and flash cooled at
2000gallon/hr rate-- soup processed not the steam rate).

The cooling coil on what you are talking about is where the vaccum is and
an
expansion valve is controling how low of a vaccuum.opening and closing as
needed.(boil rate in other words)
At 15in.....water boils at room temp........29in water boils at -60.

At 15 inhg vacuum, water boils at about 175F. Hardly 'room temp'. Draw the
vacuum down to 29 inhg and you get about 33F to 35F. Nowhere near your
'-60'.

Steam jet air ejectors, or any other form of 'ejector' need a compressible
fluid as the driving fluid. It passes through a convergent/divergent nozzle
so it can reach supersonic velocities as it entrains the suction vapor and
pushes it to the outlet nozzle (another convergent/divergent arrangement).
Ejectors are used to 'pump' compressible fluids such as air or water vapor.
Most commonly used to draw vacuum in power plant steam condensers. They
don't work very well at all with water driving them, nor in 'pumping' water.

Eductors use non-compressible fluid such as water. The inlet nozzle is
convergent with a straight outlet. Using water in a convergent/divergent
nozzle *reduces* the velocity of the driving fluid from that of a simple
convergent and thus reduces the effectiveness of the unit. After entraining
the suction fluid, eductors then pass it through a divergent nozzle to
convert the kinetic energy back to potential ('flow energy'). These are
sometimes used to draw water out of bilges on ships or tanks. Just need a
supply of pressurized water (often use fire main water).

Injectors use a compressible fluid (almost always steam) to move a
non-compressible fluid (such as water). The steam inlet nozzle is similar
to that of an ejector (convergent, then divergent to achieve supersonic
velocities in the steam), while the outlet nozzle is similar to an eductor
(strictly divergent). The steam entrains the water and imparts a lot of
kinetic energy, then is condensed in the mixture. The outlet nozzle
converts the kinetic energy of the non-compressible fluid to pressure.
These are what was used to inject feed-water into low pressure boilers using
some of the boiler steam. One application was railroad locomotives.

All three *look* similar at first, but the nozzle construction of each is
different. While one will sort of work in place of another, the
effectiveness will be less. A good steam jet air ejector can draw down to
about 23-25 inhg vacumn (about 4 psia). Any further drop in suction
pressure and it loses a lot in capacity. Steam plants typically use
two-stage units where the outlet of the first feeds the inlet to the second
(usually with an intermediate condenser to condense out the motive steam).

A vortex tube is a completely different animal. Compressed air (the ones
I've seen use about 100 psig) enters the tube near one end through a
tangential nozzle. The cover at one end of the tube has a hole in the
center, through which you get cooled air. The other end has a cover with
holes in the periphery, through which comes out hot air. By adjusting the
periphery ring hole size, you can regulate the amount of cold air that comes
out the other end.

daestrom