Aquaponics Digest - Thu 11/11/99
Message 1: Re: heating revisted
from "Barry Thomas"
Message 2: Re: Heating revisited.
from "Barry Thomas"
Message 3: Re: Unusual colored salad ingredients
from Adriana Gutierrez & Dennis LaGatta
Message 4: Blue veggies
from Peggy & Emmett
Message 5: Re: Blue veggies
from William Evans
Message 6: Re: heating revisted
from Marc & Marcy
Message 7: Re: Heating revisited.
from Marc & Marcy
Message 8: Re: Aquaponics again! (mostly)
from dreadlox@cwjamaica.com (michael kent barnett)
Message 9: Re: Aquaponics again! (mostly)
from dreadlox@cwjamaica.com (michael kent barnett)
Message 10: Re: Aquaponics again! (mostly)
from Marc & Marcy
Message 11: Re: Blue veggies
from Adriana Gutierrez & Dennis LaGatta
Message 12: Co-op seed order
from Adriana Gutierrez & Dennis LaGatta
Message 13: Re: Co-op seed order
from "TGTX"
Message 14: Re: heating revisted
from mmiller@pcsia.com
Message 15: Re: heating revisted
from "TGTX"
Message 16: Re: heating revisted
from Ronald Polka
Message 17: Re: heating revisted
from Marc & Marcy
Message 18: Re: solar salt ponds
from Carolyn Hoagland
Message 19: about solar ponds
from Carolyn Hoagland
Message 20: Re: Unusual colored salad ingredients
from MUDDTOO
Message 21: Re: heating revisted
from "Barry Thomas"
Message 22: Re: Aquaponics again! (mostly)
from "Sam Levy"
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| Message 1 |
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Subject: Re: heating revisted
From: "Barry Thomas"
Date: Thu, 11 Nov 1999 11:06:40 -0000
Hi John,
This seems to be a week for coincidences. I've been up all night reading
and one fact that I came across and was about to pass on was that brine
(25% by weight) has a specific heat capacity of 3.4. I thought this
might offer simply achieved performance gain for people using passive
heat sinks filled with water. Seems like it might be worth upping the
concentration still further but whether (in that situation) it would be
worth using just salt I don't know.
The kind of timescales I had in mind though were more around the
hours/days kind thing. What you're talking about is pretty happening
heat storage. :)
I suppose you could work out roughly how much salt would be required for
a given GH and it might turn out that it's not so much after all but
still boggling a bit at the general idea for the moment - maybe later.
:)
Certainly, as you say, worth some thought though.
Barry
barrythomas@crosswinds.net
PS Just done some quick (and possibly dodgy) scribbles and worked out
that - assuming an SHC for salt of 10.0 - if you had a 10 ton
salt-filled heat sink/source starting the winter at 130 F and ending it
at 30 F you should be able to liberate a theoretical 22 million BTUs
over that time period. Quite a lot of heat. This is, of course, assuming
perfect insulation and the lack of this is going to lose you quite a
lot - esp with the long timescale - and the higher the starting temp,
the greater the loss but still... that is quite a lot of heat. Depends
how long your winter is I suppose. Salt definately looks useful in
relation to heat storage though.
> This is just an idea that might be worth some thought. In the oil
field we
> used salt bath heaters to distill products. So why can't you dig a pit
and
> line it with something that would not let the salt leach into the
ground.
> Use solar panels to heat the salt all summer for use in the winter.
Salt
> holds 10 times tie energy as water. You could run a fire tube through
the
> bottom, ( make it a U-tube) enter on one end and exit an the same end.
You
> could fire it with gas, wood, or any combustible product. This is
after you
> have extracted all the energy out after a long winter. This is an idea
not
> a design.
> Best regards
> John Hays
>
> John Hays
> 1903 Pebble Hill Rd.
> Carlsbad, NM 88220
> 1-505-887-0102
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Subject: Re: Heating revisited.
From: "Barry Thomas"
Date: Thu, 11 Nov 1999 11:06:58 -0000
> Is there any reason why PVC tubes passed thru a compost
> heap cannot have holes (small? or large?) drilled through
> them in order to introduce additional circulation? Much like
> a drainage pipe. Heck, why not just introduce a drainage
> pipe now that I am voicing.
Sounds ok to me - pretty much what I had in mind in fact. I would like
to try adding a (pref variable output) blower though to force air
through the tubes and up through the heap. Although this would require
power input, two good reasons why it might be worth it. First is the
previously mentioned acceleration of composting due to better oxy
availability. Second is that with the addition of a couple of temp
sensors (long spike probes - easily repositioned after adding/removing
material) into the heap, the amount of air blown through can be varied
so that heap core temps are maintained at best level with excess heat
being carried to the top where it is removed for use or storage. You
might be able to recycle at least some of this air back through the
blower to cut down further on losses.
Still haven't found out how much of the "available" heat can be safely
removed - build it and see I suppose. :)
Barry
barrythomas@crosswinds.net
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Subject: Re: Unusual colored salad ingredients
From: Adriana Gutierrez & Dennis LaGatta
Date: Thu, 11 Nov 1999 06:13:58 -0500
Joel,
Have you had any luck growing lavender peppers? I have baby (2-4")
plants of Islander and Tequila hybrids for my first pepper attempts.
The Islander is supposed to be lavendar and the Tequila is a vivid
purple.
Adriana
> How about lavendar colored bell peppers or purple egg plant... scratch that
> egg plant- I wouldn't want to eat that raw either. The bell pepper is pretty
> but may be a bit hot for a salad.
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Subject: Blue veggies
From: Peggy & Emmett
Date: Thu, 11 Nov 1999 09:35:16 -0500
Adriana,
Borage is light blue. Tastes like cucumbers as I recall........Em
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Subject: Re: Blue veggies
From: William Evans
Date: Thu, 11 Nov 1999 07:01:02 -0800
Peggy & Emmett wrote:
>
> Adriana,
> Borage is light blue. Tastes like cucumbers as I recall........Em
Yup ,an a taprooted, selfsowing son of a gun ....eaasy to grow
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Subject: Re: heating revisted
From: Marc & Marcy
Date: Thu, 11 Nov 1999 08:13:15 -0700
..snip..
> Seems like it might be worth upping the
> concentration still further but whether (in that situation) it would be
> worth using just salt I don't know.
..snip..
There are salts available that will go through a phase
change at room temperatures. These have uses as a storage
element and you are considering pumping a saline solution
anyway. I'm just pulling this out of a 25 year old reading
memory so I don't remember the name or environmental
considerations.
..snip..
Marc
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Subject: Re: Heating revisited.
From: Marc & Marcy
Date: Thu, 11 Nov 1999 08:38:02 -0700
Barry Thomas wrote:
>
> > Of interest to Aquaponics was a presentation on solar
> > heating for greenhouses. It is available through SARE. It
> > directly dovetailed with the discussion on heating and heat
> > control from a week or two ago.
>
> Marc: I emailed a request to the SARE site for the info when I saw your
> post but have heard nothing back as yet. Which particular discussion did
> you mean? Could you give the basic idea of what was attempted and what
> the results were?
We'll dig through our winter reading pile and get back to
you with it as soon as we find it.
It had to do with heat storeage and heating along the lines
of what we were discussing a couple of weeks ago.
Marc
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Subject: Re: Aquaponics again! (mostly)
From: dreadlox@cwjamaica.com (michael kent barnett)
Date: Wed, 10 Nov 1999 06:50:25 +0000
Bill wrote:
Hi Bill ,
I know your voice from the Aquaponix group. :>
You wrote...on another group...
Acetylene 'guns' also work. Acetylene has a VERY wide 'fuel-to'air'
ratio, at which it will explode. Be careful making yours.
I would like to help the bird preying situation on the farm. Do you have
any diagrams of how I could make one of these things? I have seen them
overseas operate on LPG, but never on Acetylene. At presemt we use a
method of weaving string over the ponds but this cn be costly for labour
etc. If we can put this in place this would save us a lot of dosh.
Ideas, sites or any info is welcome...
Peace, Mike (Jamaica)
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Subject: Re: Aquaponics again! (mostly)
From: dreadlox@cwjamaica.com (michael kent barnett)
Date: Wed, 10 Nov 1999 06:57:58 +0000
This was for Bill Oowon at Netscape..sorry but any ideas welcome...
michael kent barnett wrote:
>
> Bill wrote:
>
> Hi Bill ,
> I know your voice from the Aquaponix group. :>
>
> You wrote...on another group...
> Acetylene 'guns' also work. Acetylene has a VERY wide 'fuel-to'air'
> ratio, at which it will explode. Be careful making yours.
>
> I would like to help the bird preying situation on the farm. Do you have
> any diagrams of how I could make one of these things? I have seen them
> overseas operate on LPG, but never on Acetylene. At presemt we use a
> method of weaving string over the ponds but this cn be costly for labour
> etc. If we can put this in place this would save us a lot of dosh.
>
> Ideas, sites or any info is welcome...
>
> Peace, Mike (Jamaica)
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Subject: Re: Aquaponics again! (mostly)
From: Marc & Marcy
Date: Thu, 11 Nov 1999 10:21:58 -0700
We used a compressed air "machine gun" simulator when I was
in the US army. Sounded like the real thing. This would only
need a compressor and no flames.
Marc
michael kent barnett wrote:
>
> This was for Bill Oowon at Netscape..sorry but any ideas welcome...
>
> michael kent barnett wrote:
> >
> > Bill wrote:
> >
> > Hi Bill ,
> > I know your voice from the Aquaponix group. :>
> >
> > You wrote...on another group...
> > Acetylene 'guns' also work. Acetylene has a VERY wide 'fuel-to'air'
> > ratio, at which it will explode. Be careful making yours.
> >
> > I would like to help the bird preying situation on the farm. Do you have
> > any diagrams of how I could make one of these things? I have seen them
> > overseas operate on LPG, but never on Acetylene. At presemt we use a
> > method of weaving string over the ponds but this cn be costly for labour
> > etc. If we can put this in place this would save us a lot of dosh.
> >
> > Ideas, sites or any info is welcome...
> >
> > Peace, Mike (Jamaica)
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Subject: Re: Blue veggies
From: Adriana Gutierrez & Dennis LaGatta
Date: Thu, 11 Nov 1999 12:43:49 -0500
Thanks for the suggestion. Blue is rare in flowers and I had never
heard of any blue vegetables except for the potatoes. I suppose that
taproot won't be too happy in my 3" deep perlite beds, huh? Maybe I can
rig a dripper into some deeper pots...I will definitely look into it.
Adriana
> > Borage is light blue. Tastes like cucumbers as I recall........Em
> Yup ,an a taprooted, selfsowing son of a gun ....eaasy to grow
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Subject: Co-op seed order
From: Adriana Gutierrez & Dennis LaGatta
Date: Thu, 11 Nov 1999 13:31:45 -0500
I'm getting ready to place an order with Stokes for some Revolution
lettuce seed. It is THE prettiest red lettuce I've tried yet. (And
believe me I've tried lots of them). It's a beautiful burgundy color
with small very frilly leaves and a good crispy texture. It's also very
expensive to order in the smaller packages,, coming out to over
$900/#!!!!!#@$
Once you order larger quantities you get a substantial price break,
cutting the cost by more than 50%. For 1/2 a pound the price is $213.25
and a pound is $404.75. Would anybody be interested in splitting an
order? I'd be happy to take care of the logistics of ordering and
resdistribution. If this works out we could repeat the process for
other varieties. Let me know by e-mail if you're interested.
Adriana
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Subject: Re: Co-op seed order
From: "TGTX"
Date: Thu, 11 Nov 1999 12:34:24 -0600
>Would anybody be interested in splitting an
> order? I'd be happy to take care of the logistics of ordering and
> resdistribution. If this works out we could repeat the process for
> other varieties. Let me know by e-mail if you're interested.
>
Adriana, I might consider it in a few months. Right now I am moving.
Keep me in mind, tho.
Have not tried Revolution yet, but I am aware of it. If you say it is good,
that's good enough for me.
Ted
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Subject: Re: heating revisted
From: mmiller@pcsia.com
Date: Thu, 11 Nov 1999 12:26:08 -0600
Are we on the Great Mandella? The salt you are looking for is Glauber's
salt or sodium sulfate. Mike Miller
At 08:13 11-11-99 -0700, you wrote:
>
>..snip..
>> Seems like it might be worth upping the
>> concentration still further but whether (in that situation) it would be
>> worth using just salt I don't know.
>..snip..
>
>There are salts available that will go through a phase
>change at room temperatures. These have uses as a storage
>element and you are considering pumping a saline solution
>anyway. I'm just pulling this out of a 25 year old reading
>memory so I don't remember the name or environmental
>considerations.
>
>..snip..
>
>Marc
>
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Subject: Re: heating revisted
From: "TGTX"
Date: Thu, 11 Nov 1999 12:55:39 -0600
> Are we on the Great Mandella? The salt you are looking for is Glauber's
> salt or sodium sulfate. Mike Miller
>
Right. Also known as eutectic salt mixtures...Sodium sulfate plus some
waters of hydration, plus some traces of other alkaline earth salts to fine
tune the temperature of the melting point and thus the phase change energy
storage
Ted
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Subject: Re: heating revisted
From: Ronald Polka
Date: Thu, 11 Nov 1999 14:42:05 -0700
At 11:06 AM 11/11/1999 -0000, you wrote:
>Hi John,
>
>This seems to be a week for coincidences. I've been up all night
reading
>and one fact that I came across and was about to pass on was that
brine
>(25% by weight) has a specific heat capacity of 3.4. I thought this
>might offer simply achieved performance gain for people using passive
>heat sinks filled with water. Seems like it might be worth upping the
>concentration still further but whether (in that situation) it would
be
>worth using just salt I don't know.
>
Barry
I feel a need to add some comments regarding this salt debate. The use
of brines and eutectic salts is not as simple as it sounds. Twenty years
ago eutectic salts were receiving positive reviews in the solar
community. But they never made much of an impact on the market in
consumer applications. There were a number of drawbacks. They were and
still are expensive. They had a limited number of life cycles, one source
I have says 1,000 cycles, that's a 3 year life span. After several years
of use they have a tendency to destratify. The containers often develop
leaks. This leads to environmental problems. These salts are rather nasty
chemicals. Most common eutectic salts are as follows.
Chemical Melting Heat of
Fusion Density
Compound Point Deg F Cp
Btu/lb lb/ft3
Calcium chloride hexahydrate CaCl2
6H2O 84-102 75 102
Sodium carbonate
decahydrate Na2CO3
10H2O 90-97 106 90
Disodium phosphate
dodecahydrate Na2HPO4
12H2O 97 114 95
Calcium nitrate tetrahydrate Ca(NO3)2
4H2O 102-108 60 114
Sodium sulfate decahydrate
(glaubers) Na2SO4
10H2O 88-90 108 97
Sodium thiosulfate
pentahydrate Na2S2O3
5H2O 118-120 90 104
This source goes on to state in the average environmental conditions that
may be encountered in using these chemicals for heat storage through
solar gain, ie 30 deg delta temp at about room temperature, each lb
stores about 105 Btu in latent heat and about 20 Btu in sensible heat,
for a total of about 125 Btu. To store the same amount of heat one needs
approximately 4 lbs of water or 20 lbs of rock. Eutectic salts have
thickening agents, up to 7% by weight, to prevent chemical separation in
the liquid phase. Borax is often added to prevent supercooling before
phase change. They must be encapsulateed in plastic to prevent spillage,
but this is not always foolproof. Installed costs for eutectic salts were
about $.20 per pound when this was written (1977). In addition to the
potential corrosion, toxicity problems, and long term performance one
must consider the cost benfit ratio.
Ref Anderson, Bruce, Solar Energy: Fundamentals in Building Design,
McGraw-Hill 1977
The other matter that needs clarification here is brine specific heat.
The two most common brines used in heat transfer are sodium chloride and
calcium chloride. Sodium chloride brines will vary in concentration from
0 to 25.2 percent by weight at saturation. Specific heat Cp varies from
1.0 Btu/lb deg F at 0% to 0.706 Btu/lb deg F at 25%. Specific gravity Sg
at saturation is 1.20. Calcium chloride brines will vary in concentration
from 0 to 34 percent by weight at saturation. Specific heat Cp varies
from 1.0 at 0% to 0.630 Btu/lb deg F at 34%. Specific gravity Sg at
saturation is 1.34. There is also a slight variation in Cp due to the
temperature of the brine. I can say from experience that brines at the
saturation point are very nasty liquids to work with. Its not the type of
fluid that I would bring into a greenhouse environment. The use of
eutectic salts never caught on in the solar community due to the expense
and practical shortcomings in the technology.
Ref ASHRAE Handbook, 1977 Fundamentals, American Society of Heating,
Refrigeration, and Air Coniditioning Engineers
Ron Polka
Southwest Technology Development Institute
New Mexico State University
Box 30001, Dept 3SOL
Las Cruces, NM 88003
rpolka@nmsu.edu
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Subject: Re: heating revisted
From: Marc & Marcy
Date: Thu, 11 Nov 1999 15:07:13 -0700
> to the expense and practical shortcomings in the technology.
> Ref ASHRAE Handbook, 1977 Fundamentals, American Society of Heating,
Refrigeration, and Air Coniditioning Engineers
>
> Ron Polka
> Southwest Technology Development Institute
> New Mexico State University
> Box 30001, Dept 3SOL
> Las Cruces, NM 88003
> rpolka@nmsu.edu
Wow!! Thanks again Ron for another great post!
Marc S. Nameth
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Subject: Re: solar salt ponds
From: Carolyn Hoagland
Date: Thu, 11 Nov 1999 21:27:40 -0500
Seems like I've read somewhere that the Australian Greenhouse growers have
the kinks
worked out of this strategy...
A quick search of the web turns up this link:
http://starfire.ne.uiuc.edu/ne201/course/topics/solar_thermal/pond_utilizati
on.html
The above should all be on one line. You may have to cut and paste and cut
and paste.
Carolyn Hoagland
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Subject: about solar ponds
From: Carolyn Hoagland
Date: Thu, 11 Nov 1999 21:52:19 -0500
>From :
http://www.eren.doe.gov/consumerinfo/refbriefs/ac5.html
(our tax dollars at work - Thanks to the U.S. Dept of Energy)
Solar Ponds
Solar ponds have a high concentration of salt near the bottom, a
non-convecting salt
gradient middle layer (with salt concentration increasing with depth), and a
surface
convecting layer with low salt concentration. Sunlight strikes the pond
surface and
is trapped in the bottom layer because of its high salt concentration.
The middle gradient layer acts as an insulator, preventing convection and
heat loss
to the surface. Temperatures may approach the boiling point at the bottom of the
pond. A transfer fluid piped
through
this layer carries heat away for direct end-use application. The heat may
also be
part of a closed-loop, Rankine cycle system that turns a turbine to generate
electricity. Israel leads the world in salt-gradient solar pond technology.
Ormat
Systems, Inc., an Israeli firm, has installed several systems in the Dead
Sea. The
largest is a 5 MW electric system. A man-made, salt-gradient solar pond in
Miamisburg, Ohio, heats a municipal swimming pool and a recreational building.
Here is some more from:
http://www.author.co.uk/pools/conservation.htm
Solar route step 1 A solar pool is a large container where the water as the
energy
circulation system collects, stores and distributes heat at marginal cost.
When the
ability to gather more energy (with solar collector, heat pump, etc.) is
built into a
scheme at low cost, gathering more 'free' energy (with solar cover, solar
decking,
etc) and adding extra benefits (such as solar fencing for security - see the
Queensland photograph), our everyday swimming pool is made even more
environmentally
friendly. Solar route step 2 Saline lakes whose topmost layers of fresh
water act as
protective insulation, initially drew our attention to the sun's deep water
heating
power. An inground liner pool can be made into a solar pond by adding salt
(to lower
freezing point) in the water which then collects solar heat intensively and
increases
thermal storage capacity. Solar pond temperatures can soon reach boiling
point, and
already several Dead Sea ponds have been set-up to drive turbines and so
generate
electricity. In America, a Monsanto experimental solar pond built beside a
swimming
pool (see Miamisburg photographs) acts as heater and storage unit, even when there is ice
covering the water surface! Solar route step 3 With modifications to the
liner type
pool structure and to its contents, it becomes possible to achieve 900 degrees
Centigrade, enough to reach power station generating potential. By
installing a high
temperature liner (316 stainless steel) and filling with a high thermal capacity
medium (such as molten salt and magnesia pellets), the Solar Energy Research
Institute (SERI) in Colorado has shown how an inground open type 'pond' can
easily
co-generate process heat and electricity from daily supplies of normal sunshine.
Carolyn
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Subject: Re: Unusual colored salad ingredients
From: MUDDTOO
Date: Thu, 11 Nov 1999 22:56:24 EST
Adriana,
Lavender peppers grew good out here in California and like a lot of warmth
and sun shine. They should do great in your area. I kept the nutrient at
about 2500 uS and had loads of peppers per plant. The peppers don't get as
big as a bell, keep a cone shape, and have a hot spicy taste.
A big seller with your lettuce crop may be yellow pear tomatoes. These are
sweet tasting, thin skinned, bright yellow cherry sized tomatoes that at
times look more like a bowling pin then a pear. They are heavy producers,
about a gallon per plant per day, that need a lot of trellis type support.
The ones I have grew over 10 feet tall before I cut them back to stumps like
a rose bush. They regrew quickly and the suckers root easily. Sound like a
great plant doesn't it?! They produce a large root mass - which might
interest those needing a good plant to provide water filtering. I have mine
growing inside cheap nylon sand bags (used for flood control) with perlite
and nutrient constantly dripping over it. This plant also grows well with
the roots completely under aerated water. Sounds like a better candidate
for aquaponics doesn't it!
Try some of these this year along with your peppers.
Joel
In a message dated 11/11/99 3:10:37 AM Pacific Standard Time,
gutierrez-lagatta@home.com writes:
> Have you had any luck growing lavender peppers? I have baby (2-4")
> plants of Islander and Tequila hybrids for my first pepper attempts.
> The Islander is supposed to be lavendar and the Tequila is a vivid
> purple
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| Message 21 |
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Subject: Re: heating revisted
From: "Barry Thomas"
Date: Fri, 12 Nov 1999 04:59:19 -0000
> I feel a need to add some comments regarding this salt debate.
Was hoping you would. Hadn't expected this level of info though - _many_
thanks for taking the time.
Looks like I ought to make it clear to everyone that if there have been
fewer IMHOs and ?s in my last few posts it is only because I assumed
everyone knew the score by now - that I'm merely putting up
questions/thoughts/ideas that either come to me as I learn about all
this or are sparked by others comments and ideas. Will be more careful
to make this plain in the future.
> The use of brines and eutectic salts is not as simple as it sounds.
I believe you but it wasn't me that mentioned using eutectic salts. I
looked at some when they were suggested and found them interesting but,
as you say, expensive and unfriendly.
Brines. I must admit I thought that brine meant a solution of sodium
chloride - didn't realise it was such a general term.
As I said, I was reading about heat transfer/capacity last night and
came across a table of materials which listed brine (25% wt. - didn't
say what kind) as having a specific heat capacity of 3.4. I understood
this to mean that given two identical tanks, one filled with brine and
one with water, you could transfer 3.4 times the amount of heat to/from
the brine than the water for the same change in temperature. This seemed
to offer a nice KISSy way for anyone who uses containers of fresh water
as passive heat sinks/stores to increase their storage capacity. That's
all I meant to say really and to ask whether anyone had tried it or had
thoughts/info. I tried to address John's interesting NaCl idea in the
same post - bad plan.
I doubted that - in this application - you could actually achieve these
figures (3.4) anyway but it did seem that the addition of some salt to
the water could increase your storage.
I note your warning about handling saturated brine but does this include
NaCl brine?
> Twenty years ago eutectic salts were receiving positive
> The other matter that needs clarification here is brine
> specific heat. The two most common brines used in heat
> transfer are sodium chloride and calcium chloride. Sodium
> chloride brines will vary in concentration from 0 to 25.2
> percent by weight at saturation. Specific heat Cp varies
> from 1.0 Btu/lb deg F at 0% to 0.706 Btu/lb deg F at 25%.
> Specific gravity Sg at saturation is 1.20.
Hmm...so... it seems that the reference I was using (old physics book)
can't have been talking about a sodium chloride brine anyway and that
adding NaCl to heat sink water is only likely to be worthwhile if
you're _really_ pushed for space?
Any idea what kind of brine the ref may have meant? SHC seems very high
in comparison to the ones you give.
What is the best heat storage media then (that doesn require a team of
tech's and a national evacuation plan) - plain water?
Thanks again,
Barry (fairly sure anyway... could be wrong... ideas anyone?)
barrythomas@crosswinds.net
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| Message 22 |
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Subject: Re: Aquaponics again! (mostly)
From: "Sam Levy"
Date: Thu, 11 Nov 1999 21:21:20 PST
> > Acetylene 'guns' also work. Acetylene has a VERY wide 'fuel-to'air'
> > ratio, at which it will explode. Be careful making yours.
> >
> > I would like to help the bird preying situation on the farm. > Peace,
>Mike (Jamaica)
mike--
if your bird population stays around for a while, i wouldn't count on the
guns giving much relief.
sometimes recordings of "distress calls" help. sometimes not.
talk w/your local birdwatcher professional & see if there is some behaviour
you can interfere with that will prevent depredation. for example, long
lines of 1 gal plastic containers floated in a pond will discourage some
species from landing.
sam
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