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ICE MAKING. I
"Quizzy," Grass Pateo., writes:-Can
you give u:e a rough outline of ice
j 'making? I am pretty handy and
j have beeni wondering if I could rig
up a plant to make enough for home
use.
The principle of ice making machine*
ieilo use .some quickly evaporating sub-
stance dike ammonia in order to remove
- the heat from a liquid like brine which .
has a lower freezing temperature tuan
ordinary water. The substance which it
is intended to evrriorate to remove heat
is subjected to heavy compression by
mean® of comyreiasor pumps. When the
pressure ia released from this compressed
liquid it rapidly take away heat from
the bric* in the v?:pes andi then diese cold
pipes, can be made in their turn to take
«way the heat from water which has to
be frozen. That isi a very crude and
general ¿'tatement, but cohere -the es-
sential principle.
I do not know of any "means by which
one can- rig up an ice making plant with-
out having the proper compressor, chemi-
cals, acd'al! the apparatus. Ice making
plants are of various sizes, and I believe
it is possible to buy coniiparativeùy small
ones. Wt they are aU relatively expensive.
It may be worth while making inquiries
from engineering finns. a& to the cost of
refrigerating machinery*
On a email scale it is possible to use
certain chemicals to- lower temperature.
These are known as. refrigerating or
freczirtg mixtures'. It is. ryossCble with
son-* of 'these- mixture» to make a small
quantity of ice as au experiment, 6ay, in
a test* tube, but not enough for domestic
purpose's.
Henley's. Twentieth-CenturyiFormulas
gives the following refrigerant mix-
tures':
1. (Potassium nitrate. 2 pounds. j
Ammonium cb'oride, 2 poundec J
Water, 6 pints.
2. Potr.sis.iuai nitrate, 2i pounds'.
Ammonium chloride,. 2J çoundi».
Sodium sulphate, 4 pounds.
Water, 4 pounds'. j
8. Amnion a nitrate, 4 pounds. - !
Water, 4 pints. -
4. Sodium sulphate, 8 parte.
Dilute hydrochloric acid, 5 paris.
. A dimple chemical refrigerant which
ls efficient and nt the same time low in
cost is the following:-"Prcware a 10 per
cent, dilution, of sulphuric acid in water.
Place this'-in a wooden tub or stone jug
andi allow to cool. Add a handful of
Glauber1* ealtti for each quart of salu-
tion. The-temperature will drop eharply,
and the eooier the solution' » to start
with the lower the resulting tertr.ipérature
will be. "Under good conditions a test
tube of water may be frozen by placing
it in the mixture."
The following instructions "for making
ice cream freezing mixtures are taken
from "Inquire .Within Uçon Every-
thing":- . ,
Sulphate of Soda and Hydrochloric Acid.
Efficient andi really freezing mixtures
may be madte. by. using acidei to dissolve
i . ?
tlie sates. The cheapest, and perhaps
the best, of these for ordinary use, is
one which is frequently employed in
France, both foir making deissert-iccßv
and cooling wine®, etc. It consists ot
coarsely-powdered Glauber galt (sul-
phate of siddiuin), on which is poured
I about two-third© its weight (spirits of
salt (hydrochloric acid). The mixture
f hould be made ia a wooden vessel, a«s
.that is preferable to oma made of metal,
which conducts the external heat to
the materials- with great rapidity; and
wheo the substance to be cooled is plac-
ed in the mixture, the whole ©hould be
covered with à blanket, a piece of old
woollen, carpet doubled, or some other
non-conducting material, to prevent the
acece* of the external warmth; the vciS
sel us-edi for icing wines sJiould not be
too large, that there may be rio waste
of thc freezing mixture. This1 combina-
tion producer a toild1 thirty degrees be-
low freezing; and if the materials, are
bought of any. of the wholesale drug-
gets, or dfrysalters,. it i®, however, to thc
very great objection, that" the spirits ol
salt ¡6' an exceedingly, corrosive liquid
and of a pungent, disagreeable odour:
thisi almost preckwles its uee for anj
purpose except that of icing wines.
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