Improvements in Liquid Composition for use in Heating Systems.
Year: 1889

page_text: COMPLETE SPECIFICATION.
Improvements in Liquid Composition for use in Heating Systems.
I, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the county of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which has
been communicated to me from abroad, by the "Colorado and Now York Heating,
Cooling and Power Co.," a corporation organized and doing business under and by
virtue of the laws of the state of Colorado, United States of America, having its
principal office at the city of Denver in said state,) and in what manner the same
is to be performed to be particularly described and ascertained in and by the following
statement:-
My invention relates to a new liquid composition for use as the circulating medium
for the absorption, transportation and diffusion of heat in pipe systems of heating
analogous to what are termed steam and hot water systems.
In such systems water either as a liquid or as steam or vapor has generally beon
use and recognized as the best available circulating medium, but the only
characteristic advantage it possesses for such use is its high specific heat. On the
other hand it possesses several characteristic disadvantages counterbalancing in part
at least such advantage; 1st, its comparatively low boiling point causes it to have at
relatively low temperatures comparatively great internal pressure or strain which is
transferred to the containing mechanical devices causing therein oftentimes great and
dangerous, sometimes destructive, strain upon the heater and pipes of the system,
necessitating for the decrease of such dangers, extra weight and strength of material
in boiler and pipes and great care at joints to avoid leakage, while its tendency to
condense, when used, steam involves in addition not only the employment of steam
traps etc., but also. an impairment of heating capacity in pipes and radiators by the
presence therein of water of condensation; 2d, its crystalizability under even
moderately low temperatures renders its use dangerous in exposed pipes and situations
as the freezing or solidifying of the medium therein under such conditions may work
destruction to the whole system.
It seems therefore that a more perfect and fit medium for circulating in such
systems should be used. By investigation I have found, and such will be generally
recognized as the fact, that such a medium, comparatively perfect, if not a totally
perfect one, should possess certain characteristics which are, 1st, high specific heat
that it may be able to absorb and retain for the time being a large amount of caloric
to be given off or diffused unler proper conditions; 2d, a high boiling point that it
may not be easily vaporized and be free from any great internal pressure, thus
relieving the heating and circulating system of disruptive forces and the dangers
therefrom, permitting as a consequence the use of simplified and lighter mechanical
devices; 3d, lack of crystalizability even under quite low temperatures that danger of
clogging the pipes by frozen or crystalized masses be avoided.
In view of these things the object of my invention is to produce a liquid com-
pound having the characteristics noted for the circulating medium in fluid
circulating systems of heating; to which end it consists, 1st, in a fluid composition
having a high specific heat, a high boiling point and which is non-crystalizable or
solidifiable under ordinary low temperatures down to say-10° F.; and 2d, in a fluid
composed of a mixture of any of the higher alcohols as a mono, di, tri or tetra
hydric alcohol and an ester or acetine thereof, all as more fully hereinafter set forth
and claimed.
In practicing the invention to form the compound which is the subject thereof, any
one of the higher alcohols such as the di-hydric (glycil) or the trihydric (ordinary
glycerine) or any of the poly-glycerines is taken and mixed with an equal amount of
the ester or acetine of the same alcohol, the two being mixed cold. They are
then heated to about 250° C. or to the boiling point of the mixture, such boiling
P

page_text: point having about 260° C. to 270° C. (500° to 518° F.) and afterwards cooled and
preferably to below zero, the result being a perfectly stable compound possessing the
required characteristics.
For a clearer understanding the formation of the compound will now be traced
step by step, taking one of the higher, say tri-hydric alcohol, as the base thereof.
First: to prepare the ester, a quantity of the tri-hydric is placed in an open vessel
or boiler and heated to about 225°C and while heated the vapors of acetic acid are
passed therethrough until ebullition (a sign indicative of continued reaction)
ceases. The product is then raised to its boiling point (about 290° C.) and
the boiling continued for a short time to eliminate and drive off any traces of
free acctic acid. It is essential that no trace of free acetic acid be left. Hence
if this mere boiling does not drive off all the free acetic acid, the compound
should be boiled in the presence of lead oxide, the affinity of the lead for the acetic
acid insuring the complete removal of any free acid. The result of this treatment is
that all the glycerine has been converted into a di-acetine of glycerine, which is then
cooled preferably to below zero. After cooling it is permitted to stand from 12 to 24
hours after which equal parts of such ester or di-acetine and of the tri-hydric
alcohol are mixed and the compound heated to near its boiling point, say 250° C., and
then cooled. There has been thus formed a composition consisting of tri-hydric
alcohol and an ester thereof.
Though ordinarily the use of equal parts of alcohol and its oster in forming the
compound is deemed preferable, I do not wish to limit myself to these proportions,
for the reason that upon the respective proportions of the higher alcohol and the
acetine or ester thereof depend, the boiling point, specific heat and the degree of
non-solidification of the resulting compound. For example, the compound resulting
from heating to 200° (1. of one molecule of a tri-hydric alcohol and one molecule of
acetine of the same, a compound results whose boiling point is 272° C., its specific 1. 3,
water being the standard, and its point of congealing-56° C. To vary from these
proportions in either direction affects the characteristics of the resulting compound.
These characteristics will approach more nearly those of the ingredient predominating
in the compound. For instance, a greater proportion of the acetine will reduce the
boiling point, lower the point of congealing, but increase its specific gravity and capacity
for heat. On the other hand a greater proportion of the alcohol raises the boiling point,
raises the point of congealing and decreases the specific gravity and heat capacity or
specific heat. It may therefore be necessary to vary the proportions according to the
climatic conditions of the locality where the compound is used. The liquid for use
in northern parts of our country, for instance, may have to be so constituted that the
point of congealing is lowered even at the expense of reducing the boiling point,
whereas the reverse of this may be necessary further South.
Such a compound may be repeatedly heated under atmospheric pressure to its
boiling point and alternately cooled below zero, but such tests will leave it un-
affected, neither lowering its boiling point on the one hand nor causing it to
solidify on the other hand, such tests proving it to be an exceedingly permanent,
stable compound.
It has a high specific heat rating, standing at about 97 to the 1 of water thus having
large capacity for the storage of heat from a prime source thereof.
Its boiling point under atmospheric pressure is over 260° C. (500° F.) so that it may
be safely heated to 230° C. (446 F.) at which point it is equivalent to steam or water
under three hundred pounds pressure, but at that temperature the compound is still
30° C. below its boiling point, consequently it exerts no disruptive strain or pressure
on the boiler or the pipes or radiators, hence such device may be of lighter con-
struction while, as it may be heated safely to so high a degree, the plant, pipes,
radiators, etc., may be much reduced in size to attain equal efficiency. As at such
heat or below its boiling point no condensation can occur clogging pipes,
impairing the heating capacity of radiators and necessitating the use of steam traps.
It can deposit no sediment or scales and does not injuriously affect the metal, hence
it may remain in the pipes of the system when not in use without impairment thereof

page_text: or of itself and as it does not readily, if at all, solidify, it may be safely used in
exposed pipes. As a smooth, bland compound it can circulate with little friction
in the pipes, contacting closely with the surfaces of the prime source of heat and
of the radiators and pipes, it also has a maximum of efficiency in first the absorption
and then the diffusion of caloric.
These characteristics and its behaviour under various and varying conditions
show it to be better adapted for the desired use than any fluid or liquid yet
proposed therefor.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what [
claim is
:-
First A liquid composition for use in systems of heating, said composition being
composed of any of the higher alcohols and the acetine of the same, in proportions
giving the compound a high specific heat, a high boiling point and rendering it
non-solidifiable under ordinary low temperatures, substantially as described.
Second:-A liquid composition for the absorption, transportation and diffusion
of heat, in fluid circulating heating systems, consisting of a higher alcohol and an
ester or acetine thereof combined substantially in the proportions specified.
Third-A liquid composition for use in fluid circulating heating systems, con-
sisting of a higher alcohol and an ester or acetine thereof, combined in the proportions
specified.
Dated this 10th day of December 1889
ALLISON BROS.,
Agents for the Applicant.