IMPROVEMENTS IN APPARATUS AND IN THE MEANS EMPLOYED FOR HEATING, COOLING, OR EVAPORATING LIQUIDS, AND FOR CONDENSING VAPOURS
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by George Clark at the Office of
the Commissioners of Patents, with his Petition, on the 30th March
1870.
I, GEORGE CLARK, of No. 10, Craven Buildings, Drury Lane, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN APPARATUS AND IN THE MEANS EMPLOYED FOR HEATING,
COOLING, OR EVAPORATING LIQUIDS, AND FOR CONDENSING VAPOURS," to be as
follows:-
The object of this Invention is to heat, cool, or evaporate liquids and
condense vapour by means of an apparatus constructed and arranged on
a plan of which the main principle is, that the apparatus shall admit
of the liquid to be cooled or the vapour to be condensed flowing or
passing in slender rills or thin films over and between two cold surfaces
on the plan of what is well understood as surface cooling or surface
condensation, or in the case of a liquid or vapour to be heated that it
shall in a like manner and form pass over and between two hot
surfaces.

page_text: E
An easy and convenient mode of constructing an apparatus to carry
out this principle for cooling purposes is to fix two pipes of thin metal
lightly dufering in diameter one within the other, so that there be a
narrow space (say of th or th of an inch more or less) between the
inner and the outer pipe, and to enclose one or any number of these
double pipes in an outer casing of the same length as the pipes, both
ends of the outer pipe or pipes (if more than one) and of the outer
casing being fastened in a plate at each end of the pipes, in such manner
that there is a free passage wholly or partially open through and through
the space or spaces between the said cooling pipes, admitting of the
liquid to be cooled or the vapour to be condensed running through the
said space or spaces. The joints of the closing plates at either end will
be made water or if required steam-tight over the space between the
outer casing and the outer cooling pipe or pipes, the outer casing thus
forming a close chamber which may be cylindrical or of any other form
and admitting of cold water flowing through such chamber by providing
an appropriate opening at each end. Each one of the inner cooling
pipes will be prolonged at both ends beyond the covering plates of the
close chamber, and consequently will project beyond the close chamber,
one end communicating by a continuation of every such projecting pipe
with the supply cistern of cold water, and the other end with a reservoir
or tank into which the water will be discharged.
The apparatus being arranged in the way above described the hot
liquid or vapour will be caused to pass through the narrow space or
spaces between the inner and outer cooling pipes in one direction, and
cold water or any other cooling liquid will be caused to flow through the
outer close chamber surrounding the cooling pipes and through the
interior of the inner cooling pipes in an opposite direction to that of
the hot liquid or vapour. If under some circumstances it were found
advisable the hot hot liquid or vapour and the cooling liquid may flow in
the same direction, but as a rule it will be more advantageous that they
should flow in opposite directions. As the apparatus will be of considerable
length in proportion to its diameter even if several pipes are enclosed in
the close chamber in order to agitate and retard the flow of the cooling
liquid through the latter and around the former plates will be fixed at
short intervals one from the other inside the chamber, having holes in cach
plate alternately through the outer edges or through the centre of tho
plates.

page_text: If the apparatus is to be applied to heating or evaporating purposes
the mode of using the double pipes will be reversed. The liquid or
vapour will be caused to flow or pass through the narrow spaces between
the said pipes, hot water or steam at any required temperature will be
introduced into the interior of the close vessel and of the inner of the
double pipes. The pipes may be round, oval, or flattened with plain or
corrugated surfaces. As to dimensions of the double pipes whether for
cooling or heating purposes I consider a round pipe 2 inches in diameter
and 6 feet long a suitable size and length for the outer pipe presenting
on its interior side a surface to the liquid or vapour to be cooled, heated,
or evaporated of 3 square feet, whilst the outside of the inner pipe being
only th to th of an inch less in diameter will present nearly the
same amount of surface on the other side of the liquid or vapour to be
cooled, heated, or evaporated.
For the purpose of carrying out this Invention efficiently I consider
that the apparatus consisting of the pipes and outer casing and constructed
as above described should be placed vertically, but where circumstances
make a different arrangement desirable the apparatus may be placed in
an inclined or horizontal position. Whatever the position may be
suitable arrangements will have to be made by using inlet and outlet
pipes and stop taps to regulate the quantities and rates of flowing of the
liquids or vapour respectively to be passed through the cooling spaces by
pressure or other means, so as to attain the refrigerating, condensing, or
evaporating result desired. Although double surface licating or cooling
by means of pipes one within another is as I have said the main
principle of my Invention, I propose that the apparatus constructed as
above described and placed in a vertical position shall in some cases be
fitted with one or more single pipes only enclosed in an outer casing in
the manner herein-before described, and that each of such pipes being
fitted and fixed in the end plates of the close chamber the upper end of
every pipe shall be covered with a plate or fitted with a plug, in each of
which plate or plug small openings immediately over the inner edge of the
pipe shall be perforated so as to allow the liquid or vapour to be cooled or
heated to percolate from a trough into the pipes and flow in a thin
stream or film down the sides of the interior surface of the pipe, and in the
case of that arrangement being adopted a stream of cold air may be made
to pass through the inside of each single pipe from the bottom upwards
on the following plan:-An air box is placed underneath the pipes, such

page_text: box having at its top holes fitted with short tubes rising above it of a
less diameter than the pipes in the close chamber of the apparatus so
that sufficient space is left for the nozzle of these short tubes to be inserted
inside the pipes of the apparatus and to allow a film of hot liquid to
run freely between the inner surface of the larger and the outer surface of
the smaller tubes. Air will be supplied to the box through a main, and
after passing through the pipes of the apparatus will be carried away
through short tubes in an air box over the apparatus or by some other
suitable arrangement. When double pipes are used as before described a
current of cold air or of hot air or steam (as the one or the other
may be required for refrigerating or heating purposes) may be made to
pass through the inner pipe.
An advantageous feature of he apparatus constructed as above
described is the facility with which every part of it may be got at for
examination and cleansing. The sides of the outer casing of the close
chamber may be connected together and with the end plates by flanges
and water-tight joints in such manner that they may readily be opened
wholly or in part, laying the pipes bare so that any sediment or incrus-
tation deposited by the liquids may be removed from the chamber or
the outside of the pipes, and the interior of the pipes can at any time
be readily cleansed by passing a long handled brush up and down through
them. As to the inner pipes of the double pipe system they may be
made in two lengths, each length fitting into the other by means of
water-tight nozzles fitting into each other by which means they may be
drawn out of the outer pipes and thoroughly cleaned.
I have mentioned some dimensions of parts of the apparatus which
forms the object of my Invention, but I do not restrict myself to these
dimensions as they may have to be varied according to the work to
which the apparatus has to be applied or the locality in which it has to
be used.
But I have to mention as a part of my Invention that under the
adaptation of only single pipes in the closed chamber for cooling or
heating I propose as a variation of construction that the tubes through
which the liquids to be cooled or heated are to flow shall be of smaller
diameter than any hitherto used, as I consider that if the stream of
liquid passed through cach tube is a slender rill it will be more rapidly
heated or cooled according as the apparatus is applied to one purpose or
the other.

page_text: For this particular adaptation of my Invention composition metal
tubing such as is employed for gas pipes and drawing beer may be advan-
tageously used both for cconomy and facility of fitting the pipes to the
end plates of the closed chamber.
It is obvious that the passage of the hot and cold liquids through the
apparatus may on the double or single plan be reversed, that is to say,
on the former plan that the hot liquid may be made to pass inside the
inner pipes and outside the outer pipes and the cold liquid between the
two pipes, but in that case the space between the two pipes would have
to be larger than that before mentioned, and on the single pipe plan the
cold liquid may be made to pass inside the pipes and the hot liquid to
flow outside the pipes, either enclosed in a chamber surrounding the
pipes and constructed as herein-before described; or the apparatus being
placed in a vertical position and the cold liquid passing through the
interior of the single pipes, or the outer of the double pipes, the hot
liquid may be made to trickle down the outer surface of the single
pipes or of the outer pipes of the double pipes through small holes in a
plate or plug fixed round or at the top of cach of the single or double
pipes with or without an outer casing.