from One Current of Air or other Fluid to Another.
Year: 1884

page_text: from One Current of Air or other Fluid to Another.
We, CHARLES LLOYD BRAITHWAITE the younger, and ISAAC BRAITHWAITE, both
of Kendal, in the County of Westmoreland, Manufacturers, do hereby declare the
nature of our said invention for " IMPROVEMENTS IN OR RELATING TO APPARATUS
FOR TRANSFERRING HEAT FROM ONE CURRENT OF AIR OR OTHER FLUID TO
ANOTHER," to be as follows:-
:-
In drying goods by means of heat either the atmosphere surrounding the article
heated is more or less confined, in which case the moisture evaporating from the
goods is confined with it injuring the drying effect of the heat, or the hot
atmosphere charged with vapour is allowed to escape in a constant current to the
great loss of heating power.
Now our invention is designed to allow of a constant circulation and escape of
moisture-laden air without any material sacrifice of heat as while allowing the
moist air to escape, we abstract its heat and give it to the incoming current of air.
Our invention is not merely applicable in the case of drying, but also for
ventilation, likewise, and in all cases where heated air, gas, vapour or even liquid is
allowed to escape and an incoming current of air, gas, vapour, or even liquid is
required in the warm state, the heat of the effluent fluid being transferred in all
these cases to fresh inflowing one. It is also applicable to heating air, gas, vapour
or liquid by means of steam or the gaseous products of combustion.
The invention consists in causing the hot foul air to escape through a series of
very thin passages separated by thin metallic foil from similar passages through
which fresh air enters the compartment, also in the form of the apparatus and the
cheap simple plan of making saine.
We form the passages of a long sheet or web of metallic foil such as tin, brass or
copper foil. This is doubled backwards and forwards over two series of bars
or wires in two long rows, each row forming one set of the smaller side walls of the
narrow partitions a strip of metal, pasteboard, wood or other toaterial forming 'the
other small side wall, and each end wall. Close to each end, the narrow side walls,
not formed of the bars or wires are omitted, or close to each side wall of this
[Price 6d 1

page_text: character about half the end wall nearest to it is omitted, and opposite these hiati
the mouths of the air passages are placed, the current inflowing into the drying or
other chamber entering and exiting at one side of the apparatus, at the two ends,
and the exit current passing in and out (the reverse way to that taken by the other
current) by the two openings on the other side of the apparatus. This method of
simply folding a long web of metal over two rows of wires or bars, and closing in
the spaces formed, so as to make a series of narrow parallel chambers could be
applied for heavier material than foil, for such things as hot blast stoves, sheet metal
taking the place of foil.
In some cases the wires or bars may be omitted the folds being kept in place by
the pieces of material forming the ends of the apparatus.

page_text: Improvements in or relating to Apparatus for Transferring Heat
from One Current of Air or other Fluid to Another.
We, CHARLES LLOYD BRAITHWAITE the Younger and ISAAC BRAITHWAITE of
Ghyll Close Kendal in the County of Westmoreland Manufacturers do hereby
declare the nature of our said invention for IMPROVEMENTS IN OR RELATING TO
APPARATUS FOR TRANSFERRING HEAT FROM ONE CURRENT OF AIR OR OTHER
FLUID TO ANOTHER and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
In drying goods by means of heat either the atmosphere surrounding the article,
heated is more or less confined, in which case the moisture evaporating from the
goods is confined with it, injuring the drying effect of the heat, or the hot
atmosphere charged with vapour is allowed to escape in a constant current to the,
great loss of heating power.
Now our invention is designed to allow of a constant circulation and escape of
moisture laden air without any material sacrifice of heat, as while allowing the
moist air to escape, we abstract its heat and give it to the incoming current of air.
Our invention is not merely applicable in the case of drying, but also for
ventilation likewise, and in all cases where heated air, gas, vapour or even liquid is
allowed to escape; and an incoming current of air, gas, vapour, or even liquid is
required in the warm state, the heat of the effluent fluid being transferred in all
these cases to fresh inflowing one. It is also applicable to heating air, gas, vapour,
or liquid by means of steam or the gaseous products of combustion or hot water.
The invention consists in causing the hot foul air to escape through a series of
very thin passages, separated by thin metallic foil from similar passages through
which fresh air enters the compartment, also in the form of the apparatus and the
cheap simple plan of making same.
The invention is best described by the accompanying drawings which show (in
the original drawing filed) full sized views of an apparatus made by us. In these
Figure 1 is an elevation.
Figure 2 transverse section through A B. Figure 1 and Figure 3 section
through D.
In these E is a sheet of thin metal foil, preferably copper, but in some cases
another metal may be used where circumstances or the chemical nature of one or
both of the currents make it desirable; we use metal foil as being of greater
conductivity than other material. This sheet is folded backwards and forwards
alternately (the folds being preferably across the length of the sheet) leaving
narrow spaces between the folds for the passage of the two currents of air, vapour,
or liquid proceeding along the alternate openings preferably in opposite directions.
The object of making them pass in contrary directions, is to obtain the greatest
interchange of heat since each current as it becomes cooler or hotter respectively
comes opposite cooler and cooler, or hotter and hotter parts respectively of the
other current, and so can continue to extract or give out heat to the very last.

page_text: This secures a transference of heat from the hotter of the two currents to the
cooler. The folds are filled up or closed at the ends by small blocks F of metal,
wood, cement or other material, or by plunging the ends of the folds into a shallow
trough containing melted metal or other material of a lower melting heat, and
allowing the whole to cool together and they are also guarded along the central
portions of their length on each side by sheets or blocks G of any suitable material
preventing lateral escape of the current from between the folds.
The spaces H1, H2, H3, H4 left on each side between the end blocks F and the
central sheets or blocks G provide for the entrance and exit of the currents, so that
the one current will enter at the one end of one side say at H and leave the
apparatus by the other end of the same side, say at H2 while the other current
enters and leaves by the openings H3 and H4 respectively on the opposite side
(proceeding along the folds preferably in the reverse direction to that taken by the
other current).
In this apparatus a very complete transference of heat within a small space, is
obtained by the use of thin divisions between the currents, and by the subdivision
of the currents in the large number of narrow alternate passages so that within
a comparatively small apparatus, a very large amount of heating surface is obtained,
and the form of the apparatus is convenient for allowing the, currents to pass
through it in opposite directions by which the maximum effect is secured.
In case of transference of heat from gaseous currents to water or liquid (or vice
versâ) or from steam to air or where the volume of one current is largely in excess
of the other, it is desirable to fold the foil, so that one set of passages should be
wider than the other set.
Although we have hitherto spoken of foil only, and with gaseous or atmospheric
currents not under different pressures, foil is best, yet where a considerable difference
of pressure exists between the two currents it will be necessary to use much stronger
material, and perhaps to put supporting stays at intervals to prevent collapse. If
stronger and thicker material be used however the other dimensions must be
increased to correspond. For ventilating purposes the apparatus should be placed
vertically with a tube K from one of the two openings in the lower end, leading to
the outside and a tube L from the other lower opening leading to the chimney or
other point of exit. This latter draws the air from near the ceiling by means of
a tube M connected with the opening in the upper end of the apparatus, and the
fresh air from outside is preferably delivered near the floor by means of a tube N
from the other upper opening. If the apparatus be near the ceiling or near the
floor one of these tubes M or N can be dispensed with and in like manner so can
tube K where circumstances admit of it.
+
It will be obvious that in place of the guard G being placed for a part of the way
only on both sides, and the blocks F fitting the entire ends, one side, say that which
is shown open at H1 H2 could be closed entirely, and the passages now opening
at HH could open at the ends the blocks F only closing every alternate passage
namely those opening at H3 H4. If in any case the foil cannot be obtained of
a sufficient width for the length of passage needful for the full transfer of heat, the
passages can be made length ways of the foil, with a width nearly equal to the
width of the foil; the foil being folded back and forwards, each fold being as long
as the passages are intended to be, so that each passage will be closed at one end
by the folding of the foil The spaces between the foil at the sides must be blocked
up, with the exception of a space at each side next to the closed end of each passage
about equal in length to half the width of the foil.
The currents are admitted at the ends of the apparatus leaving it at the openings
in the sides or vice versa.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that
we are well aware that in freezing and condensing apparatus. the fluid to be cooled

page_text: is separated from the cooling fluid by thin conducting material and that the cooling
fluid surrounding the pipes containing the fluid to be cooled is caused to traverse.
in the reverse direction to that taken by the latter also that concentric tubes have
been used containing alternately the condensing fluid and the fluid to be condensed,
and we make no claim for such, but we believe that never before has an apparatus
been made or designed in which two unimpeded currents have been alternated or
sandwiched together so that the one in passing shall take up the heat from the
other, and what we claim is
י
1st. In apparatus for transferring heat from one current to another, the thin
metal foil folded so as to form a series of thin spaces separated from the alternate
spaces by a single layer of foil, substantially as described.
2nd. In apparatus for transferring heat from one current to another the com-
bination of the thin sheet of metal E folded into a series of thin passages, open
alternately on opposite sides, with the guards F and G, substantially as described.
3rd. In combination with two alternating sets of narrow passages, separated by
thin metal partitions, the outgoing currents entrance H¹ and ingoing currents
exit H at one end of the apparatus and the outgoing currents exit H and ingoing
currents entrance H³ at the other end, whereby the two currents pass in contrary
directions, and are thus able to continue the transference of heat to the very last,
substantially as described.
4th. The method of transferring heat from one current of air or other fluid to
another which consists in causing the two practically unimpeded currents to pass in
contrary directions cach through a series of thin parallel passages, alternating with
and separated from the other by thin partitions of good conducting material,
substantially as described.
WM P, THOMPSON & Co.,
J. O. O'Brien,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicants.