Year: 1899

page_text: Date of Application, 21st Apr., 1899-Accepted, 2nd June, 1899
Addresex and State
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by.
the following statement, reference being had to the accompanying three sheets of
drawings in which;
--
Fig. 1 is a vertical transverse section of my cooling apparatus.
Fig. is a plan view thereof with the cover removed.
Fig. 3 is a section below the cooling duct, showing the method of operating the
chain pump.
Figs. 4 and 5 are details, and—
Fig. 6 is a modification.
My apparatus is based on the principle of abstracting heat from a current of air
to be delivered into an apartment by evaporating in immediate proximity thereto
a liquid, preferably water, by means of a second current of air. The object is to
render comfortable, in summer or in hot places or seasons, houses, living apart-
ments, hospitals, hotels, restaurants, and other places.
Various cooling devices based on this principle have been proposed, from
which mine differs in many important respects.
In order to attain a practicable device, it becomes necessary to separate the
evaporating chamber from the one containing the air to be cooled, in order that
the air delivered to the apartment may remain dry enough for use and to
accomplish this separation, with even approximate economy and capacity, I have
found it necessary to provide two ducts through which the respective currents are
passed, separated by a wall of a novel character. Thus, instead of a separating
wall of earthenware, iron, or ducts of metal, such as might be capable of sustaining
a stream of liquid or unbalanced air pressure, I use an extremely thin wall of
copper with suitable devices for maintaining its shape and protecting the same
against deformation by mechanical strain and pressure. I have used with success
a wall as thin as four thousandths (.004) of an inch in thickness which will
afford an approximate conception of its general nature. Instead of copper,
aluminium or a suitable alloy might be used, but with less favorable results. I
arrange the ducts separated by this wall in a novel manner and provide, on the
evaporating side, a distributing mantle of a character, which will be hereinafter
described. This mantle will be kept moistened with water by devices which I
have invented and the evaporation of such moisture by the air current will produce
a cooling effect that will abstract the heat from the air current on the other side of
the wall.
The reason for the inefficiency of various other structures and the success of the
one I have produced, seems to lie, so far as the character of the wall is concerned,
in the fact that the evaporation of water by an air current produces such a com-
paratively low difference of temperature between the opposite sides of the wall at

page_text: any given point, that no practicable amount of heat can be conducted through
the wall unless composed of such a thin material as I have provided. Moreover,
the chilling effect of the evaporation should take place on the surface of the wall
in the closest possible proximity to the air in the cooling chamber, so that the
resistance of heat conduction to said air shall be as small as possible, with relation
to the resistance through the layer of moisture. In this way the percentage of
cooling energy absorbed by said air in the cooling chamber or duct is large in
relation to the percentage absorbed by the water and by the air in the evaporating
chamber. By reason of the feature just mentioned and those to be hereafter
described, I have already succeeding in securing a discharge of a cubic foot of air
per second at a temperature of 65°, with an expenditure of 200 watts of power,
this temperature being nearly independent of the initial temperature.
I provide, moreover, an arrangement whereby the cooling energy absorbed by
the unevaporated water may be almost entirely recovered and the efficiency of the
apparatus largely increased thereby.
I have also provided arrangements for adjusting and regulating the admission
of water to the evaporating chamber and distributing it properly over the surface
of the separating wall.
I have also devised various details, essential to a structure capable of practical
service, including the construction of the cooling ducts in a spiral contained in a
case of heat-insulating material, the successive turns of the spiral serving to form
between them a second co-axial duct through which passes the evaporating blast.
The axis of the spiral is vertical and the particular advantage of this is that but a
single drip-nozzle or group of nozzles at the head of the incline is required for
moistening the entire mantle which covers the top wall of the spiral duct, and
also that it presents no sharp turns to obstruct the air current, effecting thereby
a saving in power. The supply nozzle is placed at the top of the spiral and the
water therefrom is conducted by gravity down the incline of the spiral to its lower
end, where it escapes into the drip tank.
The invention embraces also certain other features of improvement in apparatus
of this kind which will be hereinafter described.
Referring to the accompanying drawings, A represents a cylindrical enclosing
casing, comprising a layer a of wood, felt or similar non-conducting material, a
layer of sheet iron and an inner layer c of felt, rubber or other non-conducting
material. In the centre of this casing is a hollow central shaft B serving as a
newel-post, around which extends a spiral air duct C. rectangular in cross section
and having its upper surface composed of an external thin sheet of copper D sup-
ported and maintained in shape by its connection at the edges to the newel-post
on one side and the casing on the other, as is shown by the detailed drawing Fig. 5.
On the upper side of this copper wall is a mantle E of unsized, fine-meshed netting
of suitable fibrous material, held in place by a retaining strip or rod F. A mantle
of felt or other heat-insulating material is objectionable.
The enclosing casing A, with its contained spiral cooling duct is made in
sections, which telescope one within the other. Thus at a point r, midway of the
length of the casing, there is a telescopic joint in the casing itself and also in
the hollow shaft or newel-post B, while the spiral duct would, in like manner,
have a telescopic joint and the two parts can be fitted one with the other by a
slight turning of the upper half of the casing after it is placed in position on the
lower half. The edges of the upper part of the tube should lap on the outside of
the edges of the lower part so as to make a tight joint, both for the descending
water on the outside and the ascending air current on the inside of the duct.
In the upper part of the casing, above the cooling duct, is a supply tank G
provided with an ordinary float and stopcock, controlled thereby, which will admit
water from the supply pipe H at a predetermined low level of the water in the
tank to supply the amount evaporated by the air blast. In the lower part of the
casing and below the spiral duct is a drip tank J, which receives the unevaporated
water from the lower extremity of the incline. K is a blower, operated by an

page_text: electric motor L (Fig. 3), or any other suitable power, which, as also appears in
Fig. 3, delivers the air from a funnel shaped extension M, which passes, partly
into the evaporating duct or passage and partly into the cooling duct or passage,
whence it proceeds into the upper part of the casing and is thence withdrawn
by the exit pipes N and N1 (Fig. 2), the former taking the saturated air of the
evaporating blast and the latter the cooled air of the cooling duct and delivering
the same to a dwelling house or other apartment which it is desired to cool.
Within the hollow shaft B is a pumping device, consisting of a bucket chain,
comprising a link belt O, carrying buckets P at intervals and mounted on upper
and lower sprocket wheels S and S¹.
On the shaft of the sprocket wheel S¹ is a gear wheel R, which engages with a
pinion on the shaft of a small fan wheel V. The air for this fan wheel is delivered
by a pipe Q (Fig. 3), forming a branch from the main delivery pipe U and
separated therefrom by a damper 3. In the tank J is a box float T, held in place
by parallel links t, (Fig. 4), so that it may rise and fall with the level of the water
in the tank. This float operates three dampers, 1, 2, and 3, being adapted to
open 1 and 3 and to close 2 when in its highest position and, conversely, to close 1
and 3 and open 2 when in its lowest position. When damper 2 is closed or partly
closed, and damper 3 is open, the main air blast in pipe U is diverted wholly or
partly through pipe Q to the fan wheel V and passes thence either by a special
pipe, or by the air space in the lower part of the casing to the open damper 1 into
the funnel shaped extension M and thence into the cooling and evaporating ducts,
as before described.
In operation the water from supply tank G, which, it will be remembered,
cannot fall below a certain level without having fresh water delivered thereto
from pipe H, passes to a pipe W (Fig. 2) provided with a number of drip nozzles
from which the water falls on to the mantle E and flows downward along the
same by gravity, while at the same time the air blast in the evaporating duct
passes upward over the moistened mantle and, by evaporation of a portion of the
moisture therein, produces a cooling effect which is transmitted through the thin
wall of the cooling duct to the air contained therein, the latter air current being
delivered in the manner already described, to an apartment to be cooled. The
cooling effect is also taken up to a certain extent by the moisture of the mantle
and, in order that this may not be lost, it is desirable that the unevaporated water
should be collected and returned to the supply tank. This excess of water in the
mantle falls into the drip tank J and when a definite amount has been collected
the float T rises to a point where it operates the dampers as already described and
diverts sufficient air to the fan wheel which operates the chain pump, as described,
to elevate the water from the drip tank J to the supply tank G. When the level
of water in the former tank is sufficiently low, the float acts again to restore the
lampers to their normal condition and the apparatus continues to operate as
described. The float in tank G admits just enough water to make up for that
evaporated. Any other suitable form of pumping apparatus may be employed to
lift the water from the lower tank J.
In Fig. 6 I have shown a modified form of the apparatus which may be used
to advantage in certain situations. In this form the inclined cooling duct is
composed of parallel straight lengths X and Y, connected by curved end lengths Z,
which may be square-cornered, if desired, instead of round, into a continuous
passage forming what may be described as a flattened spiral and being arranged
and operating in all respects like the circular spiral form shown in the remaining
figures of the drawing. In this form the hollow shaft B will be elliptical instead
of circular in cross section and will admit of a chain pump being employed just
as in the form previously described. One advantage of this form is that several
different sizes of apparatus can be made with the same dimension at the curved
ends, the difference being introduced by using longer or shorter straight sections
between the curved sections,

page_text: 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 I
claim is;
1. A cooling apparatus comprising a duct for the air to be cooled, and an
adjacent evaporating duct separated therefrom by an extremely thin wall of
copper or equivalent material, and provided with a moisture-distributing mantle,
combined with means for supplying the mantle with a liquid to be evaporated and
directing air blasts through the two respective ducts, substantially as described.
2. In a cooling apparatus of the general type described, the arrangement of the
thin mantle-covered separating wall on an incline, with the liquid supply delivered
at its upper end, whereby the liquid may gradually pass longitudinally down the
said wall and distribute itself over its entire surface, substantially as described.
3. In a cooling apparatus of the general character described, the arrangement of
the respective cooling and evaporating ducts in the form of a spiral, substantially
as described.
4. The combination with an air cooling apparatus of the general character
above described, of a pumping apparatus for lifting the unevaporated liquid and
passing it over the mantle a second time to recover the cooling energy absorbed
therein, substantially as described.
5. In a cooling apparatus of the general character described the automatic
devices for maintaining the liquid supply and for operating the pumping apparatus
at the required times, substantially as described.
6. In a cooling apparatus of the general character described an arrangement for
mechanically supporting and retaining in shape the thin separating wall between
the two adjacent ducts, substantially as described.
7. A cooling apparatus of the kind described having the containing casing and
the respective cooling and evaporating ducts constructed together but in two
detachable sections, substantially as described.
8. A cooling apparatus constructed in detail substantially as described.
Dated this 20th day of tum 1000
H. B. BARLOW & GILLETT,
Agents for Applicant, 17, St. Ann's Square, Manchester.