Improved Means and Apparatus for Refrigerating Air.
Year: 1895

page_text: Date of Application, 15th May, 1895
Complete Specification Left, 14th Feb., 1896-Accepted, 21st Mar., 1896
ᏞᎪ
[Communicated from abroad by LA COMPAGNIE GENERALE POUR
PRODUCTION DU FROID (procedés E. Fixary), of 49 Rue Taitbout, Paris,
France, Manufacturers.]
Improved Means and Apparatus for Refrigerating Air.
I, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery
Lane, in the County of London, Consulting Engineer and Chartered Patent Agent,
do hereby declare the nature of this invention to be as follows:-
It is known that the main obstacle to the direct transmission of cold to the air
consists in the formation of rime upon the refrigerating surfaces within which
circulates the refrigerating fluid. When it is required to maintain the refrigerating
chambers at a temperature above 0° C. this obstacle is surmounted by the direct
circulation of the air from the chambers to be refrigerated over the tubes &c.
covered with rime, within which the circulation of the refrigerating medium is
momentarily suspended.
But when the chambers have to be maintained at a temperature below 0° C. this
cannot of course be done.
According to the present invention this object is attained under these circum-
stances by the following means.
A horizontal chamber contains a number of upright metal sheets arranged
side by side with small spaces intervening, the plates being placed at a slight angle
to the vertical.
The upper edges of the sheets are slit so as to form a number of small tongues,
that are slightly bent alternately to the right and the left of the plane of the
sheet. The top of the enclosing chamber is formed by a shallow tank with a
corrugated and perforated metal bottom, the corrugations being such that there is
one situated immediately above each metal sheet. Refrigerating liquid being
conveyed from a refrigerating apparatus of any suitable construction, into_the
said tank, the liquid flows m a fine shower on to the tongues at the upper edges
of the sheets, which tongues effectually distribute it over both surfaces of the
sheets, down which it consequently descends in a thin film, while a certain quantity
of the liquid also falls in a fine spray through the narrow spaces between the
sheets.
The chamber communicates at one end with a forced air supply produced
by an air propeller or other meaus, so that the air to be refrigerated in passing
through the narrow spaces between the sheets, is subjected to a double
refrigerating action by coming in contact with the film of liquid on the sheets and
by mixing with the spray of liquid descending in the spaces. The refrigerating
liquid arriving at the bottom of the chamber after having taken up heat from the
air, is either drawn off by a pump and conveyed to the refrigerating apparatus,
whence after having its temperature reduced to the required degree, it is conveyed
back into the distributing tank again. Or, according to another arrangement, the
chamber has at bottom a compartment containing coils of refrigerating pipes
through which refrigerating gas or vapour such as ammonia is passed, while the
liquid descending from the sheets passes in contact with the outer surfaces of the
pipes so as to be reduced in temperature again thereby, and is then raised by a
pump into the distributing tank again.

page_text: According to another modification the horizontal chamber through which the air
to be refrigerated is made to pass contains, in place of the metal sheets, a number
of pipe-coils through which refrigerating fluid is made to pass, while the air
passes horizontally through the chamber in contact with the outer surfaces of the
coils.
Above these coils are arranged perforated pipes through which brine or other
unfreezable liquid can be made to How over the refrigerating pipe coils, this being
effected either continuously, so as to prevent the formation of rime on the pipes
from the moisture of the air, or the liquid may be made to flow over the coils at
intervals for removing the rime when formed.
In this case it is preferred to divide the chamber by longitudinal partitions into
a number of compartments in each of which are two or more of the refrigerating
coils, and each compartment is provided, at the end through which the air enters,
with a flap-valve or slide by means of which the compartment can be temporarily
cut off from the air supply.
Thus when the pipe-coils in one compartment are covered with rime, it is cut off
from the air inlet and the brine is allowed to flow over the coils so as to remove
the rime therefrom, the refrigerating fluid being also cut off from the coils during
that time if necessary.
This having been done, the air supply is again admitted, and another compartment
is cut off, to be treated in the same manner. By this means the refrigerating
process is kept continuously in operation.
The brine or other liquid, after having descended over the coils into a bottom
compartment of the chamber, is raised thence again to the perforated pipes at top.
As in all the above arrangements, the brine or other liquid will gradually become
diluted by taking up the moisture from the air, it will be necessary to increase its
strength from time to time.
Dated this 15th day of May 1895.
ABEL & IMRAY,
Agents for the Applicant.
1, CHARLES DENTON ABEL, of No. 28 Southampton Buildings, Chancery
Lane, in the County of London, Consulting Engineer, and Chartered Patent Agent,
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:-
It is known that the main obstacle to the direct transmission of cold to the air
consists in the formation of rime upon the refrigerating surfaces within which
circulates the refrigerating fluid. When it is required to maintain the refrigerating
chambers at a temperature above 0° C. this obstacle is surmounted by the direct
circulation of the air from the chambers to be refrigerated over the tubes &c.
covered with rime, within which the circulation of the refrigerating medium is
momentarily suspended.
But when the chambers have to be maintained at a temperature below 6° C. this
cannot of course be done.
According to the present invention the difficulty is obviated under the said
circumstances by means of apparatus, the arrangement and action of which I will
proceed to describe with reference to the accompanying drawings.
Figures 1 and 2 shew respectively a longitudinal section and a cross section of
one construction of the apparatus. It consists of a large chamber A of masonry,
sheet metal or wood, containing a series of inclined sheets of metal B connected
together by bolts and distance pieces I, as shewn more clearly in the enlarged part

page_text: section and elevation at Figures 3 and 4. In the upper part of the chamber A is
provided a distributing tank A' formed of corrugated sheet metal having a number
of perforations o, which tank is filled with refrigerating liquid, that flows through
the perforations in the form of a shower on to the plates B. These plates are slit
at distances apart along their upper edge and the successive slit pieces B¹ are bent
alternately over in opposite directions to a slight angle, as shewn at Figure 3.
The refrigerating liquid in falling from the tank on to the slit portions of the
plates B, flows down these to the bottom of the chamber whence it is drawn by
a rotary pump E which conveys it back to the refrigerating machine through the
pipe F.
The cooled liquid is then reconveyed to the tank A' through the pipe D and
again flows down the plates B, and so on continuously.
An air propeller C draws in the air to be cooled at G and propels it through the
spaces between the inclined plates B. The air thus becomes cooled by its contact
with the liquid flowing down the plates, and with the spray of liquid falling between
them, and then passes away through the passage H to the chambers or apparatus or
objects to be cooled.
Figures 5 and 6 show a modification of the apparatus in which the inclined
plates B are arranged in the upper part of a chamber A, in the lower part of which
are situated refrigerating pipe coils a a in which refrigerating vapour is made to
circulate, the vapour entering at band issuing at c. These coils are immersed
in uncongealable liquid which is made to circulate by means of an agitating
propeller d.
The casing K enclosing the above parts is made of sheet metal.
This apparatus operates as follows:-
The uncongealable liquid cooled by the refrigerating coils a is raised by the
pump E through the pipes D F into the tank A' whence it flows down on to the
plates B as before. Owing to the slight inclination of the plates B the drops of
quid which may not fall on the upper slit portions of one plate will fall upon the
mclined lower part of the contiguous plate. The inclination is sufficiently slight
to allow of the liquid that flows on to the slit portions B to descend along both sides
of the plates.
By the above described arrangement the formation of rime in the refrigerating
apparatus is prevented, and a large amount of refrigerating surface is afforded
which is continuously supplied with cold liquid.
The corrugated form of the tanks A and the arrangement of the openings
therein also insure the moistening of the whole of the under surface of the tank and
thus prevent the formation of rime thereon, while at the same time insuring a
uniform distribution of the cold liquid over all the surfaces of the plates B.
The plates B are arranged very close together in order to obtain a large extent
of refrigerating surface in a comparatively small space, and to insure by the intimate
contact of the air with the moistened surfaces, the effective cooling of the whole
body of air forced through by the propeller C. The air is thus cooled firstly by
the radiation from the plates on both surfaces of which the refrigerating liquid flows
down, and secondly by the direct mingling of the air with the shower of refrigerating
liquid passing down between the plates. The action of the apparatus is therefore
exceedingly energetic, enabling a maximum refrigerating effect to be produced with
a minimum extent of apparatus.
The air in becoming cooled gives off its moisture to the refrigerating liquid,
which renders it necessary to increase the amount of brine in the refrigerating
liquid after a certain time.
Figures 7, 8 and 9 shew respectively a longitudinal section, a cross section and a
sectional plan of an arrangement in which the upright plates are replaced by
refrigerating coils a divided into several compartments separated from each other
by means of isolating partitions e. The refrigerating vapour is made to circulate
through the coils, entering at 6 and issuing at c. The air to be refrigerated is
propelled by the fan C in contact with the outer surfaces of the pipe coils.

page_text: Above these coils there are arranged in each compartment pipes A having the
same form in plan as the coils, and which are perforated over their entire upper
surface with small holes through which an uncongealable liquid can flow uniformly
and alternately over the upper surface of the pipe coils of each compartment.
In cach compartment the inlet and outlet extremities of the pipes A¹ for the
uncongealable liquid are connected together by a branched main supply pipe g at
the inlet end. and a branched main discharge pipe at the outlet end.
The pump E draws the urcongealable liquid, as before, from the bottom of the
chamber and forces it through the pipe F into the pipes A¹ again.
Flaps V are pivotted to the entrances of the compartments at the inlet end, for
the purpose of enabling the circulation of air to be interrupted in any one of the
compartments.
Assuming that the refrigerating vapour is circulating through all the coils a and
that the air to be cooled circulates over the outer surfaces, then as soon as these
surfaces begin to be coated with rime, the circulation of the refrigerating vapour
and the air is stopped in one of the compartments by closing the cock on the
corresponding supply pipe and also the corresponding flap V, and the coils of that
compartment are then subjected to a shower of uncongealable liquid supplied by
the pump to the pipes A¹ of the said compartment.
The uncongealable liquid falling in showers from top to bottom over the surfaces
of the coils will rapidly melt the rime. As soon as this is melted the circulation
of vapour and air is renewed in the said compartment, and a second compartment is
then acted upon in the same manner as above, then a third, and so on, in continual
rotation.
By this means clean dry surfaces are acted upon, without mixing the air with the
uncongealable liquid. When this mixture is not detrimental, the same arrangement
will allow of effecting the removal of the rime in one or several compartments at
the same time without interrupting the circulation of the refrigerating vapour
through the coils, or that of the air over the outer surfaces thereof. It is therefore
possible according to circumstances, to effect the cooling of the air partly by contact
with dry surfaces and partly by surfaces over which uncongealable liquid is made
to flow.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is :-
Means for effecting the refrigeration of air at low temperatures without formation
of rime, presenting the following characteristic features:-
1. The distribution of refrigerating liquid over an upper tank of corrugated sheet
metal perforated with numerous holes, through which the liquid flows in showers
onto sheet metal plates placed directly under the tank and over which the air to be
cooled is made to flow.
2. The arrangement of the sheet metal plates in groups slightly inclined and
placed very close together, the upper ends being slit and the slit portions bent to an
angle in alternately opposite directions, so as to insure the distribution of the liquid
over both surfaces of each plate and the prevention of rime.
3. The arrangement of coils, for the circulation of the refrigerating vapour,
contained in several compartments in any one or more of which the circulation of
the vapour and the air can be interrupted at will and the removal of rime effected
by the flow of uncongealable liquid over the surfaces covered with rime, while at
the same time the air circulates over the dry and clean surfaces of the other
compartments.
Dated this 14th day of February 1896.
ABEL & IMRAY,
Agents for the Applicant.