Improvements in Refrigerating Machinery.
Year: 1892

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the latents, &c., Act, 1883), as allowed by
the decision of the Chief Examiner of the 22nd day of September 1896.
Date of Application, 1st Mar., 1892
Complete Specification Left. 1st Dec., 1892-Accepted, 14th Jan., 1893
PROVISIONAL SPECIFICATION.
Improvements in Refrigerating Machinery.
1 RICHARD JOHN CRACKNELL of 50 Finsbury Park Road, in the County of
Middlesex, Engineer, do hereby declare the nature of this invention to be as
follows;
This invention relates to refrigerating machinery working on the ammonia
work intermittently
absorption principle and especially to those machines which
as evaporators and
and have two ammonia boilers which are alternately used
absorbers so that when one is an evaporator the other is an absorber. Machines of
this class as hitherto made are very efficient owing to the time taken up and the
loss of heat involved at every reversal of the operation before the machine assumes
its normal working conditions. The loss of time seriously affects the action of that
part of the apparatus when the cooling is effected. There have also been no proper
means hitherto provided to enable the weak ammonia to absorb quickly the full
amount of ammonia gas which it was capable of taking up.
The object of this invention is to overcome these defects, which I accomplish in
the following manner. I provide machinery of the class herein before referred to
with means for opening communication between the vapour chambers of the two
ammonia boilers.
When it is required to reverse the operation the machine. can be much more
quickly brought to its normal working condition by opening this communication,
thereby transferring heat from. the boiler which for the time being is acting as an
absorber and which it is required to cool, to the other boiler which will presently.
require to be heated. By this means a considerable saving of heat is effected.
By opening communication between the two ammonia boilers as aforesaid, two
other advantageous results will be produced. (1) The ammonia solution in the
absorber boiler will become weaker, and will consequently absorb more of the
ammonia gas; and (2) The strength of the solution in the other boiler will be
increased.
..
To enable the weak ammonia, to absorb its full amount of ammonia gas I provide
means whereby the gas on entering the boiler where it is to be absorbed, causes the
weak ammonia solution contained therein to circulate, thus continually bringing a
fresh quantity of liquid into contact with the entering gas, and with the surface of
the containing vessel which is kept cool in any suitable manner.
F: W. GOLBY..
36 Chancery Lane, London, "W.C., Patent Agent for the Applicant,

page_text: COMPLETE SPECIFICATION (AMENDED).
Improvements in Refrigerating Machinery.
I RICHARD JOHN CRACKNELL of 19 Church End Villas, Finchley, in the
County of Middlesex, and late of 50 Finsbury Park Road also in the County of
Middlesex, 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:—
This invention relates to refrigerating machinery working on the ammonia
absorption principle, and especially to those machines which work intermittently
and have two ammonia boilers which are alternately used as evaporators and
absorbers, so that when one is an evaporator, the other is an absorber.
Machines of this class, as hitherto made, are very inefficient owing to the time
taken up and the loss of heat involved, at every reversal of the operation before
the machine assumes its normal working conditions. This loss of time seriously
affects the action of that part of the apparatus where the cooling is effected.
There have also been no proper means hitherto provided to enable the weak
ammonia to absorb quickly the full amount of ammonia gas which it was capable
of taking up.
The object of this invention is to overcome these defects, and this I accomplish
in the following manner:- provide machinery of the class hereinbefore referred
to with means for opening communication between the vapor chambers of the two-
ammonia boilers. When it is required to reverse the operation, the machine can
he much more quickly brought to its normal working condition by opening this
communication between the two ammonia boilers, thereby transferring heat from
the boiler which is about to be used as an absorber, to the other boiler which
requires to be heated. By this means a considerable saving of heat is effected.
By opening communication between the two ammonia boilers as aforesaid, two other
advantageous results will be produced:-
(1) The ammonia solution in the absorber boiler will become weaker and will
consequently absorb more of the ammonia gas, and (2) the strength of the solution
in the other boiler will be increased.
To enable the weak ammonia to quickly absorb its full amount of ammonia gas,
I provide means whereby the gas on entering the boiler where it is to be absorbed.
causes the weak ammonia solution contained therein to circulate, thus continually
bringing a fresh quantity of liquid into contact with the entering gas, and with the
surface of the containing vessel which is kept cool in any suitable manner.
In order that my invention, and the manner in which the same may be carried
into practice, may be well understood, I will further describe it with reference to
the accompanying drawings wherein
Figure shews refrigerating mechanism constructed and arranged in accordance
with this invention;
Figure 2 is a part, longitudinal section of one of the ammonia boilers; and
Figure shews sections of the three different positions of the three way cock Z
shown in Figure 1.
A and B are the ammonia boilers which act alternately as generators and
absorbers, and as both are alike in construction, a description of one will serve for
both. The ammonia boiler consists of a cylindrical vessel S having inside it, two
coils, through one of which U. steam is passed when the vessel is used as it
generator, water being passed through the other coil T when the vessel is used as
an absorber.
Suitable means may be provided so that one movement of a lever
will admit steam to one hoiler and water to the other. C is a pipe opening
communication between the upper parts or vapour chambers of the two boilers A
and B, or for opening communication between either boiler and the returu gas

page_text: pipe D leading from the cooling pipes E. At the junction of the pipes C and D is
a three way cock Z, sections of which are shewn in Figure 3. When the cock is
turned into the position shewn at a, communication is opened between the pipe D
and the generator A; when it is turned to the position shewn at e, the pipe D is
open to the generator B; and when it is turned to the position shewn at 6 com-
munication with the pipe D is cut off, and the two generators A and B are open to
each other. Within the boiler the pipe C tapers inwards at its extreme end which
latter opens into a constricted chamber F, the outlet from which is situated just
above the dotted line f which represents the maximum height of the liquor
ammonia when the vessel is fully charged. Opening communication with the
chamber F. is a vertical pipe G, the lower end of which reaches to near the bottom
of the boiler. As the ammonia gas entering by the pipe C passes through the
chamber F, it will create a partial vacuum in the said chamber, causing the liquor
ammonia to be drawn up through the pipe G, into the chamber F and to be
discharged therefrom in the form of a spray with which the entering gas will be
intimately mixed. By this means the weak liquor ammonia will be constantly
agitated and circulated by the entering gas whereby the latter will be quickly
absorbed by the weak solution.
The
Each of the ammonia boilers A and B is furnished with a pressure gauge A, B,
and with a pipe A² B² leading from the vapour chamber to a common pipe H
passing to the rectifier J. X and Y are stop cocks respectively for the purpose of
placing either the boiler A or the boiler B in communication with the pipe II.
Any suitable form of rectifier may be adopted, although
constructed and arranged as shewn at T Figure 1.
prefer to use the form
The vessel J where any watery
vapour which may pass over with the ammonia gas is condensed. is of cylindrical
form, closed top and bottom, with two pipes passing through the top cover.
gas entry pipe H is continued inside the rectifier to near the bottom thereof so that
the gas is discharged at the lower end of the rectifier. The gas exit pipe K leading
to the condensing coil N is furnished with a check valve L to prevent the gas
passing back into the rectifier J. The rectifier J is situated within the convolutions.
of the condensing coil N which latter is contained within a casing M through
which water constantly circulates from the bottom to the top, as in ordinary
condensers of this description. The bottom of the condensing coil discharges into
a receiver from whence a pipe 0 leads to the cooling pipes E, in which the
ammonia is expanded, and situated in the room or other place which is to be cooled.
or into the ice box, when the machine is used for ice making. P, is a valve for
regulating the quantity of ammonia to be passed into the cooling pipes E, and Q is
a check valve to prevent the return of gas into the cooling pipes E after it has
passed said valve Q in its passage through the return gas pipe D leading to the
absorbing boiler.
The
To bring the machine to a working condition, the following preliminary operation
will be required. This preliminary operation would only have to be performed
once, namely when the machine is first started to work. A charge of ammonia of
say 880 specific gravity is placed in each of the ammonia boilers A and B, but not
more than will reach to the height indicated by the dotted line in Figure 2.
The cocks are placed in the position shewn in Figure 1, viz.:-the cock X open,
the three way cock Z in the position Figure 3, and the cock Y, and the regulating
valve P. closed. Heat is applied to the boiler A by the steam coil U, and the
ammonia gas passes off into the rectifier J, condenser N, and receiver R.
pressure rises to about 120 lbs. per square inch, according to the temperature of
the condensing water. As the gas passes through the rectifier. any watery vapour
it may contain is condensed and falls to the bottom, where it remains until it is
returned to the boiler as will be explained hereafter. When as much of the
ammonia gas in the boiler A as can be driven off, has been condensed, the cock X
is closed and the steam shut off. The liquor remaining in A is what is technically
known as "weak liquor." The three way cock is now turned round into the
position shewn at b, Figure 3. This opens communication between the two boilers,
T

page_text: and the ammonia gas rushes out of A into B, bringing down the pressure in, and
cooling A, raising the pressure in and heating B. It will ouly be necessary to
keep the three way cock in this position sufficiently long to equalize the pressure
in A and B which can be ascertained from the gauges A and 1 when the cock Z
is turned into the position shewn at in Figure 3. This opens communication
between the cooling pipes E and the boiler A which now becomes. the. absorber.
There is now a pressure in the condenser and rectifier of about 120 lb., and in the
two boilers of say about 50 lbs. per square inch. The cock X is next opened and
immediately the watery vapor in the bottom, of the rectifier J is, by the greater
pressure therein, blown over into the boiler B. Steam is now admitted to the
coil U in B which now becomes the generator, and cold water to the absorber A,
and the ammonia gas is driven off from B through the rectifier, and, as soon as the
pressure reaches about 120 lbs., into the condensing coil, where it condeuses as
before, the watery vapour remaining behind in the rectifier. During this time the
pressure in the absorber boiler A, is falling. The regulating valve P' may now be
opened and the liquid ammonia will begin to flow into the cooling pipes E where
it vapourizes and thus cools the room or other place, or the ice box, as the case
may be, the ammonia vapour flowing back through the return gas pipe D to the
absorber A. where it is absorbed. After a lapse of time sufficient to enable the
weak liquor in A to absorb all or nearly all the ammonia gas which was evaporated
off from it, the cock Y is closed, steam is run off from B and into A, cold water is
run off from A and into B, the three way cock Z is turned first into the position
and then into the position shewn at Figure 3, and B. now becomes the absorber
The cock X is opened, and the condensed liquor in the rectifier blown back into the
generator A, and the gas in this vessel is driven off and condensed as before.
Thus the cooling process goes on almost continuously, the pressures in the condensing
coil and cooling pipes remaining constant.
I wish it to be distinctly understood that I do not limit myself to the use of a
three way cock, as any mechanical means for opening communication between the
vapour chambers of the two boilers may be adopted without departing from the
nature of this part of my invention.
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
The general arrangement and combination of parts forming my improvements
in refrigerating machinery working on the ammonia absorption principle, designed
so as to operate substantially in the manner and for the purpose herein described
and shewn in the drawings.
1000
F. W. GOLBY,
36, Chancery Lane, London, W.C., Patent Agent for the Applicant.