refrigerating appar
Year: 1886

page_text: I, WILLIAM HENRY BECK, of 115 Cannon Street, in the City of London, Con-
sulting Engineer do hereby declare the nature of my said 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 two
sheets of drawings, and to the letters and figures marked thereon :-
My invention relates to improvements in refrigerating apparatus of the kind for
which Letters Patent were granted to Rees Reece, dated respectively, the 31st May
A.D. 1867, No. 1621, and the 2nd November A.D. 1870 No. 2891, that is to say,
in refrigerating apparatus in which gaseous ammonia is distilled from its aqueous
solution, rectified and condensed in a more or less anhydrous form, then expanded
in a refrigerator so as to do refrigerating work on some body subjected to its
cooling action, then absorbed into a weak solution of ammonia derived from the
still or generator, and the strong solution of ammonia thus produced returned to
the still or generator. My improvements relate firstly to that portion of the
apparatus in which the distilling of the ammonia is effected, and the object of this
part of the improvements is to separate the water from the ammonia more perfectly
than heretofore so as to make the ammonia as anhydrous as possible, it being of
the utmost importance for the efficient working of refrigerating apparatus of this
kind that the ammonia passing into the refrigerator shall be as free from water as
possible. Another object of this part of my improvements is to cheapen and
simplify the construction of certain parts of the distilling apparatus. The improve-
ments relate secondly to that portion of the apparatus in which the absorption of
the ammonia gas by water, or a comparatively weak aqueous solution of ammonia
is effected, and the object of this part of the improvements is to facilitate such
absorption. And the improvements relate lastly to the general arrangement of the
apparatus so as to simplify and cheapen its construction.
Figure 1 of the drawings hereto annexed, represents a transverse vertical section
of an ammonia distilling apparatus with the first part of my improvements applied
thereto. A is the boiler or generator constructed as usual with a coil or serpentine
of steam pipe B for heating the ammonia solution contained in the generator A.
C is the analyser vessel which may be placed on the top of the generator A, and
[D11

page_text: put in direct communication therewith, by the holes D, or it may be placed at a
distance from the generator A and be connected therewith by pipes. The analyser
vessel C is closed at the top with a cover in the usual way. E is a wrought iron
or steel internal casing suspended by its flange F in the analyser vessel C. In this
internal casing E are placed the shallow trays G G¹ forming the analyser plates.
They are preferably made of sheet iron or steel, each alternate tray G is rivetted
or bolted by its turned-up edge to the casing E, and each intermediate tray G¹ is
made somewhat smaller in diameter than the casing E and is supported from the
tray G beneath by short pillars or standards G. The trays G¹ are perforated with
holes H about inch diameter, punched through them from their under sides, the
edges of these holes being drifted or set by a suitable tool so as to stand up round
the holes as shown in the drawing, whereby a series of short adjutages are formed
favourable to the passage upwards through them of the vapours disengaged from
the solution in the generator A and from the solution retained upon the said
trays in the spaces between the margins of the holes H. Each alternate tray G,
has a larger opening J for the passage of vapour which is thus caused to impinge
upon the underside of the tray Q' next above and to be thereby broken up_80
as to facilitate the separation of the water from the ammonia vapour. The
solution entering the analyser by the pipe Q is conducted from tray to tray as it
becomes weaker by overflowing round the outer edge or lip of the trays G¹ and
round the lip of the openings J in the trays G. Holes or passages R¹ are made in
the inner casing E for the purpose of equalizing the pressure in the generator A
and in the analyser. Instead of perforating the trays with a series of holes
I sometimes provide only the central hole in each alternate tray leaving only
the narrow annular space between each intermediate tray and the casing E, for
the passage of the vapour as shown in connection with the four upper trays in
Figure 1. Above the trays G and communicating with and surrounding the mouth
of the vapour outlet pipe K, may be placed an outlet chamber L of any suitable
shape and perforated with a sufficient number of small holes as shown, each about
or inch diameter or the said outlet chamber may be formed of iron wire gauze.
All the ammonia and other vapour escaping from the plates of the analyser is
forced to pass through the holes or through the meshes of this chamber L and is
thereby still further broken up and the watery particles separated therefrom and
allowed to return from tray to tray of the analyser to the generator A.
•
Figure 2 represents a vertical section of an ammonia rectifier with the first part
of my improvements applied thereto. C is a strong vessel with a cover, somewhat
similar to the analyser shown in Figure 1. This vessel contains an internal
casing E with a series of trays G G₁ and perforated chamber L similar to those
indicated by the same letters of reference in the analyser, Figure 1. M is a coil of
pipe connected at its upper end with the outer pipe K of the analyser and at its
lower end with the lower part of the vessel C, which has an outlet N from the end
of which a pipe leads back to the generator A at the point N' for example (see
Figure 1), or to a separate vessel. The whole apparatus is contained in a tank O
through which there is a circulation of cool water coming from the condenser tank.
The vapours coming over from the analyser traverse the coil M, which is similar
to that comprising a rectifier as usually employed in ordinary distilling apparatus
and any water condensed therein flows into the lower part of the vessel C and
thence through the outlet N back to the generator A or to abovementioned separate
vessel from which it can be withdrawn from time to time, and returned to the
generator A by the return liquor pump. The vapours are then forced to pass
through the holes in the trays G and in the chamber L before finally leaving by
the pipe P leading to the condenser. The constant subdivision of the vapour by
passage through the numerous holes, and the frequent impact of the streams of
vapour thus formed against the lower surfaces of the trays G₁ and the impact
of these streams against one another in the chamber L has the effect of condensing
the watery vapour and of separating it from the ammonia vapour, the said con-
densed watery vapour passing down from tray to tray and ultimately escaping in

page_text: the form of a solution of ammonia into the bottom of the vessel C whence it
escapes back to the generator A, or to the separate vessel above mentioned by the
outlet. N.
The arrangement of the inner casings E and trays G G¹ as above described,
enable these parts of the analyser and rectifier to be cheaply constructed, and to be
easily and quickly taken out for inspection or repair, and to be easily and quickly
replaced.
Figure 3 represents a vertical section of an ammonia absorber with the
second part of my improvements applied thereto. A is a primary absorption vessel
of cylindrical or other suitable shape, with an air tight cover B, and a closed
bottom C. From the centre of the bottom C of this vessel rises an overflow pipe D,
and in the annular space bounded by the said overflow pipe D and the sides of the
vessel A, is placed a coil of pipe E, for the circulation of cold water or several such
coils, one within the other, may be employed, according to the size of the apparatus.
Below the vessel A, and jointed air tight thereto, is a secondary absorption vessel F,
containing a coil of pipe G for the circulation of cold brine, or of a separate current
of cool water, or of cold water cooled to a lower temperature than that of the
condensing water by the refrigerating action of the machine itself or by other
means. His a pipe for the admission of gaseous ammonia from the refrigerator ;
it passes down through the upper vessel A, to the lower part of the vessel F, it is
closed at the lower end and perforated with a number of small holes below the
level of the liquid in the vessel F. Branches H¹ of the same pipe perforated with
small holes near their lower ends pass down to near the bottom of the annular
space round the overflow pipe D. I is a pipe for conveying the weak liquor
coming from the generator to the lower part of the vessel A. J is the outlet for
strong liquor going back to the analyser, or direct to the generator, according to
circumstances. L is a gauge to indicate the level of the liquor in the vessel F and
L is a pressure gauge to indicate the internal pressure. The weak liquor coming
from the generator, partly cooled as usual in the temperature exchanger, and in the
cooler H (Figure 4), enters the upper vessel A by the pipe I, and is delivered
to the lower part of the annular space of such vessel and rises therein, absorbs
therein as much of the ammonia gas entering by the pipe H and its branches H¹
(Figure 3) as it will take up at the temperature to which the cooling water
traversing the coil E is able to reduce it, being subjected, as it does so, to the
cooling effect of the water passing through the coil E which water takes off the
heat generated by the absorption of the ammonia by the weak liquor. On reaching
the upper edge of the overflow pipe D the liquor thus strengthened flows over and
passes down the said pipe and falls upon a perforated tray M, whence it is delivered
to the lower part of the vessel F below, is there further cooled by the cold brine or
cooled water passing through the coil G, and is thereby reduced to a temperature
below that to which it can be reduced by the action of the ordinary cooling water
alone. It is thereby enabled to absorb more ammonia gas entering through the
straight part of the pipe H so as to become more strongly impregnated or saturated
with ammonia than when reduced only to the temperature of ordinary cooling
water. The cold brine circulating through the coil G need be only a comparatively
small portion of the total quantity of brine cooled by the refrigerator; or the
cooled water, when such is employed instead of brine, need only be in such quantity
and reduced to such temperature as will produce the desired increased absorbing
effect; and although it would appear at first sight that as the abovementioned
additional reduction of temperature of the liquor is produced at the expense of a
certain fraction of the refrigerating effect of the apparatus, there could be no gain
of useful effect thereby, yet, when it is considered that the efficiency of the whole
refrigerating apparatus is very largely dependent upon that of the absorber, and
that the latter is very liable to imperfect action, especially when the cooling water
is comparatively hot, as in warm climates for example, it will be readily under-
stood that the increased efficiency of the absorber not only in some cases balances
the fraction of power expended to produce it, but yields a further advantage in

page_text: respect of increased regularity and certainty in working, and a corresponding
reduction in the trouble and cost of supervision.
The circulation of cold brine or of cooled water through the secondary absorber
is not required when the temperature and pressure in the absorber is such as will
allow of the absorption of gas in sufficient quantity; but when the temperature
and pressure is too high, the use of cold brine or cooled water is a convenient
means of reducing the same and securing efficient action in the absorber. When
cold brine or cooled water is not being used in the secondary absorber the ordinary
condensing water may be passed through the coil therein before entering the coil
in the primary absorber, suitable bye pass pipes and cocks being arranged for that
purpose.
Figure 4 is a sectional elevation and Figure 5 a plan showing the general
arrangement of an apparatus constructed in accordance with the third part of my
improvements, and embodying the improved analyser and rectifier forming the first
and second parts thereof. A is the generator constructed in the usual way, B the
analyser constructed as shown in Figure 1, C the rectifier constructed as shown in
Figure 2, D the condenser, E the liquid ammonia receiver, F the refrigerator, G the
temperature exchanger, (each of the parts D, E, F and G being of the usual con-
struction), H is a cooling coil, through which the weak liquor passes on its way to
the absorber, I the absorber constructed as shown in Figure 3, J the ammonia
pump for returning the strong liquor to the analyser or generator in the usual
way, K the brine or cold water pump for supplying the coil G in the absorber
(Figure 3), L the steam or other motive power engine for operating the said pumps
and giving motion by belting or otherwise to agitating gear for making trans-
parent ice, to hoisting gear for raising the blocks of ice out of the congealing tank,
or to any other machinery to which it may be required to give motion.
It will be seen that the rectifier C, the condenser D, the liquid ammonia
receiver E, and the weak liquor cooler H, are all contained in separate compart-
ments of an open tapped tank M. The condensing water first passes through the
upper coil in the absorber I thence it passes by a pipe N into the bottom of the
compartment of the tank M containing the weak liquor cooling coil H, and passes
over the top of the partition M¹ into the compartment containing the liquid
ammonia receiver E, thence it flows under the partition M2 into the compartment
containing the condenser D, thence over the partition M³ into the compartment
containing the rectifier, and after passing through the said compartment, it flows
away to waste by an overflow pipe P or otherwise. Or the cooling water may be
caused to flow through the compartments of the tank in any other suitable order.
By these arrangements the apparatus is made more compact than heretofore and
its construction is simplified and cheapened, while the inspection of every part for
repair or cleansing is much facilitated.
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:-
First In the analyser or the rectifier of an ammonia absorption refrigerating
apparatus the use, with or without a finely perforated or wire gauze chamber com-
municating with and surrounding the mouth of the vapour outlet pipe, of a series
of sheet iron or steel trays, perforated or not with holes, the edges of which are
drifted or set up so as to form short adjutages, each alternate tray having a central
opening and each intermediate tray an annular space left between its circumference
and the containing casing, as herein before described, and illustrated in Figures 1
and 2 of the drawings hereto annexed, and for the purposes specified.
Second In the analyser or the rectifier of an ammonia absorption refrigerating
apparatus the use of an inner sheet or plate metal casing in which the water
separating trays are secured, and which, together with such trays, can be easily
removed from and replaced in the analyser or rectifier vessel, as hereinbefore
described and illustrated in Figures 1 and 2 of the Drawings hereto annexed.

page_text: Third The construction of the absorber of an ammonia absorption refrigerating
apparatus with a primary absorbing vessel in which the absorption of the ammonia
gas is effected to an extent dependent upon the temperature of the ordinary cooling
or condensing water, combined with a secondary absorbing vessel in which a further
absorption of the ammonia gas is effected by the cooling action of a current of cold*
brine or of water cooled to a temperature below that of the ordinary cooling or
condensing water used in the primary absorber, as hereinbefore described, and
illustrated in Figure 3 of the Drawings hereto annexed, and for the purpose
specified.
Fourth In an ammonia absorption refrigerating apparatus the arrangement of
the weak liquor cooler, the liquid ammonia receiver, the condenser, and the rectifier
in a single open topped tank having divisions arranged so as to ensure the passage
of the cooling or condensing water successively through each compartment, as
bereinbefore described, and illustrated in the drawings hereto annexed, and for the
purposes specified.