Improvements in Condensers and Refrigerators used in Ice-making and Cooling Machines.
Year: 1894

page_text: Date of Application, 27th Feb.
004
Complete Specification Left, 26th Nov., 1894-Accepted, 29th Dec., 1894
Date of Applicatio,
Complete Specification Left, 26th Nov., 1894-Accepted, 29th Dec., 1894
PROVISIONAL SPECIFICATION.
Improvements in Condensers and Refrigerators used in Ice-making
and Cooling Machines.
PETER DUNLOP 10 Thurlow Terrace Larkhall Rise Clapham London S.W.
Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
My invention has for its objects increasing the efficiency and simplifying the
construction of condensers and refrigerators used for ice making and cooling
machines.
The condenser and the refrigerator are each constructed of a number of
comparatively short tubes, which may be straight or bent in U or similar forms,
through which the acting fluid is circulated, such fluids for instance as ether,
ammonia, carbonic dioxide, sulphurous anhydride or other fluids used for ice
making and cooling.
According to my invention I fix at the outlet or inlet end of each tube a nozzle
decreased or increased in diameter or form in a certain ratio to the pressure
and density of the acting fluid, a decreasing nozzle being used on the outlet of
condenser tubes, and an increasing nozzle on the inlet of refrigerator tubes.
These nozzles may be of any suitable form internally, such as parallel with a
round or other shaped aperture, tapering, conical or conoidal, annular, or annular
and conical combined. The aperture in the nozzle is not necessarily central with
the tube.
Another method consists in forming the nozzles in the plate, block or casting
into which the tubes are fixed. Also in fixing the nozzles to the plate, block
or casting in place of on the tube ends.
The practical effect of these improvements is to form a liquid piston in the
nozzle thus keeping the pressure practically uniform throughout the length of
each tube, obviating priming and irregularity in working and allowing ice making
and cooling machines to work with a less charge of fluid than heretofore.
Combined with these modifications may be used a return tube or tubes open
at the inlet end to receive the acting fluid from the discharge of the other tubes
and controlled at the outlet by a valve or valves.
Each return tube is exposed externally to the condensing or evaporating
medium used, the resulting action from the return tube or tubes is a reduction
of pressure in the space or spaces into which the other tubes discharge and a
corresponding circulation through these tubes.
The condenser and the refrigerator to which these improvements are applied
may be placed horizontally, or vertically or in any other suitable position.
Simplicity of construction is obtained by these improvements obviating the use
of a continuous length of coiled or bent tube or tubes with only one inlet and
one outlet for the acting fluid.
The condenser and refrigerator under my improvements being constructed with
a number of comparatively short tubes, the giving out of a tube affects the
particular tube only, and which may be stopped by a cap or plug at each end and
does not stop the working of the machine, but only for the time necessary to
to stop the tube, and also the efficiency of the machine is not seriously affected
even with a few tubes giving out and stopped as described.

page_text: It is to be understood that these improvements are equally applicable to the
absorption and compression systems for ice making and cooling, and also to
submerged and exposed pipes used for freezing and cooling.
Dated this 27th day of February 1894.
Improvements in Condensers and Refrigerators used in Ice-making
and Cooling Machines.
I, PETER DUNLOP Mechanical Engineer 10 Thurlow Terrace Larkhall Rise
Clapham S.W. 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 has for its objects increasing the efficiency and simplyfying the
construction of condensers and refrigerators used for ice-making and cooling.
In carrying out this invention the nozzles shewn by Sheets 1 and 2 of the
annexed drawings are used. The capital letters A, B, C, D, E, F, G, H, Sheet 1,
denote various forms of nozzles for application to the outlet ends of tubes and
plates in condensers.
A represents a tapering conical nozzle to screw on to the outlet end of each tube.
B is another form with an aperture out of centre, this aperture is put to the upper
side of the tubes in horizontal condensers when the nozzle is screwed in place, to
keep the tubes full of the fluid to ensure complete condensation and may be used in
the case of large tubes. C is a plug form to be driven into the outlet end of the
tube and may be used with brass or copper tubes. D is a conoidal form of nozzle
giving a very efficient discharge of the condensed liquid. E is an annular-conoidal
form that may be used where a retarded discharge of the condensed liquid is
required. F is a central and annular form of nozzle suitable for large diameter of
tubes, and, in condensers constructed of Serve or Mannesman tubes, or in the case
of small tubes where the velocity of the fluid is excessive, the annular liquid
discharge is used to help to liquify any uncondensed gas passing through the centre
of the tube and not coming in contact with the tube surface. G shews a nozzle or
aperture formed in the plate in which the tubes are held. H is a form of nozzle
screwed into the plate holding the tubes.
Sheet 2 shews some forms of nozzles applicable to the inlet ends of tubes for
refrigerators. The capital letters J, K, L, M, N, denote these forms. J is a
tapering conical form with a minimum aperture at the inlet end and increasing in
size this form may be pushed into the tube and held in place by a ferrule with an
.internal collar, screwed on to the end of the tube. K is a similar form to J but is
shewn for screwing on to the tube end. L is a tapering curved form with an
annular opening at its large end to ensure the liquid being distributed on the
internal surface of the tube, and may be used in the case of large tubes.
M shews the expanding nozzle formed in the plate carrying the tubes. N is the
expanding nozzle screwed into the plate.
The practical effect of the application of these nozzles to the outlet ends of
condenser tubes is to form a liquid piston in the nozzle and thus keeping the
pressure practically uniform throughout the length of each tube, and without
affecting the efficiency of the discharge as the liquid is many times less in volume
than the fluid before condensation, irregularity in working and priming is obviated,
comparatively short tubes can be used, of any simple form, and dispensing with
continuous lengths of pipes and coils so much used hitherto.
In the case of refrigerators the application of the forms of nozzles described
ensures a complete circulation and vapourisation of the liquid entering at the

page_text: minimum end of the nozzle. The expanding form of nozzle effectually prevents
any back pressure accumulating in the tube, the excess pressure at the large end of
the nozzle causes the circulation of the vapour towards the outlet of the tube.
Suitable proportions for the nozzles will depend upon the pressure, density and
velocity, and according to the fluid used.
The application of a nozzle to each tube, converts the tube into an independent
condenser or refrigerator, thus allowing of the working of the machine, even with a
number of the tubes stopped, and a lighter charge of the acting fluid may be used
without affecting the efficiency.
Sheets 3 and 4 shews the application of the nozzles to condensers and
refrigerators.
Figures 3 and 4 is a condenser or a refrigerator constructed of U shaped tubes a.
The tubes are held in the tube plate b, of the chamber c and with branches d and e,
and cover f. Enclosing the tubes is a casing g, of any suitable form with
branches h and i, a diaphragm plate j extends from side to side of the casing and
near to the bend of the inner tube. Figure 4 is an enlarged view with cover
removed to show the distribution of the tubes a.
Figure 5 is an enlarged view in section, of the outlet end of a condenser tube a,
with a nozzle B screwed into place on the end of the tube.
Figure 6 is an enlarged view in section, of the inlet end of a refrigerator tube a,
with a nozzle K screwed into place on the end of the tube.
Figure 7 is an enlarged view in section of a return tube k, referred to hereafter.
In the case of a condenser the fluid to be condeused enters by the branch d, into
chamber c passes into the tubes a, at their open end, circulates through the tubes
and passes out at the nozzle end into chamber c and by branch e, a diaphragm l,
divides chamber c into two, separating the inlet and outlet spaces. The condensing
liquid enters by branch h, travels along the surface of the tubes a, under the
diaphragm platej, up the end and along the upper side of the plate j, and out at
branch i, a complete condensation of the fluid inside the tubes a, is thus effected.
In the case of a refrigerator the liquid to he vapourised enters by the branch e,
into chamber c, passes into the tubes a, at the nozzle end, circulates through the
tubes and passes out at the open ends into chamber c and out at branch d. The
circulating liquid which may be brine, or other fluids used, enters by branch i, and
along the upper tubes a, down the end and along the lower tubes a and out at
branch h. Effective vapourisation and cooling is thus effected.
If a further condensation or vapourisation of the fluid is desired a return tube or
tubes k, may be used one end of the tube opens into the discharge space of the other
tubes and receives their contents.
Fig. 4, Sheet 3 shows a return tube k, opening into the discharge space of the
chamber e the enlarged view is shown by Figure 7, in this modification a U shaped
tube is used, one end is stopped by the plug m, and the contents pass out by
passage n, formed in the tube plate and which may be controlled by the valve o.
The return tube or tubes being exposed externally to the condensing or vapourising
fluid used, a reduction of pressure in the space or spaces into which the other
tubes discharge and a corresponding circulation is ensured.
The description and the figures shew the return tube applied to a condenser. In
the case of a refrigerator the return tube or tubes will be in the upper or discharge
space previously described of chamber c.
Sheet 4 shews the nozzle applied to other forms of condensers and refrigerators.
The same letters are used as in Sheet 3 for the various parts. Figure 8 is a
condenser constructed of plain tubes a. k, is the return tube. It is to be under-
stood that when the return tubes are used the discharge branch for the other tubes
is not then used, in the various figures.
The tubes a, are shewn in an open casing or tank g in which the circulation of
the condensing or vapourising medium may be effected in any convenient manner.
Figure 9, shows the nozzle end of refrigerator tubes constructed as in Figure 8.
Figure 10 represents a condenser or refrigerator constructed of central and

page_text: annular tubes. The same letters denote similar parts as in the previous descriptions.
In the case of a condenser the fluid passes first into the annular tubes a', down and
in at the lower end of tubes a, rising in these tubes and out at the nozzle end.
The reverse action takes place with a refrigerator the liquid entering at the nozzle
end of the central tubes a, down into the annular tubes a' and out at their
.open end.
Condensers and refrigerators to which these nozzles are applied, may be placed
in any position ranging from horizontal to vertical or into any irregular space,
without affecting the efficiency of such condensers and refrigerators.
In Sheets 3 and 4 the various figures are intended to show how the nozzles are
applied to condensers and refrigerators, and not necessarily to these forms
exclusively, they are intended more as examples.
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:
First. In a condenser for ice-making and cooling machines the application of
a nozzle or nozzles to the outlet or discharge ends of tubes and tube plates
such nozzles being reduced in size or form, or any mere modification thereof,
substantially as and for the purposes herein before described.
Second. In a refrigerator for ice making and cooling machines, the application
of a nozzle or nozzles to the inlet ends of tubes and tube plates, such nozzles
being increased in size or form or any mere modification thereof, substantially
as and for the purposes herein before described.
Third. In a condenser for ice making and cooling machines to which reduced
nozzles are applied, the combination of the said nozzles with one or more return
tubes through which the products of condensation pass before being finally
discharged, substantially as and for the purposes hereinbefore described.
Fourth. In a refrigerator for ice-making and cooling machines to which
increased nozzles are applied, the combination of the said nozzles with one or
more return tubes through which the products of vapourisation pass before being
finally discharged, substantially as and for the purposes hereinbefore described.
Dated this 26th day of November 1894.
PETER DUNLOP.