Improvements in Apparatus for Condensing, Evaporating, or Refrigerating Fluids.
Year: 1894

page_text: Date of Application, 4th Oct., 1894
Complete Specification Left, 3rd July, 1895-Accepted, 3rd Aug, 1895
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Condensing, Evaporating, or
Refrigerating Fluids.
I, EDUARD THEISEN, of No. 15 Werder Strasse, Baden-Baden, Germany,
Eugineer, do hereby declate the nature of this invention to be as follows:-
My invention relates to that description of apparatus for condensing, evaporating
or refrigerating fluids in which a thin film of liquid is made to flow down over the
outer or the inner surfaces of tubes while hot or cold air or gases are brought in
contact with such film so as to evaporate the liquid and thereby also to produce
cold for effecting the condensation of steam or other condensible vapour, or the
refrigeration of a liquid flowing in contact with the outer surface of the tube.
One of my present improvements has reference to that construction of such
apparatus in which the film of liquid is made to flow down the inner surface of the
tubes while a current of air is made to flow upward through the same for
evaporating the liquid, while the outer surfaces of the tubes are in contact either
with steam or hot gases to be condensed or to assist in the evaporation of the
liquid by imparting heat thereto. My improvement has for its object to prevent
the necessity of the an currents passing transversely through the liquid flowing
from the lower end of the tube before they can gain access to the interior thereof,
and thus to prevent the loss of effect by frictional resistance due to such an
arrangement.
For this purpose, the upper and lower ends of the tubes are fixed in flat shallow
boxes, in the bottom surface of the lower box, and m the upper surface of the
upper box openings are formed opposite the tubes and in these openings are fixed
trumpet mouthed nozzles projecting respectively into the lower and the upper end
of the tubes but leaving small annular spaces between them and the inner surface
of the tubes. Thus the liquid flows from the upper box down through the upper
annular orifice in a thin film over the inner surface of the tube and falls through
the lower annula ofice into the lower box, while the air curients flow freely
upward through the lower nozzles into the interior of the tube without having to
traverse the falling liquid, and the air charged with the vapour of the liquid issues
from the upper ends of the tubes through the upper nozzles
In cases where the upper receptacle is formed as an open tray, the upper nozzles
are fixed in the upper ends of the tubes by distance pieces, so as to leave the
requisite annular space between the two.
In the reverse aangement of the apparatus, namely where the film of liquid 18
made to pass down over the outer surfaces of the tubes whilo the fluid to be
iefrigerated or condensed is made to flow up through the interior of the tubes, the
lower ends of the tubes are fixed to troughs or gutters which catch the falling
liquid so that the fluid to be refrigerated or condensed will gain access to the
interior of the tubes below the troughs, without coming in contact with the liquid.
The uppe ends of the tubes are extended up through the upper tray containing
the liquid to be evaporated which flows down through a narrow annular orifice in
the tray surrounding each tube.
In either of the above arrangements, 1 prefer to provide the surface of the tubes
over which the film of liquid flows, with helically coiled wires of
any desired section
in a similar manner to that described in the Specification to my Patent No. 6700

page_text: of 1892, and, according to another improvement replace such wires by cords,
ropes, or strands of fibrous material, such as hemp, asbestos, and the like,
impregnated or coated with a suitable material such as paraffin, gutta-percha, and
the like, so as to render then more durable, as I find that such cords, ropes or
strands are more easily coiled round the tubes than the metal wires, and possess
sufficient durability when suitably impregnated.
Such ropes, cords or strands would of course only be applicable when applied to
the outer surfaces of the tubes, metal wines being necessary for the inner surfaces.
It will be obvious that such cords, ropes or strands are equally applicable to all
constructions of apparatus of the above mentioned kind in which a liquid film is
made to flow over the outer surfaces of the tubes, the object being to insure a
uniform and retarded flow of the, liquid over the entire surface of the tube, and to
prevent the liquid from being blown off the sui face of the tubes by strong current
of the evaporating air or gases, these results being obtained both by causing the
liquid to. flow helically round the tube in the channels formed between the
contiguous convolutions of the wires ou corde, and by the capillary, attraction
exercised by such wues or cords upon the liquid.
In some cases I also employ a combination of wires and fibrous cords or strands
for the above purpose in which case such combination may also be employed for
the interior of the tubes, as the wire affords the requisite stiffness. Also, in some
cases I construct the tubes of the above described apparatus with helical
Corrugations, either alone or in combination with the helically coiled wires, cords
or strands.
Dated this 1th day of October 1801
ABEL & IMRAY,
Agents for the Applicant
Improvements in Apparatus for Condensing, Evaporating, or
Refrigerating Fluids.
EDUARD THEISEN of No 15 Weider Strasse Baden-Baden Germany
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
-
My invention relates to that description of apparatus for condensing evaporating
or refrigerating fluids in which a thin film of liquid is made to flow down over the
uner surfaces of tubes while hot or cold air or gases are brought in contact with
such film so as to evaporate the liquid and thereby also to produce cold for affecting
the condensation of steam or other condensible vapour or the refrigeration of a
liquid flowing in contact with the outer su face of the tube.
My improvement has for its object to prevent the necessity of causing the
currents of air or gas to pass transversely through the hquid flowing from the
lower end of the tube before they can gain access to the interion thereof for
evaporating the liquid and thus to prevent the loss of effect by frictional resistance
due to such an arrangement.
For this pui pose the upper and lower ends of the tubes are fixed in flat shallow
boxes or trays in the bottom surface of the lower box and in the upper surface of
the upper box openings are formed opposite the tubes and in these openings are
fixed trumpet mouthed nozzles projecting respectively into the lower and the upper
end of the tubes but leaving small annular spaces between them and the inner
surface of the tubes. Thus the liquid flows from the upper box down through the
upper annular orifice in a thin film over the inner surface of the tube and falls
through the lower annular orifice into the lower box while the air or gas currents

page_text: flow freely upward through the lower nozzles into the interior of the tube without
having to traverse the falling liquid and the air charged with the vapour of the
liquid issues from the upper ends of the tubes through the upper nozzles.
The above described arrangement may be carried out either by employing &
single tray for receiving the liquid from the lower ends of a number of tubes as
described or each. tube may be provided with a separate tray or gutter of annular
form, the end of the tube being fixed to the outer circumference of such tray or
gutter while the nozzle is fixed to the inner opening of the tray or gutter, which is
provided with an orifice at one point for the discharge of the liquid flowing in.
This construction may also be constituted by turning inwards the lower end of the
tube so as to constitute both the tiny or gutter and the nozzle.
In cases where the upper receptacle is formed as an open tray the upper nozzles
are fixed in the upper, ends of the tubes by distance pieces so us to leave the
requisite annular space between the two.
In either of the above arrangements I prefer to provide the surface of the tubes
over which the film of liquid flows with helically coiled wires of any desired section
in a. similar manner to that described in the Specification to my Patent No. 6700
of 1892, and according to another improvement I replace such wires by cords,
ropes or strands of fibrous material such as hemp, asbestos, and the like, which
may be impregnated or coated with a suitable material such as paraffin, gutta
percha and the like,, so as to render them more durable, as I find that such cords,
ropes or strands are more easily coiled. round the tubes than the metal wires,, and
possess sufficient durability when suitably, impregnated.
Such ropes, cords or strands, would of course only be applicable when applied to
the outer surfaces of the tubes, metal wires being necessary for the inner surfaces.
It will be obvious that such cords, ropes or strands are equally applicable to all
constructions of apparatus of the above mentioned kind in which a liquid film 13
made to flow over the outer surfaces of the tubes, the object being to ensure a
uniform and retarded flow of the liquid over the entire surface of the tube, and
to prevent the liquid from being blown off the surface of the tubes by strong
currents of the evaporating an or gases, these results being obtained both by
causing the liquid to flow helically round the tube in the channels formed between
the contiguous convolutions of the wires or cords, and by the capillary attraction
exercised by such wires or cords upon the liquid.
In some cases I also employ a combination of wires and fibrous cords or strands
for the above purpose, in which case such combination may also be employed for
the interior of the tubes, as the wire affords the requisite stiffness. Also, in some
cases, I construct the tubes of the above described apparatus with helical
corrugations, either alone or in combination with the helically coiled wires, cords
or stiands.
The accompanying drawing shews at Fig. 1 a vertical section of an apparatus
for evaporating liquids constructed according, to one ariangement of my above
described invention as applied to the evaporation or concentration of a liquid.
A A are tubes, fixed at their upper ends in a tiny B, supplied with the liquid to
be evaporated or concentiated, by the pipe C; the lower ends of the tubes are fixed
in the top of a flat cbamber D, which receives the liquid flowing from the lower
ends of the tubes, and from which such liquid flows off through the branch E.
The bottom of this chamber has openings opposite the tubes A, provided with
nczzles F projecting up into the lower ends of the tubes, the upper mouths of the
nozzles being smaller than the inner diameter of the tubes, so as to leave an annular
orifico between them for the passage of the liquid Similar nozzles F are fixed by
distance pieces in the upper ends of the tubes A so as to leave an annular orifice
between the nozzle and the tube for the liquid to flow down from the tray B in a
thin film over the inner surface of the tube. The nozzles are of such a height
as to reach above the level of the liquid m the tray. The space G through which
the tubes A pass may either be a chamber or part of a flue through which hot gases,
such as those coming from a furnace pass; the space below the chamber D is open.

page_text: to the atmosphere which that above the tray B is either also open to the atmosphere,
or it may communicate with a flue for leading away the air charged with aqueous
vapour ising from the tubes A The internal surfaces of the tubes A are by
eference provided with helically coiled wires II, such as were described in the
Specification to my Patent No. 6700 of 1892 for the purpose of equalizing and
retarding the flow of liquid down the tubes, these may however also be used
without such helical wires or they may be formed with helical corrugations.
Thus the liquid flows from the tiny B in a thin film down the interior of the
tubes A, and falls thence into the chamber D, while the au currents enter the tubes
ecly through the nozzles F, and consequently do not require to traverse the
liquid falling from the tubes The external surfaces of these being heated by
the hot gases passing through the flue or chamber G, an effective upward draught
15 set up in the tubes, and the liquid, is rapidly evaporated by coming in contact
with the air currents while being at the same time heated externally by the
hot gases
It will be readily understood that the apparatus may be equally well applied
to the condensation of steam or refigeration of gases passing through the
chamber G by means of the cooling effect produced by the evaporation of water
or of a more or less volatile liquid flowing down the interior of the tubes
Fig 2 lens a modified construction in which each tube A has a separate
annular trough D fixed to its lower end as before des ribed, the mue edge of the
trough being extended upward so as to constitute the nozzle F for the admission of
air In order to facilitate the discharge of the liquid from the trough, I prefer to
make it of inchned form as shewn, and with a discharge opening at the lowest
point. Fig. 3 shews the same arrangement, formed by turning inwards the lower
ends of the tubes Fo that the part F constitutes the nozzle and the part D the
trough.
Having now particularly described and ascertained the naturo of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim 18.-
1. In apparatus for evaporating condensing and refrigerating flunds of the kind
herem eleired to, causing the air of gas required for the evaporation of the
liquid floning down the interior surfaces of the tubes to enter the tubes through
nozzles projecting up into the tubes through a tough or receptacle into which
the liquid from the interior of the tubes falls, so that such an or gas can enter
the tubes without requiring to penetrate through the falling liquid for this purpose,
substantially as described
2 In apparatus for evaporating, condensing and refrigerating fluids the com-
bination of tubes down the net surface of which a liquid is made to flow, a tray
o chamber at the lower ends of the tubes for receiving the liquid falling from the
tubes and nozzles extending upward through the bottom of the said tray or
chamber into the lower ends of the said tubes for affording a free passage of au
to the tubes for the purpose of evaporating the liquid flowing down them, an
annula space being provided between the tube and the nozzle for the escape of
the liquid substantially as described with reference to Fig. 1 of the drawings
3 The modified construction of the apparatus releired to in the pieceding
claims, wherein the lower end of each tube is provided with an annular trough and
mozzle either foin.ed thereon or fixed thereto, substantially as described with
reference to Figs 2 and 3 of the drawings.
4 lo apparatus for evaporating condensing and refrigerating fluids, the com-
bimation of tubes down the inner surface of which a liquid is made to flow a thi
film from a tray or chamber to which the upper ends of the tubes are fixed, a tray
o chamber at the lower ends of the tubes foi receiving the liquid falling from the
tubes, nozzles, extending upward through the bottom of the lower tray into the
lower ends of the said tubes so as to leave an annular ofice between the two for
the escape of the liquid, and other nozzle extending downward into the upper ends of

page_text: the tubes so as to leave an annular orifice between the two for the entrance of
liquid from the upper tray into the interior of the tube, substantially as and for the
purposes set forth
5. In apparatus for condensing refrigerating and evaporating fluids wherein
liquid is made to flow in thin layers over the surfaces of tubes or cylinders for the
purpose of being evaporated by currents of air or gases, the use of ropes cords or
strands of fibrous material coiled helically round the interior or exterior of the
tubes, such cords or filaments being employed either with or without treatment with
gutta percha, paraffin, or other protective substances substantially as described.
6. The combination with the cords or filaments of fibrous material referred to
in the preceding claim, of metallic wire or wires embedded therein, or interwoven
therewith, substantially as described.
7. In apparatus for condensing refrigerating and evaporating fluids such as are
above referred to, constructing the tubes with helical corrugations substantially as
described.
ABEL & IMKAY,
Agents for the Applicant.