Improved Method of and Apparatus for Evaporating, Condensing, and Cooling Fluids.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improved Method of and Apparatus for Evaporating, Condensing,
and Cooling Fluids.
I, EDUARD THEISEN, of No. 15, Werder Strasse, Baden-Baden, Germany,
Engineer, do hereby declare the nature of this invention to be as follows :-
:-
My invention relates to apparatus for evaporating, condensing, and cooling
fluids in which these operations are effected by the surface evaporation of
liquids.
In order to increase the effectiveness of such apparatus, that is to say, in order
to render the abstraction of heat from the one side of the surfaces acted upon
and consequently the absorption of heat by the other side of such surfaces as
great as possible relatively to the size of the apparatus, it is, as is well known,
necessary on the one hand to cause a thin layer of liquid to flow over the one
side of the said surface, and on the other hand to cause a current of air or gas
to pass over such moistened side (the other side of the surface being made to
take up heat) which current is made to act as intensively as possible, in order to
produce an energetic evaporation of the said layer of liquid, inasmuch as the
stronger the evaporation on one side of the surface is, the greater is the
absorption of heat by the other side.
This increased evaporative action bas mostly been produced, firstly, by causing
a fan or other appliance to propel large quantities of air along the surfaces to
be acted upon, and secondly, for maintaining the flow of liquid over the surface,
it has been necessary to raise or propel a body of liquid by a pump or other
means, so that two separate mechanisms were necessary for carrying out the
operation.
My present invention has for its object to simplify the means required for the
operation, and consists in an inproved method of operating whereby the one
propelling device is dispensed with and the required two fold effect is produced
by the single action of jets of liquid subject to water, stenm, gas or air pressure,
which jets are made to produce not only an effectual moistening of the surface
to be acted upon, but also simultaneously to induce strong currents of air or gas,
the frictional contact of which with the layer of liquid will produce an intense
evaporative and cooling action.
Furthermore, this simple method of operating also has the effect of causing
the aqueous vapour resulting from the evaporation from the hot surfaces, and
which is carried along by the current of air or gas, to be partially condensed again
by contact with the injected liquid spray, while by admission of fresh quantities of
air as will be presently explained, such liquid spray, which furnishes the evaporative
liquid, can be cooled down again.
The complete or almost complete condensation of the vapours resulting from the
evaporation in the first evaporator or condenser, can be effected by subjecting the
air charged with the vapours to the condensing action in similar apparatus by
means of fresh quantities of air, with simultaneous moistening of the condensing
surfaces, so that practically only as much water will be lost as is taken up by the
saturation of the cooling air.

page_text: Thus, by my improved method of operating the following advantageous results
are obtained:
1. Effective moistening of the tubes or evaporative condensing surfaces.
2. The production of a strong air-current for the evaporation.
3. Re-cooling of the liquid employed for moistening the evaporative surface.
4. Partial regaining of the vapours resulting from the evaporation of the layer
of water.
This method of operating also produces an increased effectiveness of the action,
by the fact that the upward directed jets of liquid force the body of air carried
along with them in great part against the evaporative condensing surfaces, and it
thus not only comes in intimate contact therewith, but also, the air enters into
a reciprocal action with the film of liquid flowing down the surface.
By the not unconsiderable pressure of the air induced by the jets of liquid and
exercised against the liquid flowing down the evaporative surface there will be
obtained an increased effectiveness and consequently a good utilisation of the
induced air currents.
The apparatus for carrying out the above described improved method of
operating can be constructed in a variety of ways. Thus according to one
arrangement, where the liquid is made to flow in a thin layer over the inner
surfaces of vertical tubes while the fluid from which heat is to be abstracted is in
contact with the outer surfaces, the said jet of liquid may be situated at the lower
ends of the tubes, so that the liquid in being propelled into the tube and more or
less against the sides thereof will induce the requisite currents of air through the
tubes, and the liquid issuing from the upper end of the tube and falling on to a
plate or tray forming the top of the chamber in which the tubes are fixed, will
partly flow in a thin layer down the interior of the tube again and is partly drawn
off by a pump to be again forced thereby through the jets. According to another
modification, the jet is situated at a certain height within the said tube, and in
order to separate the liquid issuing at top from the liquid issuing from the other
tubes, the upper end of the tube may be surrounded by a second tube of somewhat
larger diameter and extending up any desired height, the liquid falling into the
annular space at the bottom of the upper tube being drawn off by a branch pipe.
This arrangement may also be used when the water jet is at the lower end of the
lower tube as in the first arrangement. The upper tube, which may be either
cylindrical or tapering, may have one or more circular rows of holes in it, or it
may be made of wire gauze, through the openings of which a fresh supply of air is
drawn by the jets or spray of liquid rising in the tube, which air will consequently
exercise a cooling action on the water before it passes back to the pump to be
again injected.
According to another modification, the water jet or jets is or are applied to the
exterior of the tubes, in the interior of which is the fluid from which the heat is to
be abstracted.
With this arrangement, the tube or a group of such tubes is surrounded by a
tubular casing into the lower end of which the water jet is injected, so as to induce
a current of air through the tubular casing, such air current being thus brought in
contact with the outer surfaces of the tubes over which the water from the jet is
made to flow.
The water that is not evaporated flows down the tubes and casing into a tray or
trough below and is drawn off by the pump.
According to another modification, the tubes through which the fluid from which
the heat is to be abstracted is made to flow are arranged either horizontally o
inclined or in the form of coils in a casing at the bottom of which are provided any
desired number of injector nozzles, through which jets of liquid issue that at th
same time are made to induce air currents, which, together with the liquid ar
propelled over the outer surfaces of the tubes, in order to produce the requisit
surface evaporation thereon.
This apparatus may be employed either as a condenser or refrigerator of th

page_text: Aluid inside the tubes, or it may serve mainly for effecting the evaporation of the
liquid injected, by means of hot gases passing through the tubes, the liquid that
is not evaporated and that falls into the bottom of the casing being either led
thence to the pump, to be again forced through the nozzles, or it may be directly
supplied to the nozzles again.
In all the above constructions the evaporative surfaces over which the layer
of liquid is made to flow may be either smooth, or corrugated or fluted for
increasing the surface, or they may have wires coiled helically round them as
described in the Specifications to my Patents No. 6700 of 1892 and No. 3664
of 1894.
A condenser operating according to my improved method can be constructed as
follows.
A closed casing into which the steam or other vapour to be condensed enters
at one end, and from which the air or other non condensible vapour is withdrawn
by a pump at the other end, has a series of the before described tubes passing
vertically through it, these being fixed in the top and bottom plates of the
chamber; at the lower end of each tube is situated a nozzle through which a
jet of water is injected into the tube, thereby also inducing air currents as
described. Surrounding the upper end of each tube is a slightly larger tube,
having one or more rings of holes near the bottom for the entrance of air, while
the upper ends project into the bottom of a box the upper side of which has a
series of concentric or otherwise arranged tubes, at the lower ends of which are
other nozzles connected with a water pressure supply, so as to propel water jets
up the tubes. Thus the water vapour carried along by the air from the con-
denser tubes into the. intermediate tubes will be there partially condensed by
the entrance of fresh air, the remainder passing through the box into the upper
tubes, where their condensation is completed by the combined action of the water
jets and the air currents induced by the latter, so that the condensing process
is carried on without any loss of water beyond that with which the air currents
are saturated and which is consequently carried away thereby.
The water used both for the lower and upper jets is collected in trays, together with
that resulting from the condensation of the vapour given off from the evaporating
surface and is led back to the pumps or other propelling apparatus, so that the
same body of water is made to circulate continuously, with only such small
addition as is necessary to make good the quantity carried off by the air.
Dated this 90th day of Max 1895.
ABEL & IMKAI,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Method of and Apparatus for Evaporating, Condensing,
and Cooling Fluids.
I, EDUARD THEISEN of No. 15 Werderstrasse, '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 apparatus for evaporating condensing and cooling fluids
in which these operations are effected by the surface evaporation of liquids.
In order to increase the effectiveness of such apparatus, that is to say, in order
to render the abstraction of heat from the one side of the surfaces acted upon and
consequently the absorption of heat by the other side of such surfaces as great as
possible relatively to the size of the apparatus, it is, as is well known, necessary on
the one hand to cause a thin layer of liquid to flow over the one side of the said
surface and on the other hand to cause a current of air or gas to pass over such

page_text: moistened side (the other side of the surface being made to take up heat) which
current is made to act as intensively as possible, in order to produce an energetic
evaporation of the said layer of liquid, inasmuch as the stronger the evaporation on
one side of the surface is, the greater is the absorption of heat by the other side.
This increased evaporative action has mostly been produced, firstly, by causing a
fan or other appliance to propel large quantities of air along the surfaces to be
acted upon, and secondly, for maintaining the flow of liquid over the surface, it has
been necessary to raise or propel a body of liquid by a pump or other means, so
that two separate mechanisms were necessary for carrying out the operation.
My present invention has for its object to simplify the means required for the
operation, and consists in an improved method of operating whereby the one
propelling device is dispensed with and the required two fold effect is produced by
the single action of jets of liquid subject to water, steam, gas or air pressure,
which jets are made to produce not only an effectual moistening of the surface to be
acted upon, but also simultaneously to produce strong currents of air or gas, the
frictional contact of which with the layer of liquid will produce an intense
evaporative and cocling action, while at the same time they will increase the
velocity which the vapour generator has attained through the difference of
temperature.
Furthermore, this simple method of operating also has the effect of causing the
aqueous vapour resulting from the evaporation from the hot surfaces and which is
carried along by the current of air or gas, to be partially condensed again by
contact with the injected liquid spray while by admission of fresh quantities of air
as will be presently explained such liquid spray, which furnishes the evaporative
liquid, can be cooled down again.
The complete or almost complete condensation of the vapours resulting from the
evaporation in the first evaporator or condenser, can be effected by subjecting the
air charged with the vapours to the condensing action in similar apparatus by
means of fresh quantities of air, with simultaneous moistening of the condensing
surfaces, so that practically only as much water will be lost as is taken up by the
saturation of the cooling air.
Thus by my improved method of operating the following advantageous results
are obtained :-
1. Effective moistening of the tubes or evaporative condensing surfaces.
2. The production of a strong air current for the evaporation.
3. The cooling of the liquid employed for moistening the evaporative surface.
4. Partial regaining of the vapours resulting from the evaporation of the layer
of water.
The above described method of operating can be carried out in a variety of
ways on the accompanying drawings I have shewn several arrangements of
appliances for this purpose.
Fig. 1 shews a vertical section of a tube, the inner surface of which is subjected
to the action of a water jet and induced air currents while the outer surface is in
contact with fluid to be condensed or from which heat is to be extracted.
Figs. 2, 3, 34 and 4 shew vertical sections of modified arrangements of the tube
and jet shewn in Fig. 1.
Fig. 5 shews a vertical section of an arrangement in which the water jet and
induced air current are applied to the outside of a series of tubes while the Huid to
be condensed or from which beat is to be extracted, passes through the tubes.
Fig. 6 shews a vertical section of a condenser with tubes and jets arranged as
shewn at Fig. 1;
Fig. 7 shews a vertical section of a modification of the condenser shewn at
Fig. 6.
Fig. 8 shews a longitudinal section and Fig. 8A a cross section of a condenser with
horizontal tubes over the outer surface of which the water jets and induced air
currents are made to flow, while the fluid to be condensed or from which heat is to
be extracted passes through the tubes.

page_text: Fig. 9 shews a vertical section of a condenser arranged similar to Fig. 6, but in
which a second set of water jets and tube are provided for condensing vapours
produced by the evaporation in the lower tubes.
In Fig. 1, A is a tube fixed in upper and lower plates B B¹ forming part of a
chamber into which fluid passes that is to be condensed or to have heat abstracted
therefrom. Below the lower end of the tube is a fixed nozzle or rose C through
which water or other liquid is forced under any desired pressure so as to enter the
tube at some velocity in the form of spray, whereby air or gas is drawn into the
tube at D, while the liquid jets are so directed as to partially serve to moisten
the inner surface of the tube and partially to force the induced air currents against
such moistened surface and thus constitute currents flowing in the contrary direction:
to that of the thin layer of liquid flowing down the inner surface of the tube,
whereby the vapours resulting from the vapourisation of such liquid will be carried
off by the air currents.
According to the greater or less force with which the fluid jets issue from the
tube A, a stronger or weaker air current will be produced. On issuing from the
tube, the water falls into a tray formed on the top B of the condensing chamber,.
whence it passes off, together with the water falling from the lower end of the
tube A, to a pump which again forces it through the nozzle C.
Fig. 2, shews a modification in which the tube A is corrugated instead of being.
smooth, the arrangement being otherwise the same.
Fig. 3 shews a modification in which the nozzle C for the liquid jet is situated in
the upper part of the tube A instead of below it. This arrangement is particularly
advantageous where it is desired that the air currents shall have a comparatively
high velocity.
The velocity of the liquid jet is of course highest, the moment it leaves the
nozzle, from which point it gradually decreases as it rises, until it reaches a point.
where the action of gravity overbalances the vis viva and the liquid consequently
falls again. As the liquid jets will only have the intended beneficial action as.
long as the speed of that part thereof which is within the tube A is greater than
the desired speed for the air currents, it follows that it is necessary, if the speed of
the latter is to be high, that only the lower portion of the liquid jet shall act.
within the tube, and consequently that the nozzle C shall be situated in the upper
part of the tube A, as at Fig. 3.
In this arrangement there is provided on the tray B, an enlarged open tubular
extension E surrounding the top of tube A, for the purpose of confining the spray
of the water jet and keeping it separate from the water of contiguous tubes.
The water flows down the inner surface of the extension and collects in the annular
space between the mouth of A and E, whence a portion is made to flow in a thin
layer down the inner surface of A again, while the remainder flows off through a.
pipe F, and, together with the water falling from the lower end of A, is fed back to
the pump to be again forced through the nozzle C. With this arrangement the air
that is drawn into A is always dry when it comes in contact with the wet surface
of the tube.
From what has been above stated it will be seen that it would be of advantage
to deflect laterally the upper part of liquid jet at a point where the liquid still has
a high velocity, so that the speed of the air currents induced by the lower part of
the jet shall not be retarded by coming in contact with the part of the jet travelling
at a comparatively low speed.
Figure 3 shews an arrangement for this purpose in which there is provided
within the tube E a second tube E¹ of wire gauze through which the liquid spray
passes while still at a high speed, so that the retarded part of the jet is collected
and flows downwards in the annular space between the tubes E and E', and is thus
prevented from interfering with the air currents passing up through the tubes.
This arrangement also has the advantage of preventing the formation, within
the centre of the tube, of liquid mist which would also interfere with the air
currents and which would be produced in the previously described arrangements.

page_text: by the water jets becoming pulverised in striking with force against the solid
surfaces of the tube E.
In the present case the liquid jets mostly pass through the meshes of the tube E¹
and there is consequently no such pulverisation.
In the arrangement at Figure 4, the nozzle C is at the bottom of the tube as
at Figure 1, and the tube E, similar to that of Figure 3, has a series of holes e
through which air is drawn in by the suction exercised by the water jets rising
through E, which air effects the cooling of the spraying liquid so that separate
means for effecting such cooling can be dispensed with.
In the arrangement shewn at Figure 5, the tubes G have the fluid to be
condensed or to have heat abstracted therefrom, flowing through them while the
liquid spray from the nozzle is made to impinge upon the outer surfaces of the
tubes, and at the same time to induce air currents through the surrounding casing H,
which air currents impinge upon the wet surfaces of the tubes and thus effect the
cooling thereof by evaporation. The liquid flowing down the tubes is caught in
troughs II and is led back to the pump.
Figure 6 shews a vertical section of a complete condenser constructed according
to my invention.
The exhaust steam enters the condensing chamber B B' through the inlet K and
any uncondensed gases are drawn off at the outlet L. A A are the tubes passing
through the chamber, at the lower ends of which are the nozzles C C, delivering
water jets into the tubes, and inducing air currents entering at D, in the same
manner as above described with reference to Figures 1, 2 and 4.
Over the upper ends of the tubes A are provided tubes E with openings for the
admission of air as at Figure 4. The water falling into the tray is led back,
together with that flowing from the lower ends of the tubes A, to the pump
supplying the nozzles C. The water of condensation is led from the chamber B B
through the pipe M.
Figure 7 shews the same construction of condenser, in which the upper tubes E¹
are made tapering and of wire gauze or perforated metal, the openings being
of sufficient size for the air to afford free access to the air for cooling, this being
drawn in by the action of the water jets within the tubes.
Figures 8 and 8 shew an arrangement of apparatus with horizontal tubes A, and
which can be used both as a condenser or refrigerator, or for evaporating liquids.
As in the arrangement at Figure 5, the fluid to be condensed or to have heat
abstracted therefrom passes through the tubes A from the inlet N to the outlet O,
while liquid under pressure passes from the nozzles Cover the outer surfaces of the
tubes, also falling back upon the same. At the same time air currents are induced
through orifices surrounding the nozzles.
The vapour resulting from the evaporation passes off with the air either through
the tube P, or, if the top of the casing is open, into the atmosphere. The liquid
that is not evaporated, falls into the bottom of the casing Q and is either led off
through a pipe to the pump, or it may be propelled upward again together with the
liquid and air jets by surrounding these with injector nozzles R.
arrangement an intimate mixture of the air and liquid will be effected which will
accelerate the evaporation.
By this
Figure 9 shews a vertical section of a complete condenser in which a second set
of liquid and air jets is provided for effecting the cooling of the liquid from the
lower jets and also to effect the condensation of the vapour resulting from the
evaporation. The lower part of the apparatus is of the same construction as
described with reference to Figures 6 and 7, the parts being indicated by the same
letters of reference they need not be farther described; the nozzles C Care
supplied by a pump T. The casing has a cylindrical upward extension S, within
which are concentric tubes S' S², through which consequently the mixed vapour and
air from the lower tubes A. F. rise. Below the annular spaces between the
tubes S S S are arranged nozzles C₁ C¹ supplied by a pump U. from which liquid
jets are projected into the annular spaces. These jets induce currents of air

page_text: entering through the openings V of the casing which currents combined with the
liquid jets refrigerate and condense the vapours rising through the tubes; the
resulting liquid falls back into the tray W. whence it is led through a pipe into a
vessel X from which the pump U draws its supply. Any liquid collecting at Y is
led through a pipe into a tray Z which also collects the liquid from the lower tubes
of the apparatus, and from which the liquid passes through a pipe into the vessel a
from which the pump T draws its supply.
Should a portion of the vapour escape uncondensed from the top of the
tubes S S S it may again be subjected to another series of liquid jets and air
currents for effecting its condensation, so that only so much of the liquid will escape
as will be taken up by the air at the temperature at which it passes oir from the
apparatus. By means of this apparatus therefore it is rendered possible to work au
engine with practically no loss of water, the same body of water being used over
and over again, which is of great importance both in localities where water
is scarce, and in cases where the water contains a large amount of solid impurities
that tend to form deposits in the boilers, as by. this means the body of water that is
used over and over again by degrees, becomes almost perfectly pure.
Fig. 10 shews a sectional plan of an arrangement in which a number of annular
condensing chambers B B B are arranged in a group within a casing a, and the
outer surfaces of which are acted upon by water jets C¹, in addition to the water
jets C acting ou the inner surfaces of each chamber, so that air currents are also
produced in the enclosed spaces surrounding the outer surfaces of the chambers
in the same manner as above described so that in this case a double condensing
action is obtained.
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 :-
1. In apparatus for evaporating, condensing and cooling fluids wherein a thin
layer of liquid flowing over surfaces is subjected to the evaporating action of
currents of air or gases, the method of causing the liquid required for moistening
the said surfaces to issue under pressure and thereby to produce the necessary
currents of air or gas required for effecting the evaporation, and to increase the
velocity which the vapour has already attained through the difference of
temperature.
2. In apparatus for evaporating, condensing and cooling fluids operating as set
forth in the first claim, the combination with a tube A the inner surface of which
is to be supplied with a thin layer of liquid to be evaporated, of a jet C the liquid
under pressure issuing from which both effects the moistening of the tube and
production of air currents for effecting the evaporation and the acceleration of the
vapours, the said jet being arranged either at the lower end or at an intermediate
point or at the upper end of the said tube substantially as described with reference
to Figures 1 to 4 of the drawings.
3. In apparatus for evaporating, condensing and cooling fluids operating as set
forth in the first claim, the combination with a series of tubes the outer surface of
which is to be supplied with liquid of a surrounding casing and one or more jets for
liquid under pressure that both effects the moistening of the tube and the production
of the necessary air currents for effecting the evaporation substantially as described
with reference to Figures 5, 8, and 84 of the drawings.
4. The modification described with reference to Figure 10, wherein the said
liquid jets are applied both to the inner and outer surface of condensers.
5. In apparatus for evaporating, condensing or reirigerating fluids operating as
set forth in the first and second claims, the combination with the tube on which the
liquid jet acts of an upper tube which receives the upper part of the liquid jet, and
which has holes for the admission of supplemental air currents, substantially as
described with reference to Figures 3, 4, 6 and 7 of the drawings.
6. The modification of the arrangement referred to in the fifth claim wherein a

page_text: wire gauze cylinder is provided within the upper tube, for retaining the liquid so as
to prevent it from falling back into the lower tube, substantially as described with
reference to Figure 3ª.
7. In apparatus for evaporating, condensing or refrigerating fluids operating as
set forth in the first, second and fifth claims, the combination with the lower tube
or tubes and liquid jet, of an upper tube with supplemental liquid jet for effecting
the condensation of the vapours rising up from the lower tube, substantially as
described with reference to Figure 9 of the accompanying drawings.
Dated this 27th day of February 1896.
ABEL & IMRAY,
Agents for the Applicant.