Improvements in Distilling Apparatus for the Production of Fresh or Drinking Water.
Year: 1896

page_text: Date of Application, 2nd Apr., 1896-Accepted, 1st Aug.. 1896
COMPLETE SPECIFICATION.
Improvements in Distilling Apparatus for the Production of Fresh
or Drinking Water.
I, LOUIS MARIE GABRIEL DELAUNAY-BELLEVILLE, of 58 bis Chaussée
d'Antin Paris, in the Republic of France, 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 consists of a novel construction of distilling apparatus com-
prising a combination of vacuum producers and steam-generators which operates
independently of any other apparatus. This arrangement is applicable to all
heaters or stills constructed for either single or multiple action and adapted to
produce fresh or drinking water by the distillation of either saline solutions or of
water otherwise unfit for consumption, whether on board ship or on shore.
The object of the improved arrangement is to attain certain novel results, of
which the following are the most important, viz. :-
1. In the last vapourising" (or steam generating) apparatus of the series,-
being the low pressure chamber, the vacuum may be maintained at the degree
recognized as being most consistent with satisfactory operation, while other
requirements may be disregarded.
2. The pressure and, consequently, the boiling temperature in the first heater or
receiver, (for a proper difference between the initial and terminal temperatures)
may be reduced sufficiently to entirely obviate the formation of saline deposits or
sediment upon the heating surfaces.
3. As a result of such allowable reduction of temperature in the first heater,
heating may take place either by means of steam supplied from a special or
"autonomous" boiler or heater; or derived from other boiler and expanded
immediately after its admission into the apparatus; or by steam having worked in
one or more cylinders of a multiple expansion engine; or by exhaust steam from
engines or any other source, and more especially exhaust steam from the engine
operating the feed-pumps of the boiler or heater; or lastly, by steam derived from
these several sources simultaneously or in combination, and,
nature of the boiler,
4. The regularity of operation, owing to the "autonomous
results in an improvement of the quality of the fresh water obtained, while
preventing the water from being carried away, as it generally is where the heaters
communicate with the auxiliary condensers of engines, owing to the variations of
vacuum which occur in those condensers.
"
The invention will be best understood by reference to the accompanying drawings
in which
Figure 1 is an elevation of the improved arrangement, with parts broken away
in the heating compartments of the boilers, the "re-heater" (or super-heater) the
cooler and the condenser.
Figure 2 is a plan thereof.
Figure 3 shews a special steam admission or supply arrangement, enabling a
mixture of exhaust steam and live steam or a mixture of vapours in the course of
o eration, to be employed in heating the first boiler.
Figures 4, 5 and 6 are respectively a side elevation, an end elevation and a plan
of a form of "autonomous" apparatus fitted with a special steam boiler.
Figures 1, 2 and 3 illustrate the applicability of the invention to a triple action
heating or distilling apparatus, the operation of which is well known.

page_text: 1, 2, and 3, are the three boiling chambers of a complete apparatus, and 4, 5
and 6 are compartments for the steam which is generated in the course of
operation.
The water to be distilled is admitted, direct into chamber 1 which is heated
either by live steam or by vapours (or different varieties of steam) in the course
of operation derived for instance from one of the reservoirs or steam chambers
intermediate between the cylinders of multiple expansion engines, or by exhaust
steam from engines; or by a mixture of these several kinds of steam.
Of the other heaters, 2 and 3 each is heated by means of steam produced in the
preceding heater.
The water to be distilled passes into each of the heaters 1, 2 and 3, in
succession and is drawn off from the last by a discharge pump 14 hereinafter
described.
7 is a tubular cooler;
8 is a tubular condenser placed over the cooler 7;
9, 10, and 11, is a reheater or superheater, having three compartments,
through which the feed-water circulates prior to its introduction into the first
heater 1;
12 is the air pump
13 is the feed pump.
14 is the discharge or extraction pump; and,
15 is the engine whereby the pumps are driven.
In the following description the sea-water which has been concentrated to the
greatest extent possible will be termed waste water. The sea water passes through
the vertical tubes in the boilers or heaters 1, 2 and 3 in succession and leaves in
each boiler a certain amount of steam which is afterwards condensed and cooled
as fresh water. It is preferable not to retain the waste water in the apparatus as
it is useless but to eject it therefrom replacing it with fresh sea water which enters
the apparatus at the upper part of the boiler 1. For this purpose the exhaust-
pump 14 is employed. After the sea water has been distilled the said pump draws
the now concentrated waste water at the bottom of the boiler 3 through the pipe 31
and forces it as hereinafter described into the compartment 9 whence it is
discharged after being used to heat the feed water.
The air pump 12 produces a vacuum in the condenser 8 through the suction
pipe 16. This pump draws the water out of the condenser, and forces it through
the pipe 17 generally leading to the water tanks, but where the apparatus is
intended to produce drinking water the pump 12 forces the water into the tubular
cooler 7 wherein the feed water circulates.
The condenser 8, through the pipes 18, 18 communicates with the steam
chamber 6 of the heater 3 and makes a vacuum in that chamber. Steam-
generation, therefore, takes place in this heater at very low pressure. The steam
is condensed in the condenser 8 by the cooling action exercised by the feed water
circulating within the condenser pipes.
The tubular chamber 19 receives the steam generated in heater 2, through the
pipes 20, 20. This steam becomes condensed and, in the act of condensing, heats
the water of the third heater. The cock 21 serves to place the chamber 19 in
communication with the condenser 8 through the medium of the pipe 22.
The tubular chamber 23, which receives the steam generated in the heater 1,
through the pipe 24, is similarly placed in communication with the condenser 8
through the cock 25 and the pipe 22 just mentioned.
All the fresh water produced in the three heaters flows, therefore, to the
condenser of the apparatus. The areas of the cock apertures, 25 and 21, are
properly controlled, so that no vacuum, equivalent to the vacuum in the heater 3,
is created in the heaters 1 and 2.
The water produced by the condensation of the heating steam in the first heater
is drawn off either by means of a cock the area of whose aperture is properly
controlled, or by means of an automatic discharge cock or valve.

page_text: The feed water drawn in by the pipe 26, is forced, by the pump 13, through the
pipe 28 into the cooler 7, and as it passes through the tubes of such cooler, it cools
the fresh water which has been produced and which circulates round the said
tubes. The quantity of feed water passing through that cooler may be as large
as required for sufficiently cooling the fresh water produced, while the surplus,
in excess of what is necessary for feeding the boiler, is rejected through the
cock 29.
As it leaves the tubes of the cooler 7, the feed water passes into the tubes of
the condenser 8 and liquefies the steam entering such condenser.
After traversing the condenser 8, the feed-water descends through the pipe 30,
whereby it is conducted to the lower part of the multiple tubular superheater 9,
10 and 11, which it then traverses in an upward direction passing-as it does so-
through tubes heated beforehand to temperatures increasing in the direction in
which the feed water flows.
In the lower compartment 9 the feed water is heated by the concentrated
waste water which is drawn from the lower portion of the heater 3 by the
pump 14 through the pipe 31. The suction may be either through the com-
partment 9 or from the heater 3 direct, the waste water being (in the latter case)
forced back into the said chamber 9 afterwards and then discharged. In the
drawings the suction is supposed to take place through the chamber 9.
In the second compartment 10, the feed water is heated by the water discharged
at 32 being the result of the condensation of the heating steam consumed in the
first heater. This water is supplied through the pipe 33 and discharged through
the pipe 34 whence it flows to the condenser of the main engine or to that of the
auxiliary engines; or in other words, returns to the reserve feed-water tanks of
the boilers.
In the upper compartment 11, the feed-water is heated by the steam which is
about to work in the first heater 1. This steam is supplied through the pipe 35,
traverses an expansion governor or pressure regulator 36, and passes on, through
the pipe 37, into the heating chamber of heater No. 1.
In the compartment 11, the feed water may also be heated directly by the live
steam, at the pressure prevailing in the main conduits or pipes. In this case the
expansion chamber 36 is placed upon the chest or chamber 1, and the several
portions of the steam which have performed their work and are to be utilised in
the distillation process, are conducted direct to that expansion chamber.
The feed water issues from the superheater 9, 10 and 11 at a high temperature,
as nearly as possible approaching the temperature at which steam has been
generated in the first heater 1; such feed water being conducted to the heater 1
by the pipe 38. The water that has not been converted into steam in the first
heater passes into the second heater, 2, through the pipe 39, and thence into the
third heater 3, through the pipe 40. The now waste water entering the bottom
part of this third henter is drawn off by the discharge or extraction pump 14 as
already explained.
1
Figure 3 represents the arrangement of the steam piping for utilising the exhaust
steam of the auxiliary engines.
The exhaust-eteam from these auxiliary engines passes off into a collector 41.
communicating with the condenser of the engines through the pipe 42. Between
the pipes 41 and 42 there is a regulating valve 43 which serves to prevent the
steam contained in the pipe 41 from exceeding a certain limit of pressure; which
limit is so determined as to ensure the proper operation of the heater, care, being
taken at the same time, that no more than a moderate counter-pressure is developed
in the cylinders of the auxiliary machines.
The pipe 44 conducts the steam from the pipe 41 into the compartment 11
of the superheater, whence the pipe 37 conducts such steam to the first
heater 1.
Where live-steam is admitted into the superheater 11 with a view to a more
effective heating of the feed water, the expansion chamber 36 is transferred to

page_text: the receiver 1, and the steam, in order to reach the said chamber, has to pass
through the pipe 37. In that case, the pipe 44 terminates at the said receiver 1,
direct.
The exhaust pipe 45 of the engine that drives the pumps branches off the pipe 44,
and the steam exhausted from such engine mixes with the steam from the auxiliary
engines.
It may happen that the auxiliary engines in operation fail to supply a sufficient
amount of steam to ensure the satisfactory operation of the heater or to obtain the
required yield. To meet this emergency, the compartment 11 of the superheater
is provided with a steam supply pipe, leading either from a steam-boiler direct,
or from the intermediate reservoir or chamber of a multiple expansion engine.
This steam is admitted through the pipe 35, after which it traverses the
expansion governor 36, which only opens when the pressure in the pipe 41 falls
somewhat below the limit to which the valve 43 is adjusted. Owing to this
arrangement, there may be maintained in the 1st heater-(for the heating steam)-
a practically constant pressure, comprised between the limit to which the expansion
governor 36 is set, and that to which the overflow valve 41 is adjusted.
Where the heater is required to operate in conjunction with a special steam
generator, the latter should be adapted to be fed with the same water, in accordance
with the following data:-
(1) The water resulting from the condensation of the heating steam in the
heater 1 is taken up again-after issuing from the compartment 10 of the heater
by a pump which forces it into the steam generator. The losses of feed water in
the generator are made up for from time to time by means of fresh water produced
by the heater itself.
(2) Figures 4, 5 and 6 illustrate another arrangement, which renders the
employment of a pump unnecessary. The first heating or distilling apparatus here
surmounts the steam generator 46. This steam generator may be constructed on
any convenient system (a Belleville generator being here shewn by way of example);
and the heater, too, may be of any suitable construction, either horizontal or
vertical. The productive capacity of the steam generator controls, or determines,
the pressure of the steam admitted into the heater.
The steam produced in the generator or boiler 46 passes directly into the
heating compartment of receiver No. 1 through the pipe 35. The water resulting
from the condensation of such steam redescends into the generator through the
pipes 33, 33; a pump (which may be operated by hand) enabling the losses of
fresh water to be compensated for from time to time.
The lettering in Figures 4, 5 and 6 serves to designate the parts which correspond
to those shewn in Figures 1, 2 and 3.
The special arrangement shewn in Figures 4, 5 and 6 is mainly noteworthy
because it simplifies the construction and operation of the whole plant, since,
here, the feed water superheater forms, as it were, a continuation of the condenser,
and is reduced to two compartments.
In the compartment 9, the heating of the feed water takes place by means of
extraction or drawn off water.
In the compartment 10 the heating is effected by means of part of the steam
generated in the first heater or receiver 1, which issues from the chamber 4 of that
heater through the pipe 47. The condensation water produced by this steam
passes through the pipe 23 into the heating compartment of the heater or receiver 2,
which, moreover, receives the steam produced in the first receiver 1 direct through
the pipes 24. This method of superheating is a substitute for that which is carried
out in the manner illustrated in Figures 1, 2, and 3, by the discharge of the
heater 1.
Superheating by means of live steam may be either employed or not.
In the arrangement shewn in Figures 4, 5 and 6, as well as in that which is
shewn in Figures 1, 2 and 3, the cooler, condenser and superheater may all be
horizontal.

page_text: described, as it is well known.
Beek Bot be there
The steam available for operating a heater of this class is of three different
kinds :
(1) The live-steam supplied from a boiler direct and not having, as yet, performed.
any work;
(2) The steam derived from one of the intermediate reservoirs or chambers of a
multiple or compound expansion engine, such steam being in the course of performing
its mechanical function and
(3) The exhaust steam from engines i.e. steam which has yielded practically all.
the mechanical work it was capable of performing.
The steam belonging to the last category has proved the most economical in.
use and it is therefore preferably employed.
It enables all the latent heat, which it contains and which would otherwise be
lost, either in a condenser or in the atmosphere, to be utilised. Such steam is
besides, always plentiful on ships (for example), where numerous auxiliary engines
are in almost constant operation, say for operating plant for electric light, or for
driving windlasses, working pumps, fans or the like.
The satisfactory operation of a heating or distilling apparatus of this class.
depends upon the regularity or uniformity of the pressures at either end of the
apparatus. At the outlet end, such uniformity is here ensured by the employment
of an air pump, which moreover serves to render the condenser independent or
"autonomous" while at the inlet, regularity of pressure is provided for by the
combination of the discharge valve and the expansion governor; the said discharge
valve entering into operation whenever there is too liberal an amount of exhaust
steam; whereas the expansion governor allows steam of the first or second category
to pass, should the quantity of exhaust steam happen to be insufficient.
In the second and third receiver or heater there is very little difference of
temperature between the heating steam and the water to be converted into steam.
In the case of the first heater things are different, as the feed water arriving
there is but imperfectly heated, so that it becomes necessary to maintain the
heating steam at a considerably higher pressure. The arrangements described
above enable the feed water to reach the first heater at a very high temperature,
almost equal to that of the heating steam, so that it only remains to impart to that
water whilst it is passing through the first heater the latent heat developed in the
process of conversion of water into steam. Thus the heating steam may be
maintained at a lower temperature than it could have been, had the feed water
been less heated, and, by such means, the formation of calcareous deposits (or
scales) on the surfaces or walls of the heater referred to can be avoided.
The addition of an air pump to the heater renders the heater "autonomous" and
enables it to operate without any risk of water being carried away at too low a
temperature. The reduction of pressure which takes place in the third heater, in
the process of conversion of water into steam, involves corresponding reductions of
pressure during the conversion of water into steam in the second and first receivers
and consequently, (given the same total difference between the initial and final
temperatures) a proportionate reduction in the pressure of the heating steam in the
first receiver or heater.
This very important reduction of temperature is a result of both the addition to
the apparatus of a condenser along with a special air-pump, and the thorough and
complete re-heating of the feed water, prior to its admission into the first heater or
receiver.
In order to ensure proper operation, it is only necessary to adjust carefully, and
once for all, the area of the cock apertures through which is discharged the steam
condensed in the heaters, since the pressures at both extremities of the apparatus
are constant.
The reduction of the pressure, and also, consequently, of the temperature of the

page_text: beating steam in the first heater is such, that the said heater may generate steam at
a somewhat low temperature, so as, in the case of sea-water, entirely to avoid the
formation of sediments of sulphate of lime.
When once the engine of the pumps has been set in motion at a predetermined
rate of speed, such speed may be indefinitely maintained without any material
alteration, inasmuch as the counter-pressure undergoes little or no change and a
constant pressure may be maintained while steam is being introduced, by means of
an expansion governor.
As a result, the air pump will at all times maintain the same vacuum, and the
extraction pump will uniformly draw off the water from the third heater, the supply
being regulated by the properly adjusted area of the aperture of the discharge
cock situated at the top of the cooler.
The conveyance of all the fresh or drinking water, produced, to the condenser,
of the heater or distilling apparatus, and the passage of such water into the cooler
of the said apparatus enable the whole of the fresh or drinking water, that has been
obtained, to be stored up, without the aid of an auxiliary cooler.
There is no danger of any bad effect being likely to result from the employment
of high pressure and high temperature steam, which retains a certain excess of heat
after its passage through the expansion governor. The fact is, that there is no
longer any heat in excess when the steam leaves the superheater. In the case of a
direct steam supply from a special boiler, such boiler should operate at the normal
working pressure of the heating steam of the first heater.
The operation of apparatus fitted with a special steam generator, as hereinabove
described, is the same, as the operation of the last mentioned "autonomous" heater.
However, the use of a special generator or boiler, so arranged as to be fed in a
continuous manner, without necessitating any particular attendance or supervision,
has the effect of rendering the heating or distilling apparatus perfectly "autonomous
and capable of being used to advantage, in this novel form, where no boiler in
working order is available, such as for the production of fresh or drinking water at
colonial stations.
""
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what
I claim is :-
The construction, and combination with apparatus for heating or distilling
sea water, or non-drinkable water generally, of arrangements adapted to render
such apparatus "autonomous," with or without the addition of a special steam
generator or boiler; steam derived from any source being used and more
particularly exhaust steam from engines; the said arrangements enabling water to
be distilled at extremely low pressures, all substantially as described and illustrated
in the accompanying drawings.
Dated this 2nd day of April 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.