An Improved Evaporating and Condensing Apparatus for Producing Fresh Water from Sea Water for Drinking Purposes and for Boiler Feed.
Year: 1887

page_text: Date of Application, 19th Oct., 1887
Specification Accepted, 22nd Nov., 1887
COMPLETE SPECIFICATION.
An Improved Evaporating and Condensing Apparatus for Producing
Fresh Water from Sea Water for Drinking Purposes and for
Boiler Feed.
1. WILLIAM FREDERIC PAMPHLETT, of Portland House, Lion Terrace, Portsea,
in the County of Hants, Marine 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 an improved apparatus for the evaporation and condensation
of fresh water from sea water, for drinking purposes or for boiler feed, and is designed
to effect the same by means of especially simple and convenient apparatus and in an
economical manner.
By a well known law boiling water under a vacuum enables the evaporation to be
effected at a comparatively low temperature, and this law I take advantage of in
carrying out the evaporation of sea water under a vacuum by means of steam,
utilising the preheated condensing water for evaportion.
As all marine boilers from which the steam is condensed in surface condensers
after use, lose some portion of the said steam by leakage or other causes while in
operation, it is most important to supply this constant loss of feed water from
some fresh water source, as any addition of sea water to make up for that loss
seriously deteriorates from the efficiency and safety of the boiler, particularly in
the case of high pressure or multitubular boilers used with forced draught, such
as those in torpedo boats.
My apparatus then in addition to being suitable for the production of fresh water
for drinking purposes is also particularly applicable for the supply of this loss of
fresh water to the boiler.
And in order that my invention may be the better understood I now proceed to
describe the same, reference being had to the drawings hereunto annexed. Like
letter refer to like parts throughout the figures.
Figure 1 represents a general combined arrangement of evaporator, .condenser and
pumps.

page_text: Figure 2 is a modified and alternative form of condenser.
Figure 3 is a modified and alternative form of evaporator.
Figure 4 illustrates a convenient form for evaporator of small size.
E is the evaporator made of any suitable material according to the pressure of the
steam used. The tubes e may be either of brass, iron or steel, and plain or corrugated
in shape. By the use of corrugated tubes, in addition to obtaining increased
evaporating surface, greater strength is obtained. The corrugations may be either at
right angles to the axis of the tube or slightly spiral so as to facilitate cleaning and
withdrawal. The salt water to be evaporated is supplied conveniently through the
pipe J into the evaporator E where it fills the lower portion E of the evaporator E,
the interior of the tubes, and is allowed to stand to some little height above the top
tube plate. Live steam from the boiler is admitted through the pipe and valve A
into the chamber containing the evaporating tubes, so as to surround the latter and
impart its heat to the sea water therein contained. The condenser C is a combination
of two distinct condensers C C', in both of which either plain or corrugated tubes
may be used; the shape of the latter being as previously described in the case of the
evaporator; the one C₁ fits within the other C and there is a partition between so as
to separate the condensed products arising from the sea water in the evaporator, from
those resulting from the steam admitted to the evaporator, and from the exhaust
steam of any engine which it may be convenient to condense therein. The said
exhaust steam might be utilized for evaporation in the evaporator.
The two chambers of the combined condenser are connected up to the evaporator
pump and engine as follows:-
The steam arising from the evaporation of the sea water in E passes through the
pipe B into the outer chamber C of the combined condenser, where it is condensed by
the cold circulating water, drawn by the pump K through the pipes L L in the
direction of the arrows. The condensed products are withdrawn through the pipe H
by the air pump M which thus maintains a vacuum in the evaporating chamber.
By reason of the division of the condenser into two distinct portions C C¹ the
condensed boiler steam from the evaporator is admitted to the inner condensing
chamber C by the pipe D, as also the exhaust steam from any engine through the
pipe G, and the condensed products are removed conveniently by the pipe
by a feed
pump to a tank for boiler use. The pure condensed steam from the evaporator is by
this arrangement collected apart from the other condensed steam, which may probably
be contaminated with grease or impurity.
In the case described the circulating water passes through the tubes while the
condensed products are around them, but if it should be desired that the circulating
water should be outside the tubes while the steam to be condensed should pass through
them, I may use a condenser of the form illustrated in Figure 2.
In this modified form the same letters refer to the same respective attachments
as before described in relation to figure 1, the condensed products being respectively
separated from one another in the outer chamber of the condenser by the webs P P.
The salt water supply for ovaporation to the evaporator is taken from the circulating
water after it has been heated in the condenser through the pipe J which can be
conveniently made self feeding upon the opening of a cock, owing to the vacuum in
the upper part of the evaporator.
The brine and sediment which will collect in my evaporator may be blown off
through the blow off cock Q either by a special admission of steam, or by a brine
pump R as most convenient.
In some cases of fitting on board ship it may be necessary to place the evaporator
at right angles to the position as shown in figure 1, and in that case I use an
evaporator of the construction shown in figure 3, the water surrounding the tubes,
and the evaporating steam passing through them.
The condensers also may be placed if desired with their axis in a horizontal position.
In some cases where small evaporators are used I construct them as. shown in
figure 4, so that the top part T can be removed entirely from the lower portion at the
joint S S in order to facilitate cleaning.

page_text: 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:
1st. The evaporator evaporating by steam pressure under a vacuum and constructed
substantially as described in relation to figure 1 in combination with one or other of
the compound surface condensers, substantially as described in relation to figures 1.
and 2.
vacuum and
2nd. The evaporator evaporating by steam pressure under a
constructed substantially as described in relation to figure 3 in combination with one
or other of the compound surface condensers substantially as described in relation to
figures 1 and 2.
3rd. The evaporator evaporating by steam pressure under a vacuum and constructed
substantially as described in relation to figure 4 in combination with one or other of
the compound surface condensers, substantially as described in relation to figures 1
and 2.
4th. The construction of the compound surface condenser consisting of two
cylindrical nests of tubes, the one fitting within the other with a partition
between, so that the impure condensed steam or water may be collected separately
from the pure condensed steam or water substantially as described in relation to
figure 1.
Dated th 10th
L1007