IMPROVEMENTS IN PURIFYING AND AERATING WATER PRODUCED BY THE CONDENSATION OF STEAM FROM STEAM ENGINES
Year: 1871

page_text: LETTERS PATENT to William Cary Selden, of the City of Brooklyn,
County of Kings, State of New York, in the United States of
America, for the Invention of "IMPROVEMENTS IN PURIFYING AND
AERATING WATER PRODUCED BY THE CONDENSATION OF STEAM FROM STEAM
ENGINES."
Sealed the 19th December 1871, and dated the 4th November 1871.
COMPLETE SPECIFICATION filed by the said William Cary Selden a
the Office of the Commissioners of Patents, with his Petition and
Declaration, on tho 4th November 1871, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CARY SELDEN, of the City of Brooklyn, County of Kings, State of New
York, in the United States of America, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS
IN PURIFYING AND AERATING WATER PRODUCED BY THE CONDENSATION OF STEAM

page_text: FROM STEAM ENGINES," and have petitioned Her Majesty to grant unto
me, my executors, administrators, and assigns, Her Royal Letters Patent
for the same, and have made solemn Declaration that I am the first and
true Inventor thereof.
NOW KNOW YE, that I, the said William Cary Selden, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention,
and in what manner the same is to be performed, in and by the following
statement:-
Wherever it is not practicable to provide a sufficient supply of water
to permit a constant fresh supply to the boiler and an escape of the
exhaust steam it has long been customary to reconvert the steam after
it has passed through the engine into water in a surface condenser and
use the same water over and over again. This process has been applied
to sea-going vessels, to stationary boilers in cities, and wherever the con-
sumption of the fresh water used to run the boiler is an item of sufficient
expense to induce the economic systim of using the water over and
over again by the condensation of the exhaust steam back to water.
Experiment and practice have, however, demonstrated beyond dispute
the fact that although no material injury is inflicted on the metal of the
boiler by the use in it of pure fresh water in the reuse or in using over
and over again the same distilled water by the process of condensation
and reuse I have alluded to, serious injury occurs to those portions of
the boiler which are exposed to the action of the water. The same kind
of water, which when supplied in fresh quantitics to or passed once
through the boiler has no injurious effect on the latter, will when used
over and over again in the same boiler injure and destroy the metal.
What chemical or other change occurs in the condition of the water by
the process of successively expanding it into steam & reconverting it
into water, or what is the cause of this known effect is a mooted question
with engineers and scientists, and various theories have been advanced
on the subject and some remedies for the evil suggested. Some have
attributed this effect to the fact that the water in passing through
certain copper or brass tubes or vessels wears off by friction and carries
in solution the copper or other metal, and that by the deposit of such
metal in the boiler a galvanic action is induced in the boiler which
destroys the iron of the boiler. Others, that some chemical change

page_text: occurs in the water which conduces to this injurious influence on the
iron of the boiler. I am not aware of any perfectly satisfactory solution
having been offered yet of the cause or causes of the evil, nor has any
successful remedy been suggested to overcome it that I know of.
I have learned by experience and experiment that in the using over
and over again the same water a large quantity of foreign matter, such,
for instance, as the tallow or other lubricating material used in the
engine, and the metallic wearings of the engine and other parts must
necessarily be taken up by the water, and that this accumulation of
foreign matters must be continually augmented by other accumulations
as the water travels over and over again through the boiler engine and
condenser. All are aware that by the process of heating and generating
into steam and again condensing the water is deprived of the air which it
contains when in a natural state, so that it will require a greater degree
of heat for a regeneration into steam than was necessary when it was in
its natural condition. And I believe that in the heating of the water
the oxygen of the expelled air probably unites with the iron leaving free
nitrogen, which may unite with the hydrogen set free by the decompo-
sition of oxygen in heating the water, thus forming ammonia, which is
known to be very destructible to iron. From these facts and experiences.
I have concluded that for the purposes of reducing the evil effect of the
water on the boiler, saving the engine from the ill effects of grinding
through it continually a mass of foreign floating matters and economising
in the generation of the steam it is important to provide some means by
which the water after it shall have passed through the boiler engine and
condenser shall be deprived, as far as possible, of all extraneous and
deleterious substances and shall be acted upon both mechanically
and chemically in such a manner as to put it in a natural and purified
condition before it is resupplied to the boiler. And to accomplish these
ends I propose to employ somewhere between the condenser and the
boiler a suitable apparatus through which the water shall pass, and in
which it shall be thoroughly filtered to extract all foreign substances,
shall be resupplied with the proper proportion of air or oxygen, and
shall be supplied with or deprived of such chemical qualities as shall be
deemed necessary to render it incapable of causing the difficulty which
I propose to effectually overcome, viz., the injurious effect on the iron
of the boiler. Precisely what sort of chemical treatment the water is to

page_text: i
receive will depend upon the nature of the water, the character of the
metals with which it brought into contact, and other conditions.
My Invention consists in subjecting the water to such mechanical
and chemical treatment after it has been generated into steam and
reconverted into, water, or has been once used and before its reuse in
the boiler, as shall purify it and restore it to its natural and proper
'condition as nearly as possible.
To enable those skilled to fully understand and operate my Invention,
I will describe the mode in which I have successfully practiced it in
one or more instances, leaving it to the judgment of the engineer and
chemist to vary the details of the apparatus and process of treatment as
.circumstances may require.
In the accompanying Drawing is illustrated an apparatus which I
have used successfully in carrying out my Invention, and with which
very beneficial results have been attained.
Figure 1 is a top view; Figure 2 is a vertical section at x, x, in
Figure 1; Figure 3, a vertical cross section at y, y, in Figure 2; and
Figures 4 and 5, detail views of the apparatus.
A represents a tank or box suitably constructed, and which when used
in connection with marine boilers and engines should be provided with
a removable cover properly fitted on to prevent the contents of said
tank being displaced or thrown out by the motion of the ship. This
tank A. is divided by partitions into a series of compartments, some of
which are filled with filtering and purifying materials, as will be
presently explained; B is an air pump adapted to force air into a
receiver C near one end of the tank A, from which it escapes through
numerous apertures in the bottom of one of the compartments of
said tank; D is a pipe leading from the condenser to one end of
the tank A, and E is a pipe leading from the opposite end of said
tank to the feed pump for the boiler or to a reservoir from which the
boiler is supplied. The compartment at F receives the water from
'the condenser while the one G next to it, is filled with coke. The
partition A¹ between these two compartments is perforated as seen
so as to permit the passage of water contained in F through it, and on
the side adjacent to the compartment F is arranged close to or in said
partition a filter 6 made of felt. The compartment H is filled with
broken chalk or lime, while compartment I is filled like G with coke ;

page_text: A³, A³, and A* are perforated partitions similar to A', all of which may
be double; A is double, and between its parts is left a space which
is filled in with wool c, to form another filter. At A' is another felt
filter d, arranged as shown, and through this filter the water has to pass
to supply the compartment J in which the filtered water is subjected
to the action of air blasts, as will be presently described, and from
which it is taken off by the tube or pipe E to be supplied to the boiler
for reuse.
The general operation of this machine or apparatus is about as I will
now explain. The water from the condenser passes continually through
the pipe D, and discharges into the compartment F which is generally
kept nearly full, and from here passes through the felt filter b, and
perforated partition A' into the compartment G, where it percolates
through the mass of coke with which this compartment is filled. And
by this means of filtration most or all the solid extraneous substances
are extracted. From here it passes on through the mass of chalk or
lime in compartment H, where a chemical action will occur to
deprive the water of any metals, which may be held in solution and
have passed through the felt and coke filters, by rendering such metals
solid, and should such solid particles be carried on by the water they
will be extracted by the wool filter c, and by the coke filter in com-
partment I, where the water is again subjected to the action of a larger
quantity of coke. After passing through another felt filter d the water
enters and fills the compartment J, from which it is drawn off at
pleasure through a tube E to supply the boiler.
The air pump B
being kept in operation in the meantime atmospheric air is constantly
forced into the receiver C, and escaping from thence upward through
the perforations in the bottom of compartment J passes in jets through
the body of water contained in said compartment. By this continuous
blast of air through the water in J said water is supplied with its
necessary or proper proportion of air. The quantity of air supplied to
or forced through the water may of course be regulated. If expedient
and if desired to have the action of the air blast periodical, or inter-
mittent, or its force should be so slight as to require it, the apertures in
the bottom of J may be provided with some suitable valve device to
prevent the water from passing down into the receiver C. If preferred,
the air or a part of it may be introduced in the tank at another point,
as for example, in the compartment F or in any of the intermediate

page_text: ones.
Not only is the requisite quantity of air mechanically combined
with the water by this injection from the air pump, but a chemical
action may occur by the introduction into the mass of water of
additional oxygen, by which it will be deprived of any contained
ammonia by the chemical union of oxygen with the nitrogen of the
ammonia, and thus the injurious effects of this substance, if it exists in
the water will be prevented.
In Figures 4 and 5 is shown in detail the construction of one of the
felt filters or d made as I have used them in a working machine.
The filter here shown is composed of a thick sheet of felt, which is
attached around its contour or edges to a stretching frame, and in the
use of the filter this frame with its attached sheet of felt is placed and
held by suitable lugs, not represented, so as to be embraced between said
frame on one side and the perforated partition plate on the other side,
as illustrated. When a removal or changing of the felt is necessary
the frame with its attached felt may be extracted and another with a
fresh felt substituted for it.
At Figure 6 is shown a modification of the apparatus in which in
lieu of permitting the water to flow through the filters and compart-
ments in a horizontal direction as in the apparatus just described, it is
caused to filter downwards or flow through the filters and mineral
masses in a vertical direction. In this modified apparatus the com-
partments and filters are so arranged that the water which is fed in from
the condenser through pipe D fills the compartment F, and flowing over
the top of the solid partition a passes down through the felt filter at
into and through the mass of coke in compartment G. From hero it
escapes at the bottom through an opening or openings at m, and filling
up the space flows over the top of the solid partition a¹, and thence down
through the wool filter at c into and through the chalk at H. From
the bottom of the chalk compartment it escapes through the opening at
n, and filling up and flowing over the top of a³ passes through the felt
filter d, thence through the coke compartment I, and out at o into the
air charging compartment J.
The process and operation it will be seen are substantially the same
in this modified form of apparatus, the only difference being in the
direction of filtration, which it may be advisable sometimes to have
downward, as just described or again in the reverse direction upwards.

page_text: It will be understood that the size, proportion, and even the con-
struction of the apparatus may be varied, and that in lieu of subjecting
the water to the necessary processes of filtration, oxygenation, and the
like in one apparatus at the same time, the necessary mechanical and
chemical actions may be made on the water in separate apparatus and
at different times without departing from the spirit of the Invention, the
gist of which lies in the idea of subjecting the water to the necessary.
processes to purify it and fit it for use in the boiler after it has been
reconverted from steam and before it is again used for the purpose of
generation of steam in the boiler. Animal charcoal, peat charcoal, or
fresh wood charcoal with suitable provisions for holding it down may
be used in one of the compartments in place of the coke or in addition
thereto.
It may be found expedient to place in the apparatus through which
the water is passed some metallic substance on which any destructive
effect the water has a tendency to inflict on metals may be produced,
and the water be thus deprived of its destructive influence before it
goes to the boiler again.
Though I have spoken only of surface condensers, my Invention may
apply with some success in those cases where jet condensers are used,
but where, as at sea, a store of fresh water for the purpose is passed
continually round and round passing through pipes cooled by the salt
water of the sea in the interval between each use. In such cases the
straining in my apparatus must allow the passage of a larger quantity
of water than in the case of a surface condenser of equal power. I may
remark in connection with this apparatus that water containing acids
which attack the metal directly or so as to induco electric currents may
be neutralized by the introduction of an alkali; carbonate of soda is a
good alkali for the purpose, and its presence is not objectionable in any
way.
I do not wish to be understood as limiting. my claim of Invention to
the use of the apparatus shown or to that of any particular apparatus,
nor to the nature of or material used for the filters, nor to the chemical
ingredients and actions to which I have alluded, as each and all of these
features in carrying out my Invention may be varied; but, having
explained the method by which I propose to prevent the injury to the
boiler which arises from the reuse of the water, and described the mode

page_text: in which I have successfully practiced my Invention with very beneficial
results, what I claim as new and desire to secure by Letters Patent is,
the method of purifying the water and rendering it fit for reuse
previous to its return to the boiler, substantially as herein set forth.
In witness whereof, I, the said William Cary Selden, have here-
unto set my hand and seal, this Nineteenth day of October,
in the year of our Lord One thousand eight hundred and seventy-
one.
Witness,
THOMAS D. STETSON,
Patent Solicitor,
New York.
WILLIAM CARY SELDEN. (L.S.)