AN IMPROVED METHOD OF AND APPARATUS FOR PURIFYING WATER FOR USE IN STEAM-BOILERS
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co, Patent
Agents, Southampton Buildings, in the County of Middlesex, do hereby declare
the nature of my Invention for "AN IMPROVED METHOD OF AND APPARATUS
FOR PURIFYING WATER FOR USE IN STEAM-BOILERS" and in what manner the
same is to be performed, to be' particularly described and ascertained in and
by the following statement :—
The use of hard water, or water holding lime in solution, in steam boilers causos
many difficulties, and is to some extent dangerous by reason of the incrustation
formed in the said boilers and on the interior parts, as is well known.
The object of this Invention is to overcome the greator portion of the difficulties
which attend the use of water containing the soluble bi-carbonate of lime, by
treating the water, before it enters the boiler, so that it will not form incrustation
when subjected to heat and pressure, and to a reduction of volume by evaporation,
causing concentration. The said Invention comprises the provision and employment
of a suitable vessel for a feed-chamber, into which substantially all of the water to
be treated enters, and passes through, or comes in contact with, quick-lime or
unslaked burnt lime, before passing out; it also comprises the combinations of
parts hereinafter set forth.
In the accompanying Drawings
Figure 1 is a vertical longitudinal section of the feed or lime chamber, and the
filter.
Figure 2 is a transverse section on the line a, a, Figure 1.
Figure 3 is a transverse section on the line y, y, Figure 1.
A B indicate a suitable tank made in two compartiments. C, D and Ę are tubes
or pipes. F, F, are openings or man-holes; and G is the line-chamber. a, a, are
perforations in the underside of the pipe C. b, c, are partitions arranged as shown
for reversing the current of the water as it passes through the filtering tank or
filtering material.
As shown, the tank is made in two parts A and B, connected by a tube or pipe D.
This will be found the most convenient mode of making the tank, but it is evident
Den

page_text: .
that the parts shown as sections A and B, may be made into one, and the connecting
pipe D be omitted. In such case it will be understood that the adjoining ends or
heads are also to be omitted.
I have designed and constructed my apparatus mainly for the purpose of purifying
the water at railway-stations for locomotive engines, and for this purpose I have
found tanks sixteen feet in length, and from eight to ten feet in diameter, made of
staves in the circular form shown, to answer well, although it is evident that the
size may be increased or diminished, according to the amount of water required at
any station, and my improvements will also be found useful in purifying water for
stationary boilers, in which case it will not require to have the capacity necessary
for a railway-station.
The supply-pipe C enters the lime-chamber G and traverses the whole or nearly
the whole of its length, and is perforated on the underside to prevent the water, in
passing from it into the lime-chamber, from forcing the lime away, and to ensure
the contact of the water with the lime. This supply-pipe is connected either with
an elevated tank, or with a pump, for the purpose of exerting some pressure on the
water. The pressure which I have found best, is that of about two atmospheres
which the wooden tank A, B being thoroughly hooped is well qualified to bear
without-lenkage, or by making the tank of boiler-iron or other suitable-material,
☐ greater pressure can be maintained with safety, but usually it would not be found
essential. The water, when purified, passes out through the pipe E which conducts
it to the tank or well from which it is to be taken for use. The pipes Cand E are
provided with stop-cocks, so that the flow of water can be regulated or cut off, as
desired. The pipe D, when used, may also be similarly provided. The space
between-the-partitions-band-c-and-the-ands or heads-of-the-tank-in-the-filtering
part of the device, aro filled with straw, hay, or other materal which will permit a
rapid passage of the water and retain or hold back the lime or other solid mintters
contained therein.
The use of such coarse-and-free filtering material permits a rapid flow of the
water, so that a large quantity can be worked off, and it is easily taken out
or replaced through the man-holes F whenever it becomes foul or inefficient in
its action.
In operation, burnt lime is placed in the chamber G, through its man-holes, in a
sufficient quantity to extend several inches above the pipe C. The water is then
carefully turned on, until the tank is filled, after which it may be permitted to
flow under its full head. By placing the perforations a of the pipe C on the
underside, the water in entering, if it acquires any considerable force, strikes
against the bottom of the tank, and its force is so far dissipated that it will not
scatter or drive away the lime, and, by keeping the lime in position, substantially
all of the water passes through it or in contact with it, and there is sufficient air
in the water or in the tank to slake the lime placed in the chamber.
By bringing substantially all of the water in contact with the burnt lime, the
carbonic acid gas which it may contain, und which is always found in water that
has not been distilled or caught as rain water, is absorbed by the lime, and the
soluble bi-carbonate of lime is changed to the insoluble carbonate, and in a condition
to be filtered out, so as to leavo the water which issues from tho exit E almost freo
from lime, and purified from earthy matters, thus leaving it in such a condition
that it will not cause incrustation in boilers, as has been found by conducting
experiments on a large scale, for a considerable length of time; and by depriving
the water of its carbonic acid gas there is nothing left by which the incrustation
(carbonate of lime) can be formed even though some or all of the lime held in
solution should fail to be precipitated.
Whenever the action of the lime-chamber becomes somewhat impaired, or
whenever desired, additional quantities of lime may be placed therein without
removing the old, as a very considerable quantity of lime in the chamber G will
not injure or impede its operation, and whenever desired, the lime can be all
removed, and new lime placed therein, but this will not be very frequently

page_text: necessary. By taking more time, a pressure or flow only sufficient to cause the
water to pass along will produce good results.
By placing the burnt lime in the vessel or receptacle before it is slaked, the
body of water in which it becomes immersed prevents the lime from becoming
heated and retards its conversion into a hydrate and its outflow from the receptacle,
and the tube C may be so formed or applied as to leave a small sub-chamber at
the bottom of the chamber G.
I am aware that lime has heretofore been applied to a small body or stream of
water to be united with a larger one, by a process known as " Clark's process," and
I do not therefore claim, broadly, the application of quick-lime, or the hydrate of
lime, to water containing lime in native solution, but I regard my process as
radically different from Clark's because I treat the whole body of water, at the first
step, by passing it through, or in contact with, a sufficient quantity of calcined
lime to enable nature to reform its combinations, and to apply the exact quantity
of such element required, and also to absorb all of the free carbonic an-hydride
(acid) from the water so as to prevent the formation of incrustation when the
water is subjected to heat and evaporation under pressure, with a resulting
tendency to condense or concentrato the mineral matters of the water, while the
Clark process depends for its success in steam-boilers, upon the knowledge of the
character of the specific water to be treated, and the skill of the mixer, which
makes that process too uncertain and unreliable for use in connection with steam-
boilers or other places where the vapors and gases are held under pressure.
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
First. The herein described method or process of extracting carbonic acid
(anhydride) and bicarbonate of lime from hard water to render the same soft and
prepare it for use in steam-generators, which method or process consists in placing
burnt lime in the lime-receptacle, before reducing it to a hydrate, and causing the
entire stream or body of water to be purified to flow under pressure through the
said receptacle, and through the lime in bulk and in a quiescent state, and thon
subjecting the stream to filtration, all by a continuous or non-intermittent process,
substantially as specified.
Second. A lime-vessel having one or more chambers containing filtering material,
combined with a water-supply-pipe in close proximity to its base and having a
series of perforations confronting the said base, substantially as set forth.
Third. A lime-vessel combined with a water-supply-pipe in close proximity to
its base and having a series of perforations confronting the said base, substantially
as set forth,