Improved Apparatus for Filtering or Purifying Feed-water for Marine and other Steam-boilers.
Year: 1894

page_text: Date of Application, 29th Jan., 1894-Accepted, 10th Mar., 1894
COMPLETE SPECIFICATION.
Improved Apparatus for Filtering or Purifying Feed-water for
Marine and other Steam-boilers.
We, JOHN WOTHERSPOON, Engineer, of Rossbank, Forest Hill, Kent, and
JAMES DAVIE, Engineer, of Hugh Street, Wallsend-on-Tyne, Northumberland,
do hereby declare the nature of the said 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 relates to improved apparatus for filtering or purifying feed-
water for marine and other steam-boilers, the same being designed to eliminate
or remove the gaseous and solid impurities from the feed-water before entering
the boiler, and to operate substantially in the manner hereinafter more fully
described.
The improved apparatus is illustrated on the accompanying drawings in
which ;-
Fig. 1, represents a partial transverse sectional elevation thereof, on about the
plane of the line a, b, Fig. 2.
Fig. 2, represents a longitudinal sectional elevation on the plane of the line e, f,
Fig. 3, and,
Fig. 3, represents a plan, omitting some of the parts represented in the
other figs.
The same reference numerals and letters indicate like parts wherever they are
repeated on the drawings.
The main body 4, of the filter is constructed of an open-ended, parallel-sided
formation (which may be turned, planed or otherwise formed of a circular, square
or other suitable shape in cross section) and with a depending sediment-collector 5,
adjacent to each end, each of such collectors 5, being fitted with a blow-off
cock 6.
The interior of the filter-body, between the mud-collectors, is fitted with piston-
like diaphragms 7,-8, conformable in shape to that of the cross section of the
filter-body, the former of which occupies a fixed position relatively to the filter-body
and the latter of which is adjustable. The diaphragm 7, is caused to maintain its
position by abutting against an inner projecting extension 9, of a cover 10, which
is fitted and bolted as at 11, to and so as to close the adjacent open end of the
filter-body. The cover is formed with a stuffing-box 12, through which passes a
rod 13, which serves as the means of adjusting the diaphragm 8, relatively to the
diaphragm 7; the operated end of the rod being fitted with a hand-wheel 14, and
formed with a screwed portion 15, which engages with a nut 16, carried by bowed
brackets 17, bolted as at 18, to the cover 10, and the operating end of the rod passing
through with liberty to rotate in the adjustable diaphragm 8, which is secured
against a collar 19, on the rod by a nut 20, or otherwise in any suitable manner.
The end of the filter-body adjacent to the diaphragm 8, is closed by a cover 21,
which is fitted and bolted thereto as at 22, and is made with an inner extension 23,
adapted to limit the outward adjustment of the diaphragm 8.
The diaphragms 7,-8, are perforated with small holes 24, (Fig. 1,) to allow of
the passage of the feed-water, and the medium or media for filtering the solid
impurities is or are arranged between such diaphragms and so can be compressed or
released from pressure at will. Such medium or media may consist of any substance
or substances best suited to eliminate the peculiar impurities that may exist in the
water to be purified, but, for ordinary marine purposes, we prefer to divide the
same into sections by perforated diaphragms 25, and to constitute the first

page_text: section a, through which the water will pass, of ordinary sponge; the next section b,
of wool or loose spun yarn; the next c, of cotton or loosely woven cloth; and the
others d, of close woven woollen or cotton cloth; as, by such an arrangement, the
heavy or larger impurities in the water are arrested by the looser medium or media,
from which the same can be easily expressed, and the finer or closer woven medium
or, media will only have to deal with and eliminate the more minute impurities
which have passed the looser filtering media; consequently, the filter, when applied
with such an arrangement of filtering media, will maintain its working capabilities
for a much longer time than filters the filtering medium of which is all of close
woven fabric.
The filter-body is also fitted, adjacent to each end, with a steam-valve 26,
(Fig. 1,) for the purpose of cleansing the filtering media. When it is required so
to do, the hand-wheel 14, is operated so as to set the diaphragm 8, back against
- the extension 23, of the cover 21, which releases the filtering media a, b, c, d, from
compression. Thereupon, steam is turned on into the water with which the filter
is filled, which scours out and softens the impurities in said media, after which the
hand-wheel 14, is operated so as to compress said media between the diaphragms 7,-8,
which causes said impurities to exude or to be forced out into the sediment-
collectors 5, from which they are blown-off through the cocks 6, or may be removed
upon removal of the covers 10, 21.
When the filtering media is required to be removed for examination or renewal,
the same can be most easily got-at upon removing the cover 10.
The feed-water to be filtered or purified is supplied to the filter-chamber by a
pipe 27, which leads it to a double-seated valve-chest 28, whence, it passes through
a non-return valve 29, to the inlet 30, to the filter-chamber Fig. 1. After passing
through the filter, the purified water emerges through an ordinary stop-valve 31,
passing through a pipe 32, leading to the boiler.
A second valve 33, in the chest 28, is kept closed while the filter is in operation;
but, when the filter is required to be shut-off for cleaning or other necessary
purpose, said valves 29, 31, are kept closed, and said valve 33, is opened, when
the water supplied by the pipe 27, will pass through the valve 33, directly into the
pipe 32, leading to the boiler.
To ensure a thorough purification of the feed-water and to cause it to part
with any occluded gaseous impurities before it enters the filter-body, we cause it
to be mixed in the filter inlet chamber with and heated by water under boiler
pressure drawn from the bottom of the boiler, which also attains the further
advantage of causing an induced circulation of the boiler-water to the bottom
thereof. For this purpose, hot water is led from the bottom of the boiler by a
pipe leading therefrom to the casing 34, of a non-return valve 35, through which
the water passes into an inlet 36, to the filter-body, opposite to said inlet 30. Or,
a pump, injector or inducing nozzles may be used to force hot water into the inlet
chamber of the filter against any excess of pressure which may exist therein over
that in the boiler.
To eliminate any occluded gases or air from the water, the inlet chamber of the
filter is fitted with an air-chamber 37, Fig. 2, provided with an air-cock 38, and
with a water-gauge 39. Any gas which escapes from the feed-water, will ascend
into and collect in the chamber 37, and will, if the outlet of the cock 38, be so
adjusted as to cause the inside pressure to be maintained,-escape into the
atmosphere; while any water will be prevented from escaping. The gauge 39,
will indicate any rise of the water in the chamber 37, or, a float valve may be
fitted to act automatically.
To ensure the safety of the apparatus against any excessive pressure which
may arise due to the filtering media getting unduly clogged, a bye-pass valve 40,
is fitted in a conduit 41, connecting both ends of the filter-body, and is loaded
by a spring 42, or otherwise to a safe pressure per square inch above the boiler
pressure, and is so arranged that when the pressure so accumulates as to cause
it to lift and allow of communication between the ends of the filter-body, its

page_text: spindle 43, will press on a button 44, which will switch-on an alarm-bell (not
shown) placed in any convenient position, or will otherwise. call the attention of
the engineer in charge.
45 represents a pressure-gauge serving to indicate the pressure within the
filter-body.
The filter-body is formed with bracket-feet 46, by means of which it can be
secured to any suitable base or seat.
The improved apparatus possesses the special advantages of being compact,
strong and safe, and of having a relatively large filtering area and capacity
compared with the space it occupies, and the special facility of the filtering media
being so easily placed, removed and cleansed as hereinbefore set forth.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is;-
1. The hereinbefore described improved apparatus for filtering or purifying feed-
water for marine or other steam-boilers.
In apparatus for filtering or purifying feed-water for marine and other steam-
boilers;-
2. The formation of the filter-body of an open-ended, parallel-sided formation
with a depending mud-collector adjacent to each end.
3. The combination of a filter-body made of an open-ended, parallel-sided
formation and with a depending mud-collector adjacent to each end; a stationary
perforated diaphragm and an adjustable perforated diaphragm fitting within such
filter-body and between such mud-collectors ;-filtering media arranged between
such diaphragms; covers adapted to close the ends of the filter-body and to limit
the outward positions of such diaphragms;-an externally projecting rod adapted
to adjust the adjustable diaphragm in relation to the stationary diaphragm to
compress or release the filtering media as may be required; and means of actuating
the rod to render it so effective.
4. The combination with the subject matter of Claim 3, of an air-chamber as
described.
5. The combination with the subject-matter of Claim 3, of the bye-pass valve
and conduit connecting both ends of the filter-body.
6. The combination with the subject matter of Claim 4, of the bye-pass valve and
conduit connecting both ends of the filter-body.
7. The described arrangement of valves for admitting the feed water to the
filter-body or direct to the boiler as required.
8. The combination of an open-ended, parallel-sided filter-body; removable
covers for closing its ends; a stationary perforated diaphragm arranged adjacent
to one end; an adjustable perforated diaphragm arranged adjacent to its other
end; filtering media arranged between said diaphragms;-and means of adjusting
the movable diaphragm in relation to the stationary diaphragm.
9. Heating the feed water within the inlet chamber to the filter-body by water
drawn from the bottom of the boiler as and for the purposes stated.
Dated this 28th day of December 1893.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicants.