Improvements in Apparatus for Filtering Water, especially applicable for Filtering Feed Water for Steam Generators.
Year: 1892

page_text: Date of Application, 30th Apr., 1892
Complete Specification Left, 30th Jan., 1893-Accepted, 8th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Filtering Water, especially applicable
for Filtering Feed Water for Steam Generators.
I, DAVID ANDREW RANKINE, of 21 Lyra Road, Waterloo near Liverpool, in
the County of Lancaster, Consulting Engineer, do hereby declare the nature of
this invention to be as follows :-
My present invention has reference to apparatus for removing impurities from
water by filtration or straining through suitable media such as flannel or the like
and wire gauze, and is specially applicable for the filtration of feed water for
steam generators, and I will describe it with reference to such application.
According to my invention I construct such apparatus as follows ;-
I provide a cylindrical casing having an inlet branch for the feed water at one
end and an outlet branch for the feed water at the other end; a removable cover
is fitted at the inlet end of the casing and the space within the latter is divided
by a transverse diaphragm which is placed close to the inlet branch and has a
large central opening. Within the casing and concentric therewith I place an
open ended tube of perforated plate which acts as a support for the filtering
media as hereinafter more fully described; one end of this tube fits closely in the
central opening in the diaphragm already mentioned and the other end fits closely
in and is supported by a suitable seating carried by ribs from the wall of the
cylindrical casing; under normal circumstances, this end of the perforated tube is
closed by the seating in which it fits and it will be seen that feed water entering
the casing by the inlet branch has to flow through the perforations of the tube on
its way to the outlet branch.
The filtering media consist of a hollow cylindrical roll of flannel or the like
material alternated with wire gauze, which is introduced through the cover and
placed as a lining within the perforated tube. This lining is retained in position
by an annular washer and a ring or flange which is jointed firmly against the
diaphragm either by bolts in the latter or by means of a central tubular
prolongation which extends to the seating at the opposite end of the casing and
is screwed thereinto; when this latter construction is adopted, the wall of the
central tube is perforated and it has a loose liner of wire gauze which acts as a
strainer and serves to intercept the grosser impurities before arriving at the
filtering media.
The inlet and outlet branches of the apparatus are controlled by stop valve
boxes which are connected by a pipe forming a by-pass to the apparatus ; this
by-pass pipe is controlled by a stop valve which is normally closed so that the
feed water passes through the filter, when it is desired to throw the filter out of
operation, the by-pass valve is opened and the inlet and outlet valves screwed down.
By making the branches of the inlet, by-pass and outlet valves sufficiently long to
meet, the by-pass pipe may be dispensed with and some joints thus saved.
In order to provide for blowing through the apparatus so as to eject the
impurities arrested therein and to cleanse the filtering media, I provide a passage
through the seating which supports the perforated tube,-this passage leads to the
outside of the apparatus and is controlled by an external cock and when this cock
is opened the feed water entering the apparatus can flow through the apparatus
without passing on to the boiler, and in this way most of the residue arrested in the
apparatus can be ejected.
A pressure gauge is fitted to indicate the resistance offered to the passage of the
feed water through the filter;-as the filtering media become fouled and the residue
accumulates, the resistance will increase and the apparatus is blown through at

page_text: intervals in accordance with the indications of the pressure gauge; when it is
found that the filtering media have become so foul that they cannot be cleaned
sufficiently by the process of blowing through, the roll can be readily removed and
replaced by a fresh one by first isolating the apparatus, then opening the cover and
removing the washer and ring by which the roll is held in position. A relief valve
is fitted to the apparatus to provide for the escape of the feed water in case the
resistance should rise unduly.
In forming the roll of filtering media I take a sheet of wire gauze preferably
brass--and solder a strip of sheet metal along two of its opposite edges. Small
eyelets are secured to these strips and the flannel or other filtering material is laid
over the gauze, the eyelets pushed through and the whole secured by passing light
rods or skewers through the two sets of eyelets. The flannel or the like may be
elsewhere further secured by short flat headed pins with washers secured by split
pins, and the whole then rolled up into a cylindrical roll of one or more convolutions
which fits, as already described, freely inside the perforated tube; either the flannel
or the gauze may be rolled outside as may be preferred.
It will be seen that the construction described permits a very large filtering
area to be enclosed within a casing of comparatively small volume and, in particular,
of comparatively small diameter.
The filter is preferably placed on the delivery side of the feed pump although it
may be placed on the suction side if preferred.
While I have described my invention with reference to boiler feed water it is
to be understood that it is capable of application generally where it is desired to
filter water.
Dated this 29th day of April 1892.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Filtering Water, especially applicable
for Filtering Feed Water for Steam Generators.
I, DAVID ANDREW RANKINE, of 21 Lyra Road, Waterloo near Liverpool in
the County of Lancaster, Consulting 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 present invention has reference to apparatus for removing impurities from
water by filtration or straining through suitable media such as flannel or the like
and wire gauze, and is specially applicable for the filtration of feed water for steam
generators and I will describe it with reference to such application.
In the accompanying drawings which illustrate my invention
Fig. I is a side elevation of the apparatus in diametral section on the line A. A.
of Fig. 11 which is a transverse sectional view, the stop valves being omitted; as
the structure is symmetrical about the diameter A. A, the left hand half of Fig. II
is a section on the line B. B. of Fig. I and the right hand half is a section on the
line C. C. of Fig. I.
Fig. III shows the method of forming the roll of filtering media.
Throughout the drawings, the same parts are indicated by the same reference
figures and in the case of sections, the directions in which they are viewed are
indicated by the small arrows adjacent to the letters denoting the planes of
section.
1 is a cylindrical casing having an inlet branch 2 for the feed water at one
end and an outlet branch 3 for the feed water at the other end; a removable
cover 4 is fitted at the inlet end of the casing and the space within the latter is
divided by a transverse diaphragm or flange 5 close to the inlet branch 2.

page_text: 6 is an open ended tube of perforated plate which acts as a support for the
filtering media as hereinafter more fully described; one end of the tube fits closely
in the diaphragm or flange 5 and the other end fits closely in and is supported by
the seating or recess 7; under normal circumstances this end of the perforated tube
is closed by the seating in which it fits and it will be seen that feed water entering
the casing by the branch 2 has to flow through the perforations of the tube on its
way to the outlet branch 3.
The filtering media consist of a hollow cylindrical roll of flannel 8 or like
material alternated with wire gauze 9, which roll is introduced through the cover
and placed as a lining within the tube 6. This lining is retained in position by the
annular washer 10 and the flange 11 which is jointed to the diaphragm 5 and
has a central tubular prolongation 12 extending to the seating 13 in which it fits.
The wall of the central tube 12 is perforated as at 14 and it has a loose liner
of wire gauze 15 which acts as a strainer and serves to intercept the grosser
impurities before arriving at the filtering media.
The inlet and outlet branches 2 and 3 of the apparatus are controlled by the
stop valves 16 and 17 respectively; the boxes of these valves are arranged on
the side of the filter as shown and the corresponding branches are turned
towards each other and connected by the box of the by-pass valve 18; by this
arrangement the necessity for a by-pass pipe is obviated and some joints thus
saved.
In order to provide for blowing through the apparatus so as to eject impurities
arrested therein and to cleanse the filtering media, I provide a passage 19 through
the seating which supports the perforated tube 6; this passage is controlled by the
cock 20, and when this cock is opened, the feed water entering the apparatus
can flow through it without passing ou to the boiler, and in this way, most of the
residue arrested in the apparatus can be ejected.
A pressure gauge, not shown in the drawings is fitted to indicate the resistance
offered to the passage of the feed water through the filter; as the filtering media
become fouled and the residue accumulates, the resistance will increase and the
apparatus is blown through at intervals in accordance with the indications of the
pressure gauge; when it is found that the filtering media have become so foul that
they cannot be cleansed sufficiently by the process of blowing through, the filtering
roll can be readily removed and replaced by a fresh one, by first isolating the
apparatus by closing the valves 16 and 17 and opening 18, then opening the cover 4,
and removing the washer 10 and flange 11 by which the roll is held in position. A
relief valve (not shown) is fitted to the apparatus to provide for the escape of the
feed water in case the resistance of the filter should rise unduly.
In forming the roll of filtering media (see Fig. III) I take a sheet of wire
gauze 9-preferably brass--and solder a strip of sheet metal 21 along two of its
opposite edges. Small eyelets 22 are secured to these strips and the flannel or
other filtering material 8 is laid over the gauze, the eyelets pushed through and the
whole secured by passing the rods or skewers 23 through the two sets of eyelets.
The flannel or the like may be elsewhere further secured by short flat headed
pins 24 with washers secured by split pins, and the whole then rolled up into a
cylindrical roll of one or more convolutions which fits, as already described, freely
within the tube 6. Either the flannel or the gauze may be rolled up outside as
may be preferred.
It will be seen that the construction described permits of a very large filtering
area to be enclosed within a casing of comparatively small volume and in particular
of comparatively small diameter.
The filter is preferably placed on the delivery side of the feed pump although it
may be placed on the suction side if preferred.
While I have described my invention with reference to boiler feed water it is to
be understood that it is capable of application generally where it is desired to filter
water.

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 ;-
1. The improved filter for feed water which consists of a cylindrical casing
baving a lateral inlet and outlet and containing a cylindrical roll of filtering media,
constructed as described, supported, so as to lie across the water way, by a per-
forated tube located in the casing by an annular diaphragm and a seating which
closes the end of the tube, the said roll and tube being kept in position by a flange
bolted to the said diaphragm, substantially as described and illustrated.
2. The improved filter for feed water which consists of a cylindrical casing
having a lateral inlet and outlet and containing a cylindrical roll of filtering
media, constructed as described, supported, so as to lie across the water way, by a
perforated tube located in the casing by an annular diaphragm and a seating
provided with a passage controlled by a cock outside the casing; the said roll
and tube being kept in position by a flange, bolted to the annular diaphragm
and provided with a perforated tubular prolongation adapted to support a liner
of wire gauze, substantially as described and illustrated.
3. In filters for feed water, in combination with the filter chamber, the cylin-
drical roll of filtering media constructed substantially as herein described and
illustrated.
4. In filters for feed water the lateral arrangement of the inlet and outlet of
the filter chamber and the valves therefor and the by-pass valve, whereby a
by-pass pipe is dispensed with, substantially as described and illustrated.
5. The combination and arrangement of parts forming the improved filter for
feed water, substantially as described and illustrated with reference to the
drawings.
Dated this 28th day of January 1893.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool, Agents for the Applicant.