Improvements in or relating to Filters for the Better Cleansing of the same.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Filters for the Better Cleansing of the
same.
I, ANTHONY HARRIS, of 73, Queen Victoria Street, in the City of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
In feed water filters, especially for water tube boilers the tendency has long
been towards increasingly larger filtering area and a closer or finer woven filter-
ing fabric. This does not much matter with a non-reversible filter in which the
dirt cannot be removed by reversing the current, and fresh medium has to be
fitted every time the filter becomes foul, and in a reversing filter it is a serious
matter as the increase of area to be cleaned causes the cleansing stream of water
to become so much diffused, that it has less power then in a more confined area,
and consequently the sludge has to be kept open an undue time causing waste
of precious water and in some cases even is unable to effectually remove the
deposit, as having removed a few patches in the way of the least resistance it
finds sufficient passage without removing the deposit from the rest of the area.
and the filter is set to work again with only a portion of its surface cleaned, so
the pressure soon increases to the point when the filter should be again cleaned
long before its proper time; this is more especially the case in Admiralty filters
which they require to be fitted with a treble thickness of cloth which gives a
much greater initial resistance. It thus appears that when you exceed
a certain area of filtering medium per I, H, P, the excess has been either use-
less or has done more harm than good after the medium has once become
thoroughly foul.
The object of the present invention is to provide a means by which, while
area can be increased at will and the advantages reaped therefrom, the sludging
shall not be so diffused as to be partly inoperative but shall be concentrated and
applied to limited portions in rotation or succession, so that the force of the
sludging water is concentrated on and forced through predetermined portions
of the area and is prevented from passing through the already cleaned portions
while a dirty portion is under treatment, as it would do unless prevented.
The means by which this effect is accomplished is by isolating portions of the
medium during the sludging operation by mechanical means, which while per-
mitting a free passage of the water when in ordinary working diverts and con-
centrates it as desired on separate portions of the medium one after the other.
As an illustration I will show how I can apply the invention to my Patent,
No. 19925 of 1892. In the central duct C, which could be annular or cylindrical
I would place a cylinder closely fitting the outer circumference, and having ports
at regulated distances. This cylinder would be turned by a hand-wheel from
above. When the cylinder was in one position the ports would all be open to
the ports of the filtering space, in another position only one port would be open
to the top group of filtering surfaces, in another a single port open only to
the second group of filtering surfaces and so on. In ordinary circumstances then

page_text: all the ports would be open and the filter would work in its ordinary course,
the cylinder of ports not interfering in the slightest with the working. When
sludging has to take place each compartment or group of compartments of the
filter would be separately opened by means of a port and thus each sludged in
succession, the other compartments being closed. In a similar way almost any
other kind of filter could be arranged in compartments so that each compartment,
or in filters not divided naturally into compartments such as a cylinder could
by the application of this device be sludged a portion at a time, the sludge water
being confined so that it can only enter or leave one. portion at a time succes-
sively till all are sludged.
It is obvious too that cutting off the remaining portions of the filter can be
done by closing the ordinary entrance of the water to be filtered or the exits
of the sludge water instead of the ports where the sludge water enters or the
ordinary filtered water exits, or any other inlet or outlet could be arranged by
which water, other than the ordinary feed might be used for sludging.
Dated this 12th day of December 1898.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in or relating to Filters for the Better Cleansing of the
same.
I, ANTHONY HARRIS, of 73, Queen Victoria Street, in the City of London,
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:-
-
In feed water filters, especially for water tube boilers the tendency has long
been towards increasingly larger filtering area and a closer or finer woven filter-
ing fabric. This does not much matter with a non-reversible filter in which the
dirt cannot be removed by reversing the current, and fresh medium has to be
fitted every time the filter becomes foul, but in a reversing filter it is a serious
matter as the increase of area to be cleaned, causes the cleansing stream of water
to become so much diffused, that it has less power then in a more confined area,
and consequently the sludge has to be kept open an undue time, causing waste
of precious water, and in some cases even is unable to effectually remove the
deposit, as having removed a few patches in the way of the least resistance it
finds sufficient passage without removing the deposit from the rest of the area,
and the filter is set to work again with only a portion of its surface cleaned, so
the pressure soon increases to the point when the filter should be again cleaned
long before its proper time. This is more especially the case in Admiralty filters
which they require to be fitted with a treble thickness of cloth which gives a
much greater initial resistance. It thus appears that when you exceed
a certain area of filtering medium per I H P, the excess has been either use-
less or has done more harm than good after the medium has once become
thoroughly foul.
The object of the present invention is to provide a means by which, while
area can be increased at will and the advantage reaped therefrom, the sludging
water or stream shall not be so diffused as to be partly inoperative, but shall be
concentrated and applied to limited portions in rotation or succession, so that
the force of the sludging water is concentrated on and forced through pre-
determined portions of the area, and is prevented from passing through the

page_text: do unless prevented.
The means by which this effect is accomplished is by isolating portions of the
medium during the sludging operation by mechanical means, which while per-
mitting free passage of the water when in ordinary working diverts and concen-
trates it as desired on separate portions of the medium one after the other, when
the current of water is reversed to clean the filtering medium. As illustrations
I will show how I can apply the invention to the feed water filters for steam
boilers shown in the accompanying drawings, in which:-
Figure 1 is a sectional elevation of a filter fitted with apparatus for concen-
trating the water on separate portions of the filtering medium;
Figure 2 an elevation of the central duct and its ported cylinder, separated
from the filter;
Figure 3 a plan thereof;
Figure 4 longitudinal section on line yy;
Figure 5, a cross section on line aa.
Figure 6, a sectional elevation showing the apparatus in a slightly altered
form for concentrating the water on separate portions of the filtering medium.
Figure 7, a sectional elevation of my invention when applied to filters with
separate filtering chambers;
Figure 8, an enlarged plan view of the diaphragm.
Referring to these figures, the filtering surfaces in the casing E are con-
structed of a cage or grate f composed of inner, intermediate and outer perfor-
ated rings HGF. are flannels on other suitable textile fabric enclosed or
otherwise in gauze. The impure water entering the central duct I through the
valve I cannot penetrate into the interior or delivery side of the filter J without
passing through the filtering flannels / but obliged to pass through the said
layers of flannels and through the perforated rings to the outside, and so through
the delivery valve L to the delivery K, which leads direct to the pump or direct
to the boiler or feed tank. It is obvious that the process may be reversed, and
the dirty water led in through the passage K into the chamber J and out through
the central duct I. The grate is held in position by the hand screws M.
Referring to Figures 1 to 5 inclusive, the central duct I, which is annular or
cylindrical, has ports at regulated distances between each of the partitions N,
thus dividing them and the filtering surfaces up into groups ABCD.
Inside
this central duct I place a cylinder closely fitting it, and having also ports P
similar in shape to the ports in the duct at regulated distances. The cylinder O
is arranged to be turned by the handle Q from above. When the cylinder 0 is
in one position, these groups of ports P' would all be opened through ports of
central duct I to the groups of filtering surfaces ABCD in another position
only one set of ports would be opened to the top group A of filtering surfaces;
in another the next set of ports would be opened only to the second group
of filtering surfaces and so on. The numbers on the plate R indicate where the
handle has to be turned to, to open any particular group of filtering surfaces,
while if the handle be turned to either end of the plate all the ports from top
to bottom are opened to the filtering spaces.
B
In ordinary circumstances then, all the ports would be opened and the filter
would work in its ordinary course, the cylinder of the ports not interfering
in the slightest with the working. When sludging or washing has to take
place, one group of. filtering surfaces of the filter are opened at a time by means
of the ports, and thus sludged, the other groups in the meantime being closed.
If therefore the current of water be reversed and the sludge valve opened the
water will pass back through the egress valve L and through the flannels in the
filtering cage, and carry the washings through the particular group of ports
which for the time being are opened, into the central duct I and thence through
the sludge valve V. V is a steam valve for use if desired in the sludging. By
this means therefore the force of water is concentrated on a particular area of

page_text: filtering surface, which thus becomes thoroughly cleaned, after which another
area of filtering surface can be exposed to the current of water by opening another
group of ports and so on, one after the other until the filter is quite clean. Fur-
thermore the dirt will be discharged out of the filter through the sludge valve,
so that there is no danger of the dirt being simply blown off the filtering surface
back amongst the water, to be re-presented to the filtering medium later on.
R is a spring-loaded valve which in the case of a suction side filter communicates
with the delivery to the pump; or in cases where the filter is on the delivery
side of the pump, leads to the boiler or feed tank. When the filter gets foul and
the water cannot pass readily through the valve I', this valve R' opens, deliver-
ing water to the boiler, and sounding if desired an alarm. W are flanges or ribs
inside the cylinder O for the purpose of strengthening it.
In Figure 6 the same idea is shown of providing a large area for filtering and
yet providing means for diverting and concentrating the water on separate por-
tions of the medium one after the other so that the sludging shall not be so
diffused as to be partly inoperative. The central duct I has ports throughout
its length, but the cylinder O is made to slide instead of to rotate, and is formed
with a number of imperforate telescopic sections o one within the other which
are capable of closing or expanding telescopically and are guided in the duct by
the flanges o. The cylinder O is closed at top and throughout its length, but
it is open at the bottom end and is provided just below the top with a number
of ports S. a are flanges which make a watertight joint between the cylinder
and the bore of the duct. T is a rotary shaft, the part t of which is screwed
into the boss of the cylinder O so that the turning of the shaft by the handle on
the outside will slide the cylinder up and down, the telescopic sections nest-
ing within the socket or part 02 of the cylinder or expanding therefrom as the
case may be. In ordinary circumstances then when the filter is put into working,
the cylinder with its various telescopic segments will be slid down by turning the
handle of the shaft T, and the segments will telescope or nest one within the
other in the socket 02 of the cylinder, and be contained within the cavity U
at the bottom of the filter chest, the cylinder not interfering in the slightest
degree with the working. When sludging has to take place the shaft T is turned
so to slide the cylinder O into the central duct, thus diverting and concen-
trating the passage of the water on a particular part of the filtering medium.
and ensuring that the sludging shall not be diffused or be partly inoperative.
After this another area of filtering surface can be exposed to the current of water
by sliding the cylinder 0 into another position, thus opening other ports in the
central duct and enabling the force of the sludging water to be concentrated and
forced through another portion of the area while preventing it passing through
the already cleaned portions, while the dirty portion is under treatment, as it
would naturally do unless prevented. The washings are thus carried off through
the particular ports in the central duct which for the time being are opened and
thence carried through the ports S into the cylinder and so out through the
exit V. In the drawing the cylinder is shown in such a position in the central
duct as to concentrate the water on the top portion only of the filtering medium.
By moving the cylinder into another position each individual part of the filter
may be sludged in succession.
In a similar way almost any other kind of filter can be arranged in groups or
compartments so that each group or compartment, or in filters not divided
naturally into compartments such as a cylinder, can by application of this inven-
tion be sludged a portion at a time, the sludge water being confined so that it
can only enter or leave one portion at a time successively until all are sludged.
It will be obvious too that cutting off the remaining portions of the filter can
be done by closing the ordinary entrance of the water to be filtered or the exits
of the sludge water instead of the ports where the sludge water enters or the
ordinary filtered water exits, or any other inlet or outlet could be arranged by
which water, other than the ordinary feed, might be used for sludging."

page_text: Thus for example my invention is applicable to filters in which there are
vertical cages or cylinders, or in which the cylinder is formed with a single or
built up series of corrugations, undulations or ribbed surfaces, or in cases where
the filter comprises a number of separate cylinders or vessels contained in an
outer shell. In all these cases my invention can be applied with equal success.
An example is shown in Figures 7 and 8 of a filter in which there is a number
of filtering chambers or surfaces 1, 2, etcetera, arranged round a centre 6 and
contained in an outer shell 3. The bottom plate 4 of the shell 3 is perforated
with ports at regulated distances which lead to the respective filtering chambers,
and working on the face of this plate 4 is a diaphragm secured to the rotary
spindle which is capable of being rotated by means of the handle 7. The
diaphragm 5 is also provided with ports 13 at regulated distances so arranged
that when the diaphragm is in one position, one or a series of its ports will open
the ports in the bottom of the shell leading to one or more of the individual
filtering chambers, while the other chambers will be shut off; in another posi-
tion it will open the ports to another chamber or chambers and so on. A dial
may be provided with an indicator so as to indicate in what position the handle
must be turned to in order to open any particular filtering chamber, while if
the handle be turned into another position all the ports leading to the entire
group of filtering chambers are open. 8 is the inlet pipe for the unfiltered
water, 9 the inlet valve, 10 the outlet valve, 11 the sludge valve. 12 is a by-pass
valve to be used when the filter gets so foul that the water cannot pass readily
through it. This valve 12 can then be opened delivering water to the boiler
direct without passing through the filter. In ordinary working then all the ports
in the plate 4 would be open so as to permit a free and diffused passage of water
through the filtering cylinders the water current passing by way of pipe 8,
valve 9, filtering chambers and exit valve 10. When cleaning however has to
take place, all but one, or at most two, of the filtering chambers in the series
are cut off by means of the diaphragm 5, thus concentrating the whole force of
the water on individual filtering surfaces, the other chambers in the meantime
being closed. If therefore the current of water be reversed by passing the cur-
rent back through the valve 10, and through the particular filtering chamber
whose ports for the time being are opened by the diaphragm, and out through
the sludge valve 11, the whole force of water is concentrated on one filtering
chamber which thus becomes thoroughly clean, and the dirt be carried off through
the sludge valve 11, after which another area of filtering surface can be exposed
to the current of water by opening another group of ports by means of the
diaphragm and so on. This arrangement is of course equally applicable to
filters in which there is one filtering chamber only contained within an outer
shell, and further the diaphragm might be arranged to control the inlet instead
of the outlet of the filter.
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 improvement in or relating to filters for the better cleaning of the
same, which consists in providing such filters with a ported cylinder or diaph-
ragm so arranged that while permitting free and diffused passage of water through
the filter in ordinary working, it can be so operated as to concentrate and apply
the water on separate portions of the filtering medium one after the other during
the cleaning process, in combination with a sludge valve so arranged that when
the force of the sludging water is concentrated on and forced through predeter-
mined portions of the filtering area and the deposit is removed, this deposit will
be carried off through the sludge valve instead of being simply blown off the
filtering surface back amongst the water to be re-presented to the filtering
medium, substantially as described.
2. In filters providing the filtering surface or grids with a cylinder having

page_text: ports which can be applied in succession or rotation to the grids or openings
of the filtering surfaces, said cylinder being so arranged as to concentrate the
water on short lengths of the filtering area one at a time for the purpose of
cleaning, while allowing the water to be diffused over the entire surface in
ordinary working, substantially as described.
3. In filters in which the dirt is removed by reversing the current, the combi-
nation with the central water duct of the filter having ports or grids of a rota-
table cylinder fitting said duct, and ports in said cylinder arranged in groups
at regulated distances, the arrangement of said cylinder being such that it can
be rotated to bring each group of its ports successively opposite the ports or grids
in the central water duct, and thus concentrate the water on short lengths of
the filtering area one at a time at the will of the operator for the purpose of
cleaning them, and of shutting the water off from the already cleaned lengths
when a dirty portion is under treatment, while when the cylinder is rotated into
its off position, the ports are all open to the ports of the filtering space to permit
of a free and diffused flow of water over the entire surface of the filter, substan-
tially as described.
4. In a filter comprising one or more separate filtering chambers or surfaces
contained in an outer shell, the combination therewith of a ported diaphragm
so arranged in connection with the outlets (or inlets) of the filtering surfaces,
that for cleaning purposes it can be turned to open said outlets (or inlets) one
series or only one at a time, and after cleaning close same and open another
and so on until all are cleaned, while when the diaphragm is rotated into its
off position, it will open all ports of the entire set of filtering surfaces so as to
permit of a free and diffused flow of water over the entire surface of the filter,
substantially as described.
5. The general combined arrangement and construction of parts forming my
improved filtering apparatus for the better cleaning of the same, whereby a large
area for filtering is provided and yet, in washing the water is concentrated or
forced through limited portions of the filtering area in rotation or succession,
and is prevented from passing through the already cleaned portions while the
dirty portion is under treatment, substantially as described with reference to
Figures 1 to 5 inclusive, with reference to Figure 6 and with reference to
Figures 7 and 8 respectively, of the accompanying drawings.
Dated this 19th day of October 1800
WM. P. THOMPSON & Co.,
Patent Agents, Of Liverpool, Manchester, Birmingham and London.