Year: 1899

page_text: Date of Application, 28th Mar., 1899
Complete Specification Left, 27th Dec., 1899-Accepted, 17th Feb., 1900
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
This improved filter is constructed after a "multitubular" system. The
liquid, which is admitted through the admission pipe passes through radial
channels (or passages) into an annular chamber, and thence into tubes located
near the periphery of the casing. The walls of these tubes are perforated and
act as strainers.
The casing of the filter is filled with sand or any other filtering material, into
which the liquid passes as it leaves the tubes located near the case. Within
this filtering material the liquid, coming from all sides, moves radially towards
the centre: and the sectional area of the circle which the liquid thus traverses
gradually decreases in extent. But inasmuch as, in consequence of progressive
filtration, the filtering material does not become clogged as much as it would
otherwise be, proportionately less resistance is offered to the passage of the
liquid, and the liquid, whose passage is thus facilitated, is therefore purified
more thoroughly.
Near the axis of the casing there are provided perforating straining tubes,
similar to those mentioned above, into which the purified liquid is delivered,
with a view to its discharge through a discharge channel and outlet pipe.
Should the filtering material become foul through somewhat protracted use, it
may be cleansed by admitting a current of water or any other suitable fluid,
said fluid passing through the pipes in an opposite direction, while at the same
time the filter is revolved about its central axis, the inlet and outlet necks may
to this end, be mounted in bearings. The impurities will for the most part
settle in the immediate vicinity of the outer tubes. As however, these pipes,
while the filter revolves, offer a certain resistance to the filtering material,
which is thereby set in motion, the continuity of impure deposits is broken,
and these impurities are readily washed away by the current passing in the
opposite direction.
Thus the "flush," moving in the reverse direction, is admitted through the
outlet pipe passes into the outlet channel is then distributed among the
central or straining tubes, through the perforated walls of which it is delivered
into the filtering material and through the latter to the tubes near the peri-
phery of the casing, which it enters through their perforated walls; then it

page_text: flows into the annular chamber, and is finally discharged through the inlet
channels and admission pipe.
In order to protect the tubes from being bent out of shape (or position), they
are, in the case of comparatively long filters, braced up at various points by
intermediate pieces; and to protect the thin perforated walls of the tubes from
damage through wear, such tubes are, at their points of support, strengthened
by means of sleeves placed around them. In the end walls of the filters, the
outer tubes are secured in the same manner as are the tubes of evaporators at
sugar-works. In the case of the tubes, serving for the discharge of the filtered
liquid, the method of securing in position the discharging parts thereof is the
same as that described with reference to the outer tubes; while their opposite
ends are inserted into suitable apertures of a ring, rigidly connected with the
corresponding end wall of the apparatus.
In all filters comprising strainers, the latter constitute the part of the struc-
ture which is probably, of all others, the most liable to injury, either in
consequence of the perforations in such strainers becoming stopped, or through
the strainers themselves being cracked and forming chinks through which
filtering material can escape. Now by imparting a tubular shape to the strainers,
in accordance with this invention, the maximum resisting force that thin sheet
metal can be at all expected to attain, is imparted to the strainers: while on
the other hand the arrangement and method of fixing the parts, which is herein
described, enables the entire apparatus to be readily controlled. The outer
tubes which have to suffer most. open into an annular chamber at both ends,
and by opening the covers of these annular chambers or unscrewing these
chambers themselves after having allowed the liquid to run off-it may he
readily ascertained whether any filtering material has found its way into the
tubes. If such be the case, it is only necessary to remove the tube which
happens to contain solid matter, after unscrewing the fittings, by means of
which such tube is fastened to the end wall, and so turning the filter that this
particular tube comes to the top and is thereby released from the pressure which
the filtering material exercised upon it. Any parts of the tube which may he
found damaged may then be repaired, or a new tube may be substituted for
that which has become unserviceable. The tube (whether new or mended) is
either re-inserted into the apparatus, its fastenings are screwed home, the covers
are replaced on the chambers, and the filter may immediately resume its opera-
tion. Should any tubes be stopped it may be sufficient to clear their minute
straining perforations and to refit such tubes in their places. Thus repairs
may be carried out in the apparatus, or it may be cleansed, without any neces-
Bity of removing the filtering material.
In regard to the discharge pipes, situated near the centre of the casing, their
removal from the filter, for repairs, is scarcely ever necessary; neither are they
likely to be clogged by any impurities or solid matter carried away by the
filtered liquid; but what may happen is that small particles of the filtering
material, too fine to be kept back-find their way into the straining holes,
or that, at the start of operations, the filtering material which may, itself, have
been insufficiently cleansed-gives off impurities which are apt to settle in the
holes. For this reason, here, also, but only at the discharge end of the filler
the tubes in question are made accessible by removing the covers of the chamber,
so that they may he readily unstopped and cleansed.
In the case of filters of considerable length where the comparatively wide
space, which should be left free next to the filter, in order to facilitate the removal
of the tubes when required. is not provided, the tubes may be arranged in
sections or lengths at the parts where they are strengthened by sleeves, where
this arrangement is adopted, the said strengthening sleeves are made, each in
two parts or halves, one of which is screwed into the other. The tubes may,
accordingly, whenever required, be drawn out through the chambers, in sections.
It need hardly be pointed out that the filter described, whilst permitting such

page_text: space to be saved by reason of its compact constructions, nevertheless enables
the layers of the filtering material employed to be of considerable depth, or
thickness.
Dated this 29th of
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.,
Agents for the Applicant,
improvements in Filters.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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:-
The invention has relation to filtering apparatus, its object being to simplify
the construction, increase the capacity and efficiency of the apparatus, and
provide means whereby ready access is had to the internal distributing and
delivery tubes for the purpose of cleansing or for the removal of and replacing
of any one or more or all of the tubes, as will now be fully described, reference
being had to the accompanying drawings, in which-
Figure 1 is a section of a filter embodying my invention, taken on line I--II
of Figure 2, which latter shows the filter by a vertical longitudinal_section.
Referring to the drawing, G indicates the filter-casing, provided with an
aperture for the introduction and discharge of the filtering material, which
aperture may in large filters serve as a manhole and is normally closed fluid-
tight by a cover C, Fig. 2. To each end of the filter-casing is secured a tube-
sheet a and g, respectively, in which are removably seated open-ended perforated
distributing-tubes d, arranged about and near the inner face of the cylindrical
casing G. In order that any one of these tubes may be readily removed, they
are screwed or otherwise removably and fluid-tightly fastened in suitable
openings in the tube-sheets a and g. so that the tubes can be readily secured
fluid-tight to their respective tube-sheets and as readily removed.
As shown in Figures 1 and 2, the distributing-tubes d are arranged in a
circular row or group, so that, as hereinafter described: access may be had to
the open ends of said tubes. About the axis of the casing G are arranged
open-ended perforated delivery-tubes e, arranged in segmental groups, so that
ready access may be had to the discharge end thereof, as hereinafter explained.
One end of these tubes e is screwed into a tube-ring h, secured to the inner
face of the tube-sheet a, so as to close said end and prevent entrance therethrough
of unfiltered liquid, while the discharge end of said tubes is secured in the
tube-sheet g in the same manner as the tubes d so that a fluid-tight joint is
likewise formed at the point of connection with the tube-sheet g, while said
tubes can be readily removed.
To avoid sagging of the tubes and when the filter-casing is of great
internal area and especially of great internal longitudinal area, I use supporting-
rings i, Figure 1, connected by radial arms and provided with peripheral radial
angle or flanged lugs, whose flanges are bolted to the filter-casing G,
Figure 2. When required the inner ring i may also be supported by girders o
extending the full length of said casing G.
In practice I have found it advantageous to use distributing and delivery
tubes and e, whose perforated walls are made as thin as possible not only

page_text: for the sake of lightness, but to lessen the liability of the perforations becoming
choked up by solid matter; and in order to prevent injury to the tubes at the
points where they are seated in the supporting-rings i, I mount on said tubes
a reinforcing-sleeve k.
The fluid end of the filter-casing G has fixed thereto a tubular journal a',
to which is connected the feed-pipe a³ in such manner as to allow the filter to
revolve. The journal a is in communication with the radial passages or
channels b, leading and opening into a peripheral circular chamber c, com-
municating with the inlet, or feed end of the tubes d, and in said chamber c
are formed openings ", facing said tubes d, which openings are normally
It will
closed fluid-tight by a ring 1, bolted to the head of the chamber c.
readily be seen that by removing the ring 7 ready access is had to the tubes d
at the feed end thereof. At the discharge end of the filter is provided a similar
circular chamber c¹, in communication with the open ends of the tubes d, said
chamber having likewise openings 1, facing said tube ends, normally closed
fluid-tight by a cover-ring so that ready access may be had to said tube ends
by removing ring. The tubular journal g' at the discharge end of the filter
is constructed to form between it and the tube-sheet g a central or axial
chamber f, into which the delivery-tubes e open, and said central chamber has
likewise openings m¹, facing the open ends of said tubes e, which openings are
normally closed fluid-tight by a cover-ring m, bolted to the chamber f
the tubular journal y', is connected the discharge-pipe g², so as to allow the
filter to revolve, the journal ag may be mounted to revolve in hearings ou
suitable standards, not shown in the drawing.
To
Any suitable granular filtering material may be used--as, for instance, sand-
and in practice I prefer to fill the filter-casing G but partially with the filtering
material or to such an extent as to leave a space between the casing and the
tubes when the filter is at rest, for purposes which will presently be explained.
During the filtration the apparatus remains stationary, the liquid to be
filtered being fed under a head or pressure to the feed-pipe a², and thence
flowing through the distributing-channels into the distributing-chamber and
tubes d, which perform the function of strainers, and is by said tubes dis-
tributed in numerous jets into the filtering material, the liquid percolating
gradually through said material from practically all points at or near the peri-
phery toward the centre, where the liquid, freed from solids held in suspension
therein, passes through the numerous perforations in the tubes e and flows from
said tubes into the delivery-chamber and from thence through the discharge-
pipe g².
It will readily be seen that the described mode of causing the liquid to be
filtered to flow from innumerable points at the surface of a filter-bed to the
center thereof causes the solid impurities to be retained on the surface of the
bed, or, at least, they will not be carried to any great extent into the filtering
material, so that the latter does not become fouled as rapidly as would be the
case otherwise. Furthermore, the surface of the filter-bed is very extensive as
compared with its cross-sectional area, so that the formation thereon of a deposit
of impurities of sufficient depth to materially interfere with the filtration will
take a much longer time than would be the case if the cylinder were an upright
one and the liquid fed thereto at its upper end and the filtrate drawn off at
its lower end, and since the interior portion of the filter-bed does not become
fouled to a great extent the speed of percolation of the liquid through the
filtering material is not materially retarded.
When it becomes necessary to cleanse the filtering material and the tubes d.
the cleansing liquid is caused to flow under pressure from the discharging-pipe g
to and through the feed-pipe coupling a², and during this operation the filter
is revolved, and as it is not completely filled with filtering material the latter
is also set in motion and can therefore be thoroughly cleansed.
Should access to the tubes d or become imperative from any cause, it will

page_text: simply be necessary to remove either one or both of the cover-rings or 13 or
the cover-ring m, as the case may be.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what I claim is:-
1. A filter comprising a casing, a series of perforated tubes arranged about
and near the inner face of the walls of said casing and extending the full
length thereof, a chamber at the feed end of the casing in communication with
one end of said tubes, means for feeding liquid to be filtered to said chamber,
a series of perforated tubes arranged about the axis of the casing and extending
the full length thereof, a chamber at the discharge end of the casing in com-
munication with the ends of said axially-disposed tubes, said chamber provided
with a discharge-passage, and a filtering material contained in the casing, for
the purpose set forth.
2. A filter comprising a cylindrical revoluble casing, a series of perforated
tubes arranged about and near the inner periphery of said casing and extending
the full length thereof, a chamber at the feed end of the casing in communi-
cation with one end of said tubes, means for feeding liquid to be filtered to
said chamber, a series of perforated tubes arranged about the axis of the casing
and extending the full length thereof, a chamber at the discharge end of the
casing in communication with the ends of said axially-disposed tubes, said
chamber provided with a discharge-passage and a filtering material contained
in the casing, for the purposes set forth.
3. A filter comprising a casing containing filtering material, a series of open-
ended perforated tubes arranged about and near the inner face of the casing-
walls and extending the full length thereof, and a series of perforated tubes
open at one end and arranged about the axis of the casing and extending the
full length thereof, a chamber at each end of the casing in communication
with the open ends of the first-named series of tubes, means at the feed end
of the casing for feeding liquid to be filtered to the chamber at said end, a
chamber at the discharge end of the casing in communication with the open
end of the axially-disposed tubes, said three chambers having openings facing
the tube ends in communication therewith, and covers for said openings, sub-
stantially as and for the purpose set forth.
4. In a filter, the combination with a casing for a filtering material, thin-
walled perforated distributing and delivery tubes d and c arranged in said
casing as described and removably secured to tube-sheets at the opposite ends
thereof, stay-rings i secured to said casing and having openings for the passage
of said tubes, and reinforcing-sleeves kon said tubes having their bearings in1
the openings in said rings, means at one end of the casing for feeding liquid
to be filtered to one end of tubes d, and means at the opposite end of the casing
for educting the filtrate discharged from tubes c; of means whereby access is
afforded to tubes d at both ends, and means whereby access is afforded to
tubes e at the discharge end of said tubes, substantially as and for the purpose
set forth.
J. In a filter such as described, the combination with the heads or cup-like
chambers cc and f, provided with openings and m³, of the cover-rings (1³
and m, substantially as and for the purposes set forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.