Improvements in Apparatus for Filtering Water, especially applicable to Feed Water Filters.
Year: 1897

page_text: Improvements in Apparatus for Filtering Water, especially
applicable to Feed Water Filters.
I, CHARLES ROLAND HONTBALL, of 161, Fountains Road, Kirkdale, Liverpool,
in the County of Lancaster, Engineer, do hereby declare the nature of this inven-
tion to be as follows:-
This invention relates more particularly to filters for feed water for steam
generators and the object of the invention is to provide a filter of compact design
having a comparatively large area of filtering material.
In filters constructed according to my invention the filtering material is
arranged in the form of a spiral roll whose axial width is about equal to or some-
what greater than its maximum diameter. This spiral roll is carried in a cylin-
drical or other suitable casing and is so arranged across the water-way that an
area of filtering material is interposed across the water-way equal to the product
of the length of the spiral into twice the axial width of the roll.
The roll is constructed as follows:-I take a suitable perforated sheet of metal
plate of length equal to that of the proposed spiral and of width equal to twice
that of the spiral roll; this perforated sheet is doubled over so as to halve its
width and form a double sheet of long Ụ shaped cross-section, and it is then rolled
in a spiral whose successive convolutions are separated from each other by a
suitable distance. The perforated sheet now forms a spiral with two parallel
perforated walls which are united together, at the fold, along the one spiral edge,
which I will term the top, but which are not connected at the opposite bottom
edges; the axial cross-section of a single convolution being, as before stated, of
a long shape. A filter cloth of a somewhat larger size than the perforated sheet
is now folded and formed into a spiral roll similar to the one just described but
sufficiently larger to envelope the latter. The perforated spiral with the filtering
material in position is placed in a cylindrical casing the bottom of which is
provided with a spiral channel of taper cross-section into which the open spiral
edges of the perforated spiral roll and the filtering material fit, sufficient down-
ward pressure being employed to grip the latter in the taper channel. The channel
communicates with the water-way, preferably with the outlet end thereof, in which
case the water to be filtered enters the casing by the inlet, passes through the
filtering material to the inside of the perforated spiral roll, then down through
the open edge thereof into the channel and so to the outlet.
The casing may have but the one filtering surface as described, or more than
one may be fitted in the one casing, the filtering surface being thus divided into
several units; thus instead of the one roll described there may be two, three or
more such rolls, the water to be filtered passing through these either in succession,
or in parallel, or partly in succession and partly in parallel. Instead of merely
duplicating or triplicating the filtering rolls, the one roll may be divided into

page_text: separate units; or a series of two or more spirals, one concentrically enclosed
within the other, may be formed; or two or more concurrent spirals may be formed,
the water to be filtered passing through the respective spirals either in succession
or in parallel. When the spirals are arranged concentrically flap valves may be
fitted to enable the sediment to be blown out from the inner surfaces.
In some cases when double or triple filtration is required I prefer to arrange the
spiral rolls in separate chambers.
The general configuration of the spiral may be circular, elliptical or polygonal,
or in the case of tanks for feed water and the like it may be adapted to suit the
configuration of the tank or the feed pipe therein.
The spiral roll may also be modified as follows: -The lower edges of the spiral
perforated sheet, which in the first described form are open, may be joined together
so that the section, is continuous and the filtering material made in the shape of a
long narrow bag which is threaded onto the spiral from, say, the inner end; in
this case the outer end would form the outlet for the water, and the spiral channel
in the bottom of the casing would be dispensed with. In this form of spiral
roll the cross-sectional area increases from the inner to the outer end where it may
be made equal in area to the supply pipes.
The inlet and outlet valves on the casing are connected by a bye-pass valve and
the casing is provided with a relief valve and the usual fittings.
When the spirals are arranged concentrically the filtering material may be so
folded as to cover more than the one spiral; and in some cases the perforated sheet
may be corrugated to give it stiffness.
Improvements in Apparatus for Filtering Water, especially
'T
applicable to Feed Water Filters.
I, CHARLES ROLAND HONIBALL, of 161, Fountains Road, Kirkdale, Liverpool,
in the County of Lancaster, Engineer, do hereby declare the nature of this inven-
tion 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 more particularly to filters for feed water for steam
generators and the object of the invention is to provide a filter of compact design
having a comparatively large area of filtering material.
I have illustrated my invention in the accompanying drawings which may be
briefly described as follows:-
Figs. I, II, III and IV illustrate a form of filter adapted for single filtration,
Figs. I and III being sectional views on the lines A, A, of Fig. III and B,B, of
Fig. I, respectively, and Figs. II and IV being respectively, an elevation and a
plan, in outside view.
Figs. V, VI and VII, illustrate a form of the apparatus in which the end of the
spiral roll forms the outlet and in which the spiral channels are dispensed with,
Figs. V and VI being sectional views on the lines C, C, of Fig. VI and D,D, of
Fig. V, respectively, and Fig. VII being a transverse section to a larger scale, of
the spiral roll.
Figs., VIII and IX are views similar to Figs. V and VI, the sections being taken

page_text: respectively on the lines E, E, of Fig. IX and F, F, of Fig. VIII; these figures
illustrate a form of filter adapted for double filtration.
Figs. X, XI, XII and XIII illustrate a modified form of filter also adapted for
double filtration, Figs. X and XII being sectional views on the lines G, G, of
Fig. XII, and H, H, of Fig. X, respectively, Fig. XI an outside elevation with
the valve and valve box cover removed, and Fig. XIII indicating the method of
arranging the filtering material for this form of the filter.
Figs. XIV and XV illustrate a modification in which the filter cloth can be
removed without removing the spiral roll, Fig. XIV being a sectional view on J, J,
of Fig. XV, and the latter being a plan view with the cover removed.
Figs. XVI, XVII, XVIII, XIX and XX illustrate the various forms of spirals
which may be used, and Figs. XXI and XXII illustrate modified forms of the
collecting chambers, the last two figures being fragmentary medial sections.
Throughout the drawings the same parts are indicated by the same figures of
reference, and in the case of sections the direction in which the section is viewed
is indicated by the small arrows placed adjacent to the letters denoting the plane of
section.
Referring in the first instance to Figs. I to IV, 1 is the casing provided with a
cover and having an inlet 2' an inlet valve 21, an outlet 3, an outlet valve 3¹
and a by-pass valve 4; the filtering material takes the form of a spiral roll 5
arranged across the water-way and supported by a perforated spiral roll of sheet
metal 6, each spire of which is of inverted "U" shaped cross-section, and whose
convolutions are separated by a suitable distance as shown. It will be seen from
an inspection of the drawing that the upper edges of the sides of the inverted "U"
are joined together while the lower edges are unconnected; these lower edges are
however held in position by.a spiral channel formed in the bottom of the casing 1,
or in a false bottom or diaphragm 7, as shown in Fig. I. The projecting spiral
remaining when the channel is formed fits in between the two sides of the "U"
as shown.
The perforated spiral roll thus formed is covered with the filtering material
which is formed as follows:-
A strip of the material is taken of length approximately equal to that of the
spiral and of width sufficient to cover the two sides and bend of the "U"; the
strip is folded along the centre of its length, its ends are suitably joined and
the material thus folded is wound into a spiral adapted to envelop the perforated
spiral, the lower edge of the one convolution being joined, as at 8, to the lower
edge of the adjacent convolution. The filtering material is held in place by
rings such as 9 carried by rods 10 from a bar 11, which bar is carried from the end
of a central stud 12, which also serves to hold the diaphragm 7 in position; the
outer edges of the cloth have a sufficient margin, as shown, to be held down by the
rings 9.
The water to be filtered enters by the inlet 2, passes the inlet valve 2¹, and if
the by-pass valve 4 be closed, enters the casing above the diaphragm, it then
passes through the filtering material, through the perforated metal support, then
through the openings 13 in the diaphragm 7 to the lower part of the casing and
thence to the outlet 3 through the outlet valve 31. If now the inlet valve be
closed and the by-pass and outlet valves be opened, the water passes directly from
the inlet to the outlet, and the filter is cut off.
Referring now to Figs. V, VI and VII:-as before, 1 is the casing, 2 the inlet
and 3 the outlet; the construction of the perforated spiral roll 6 is, in this case, a
modification of that last described; the lower edges of the perforated metal as well
as the upper edges are now joined, as shown in Fig. VII, by a bridge piece 6¹.
The inner end of the perforated spiral roll is closed but the outer end is open, and
the open end is jointed to the outlet by, say, a rubber joint as shown in Fig. VI,
and the cross-sectional area of the spiral increases from the inner to the outer end.
The joint referred to is made by forming a rectangular flange 31 on the end of
the perforated spiral 6ª and this flange slides vertically downwards into a suitable

page_text: recess formed in metal of the casing as shown, the joint being made good by a
rubber washer. Of course the flange may be bolted to the casing if preferred.
The spiral roll, as before, is covered by the filtering material, the latter being
made in the form of a bag or stocking and drawn on, or, since I have found the
latter mode somewhat inconvenient, the filtering material 5 may, after being
folded, wound into a spiral, and placed-on-the-perforated spiral roll, have its loose
edges lapped over as shown in Fig. VII, the said edges being held in position by
a clip or series of clips-14; the inner ends both of the perforated roll and roll of
filtering material are closed and the open outer end of the latter is secured to the
former by a cord 15 or by other suitable means.
In this arrangement the water to be filtered enters by the inlet 2 into the
casing 1, then through the filtering material and the perforations to the interior
of the spiral, then along the latter to the outlet.
The arrangement shown in Figs. VIII and IX is very similar to that last
described, except that in this case there are two separate perforated spiral rolls 6b
and 6, the former being placed within the latter; the lower ends of the rolls
are, in this construction, not joined together, but they are closed, when in
position, by the bottom of the casing which is provided with suitable spiral grooves
and projections which also serve to locate the spirals.
The arrangement of the filtering material in this form differs somewhat from
that last described, and, from an inspection of Fig. VIII, it will be seen that the
filtering material covers each of the perforated spiral rolls 6b and 6°.
The material is folded after the manner shown in Fig. XIII, and the outer
perforated spiral roll 6° is introduced between the inner and outer folds of the
filtering material 5 and is placed in or removed from the casing along with the
material. The inner perforated spiral roll is fixed in the casing and its open end
is connected to the outlet after the manner described in connection with Figs. V, VI
and VII. In the present instance however there is a double or successive filtra-
tion, the water to be filtered enters the casing by the inlet 2, passes through the
filtering material on the outer perforated roll 6 then through the latter, then
through the filtering material on the inner perforated roll and through the latter
to the interior thereof, after which the water passes along the inner spiral to the
outlet 3.
The spiral edges of the filtering material are joined and seamed, and the inner
end is closed; the edges of the outer end are also joined and secured in position as
shown at 16, Fig. IX, the arrangement being such that the water is constrained
to flow in the path described. The spiral rolls are kept in position by a plate 17
which is pressed down by a spring 18.
Figs. X to XIII also illustrate an arrangement adapted for double filtration;
there are two concentric perforated. spiral rolls 6d and 6, the inner one 6d extends
through the bottom 7 of the casing and its lower open end fits over wedge pieces 19
which locate it in position. The outer perforated spiral 6 terminates at the
bottom 7, and the filtering material, which is formed as shown at Fig. XIII, is
adapted to be removed with the said outer spiral; the latter is placed within
the roll of filtering material as described in connection with the form illustrated
in Figs. VIII and IX, and spiral ridges may be formed on the bottom 7 to locate
the outer spiral. It will be seen that, as in Figs. VIII and IX; when the outer
spiral 6 is inserted between the folds of the filtering material when the latter is
folded as shown in Fig. XIII, and the outer spiral and material put in position as
shown in Fig. X, the filtering material covers the exterior surfaces of both the
inner and outer spirals. The ends of the folded material, after the insertion of the
outer perforated spiral are closed, permanently at the inner end of the spiral,
and, at the outer end, by means of two flap pieces 51 (Fig. XIII) which are main-
tained in position by a brass plate 20 (Fig. XII) and studs and nuts.
It will be seen from an inspection of Fig. XII that in closing the ends of the
filtering material when folded as shown at Fig. XIII, the ends of the inner folds
are closed so as to fit over the inner spiral 6d, and the ends of the outer folds are

page_text: closed so as to fit over the outer spiral 6°; in some cases I provide rubber valves 21
(Fig. XIII) at the top and bottom of the ends last referred to, which valves open
outwards and are used when it is desired to remove grease etc., by blowing
through.
In this arrangement a rotating valve 22 is used instead-of separate inlet, -by-pass,
and outlet valves; the valve 22 is adapted to rotate about the centre of a spindle 23
by means of a handle 23, and the valve face is provided with three ports 24, 25,
and 26 connected, respectively, to the interior of the casing above 7", the interior
of the casing below 7", and the outlet 3. Water to be filtered enters by the inlet 2
and, assuming the valve to be in the position shown in the drawings, passes through
the port 24 to the upper portion of the casing, it then passes through the two
spirals in succession and into the lower part of the casing, thence by the ports 25
and 26, (which in the position shown are coupled by the valve) to the outlet 3.
If the valve be turned through 180° from the position shown it will be seen that
it cuts off the filter and allows the water to flow directly, from the inlet to the
outlet.
The spirals rolls are held down, as before, by a plate 17 and spring 18.
In Figs. XIV and XV a form of my invention is illustrated in which the filter-
ing material can be removed without removing the perforated spiral roll 6; the
latter is formed after the manner described in reference to the inner spiral of.
Figs. VIII and IX, and is fixed permanently in position in the casing; the filter-
ing material 5 is folded down the centre then wrapped into spiral form and placed
in position on the perforated spiral 6. The inner end of the material is closed and
the outer end secured to the outer end of 6 by the cord 15, and the roll is held in
position, as in Fig. I by the rings 9, rods 10 and bar 11; the latter however is not
in this case carried by a central stud 12 but is provided with a central rod 10ª having
a broad foot at the bottom adapted to press on the filtering material; the bar 11 is
held down by a projection 27 on the cover 1'.
The direction of flow in this form of apparatus is similar to that described in
reference to Figs. V and VI.
In each form of the apparatus described the casing 1 is of course provided with
the usual mountings found on filters of this class, and which it has not been
deemed necessary to illustrate in the drawings.
It will be obvious also, that the arrangement of the spirals may be considerably
modified without departing from the main features of my invention, and as
examples of the modifications in this respect I have illustrated in Figs. XVI to XX
the different forms which the spirals may take; the several convolutions of the
spirals may be integral or they may be formed in sections, which sections may
in some cases be hinged, as shown at 30 in Fig. XX.
The apparatus may also be modified by arranging the filtering surfaces in
separate units in separate or in the same compartments, and passing the water in
parallel, or in succession or partly in parallel and partly in succession through
these units.
The mechanical details of the apparatus may be considerably modified; for
instance, the perforated spiral rolls may be corrugated to give additional area
and stiffness, and the connection of the interiors of the spirals to the outlet may be
made by means of collecting chambers such as 7b Fig. XXI, and 7 Fig. XXII
which take the place of the diaphragm 7 Fig. I and Fig. X. In Fig. XXI it
will be seen that the collecting chamber 7b has a spigot 28 which fits in a suitable
recess formed on the outlet facing, so that the interiors of the spirals are connected
to the outlet 3 by the collecting chamber. In Fig. XXII the spigot 28* is formed
at the side of the chamber 7° and the latter is held in position by the screw 29.
In the drawings the general configuration of the spirals is circular but, of
course, it may be elliptical, polygonal, or, when the spirals are fitted in tanks or
feed pipes, it may be adapted to suit the shape thereof; and instead of passing the
water in parallel or succession through several units, one unit only may be used
which may be subdivided into smaller units for this purpose.

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 apparatus for filtering water in which the filtering material is
formed into a spiral roll which envelops and is supported by a perforated spiral
roll so as to lie across the water-way; substantially as described.
2. The improved apparatus for filtering water in which the filtering material
is formed into a spiral roll of "U" shaped cross-section which envelops and is
supported by a perforated spiral roll of similar cross-section so as to lie across the
water-way substantially as described.
3. The improved apparatus for filtering water in which the filtering material
is adapted to envelop the whole of the surface of a perforated spiral roll with the
exception on the open outer end thereof, which open end makes joint at its
bounding edges with the bounding edges of the water-way; substantially as
described.
4. The improved apparatus for filtering water in which the filtering material is
arranged in the form of a spiral roll which envelops and is supported by two
perforated concentric spiral rolls so as to lie across the water-way in such manner
that the water passes in parallel or in succession through the two rolls so formed;
substantially as described.
5. In combination; a casing provided with an inlet and an outlet and having
a false bottom or diaphragm dividing it into two parts; a spiral filtering roll
formed of filtering material enveloping and supported by a perforated spiral roll
whose interior communicates with holes or passages formed in the diaphragm
and whose lower edges are located by spiral grooves formed in the said diaphragm;
and means for holding the said spiral filtering roll in position; substantially
as described and illustrated.
6. In combination, a casing having an inlet and an outlet; a spiral filtering
roll formed by enveloping the whole of the surface of a perforated spiral roll,
except the open end thereof, with filtering material; and means for coupling the
said open end to the outlet of the casing; substantially as described and illustrated.
7. In combination, a casing having an inlet and an outlet; a spiral filtering roll
formed by enveloping the surfaces of two concentric perforated spirals with the
filtering material shaped as illustrated in Fig. XIII and adapted to be removed
with one of the said perforated spirals; and means for holding the said filtering
roll across the water way; substantially as described.
8. The combination and arrangement of parts substantially as described and
1ustrated in Figs. I to IV.
9. The combination and arrangement of parts substantially as described and
illustrated in Figs. V to VII.
10. The combination and arrangement of parts substantially as described and
illustrated in Figs. VIII and IX.
11. The combination and arrangement of parts substantially as described and
illustrated in Figs. X to XIII.
12. The combination and arrangement of parts substantially as described and
illustrated in Figs. XIV and XV.
Dated this '17th day of June 1898
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool.
Agents for the Applicant.