Improv IN 1244♥
Year: 1895

page_text: Date of Application, 19th Mar., 1895-Accepted, 27th Apr., 1895
Improv
IN 1244♥
I, FRIEDRICH BREYER, of I Am Hof No. 7 Vienna, Austria, 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 :-
This invention relates to improvements in that class of asbestos filters in which
a layer of asbestos is formed on the outer surface of the porous walls of flat
hollow bodies of which a greater or less number are included in the filter casing
the interior of which is in communication with a supply pipe for the water to be
filtered.
The present improvements, when used in their entirety, enable a filtering plant
to be arranged for delivering any quantity of not only sterilised water, but also
of water that is not deprived of its gaseous constituents, such as carbonic acid,
which is essential for its palatable properties.
These objects necessitate a special construction of filtering bodies, and a new
production of the filtering material and its introduction into the filter bodies, and
lastly a cleansing device which is in continuous connection with the filter so as
to be put into action at will, for freeing the filter layers of deposit.
For these purposes, the hollow bodies carrying the asbestos layers are so
arranged that the filtered liquid and the gases are led off from one or more of
them through a common discharge pipe..
The application of the asbestos layers to the hollow bodies is effected before
they are introduced into the filter casing, for which purpose all the pores of the
envelope of the hollow body are in the first instance filled in with a cement composed
of asbestos and water glass, which being rendered water resisting constitutes a
washable filtering layer of asbestos conglomerate, which after introduction of the
filter body, into the casing, is rendered perfectly impervious to micro organisms
by means of a mixture of asbestos and alumina contained in the sterilising liquid
which is then forced through.
In order to regenerate the filter layers which have become clogged through
long usage, they are scrubbed by means of a peculiar brushing apparatus, and upon
the thus cleared asbestos conglomerate a fresh layer of micro-filtering medium is
deposited by means of the sterilising liquid, as above described.
I will proceed to describe my invention more particularly with reference to the
accompanying drawings, in which
Figure 1 shews an elevation of a hollow body constituting a filtering element,
the covering layers of which are partly removed, in combination with the brushing
apparatus.
Figure 2 is a plan of several such hollow bodies with their intermediate brushes,
some of the bodies being shewn in horizontal sections taken at different levels.
Figure 3 shews a side view of several hollow bodies combined with each other
and a cross section through the brushes.
Figure 4 is a plan of part of Figure 3;
Figure 5 an enlarged horizontal section through one of the filter bodies;
Figure 6 a vertical section through part of the same on line xx Figure 1.
Figure 7 is a detail section of the joint of the fibre covering the filtering body at

page_text: Figure 8 shews an enlarged detail of one of the brushes, in vertical and horizontal
section.
Figures 9 and 10 are two sections at right angles to each other, through the
filtering apparatus, which consists of a certain number of the filter elements
enclosed in a casing and provided with the mechanically actuated brushing
apparatus.
Figure 11 is a horizontal section of the filter apparatus.
Figure 12 shews to a larger scale an automatic disengaging device for limiting
the motion of the brushes.
As shewn in Figure 1, each filter element A consists of a stamped metal plate A¹
as middle piece, having in the middle several vertical hollow ribs a of varying length,
and on either side of these inclined ribs a' rising towards the outer end, and also
ribs a running parallel to the two longitudinal edges, which ribs a² run together at
the upper narrow end of the middle piece. The ribs a a' a' serve both for stiffening
the middle piece and for producing a uniform circulation of the water and gases
being filtered.
This middle piece A¹ is covered on both sides with perforated sheet metal
which is rivetted together at the edges and is united at intervals to the inclined and
vertical ribs by means of solder introduced through some of the perforations. The
supporting body thas formed is of a lens-shaped section; at the upper and lower
ends it is rivetted to a head and foot piece a and as formed of two suitably shaped
pieces of sheet metal, as being soldered into an oval mouth piece a from which it
projects somewhat, in order to enable a packing a', Figure 1 to be laid round it,
which serves to fit the filter element watertight to the element base to be presently
described.
The head piece at is closed at top, and carries a casting terminating in a screw
bolt a³.
The support thus formed has a tube a³, open at both ends passing right through
its middle, and entering the hollow of the head at at the upper end and the mouth
piece at the lower end, which tube serves for leading off the gases that have
penetrated into the interior of the filter element.
Over the supporting body formed by the ribbed plate A¹ and the perforated
sheets as are laid two pieces of textile fabric a¹0 having the same form as the body,
and the edges of which are attached together by sewing at the longitudinal edges
as shewn at Figure 7, and after drawing the same over the body, they are also
sewn together at the lower narrow side.
In consequence of the lens shaped section of the element support and the form of
the textile covering, a uniform tension can be imparted to the latter, whereby it is
possible to impart to the asbestos filtering layer to be applied thereto, the necessary
rigidity and solidity.
The water forced from the outside into the filter element by pressure, circulates
underneath the textile covering in such manner that it flows through the inclined
ribs a¹ to the vertical middle ribs a and flows through these to the mouth piece
where it is discharged.
The carbonic acid that has entered rises up in the edge ribs a² and is drawn into
the middle tube a³ by the sucking action of the discharged filtered water in order
to be drawn off together with such water from the filter element.
The formation of the asbestos filtering layers upon the textile covering is effected
before the element is introduced into the casing, this being practicable on account
of the rigidity of the element and of its textile covering, which not only allows of
a perfect saturation and filling in thereof with asbestos fibres but also insures a
permanent cementing together of the latter, the formation of the layer being
effected as follows:-
Serpentine asbestos mechanically ground very fine, is stirred up with water to a
paste and is then rubbed into the textile covering by brushes, the excess of asbestos..
fibres being brushed off while wet, after which the element is allowed to dry.

page_text: After repeating the above operation several times a water-glass solution is
drawn through the filter element by suction, and is rubbed in with the asbestos
fibres on the surface by means of brushes. By this means a mortar is formed
having an accurately determinable consistency and cementing power which fills in
all interstices in the textile fabric.
The fixing of this mortar so as to be permanent against the action of water can
be effected either by slowly drying the filter element or by introducing the dried
element into a bath of chloride of calcium and after drying, immersing it in a bath
of pure water and then again drying.
The filter surface thus produced, silicated like hydraulic cement, already filters
water containing finely divided alumina in suspension, in a crystal-clear condition,
and it can be cleansed with brushes, when choked with deposit, without in any way
impairing its power of retaining micro organisms from the filtrate.
In the above described manner washable filter elements are produced having a
coating of asbestos conglomerate that is impervious to micro-organisms.
In order to obtain a filtrate free from germs, the filter elements, after introduction
into the casing, are sterilised by forcing boiling water through the same, to which
small quantities of a filter compound (from 12 to 15 grammes to one cubic meter
of water) are added, which renders the filter layer impervious to micro-organisms.
This filter compound consists of asbestos fibres mixed with alumina (kaolin) of
which the former are preferably first ground dry together with an equal quantity
of common salt or other suitable crystalline salt soluble in water for effecting a
very fine subdivision of the asbestos. The ground mass is moistened, then highly
dried, and again ground, and this process is repeated until the desired degree of
sub-division of the asbestos has been obtained.
The object of adding salt is, that in consequence of the moistening this is
dissolved and the flakes or small balls of asbestos are saturated with concentrated
salt lye, which crystallises again within the balls on drying, so that in the following
grinding process the asbestos fibres are effectually separated from each other again
by the action of the salt.
The addition of alumina can be effected simultaneously with the salt, so as to
accelerate the process.
This exceedingly finely subdivided filter material can be kept for a very long
time in an air-dried condition without deteriorating.
The filter casing B into which the filter elements A provided with a washable
but not yet sterilised filter layer are introduced, is a vessel, the lower part b of
which contains the element base c common to all the elements and communicating
with the filtrate discharge pipe C, the said base, as also the part 6 of the casing
being fixed watertight upon the base plate ; the mouth pieces a of the elements
are screwed on to the base.
The bolts as at the upper end of the filter element A pass through slots d of a
bridge piece D fixed to the inner surface of the casing B, and serving to hold the
elements in their proper relative position. By screwing up the nuts of the bolts a
the elements can be stretched tight in the longitudinal direction, in order to prevent
them from buckling when being brushed (Figs. 3, 4 and 9).
The top of the filter casing is closed by a hood 2 with air pipe 63 which is closed
by a float valve with bell 6 as soon as the latter is closed by the rising of the
water to be filtered, introduced into the casing. The concussions resulting from
the forcing in of the water are deadened by the air cushion within the bell.
The bottom of the casing is provided with branch pipes 66 67, which com-
municate respectively with the unfiltered water supply and the hot water supply;
it is also connected to the sludge discharge pipe E Fig. 9.
For effecting a rapid and perfect cleansing of the filter elements when choked
with deposit, which, in conjunction with special construction of the elements
and the formation of the filter layer, constitutes an essention condition for the
fulfilment of the first above named object a mechanical brushing apparatus is

page_text: employed, consisting of brushes that can be moved up and down between the
filter-elements.
Each of these brushes consists of a brush plate F which is made of a corrugated
section as shewn at Figs. 3 and 8 in order to render the bristle tufts sufficiently
elastic and yet not occupying too much room.
The bristle tufts fare inserted in the holes of the ridges projecting alternately
on opposite sides, in such manner that each brush can operate on two opposite
sides.
The several tufts are drawn into stamped sockets and are fixed therein by
pressing the edge of the socket flat, whereupon the sockets are driven with
considerable pressure into the holes of the brush plate.
The tufts, which are arranged with their flat sides in the longitudinal direction
of the plate, must be made of such a length as to fit accurately against the lens-
shaped cross section of the filter element, for which purpose a red hot piece of iron
having a surface shaped to correspond with the element, is in the first instance
drawn through between each two brushes, in a direction parallel with the vertical
width of the brush plate.
In order that, in singeing the brush tufts, these may not be shortened too much,
and thus lose their efficacy, the two opposite brushes are held, during the singeing,
at a distance apart somewhat greater than that which they occupy in the filter
apparatus.
on
The brush plates are provided at their two ends with eyes and are threaded
transverse rods f³, on which they are held at the proper distance apart
corresponding to the filter elements by means of ferrules fi threaded on between
them (Figs. and 11).
The entire brush device is fixed to the vertical guide rods f, which pass through
stuffing boxes f of the bottom band hood 62 of the filter casing, which stuffing
boxes, for ensuring a close joint, have tubes f' Fig. 10 attached to them, the
lower ones of which, extend beyond the casing B and are provided with drain
cocks f³.
The up and down motion of the guide rods together with the brushes is effected
by an open and a crossed belt on fast and loose pulleys which turn the pinion g
(Fig. 9) that gears with the rack G attached to the brush apparatus alternately in
opposite directions, according as the one or the other belt is put in gear.
For automatically interrupting the motion of the toothed rack as soon as the
brushes have arrived at their highest or lowest positions, a stopping gear is provided,
which consists of pivotted tappets g¹, Fig. 12 provided at both ends of the toothed
rack G, which, when acted upon in the one direction can turn out of the way of
the teeth of the pinion g so that this slides over them and does not impart its
motion to the rack, while when acted upon in the contrary direction they are held
by stops g2 in such positions that the pinion g in its reversed motion will gear
therewith and thus impart its motion to the rack.
The working of this filter apparatus is so arranged that the sludge pipe E and
branch pipe 6 for the water to be filtered being closed, boiling water under a
pressure about 0.7 atmospheres, and having the above described antimicro-filtering
material mixed with it, is supplied to the filter casing B, so that during the
sterilising the filter layers are at the same time rendered impervious to micro
organisms. The discharge of the warm filtrate is effected through a branch on
the pipe C, not shewn on the drawing.
The branch being then opened, cold unfiltered water is introduced into the
casing, while the hot water supply is closed. As soon as the casing B is sufficiently
cooled, the collecting pipe C for the filtered water is opened so as to allow the
filtered water, freed from gerins together with the gases to be led away to wherever
required.
If after lengthened use the filter becomes clogged with sludge, so as not to
deliver sufficient water, the discharge pipe for filtered water is closed, the brush

page_text: apparatus is put in action, the casing being full of water and the sludge removed
from the filter elements is discharged through the sludge pipe E; the casing is
then flushed with unfiltered water, and the sterilising process with supply of materials
for rendering the filter impervious to micro organisms is repeated.
The above described filter apparatus can be employed either singly or any
number thereof may be combined as one apparatus, all being connected to a common
discharge pipe.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, 1 declare that what.
I claim is :-
1. An asbesto filter consisting of a filter casing B within which are arranged a
number of upright porous hollow filter bodies A of lens-shaped section, having a
filter layer of asbestos conglomerate cement, rendered microbe proof, the lower ends
of which filter bodies communicate with an element base c, serving for collecting
the filtered water from the several elements and communicating with the discharge
pipe for filtered water C, the filter casing B being capable of connection by branch
pipes with the supply of water to be filtered, and with the supply of the
sterilising liquid, as also with the sludge discharge pipe E, substantially as
described.
2. In the construction of asbestos filter referred to in Claim 1, the use of
hollow filter bodies A formed of perforated sheet metal a³ provided with a
covering a¹ of textile fabric, and soldered at intervals to a middle piece A¹
provided with vertical and inclined ribs a and a', as also with edge ribs a² and a
central tube a for leading off the filtered water and gases to the discharge
opening a substantially as described.
3. In combination with the hollow filter bodies referred to in the second claim,
the use of a filter layer composed of an asbestos-water-glass cement which is
rubbed into the textile covering, then solidified and thereby rendered washable,
which layer is rendered microbe-proof by means of a mixture of asbestos, finely
ground by the aid of salt crystals, and of alumina, substantially as described.
4. In the asbestos filter referred to in the first claim, the use of a brushing
apparatus consisting of brush plates F of corrugated section capable of being
moved up and down between the filter elements, which plates have rows of bristle
tufts applied to the surfaces of the filter elements, the bristle tufts being intro-
duced into sockets f1 that are afterwards pressed flat and are forced into holes in
the brush plates so that the tufts lie with their flat sides in the direction of the
horizontal length of the brush plates, the said tufts being brought to the required
length by singeing with hot irons, substantially as described.
5. In the construction of brush apparatus referred to in the fourth claim, the
arrangement of the brush plates F on transverse bars 3 fixed to guide rods f
passing through stuffing boxes f and tubes f7 of the filter casing B, and receiving
an up and down motion by means of a toothed rack and pinion, the brushes being
kept at the proper distance apart by means of ferrules thread on the transverse
rods, substantially as described.
6. In the brush apparatus referred to in the fourth claim, the use of an automatic
stopping gear for stopping the motion of the brushes when arriving at their highest
and lowest positions, which stopping gear consists of pivotted tappets g' at the ends.
of the toothed rack, G, so arranged that when the pinion g gearing with the rack
is turned in one direction the tappets yield to the pressure of its teeth, while when
it is turned in the contrary direction they become fixed and serve as teeth for
imparting the pinion's motion to the rack, substantially as described.
7. In the construction of filter referred to in the first claim, the use of a
stretching device for the filter elements A for preventing these from becoming
buckled by the brushing process, such stretching device consisting of screw bolts a
fixed to the head pieces a' of the elements and passing through slots d in a bridge

page_text: piece D fixed to the filter casing B and having screw nuts by turning which the
stretching of the elements is effected, substantially as described.
Dated this 19th day of March 1895.
ABEL & IMRAY,
Agents for Applicant.