An Improved Filtering Material, and Process of Making the same.
Year: 1896

page_text: Date of Application, 30th Mar., 1896
Complete Specification Left, 25th Dec., 1896-Accepted, 6th Mar., 1897
PROVISIONAL SPECIFICATION.
An Improved Filtering Material, and Process of Making the same.
We, FRANZ JURSCHINA, of 1, Hartmann Gasse, Vienna V, Sculptor, ZSIGA
SCHNITZER, of 7, Garnisons Gasse, Vienna IX, Banker, and FRITZ HIRSCH,
of 7, Garnisons Gasse, Vienna IX, Banker, all in the Empire of Austria, do
hereby declare the nature of this invention to be as follows:-
This invention relates to the porous materials through which liquids, more
especially water, are passed in order to free them from small solid impurities
suspended therein, the object being to provide a plastic or doughy and subsequently
hardening mass, from which hollow bodies for filtering purposes can easily be formed,
and to which any desired degree of porosity or permeability can be given.
According to our invention, the said filtering material is formed of more or less
finely powdered quartz and to make the filtering body we cement together the granules
by means of water-glass leaving between them interstices or pores which are of a
size proportionate to the diameter of the granules.
To prepare our improved filtering body quartz is finely ground and sifted through
a bolting-cloth, and the powder so obtained is thoroughly mixed with from 3 to
4 parts per 100 parts by weight of wool ashes. When it is intended to pour the mass
into moulds we add to the mixed powder of quartz and wood ashes sufficient concentrated
water-glass to obtain a doughy inass. When pressure is to be used in moulding and
we prefer that it should be, it is only necessary to wet the powdered mass with the
concentrated water-glass. In the moulds, which are of a form that will give prismatic
or cylindrical hollow bodies having a narrow orifice, the mass is allowed to harden,
after which it is allowed to dry at the ordinary temperature or by being subjected to
artificial heat. In order to render the water-glass perfectly insoluble and to cause it
to form a uniform film round each granule of quartz, the moulded, hardened and
dried hollow bodies or filtering vessels are baked or burnt at a temperature of from
1000° to 1200° Celsius. Finally the soluble constituents of the wood ashes are
lixiviated by boiling the filtering vessels during about two hours in water, and in
this way, a body having fine pores is obtained.
In filters made with our hollow filtering bodies, filtration takes place from without
inwards: the hollow body is mounted within a larger vessel, and a short pipe or
coupling, secured within the orifice of the hollow body, projects to the outside through
the bottom or one of the sides of the outer vessel. The latter is filled with the water
to be filtered and when sufficient pressure is applied, or when a person sucks at the
mouth-piece or short pipe, the water passes through the porous sides of the
hollow body and from the inner hollow space out through the pipe, coupling or
mouth-piece.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.

page_text: COMPLETE SPECIFICATION.
An Improved Filtering Material, and Process of Making the same.
We, FRANZ JURSCHINA, of 1, Hartmann Gasse, Vienna V, Sculptor, ZBIGA
SCHNITZER, of 7, Garnisons Gasse, Vienna IX, Banker, and FRITZ HIRSCH,
of 7, Garnisons Gasse, Vienna IX, Banker, all in the Empire of Austria, 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 porous materials through which liquids, more especially
water, are passed in order to free them from small solid impurities suspended therein
the object being to provide a plastic or doughy and subsequently hardening mass,
from which hollow bodies for filtering purposes can easily be formed, to which any
desired degree of porosity or permeability can be given, and which shall withstand
the action of acids, alkalies and heat so that they may be sterilized after use by
subjecting them to the action of heat.
According to our invention, the said filtering material is formed of more or less
finely powdered quartz, the granules of which are coated with, and cemented together
by silicates, leaving between them interstices or pores which are of a size proportionate
to the diameter of the granules.
To prepare our improved filtering body, quartz is finely ground by means of
ordinary mills or edge mills, the degree of trituration depending upon the degree
of permeability to be obtained, and the powdered material is sifted through a
bolting-cloth. The powder so obtained is thoroughly mixed with from 3 to 4 parts
per 100 parts by weight of wood ashes which, as is well known, consist, on an
average, of 50 per cent. of carbonate of calcium, 20 per cent. of carbonate of potassium
and sodium, 6 per cent. of magnesia, 10 per cent. of phosphates of the said bases and
14 per cent. of silicic acid, all in the state of an impalpable powder and consequently
ready to combine. When it is intended to pour the mass into moulds we add to the
mixed powder of quartz and wood ashes sufficient concentrated water-glass to obtain
a doughy mass. When pressure is to be used in moulding-and we preferably employ
pressure, it is only necessary to moisten or wet the powdered mass with the
concentrated water-glass.
In the moulds, which are of a form that will give prismatic or cylindrical hollow
bodies having a narrow orifice, the mass is allowed to harden, by the combination of
the soluble free silicic acid of the water-glass with the alkaline components of the
wood ashes. The hardened hollow bodies are taken out from the moulds and allowed
to dry at the ordinary temperature or by being subjected to artificial heat, according
to requirement.
In order to distribute the silicate cement as uniformly as possible between the
granules of quartz, so that the said cement may be caused to form a film round each
granule, and also for rendering the cement perfectly insoluble by inducing the basic
silicates to combine with additional portions of silicic acid, the moulded, hardened
and dried hollow bodies or filtering vessels are baked or burned at a temperature of
from 1000° to 1200° Celsius. Finally the remaining soluble constituents of the wood
ashes are lixiviated by boiling the filtering vessels for about two hours in water.
will be readily understood that the mass formed of particles of quartz cemented
together by insoluble silicates, is porous before lixiviation, but this last operation
increases the porosity.
It
In the accompanying drawing we have shewn several filters fitted with our
filtering vessels or porous hollow bodies.
Figures 1 and 2 are sectional elevations of a pocket filter, in which the hollow

page_text: body a having porous sides, is inserted into a sheet metal box b, adapted to contain
the liquid to be filtered. The pipe c at which the user is to suck, screws through a
lateral hole in the sheet metal box b, into a bush cemented into the orifice of the
hollow body a suitable rubber packings being interposed to provide a good joint..
The filter shewn in section in Figures 3 and 4 (the latter figure being a section on
the line 4-4 Figure 3) is also a pocket filter, but without a vessel for the liquid to
be filtered. To use this filter it is dipped into, the vessel, brook or pool containing
the water to be filtered and drunk and the person who wishes to drink sucks at
the pipe or mouthpiece c. In order to prevent the filtered liquid from receding,
whilst the suction is momentarily interrupted, a non-return valve g, made of rubber
lips, may be interposed between the filtering body a and the pipe c.
Figure 5 is a sectional elevation of a filter adapted for use with water under
pressure. The vessel b is hermetically closed and connected with a tap d on the service
pipe. The outlet pipe c of the filtering body a projects through the bottom of the
vessel b.
Figure 6 is a sectional elevation of a filter for use in isolated forms and the like.
The sheet metal vessel b containing the filtering body a is made sufficiently high to
provide the necessary pressure around the filtering body. The compartment / receives
the filtered liquid.
The filter shewn in Figure 7 is adapted to be fitted to a
a supply of water under pressure so that its outer vessel
compartment in which the filtered liquid collects.
tap or valve connected with
is tightly closed. is the
It obvious that filters of the kind described can be combined with pumps, which
force or suck the liquid through the porous sides of the hollow body; or the pump
can first suck the liquid through one hollow body and afterwards force it through a
second.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. An improved filtering material, consisting of granules of ground quartz, which
are cemented together by insoluble silicates and by silicic acid, substantially as
described.
2. The described process of making a filtering material, the said process consisting
in wetting with water-glass a mixture of ground quartz and wood ashes, pouring or
pressing the mass into moulds, where it is allowed to harden, drying the moulded
hardened bodies, heating them to a temperature of from 1000° to 1200° Celsius, and
finally boiling them in water all as hereinbefore described.
Dated the 28th day of December 1806
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.