Improvements in the Manufacture of Filtering Plates, in Apparatus for Testing the same, and in Filtering Apparatus.
Year: 1890

page_text: Date of Application, 4th June, 1890
Complete Specification Left, 17th Sept., 1890-Accepted, 18th Oct..
1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Filtering Plates, in Apparatus
for Testing the same, and in Filtering Apparatus.
A communication from AUGUST EGEN, of Schwerte, Westphalia, Prussia, Merchant,
and ERNST BASSENGE, of Berlin, Prussia, Gentleman.
I, WILLIAM LLOYD WISE, of No. 46 Lincoln's Inn Fields in the County of London,
Consulting Engineer and Patent Agent, do hereby declare the nature of this invention
to be as follows:-
This invention relates to a new method of manufacturing filtering plates to
apparatus for testing the same, and to the use thereof in a new construction of
filtering apparatus.
These plates which are particularly suitable for clarifying liquids of very different
kinds as for examples water, beer, wine, vinegar, mordants and so on, and which in
addition distinguish themselves by giving an extraordinary degree of efficiency can be
made of different thicknesses and of any suitable shape.
They consist essentially of a powder of coke or of cylinder coal and are formed
internally with a number of passages crossing each other, and discharging into a main
passage which is parallel to the border of the plate.
With these filter plates, the filtering process usually takes place from the outside to
the inside, whence the filtered liquid is conducted away through the main passage. The
plates are manufactured in the following way :-A mixture of about
100 parts by weight of tar,
40 "}
330
"
"
of stone pitch and
"
""
of sifted powdered coke or of cylinder coal,
is heated in a boiler and boiled until the whole after having been thoroughly kneaded
forms a viscid plastic mass suitable for being rammed into a mould.
The proportions of the substances in the above mixture may be modified according
to the size of the pieces of coke employed. In the above formula the degree of
fineness of the powdered coke is assumed to correspond approximately with that of the
moulding sand usually employed in founderies.
The mould comprises a plate to which is applied a ring a formed of two equal
parts screwed together (see Fig. 1). The use of this two part ring has for its object
to admit of its being readily removed without injuring the filtering plates formed in
the mould.
After the space within this ring has been filled up with the plastic mass, a grate-like
web or network made of thick cord-like threads of combustible material is placed
upon the plastic mass. This web occupies a space corresponding to the size of the
filtering plate. On the border the web has a somewhat coarser thread, which
at a certain distance from the border of the filtering plate terminates in several
branches. To the main thread are connected all the several threads composing the
grate-like web.
After this web has been exactly applied to the plastic mass, a second similar ring is
placed upon the ring a and the hollow space within it above the web is filled in the
above described manner, with the plastic mass; so as to prevent the formation of any
hollow space.
To the last applied ring a another similar ring is screwed and the new hollow
space thus produced is tightly filled with a mixture of one part of coal dust and
10 parts of sand. The mass thus moulded and from which by a continued glowing
the filtering plates are afterwards obtained, must now be cooled. For this purpose

page_text: through which air can be caused to pass so as to obtain a rather rapid cooling. The
cooled moulds are now piled up upon a mixture of sand and coke resting upon a strong
bottom plate e (see Fig. 9) and held together by a ring d (see Fig. 8).
In this way about 30 moulds are placed one above the other and then, beginning at
the top, the rings a around the filtering plates are detached so that these plates and
the intermediate layers of coke and sand are one above the other as shown in Fig. 9.
To the bottom plate e is then applied the iron casing g, and the space between this
casing and the plates is then carefully filled with the above mentioned mixture of sand
and coal dust and finally the cover plate his secured in place and the whole held
together by means of the tie bolts f
The casing with its contents is then put into a glowing furnace in which it is
submitted for about 2 weeks to a continued glowing process. This long period of
time is rendered necessary on account of the slow heating of the plates and
corresponding slow cooling of the plates. Only under these conditions can
a faultless material be obtained. After the glowing process the plates are ready
for use.
The heating of the plates and their subsequent cooling require very great attention
otherwise a considerable waste of plates will be caused.
Filtering plates manufactured as described are extremely hard, and, according as
the coke powder employed is coarser or finer, they are more or less porous. A
peculiar feature of the plates is due to the formation therein of internal passages by
the complete combustion of the web b. These passages communicate with each other
and they all discharge into the main passage arranged close to the circumference of
the plate. Such plates are particularly suitable for rapidly and completely filtering
water, beer, and other liquids; as they are capable of resisting the action of acids
they can also be used for clarifying acids and the like.
A prominent property of the plates is their extraordinary solidity. Also the fact
that they will not become choked and that impurities will be deposited only on their
outside and can then be removed in a simple and rapid manner is a very important
advantage. Such plates are also very efficient in use. Thus one of such plates
of circular form, having a diameter of 310 mm. and a thickness of 21 in. will
deliver at a. pressure of about 2 atmospheres, 10 litres of liquid per minute. At a
lower pressure down to of an atmosphere, the quantity of the liquid filtered is of
course reduced, and at a higher pressure it is increased.
To ascertain whether any of the plates are cracked and in consequence unfit for use,
all the plates are subjected to a pressure test. For this purpose each plate is formed
in its periphery, at two diametrically opposite points with boles extending up to the
main passage, and the plate is then introduced into the apparatus shewn in Figs. 10
and 11 of the accompanying drawings.
This apparatus consists essentially of a chamber A, which can be hermetically
closed by a cover B. Into this chamber open the conduit pipes C and C that are
screwed to the filtering plate in an air-tight manner by means of packings of india-
rubber. E is a pressure gauge by which the pressure in the interior of the chamber
can be ascertained. D is a funnel that can be closed by a cock D¹. After the plate
to be tested has been screwed in place and the joints with CC made sufficiently
tight, a muddy and impure liquid is introduced through the funnel. D into the
chamber A; the cock D is then closed and pressure is applied through the conduit
pipe F to the liquid to be clarified. The liquid penetrates through the filtering plate,
passes through the passages therein into the main passage and thence passes into the
conduit pipes C and C. To ascertain the pressure in the interior of the filtering plate
during the filtering operation, a pressure gauge E' is screwed to the conduit pipe C.
The show vessel G which may be of clear glass and the several draw-off cocks shewn
are then connected with the conduit pipe C so that the filtered liquid can be drawn off
when required and examined. By means of the. conduit H the liquid not filtered
can be again drawn off. Residues from the combustion of the web, if any, can
be removed from the filter plate by means of the test apparatus, which can be employed
also as a filter.

page_text: To increase the efficiency, a greater number of such plates is employed. The
hereinafter described apparatus serves for this purpose. This apparatus distinguishes
itself by its high efficiency and is so constructed that the filter plates can be cleaned
without taking them out of the apparatus.
Fig. 12 is a longitudinal section of the apparatus,
Fig. 13 a side view,
Fig. 14 a cross section through the centre of the apparatus ; and
Fig. 15 a section through the eduction pipe M'.
The apparatus comprises a receiver J (Fig. 12) which is perfectly air tight and in
the interior of which are contained the filtering plates k. These plates are arranged
at a short distance apart and parallel to each other and they are formed internally
with a network of narrow passages communicating with each other and all discharging
into a main passage as in the plates hereinbefore described. Before being used the
plates are bored at two diametrically opposite points, so that the holes form the
extensions of the main passage to the outside, and each hole is provided with a nozzle
or tube b of metal which does not injuriously affect the liquid to be filtered, and is
not itself attacked by the same.
By these nozzles or tubes the main passage as well as all the secondary passages
are caused to communicate at the top and bottom with eduction pipes M M' respectively
(see Fig. 12) so that when the liquid is forced from the outside into the plate it can
only pass through the secondary passages into the main passage and thence to the
eduction pipes M and M', through which it is then conducted to the cocks N' N² N³ N
and drawn off.
Two of these cocks viz. N2 and N are arranged one above the other and connected
with each other by means of a tube, while the others N' and N³ are on the other side
of the receiver J. By these cocks the filtered liquid can be drawn off at the top or
at the bottom, or at both top and bottom, and by means of one or of two cocks.
For this purpose the cocks N and N are connected with each other by a pipe P.
QQ are two show vessels for examining the filtered liquid in respect of its
clearness.
The liquid to be filtered enters the receiver J through the four way cock R. After
the vessel has been filled with the liquid to be treated the cock R is turned so as to
admit gas or liquid under pressure so that the liquid to be filtered has a tendency to
pass through the filtering plates K into the eduction pipes M and M'and thence to the
cocks N1 N2 N4.
Q³ is a show vessel by which the nature of the liquid to be filtered can be examined
as respects its clearness. This vessel, like the two other show vessels Q'Q' is provided
with a valve for allowing the air to escape and with a funnel that can be closed by a
cock.
After the apparatus has been in use for a time it will be found that mud will have
been deposited on the filter plates; the apparatus is then cleaned in the following very
simple manner.
The cock R is closed and water, steam or other gases under pressure is passed
through one or more of the cocks N1 N2 N communicating with the eduction
pipes M M. In this way a rapid and thorough cleaning of the plates is obtained.
The mud which will then be collected at the bottom of the receiver J is removed by
introducing water or steam through the cock N³, this water or steam serving to
further clean the outer sides of the filtering plates. The receiver is then emptied
through the opening S.
By using sufficiently hot steam small living animals (microbes) that might be
adhering to the interior of the apparatus, can be killed; this is of great importance
when treating liquids intended for beverages.
The cocks R, N¹ N2 N3 and N are each made as a fourway cock provided with two
plugs, that are ground the one into the other. This construction enables the apparatus
to be used and cleaned in various ways. The same result may be obtained by employ-
ing in lieu of each fourway cock four simple crdinary cocks. The efficiency of an
apparatus such as described is dependent not only on the pressure to which the liquid

page_text: to be filtered is subjected, but also on the number and size, and on the porosity of the
plates
The arrangement of the plates is optional, but in order to save space it is advantageous
to arrange them parallel to each other.
n
1
1
CT
1000
W. LLOYD WISE,.
Per F. J. Brougham.
· COMPLETE SPECIFICATION.
Improvements in the Manufacture of Filtering Plates, in Apparatus
for Testing the same, and in Filtering Apparatus.
A communication from AUGUST EGEN, of Schwerte, Westphalia, Prussia, Merchant,
and ERNST BASSENGE, of Berlin, Prussia, Gentleman.
I, WILLIAM LLOYD WISE, of No. 46 Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Patent Agent, 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 a new method of manufacturing filtering plates, to
apparatus for testing the same, and to the use thereof in a new construction of
filtering apparatus.
These plates which are particularly suitable for clarifying liquids of very different
kinds, as for examples water, beer, wine, vinegar, mordants and so on, and which
are extremely efficient can be made of different thicknesses and of any suitable
shape.
They consist essentially of porous coke or of cylinder coal, and are formed internally
with a number of passages crossing each other, and discharging into a main passage
which is parallel to the border of the plate.
With these filter plates, the filtering process usually takes place from the outside
to the inside whence the filtered liquid is conducted away through the main passage.
The plates are manufactured in the following way :-A mixture of about :

page_text: After this web has been applied to the plastic mass, a second similar ring is placed
upon the ring a and the hollow space within it above the web is filled in the above
described manner, with an additional quantity of the plastic mass so as to prevent the
formation of any hollow space.
To the last applied ring a another similar ring is screwed and the new hollow space
thus produced is tightly filled with a mixture of one part of coal dust and 10 parts of
sand. The mass thus moulded and from which by a continued glowing the filtering
plates are afterwards obtained, must now be cooled. For this purpose the iron
bottom plate, is placed upon a wooden block c furnished with passages through
which air can be caused to pass so as to produce a rather rapid cooling. The cooled
moulds are then piled up upon a mixture of sand and coke resting upon a strong
bottom plate e (see Fig. 9) and held together by a ring d (see Fig. 8).
After the plates have been completely piled up the ring d is removed from the
casing, and does not therefore remain in the latter during the glowing process.
In this way about 30 moulds are placed one above the other, and then beginning at
the top, the rings a around the filtering plates are detached so that these plates and
the intermediate layers of coke and sand are left resting upon the other as shewn in
Fig. 9. To the bottom plate e is then applied the iron casing g, and the space
between this casing and the plates is carefully filled with the above mentioned mixture
of sand and coal dust, and finally the cover plate his secured in place and the whole
held together by means of the tie bolts f
The casing with its contents is then put into a glowing furnace in which it is
submitted for about two weeks to a continued glowing process up to high red heat..
After this period the plates are slowly cooled. This long period of time is rendered
necessary in order that the heating and cooling of the plates may be effected slowly.
Only under these conditions can a satisfactory material be obtained. After the plates
have been thus heated and cooled they are ready for use.
The heating of the plates and their subsequent cooling require very great attention
otherwise a considerable waste of plates will be caused.
Filtering plates manufactured as described are extremely hard, and, according as
the coke powder employed is coarser or finer, they are more or less porous. A
peculiar feature of the plates is due to the formation therein of internal passages by
the combustion of the webs b. These passages communicate with each other, and
they all discharge into the main passage arranged close to the circumference of the
plate. Such plates are particularly suitable for rapidly and completely filtering water,
beer, and other liquids, and as they are capable of resisting the action of acids they
can also be used for clarifying acids and the like. A prominent property of the
plates is their extraordinary solidity. Furthermore they will not become choked, and
impurities will be deposited only on their outside and can then be removed in a
simple and rapid manner. Such plates are also very efficient in use. Thus one of
such plates of circular form having a diameter of 310 mm and a thickness of 21 mm
will deliver at a pressure of about 2 atmospheres, 10 litres of liquid per minute. At a
lower pressure down to one quarter of an atmosphere, the quantity of the liquid
filtered is of course reduced, and at a higher pressure it is increased.
To ascertain whether any of the plates are cracked and consequently unfit for use,
all the plates are subjected to a pressure test. For this purpose each plate is formed
in its periphery, at two diametrically opposite points with holes extending to the main
passage, and the plate is then introduced into the apparatus shewn partly in vertical
section and partly in elevation in Figs. 10 and 11 of the drawings.
This apparatus comprises a chamber A, which can be hermetically closed by a
cover B. Into this chamber open the conduit pipes and that are connected with
the main passage of the filtering plate in an air-tight manner by means of packings
of india-rubber. E is a pressure gauge by which the pressure in the interior of the
chamber can be ascertained. D is a funnel that can be closed by a cock D¹. After
the plate to be tested has been secured in place and the joints with CC made
sufficiently tight, a muddy and impure liquid is introduced through the funnel D into
the chamber A; the cock D' is then closed and pressure is applied through the

page_text: conduit pipe F to the liquid to be clarified. The liquid penetrates through the
filtering plate, passes through the passages therein into the main passage and thence
passes into the conduit pipes C and C.
To ascertain the pressure in the interior of the filtering plate during the filtering
operation, a pressure gauge E' is screwed to the conduit pipe C. The vessel G which
may be of clear glass and the several draw-off cocks shewn are then connected with
the conduit pipe (so that the filtering liquid can be drawn off when required and
examined. By means of the conduit H the liquid not filtered can be drawn off.
Residues from the combustion of the web, if any, can be removed from the filter plate
by means of the test apparatus. By passing liquid from the inside to the outside of
the plate, the same can be cleaned after being tested as described. As will be obvious,
this apparatus can be employed also as a filter.
To increase the efficiency a number of such plates is employed as in the filtering
apparatus hereinafter described. This apparatus is distinguished by its great efficiency
and is so constructed that the filtering plates can be cleaned without taking them out
of the apparatus.
Fig. 12 is a longitudinal section of the apparatus ;
Fig. 13 is a side view, partly in section;
Fig. 14 is a cross section through the centre of the apparatus ; and
Fig. 15 is a section through the eduction pipe M².
The apparatus comprises a receiver J (Fig. 12) which is made perfectly air tight,
and in the interior of which the filtering plates K are placed. These plates are
arranged at a short distance apart and parallel to each other, and are formed
internally with a network of narrow passages communicating with each other and all
discharging into a main passage, as in the plates hereinbefore described. Before
being used the plates are bored at two diametrically opposite points, so that the
holes form the extensions of the main passage to the outside, and each hole is
provided with a nozzle or tube of metal that does not injuriously affect the
liquid to be filtered, and is not itself attacked by the same.
By these nozzles or tubes the main passage as well as all the secondary
passages are caused to communicate at the top and bottom with eduction pipes
M and M' respectively (see Fig. 12), so that when the liquid is forced from the
outside into each plate it can only pass through the secondary passages into the
main passage and thence to the eduction pipes M and M', through which it is
then conducted to the cocks N1 N2 N3 N' and drawn off.
Two of these cocks viz.: N2 and N₁ are arranged one above the other and con-
nected with each other by means of a tube while the others N' and N³ are on
the other side of the receiver J.
By these cocks the filtered liquid can be drawn off at the top or at the bottom,
or at both top and bottom. For this purpose the cocks N2 and N are connected
with each other by a pipe P. Q, Q, are two show vessels for examining the
filtered liquid in respect of its clearness.
The liquid to be filtered enters the receiver J through the four way cock R.
After the vessel has been filled with the liquid to be treated the cock R is turned
so as to admit gas or liquid under pressure, and cause the liquid to be filtered to pass
through the filtering plates K into the eduction pipes M and M and thence to the
cocks N1 N2 N'.
Qis a show vessel by which the nature of the liquid to be filtered can be
examined as respects its clearness. This vessel, like the two other show vessels Q¹
and Q, is provided with a valve for allowing the air to escape and with a funnel
that can be closed by a cock.
After the apparatus has been in use for a time, it will be found that mud will have
been deposited on the filter-plates; the apparatus is then cleaned in the following
very simple manner.
The cock R is closed and water, steam or other gases under pressure is passed
through one or more of the cocks N1 N2 N₁ communicating with the eduction
pipes M Mand forced outwards through the plates. In this way a rapid and thorough

page_text: cleaning of the plates is obtained. The mud thus removed from the plates will
collect at the bottom of the receiver J and is removed by introducing water and steam
through the cock N3; this water and steam serving to further clean the outer sides of
the filtering plates. The receiver is then emptied through the opening S which is
normally closed. By using sufficiently hot steam such as superheated steam, small
living organisms (microbes) that might be adhering to the interior of the apparatus,
can be killed; this is of great importance when treating liquids intended for
beverages.
The cocks R, N1, N2, N3 and N are each made as a four way cock provided with
two plugs, that are ground the one into the other. This construction enables the
apparatus to be used and cleaned in various ways. The same result can be obtained
by employing in lieu of each four way cock, four simple ordinary cocks.
The efficiency of an apparatus such as described is dependent not only on the
pressure to which the liquid to be filtered is subjected, but also on the number, size, and
porosity of the plates.
The arrangement of the plates is optional, but in order to save space, it is
advantageous to arrange them parallel to each other as shewn.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The herein before described method of manufacturing filtering plates by forming
a plastic mass of powdered coke or cylinder coal and an adhesive substance such as
tar or stone pitch or both tar and stone pitch, inserting a grate-like web of combustible
material in the central part of the plate during the moulding thereof, and subjecting
the plate thus moulded and whilst enclosed in coal dust and sand, to a glowing or
heating process in a muffle furnace so that by the combustion of the web, the finished
filtering plate is provided with internal passages that communicate with each other,
substantially as herein set forth for the purpose specified.
2. An apparatus for testing filtering plates produced according to the preceding
claim, and adapted for use as a filter, said apparatus comprising a chamber fitted with
an inlet for liquid to be filtered and with a pipe or pipes adapted to hold the plate to
be tested and to be placed in communication with the internal main passage therein
by one or more openings leading from such passage to the outside of the plate, the
arrangement being such that for the purpose of testing, an exterior fluid pressure can
be exerted against the surfaces of the plate, and liquid caused to pass from the outside
to the inside of the plate for the purpose of determining its firmness and also its
efficiency as a filtering plate in respect of quantity and quality of filtered liquid, and
for the purpose of cleaning the plate liquid can be caused to pass from the inside to
the outside of the tested plate substantially as hereinbefore described with reference
to Figs. 10 and 11 of the drawings.
3. An apparatus for filtering liquids comprising a vessel or receiver fitted with
filtering plates formed with internal passages as set forth and arranged the one parallel
to the other and supported by conduit pipes such as M M that communicate in an
air tight manner with the said passages, the said vessel being provided with means
such as the cock R by which the liquid to be treated can be introduced into the vessel
and be subjected to pressure, so that the liquid can be forced by this pressure through
the filtering plates and be thus clarified and pass into the conduit pipes M M', whence
it can be drawn off by means of cocks such as N N N substantially as herein before
described.
4. The herein described method of cleaning the filtering plates of filtering apparatus
of the kind referred to in the preceding claim, by closing the cock Rand admitting
liquid, steam or gas under pressure through one or more cocks N N N so that
impurities adhering to the outside of the filtering plates will be removed therefrom
and deposited in the vessel or receiver, whence they can be discharged through an
opening such as S substantially as herein described.
5. The herein described method of cleaning the filtering plates of filtering apparatus

page_text: of the kind referred to in claim 3 by closing the cock R and admitting liquid under
pressure and superheated steam through the cock N3 so that the plates will be rinsed
externally and living organisms (microbes) that might be adhering to the interior of
the apparatus, will be destroyed, substantially as hereinbefore described.
Dated this 17th day of September 1890.
W. LLOYD WISE,
Per F. J. Brougham.