IMPROVE- MENTS IN FILTER PRESSES
Year: 1878

page_text: LETTERS PATENT to Frederick Ludwig Hahn Danchell, of Oseney Crescent,
Camden Town, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN FILTER PRESSES."
Sealed the 29th March 1878, and dated the 29th January 1878.
PROVISIONAL SPECIFICATION left by the said Frederick Ludwig. Hahn
Danchell at the Office of the Commissioners of Patents on the 29th January
1878.
FREDERICK LUDWIG HAHN DANCHELL, of Oseney Crescent, Camden Town, in
the County of Middlesex. "IMPROVEMENTS IN FILTER PRESSES."
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The process of filtration has of late years been much improved by means of a
machine called the filter press. To this kind of machine the fluid or semi-fluid is
forced in by means of hydraulic pumps, and made to filter through some kind of
cloth or filter material, which is supported by a grooved or perforated back of wood
or metal. Various modifications of these presses have been introduced, but the main
feature in their construction is that of a series of frames or rings bolted together
by means of screws or tie bolts, and thus forming so many separate chambers or
partitions. The construction of my filter press varies materially from these
arrangements.
Instead of employing a series of rings or frames bolted together my machine
consists of a single box or chamber, inside of which a series of filter frames are
placed side by side, at distances from each other according to the nature of the solid
material to be separated from the fluid, and in such a manner that the material to
be filtered can find its way on all sides of the filter frames. These said frames are
made of tubes of suitable size and material, with a series of small holes or perfora-
tions at the inside of the frame to admit the fluid into the said tubes, from whence
it passes on through the bottom tube to the exit pipe with which it is connected.
Each of these frames is covered on both sides with a filter cloth or bag of suitable
material, and the one cloth lies against the other without any intermediate back of

page_text: wood or metal, as is usual in other forms of filter presses. The fluid after per-
colating through the said cloth finds its way between the backs of the same until
it reaches the sides of the frame, where it passes through the small holes or
perforations into the tubes and to the exit pipe, as already mentioned. The solid
material remains behind between the filter frames in the form of cakes, which a
ultimately have to be taken out. For this purpose one of the ends or sides of the
filter box is made to be taken off, when the whole body of solid material which has
been formed along with the filter frames are drawn out, the cakes removed, and the
filter frames replaced for fresh operation.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Frederick Ludwig Hahn Danchell in the Great Seal Patent Office on
the 29th July 1878.
FREDERICK LUDWIG HAHN DANCHELL, of Oseney Crescent, Camden Town, in
the County of Middlesex. "IMPROVEMENTS IN FILTER PRESSES."
The process of filtration has of late years been much improved by means of a
machine called the filter press. To this kind of machine the fluid or semi-fluid is
forced in by means of hydraulic pumps, and made to filter through some kind of
cloth or filter material, which is supported by a grooved or perforated back of wood
or metal. Various modifications of these presses have been introduced, but the
main feature in their construction is that of a series of frames or rings bolted
together by means of screws or tie bolts, and thus forming so many separate
chambers or partitions. The construction of my filter press varies materially from
these arrangements.
Instead of employing a series of rings or frames bolted together my machine
consists of a single box or chamber, inside of which a series of filter frames are
placed side by side, at distances from each other, according to the nature of the solid
material to be separated from the fluid, and in such a manner that the material to
be filtered can find its way on all sides of the filter frames. These said frames are
made of tubes of suitable size and material, with a series of small holes or per-
forations at the inside of the frame to admit the fluid into the said tubes, from
whence it passes on through the bottom tube to the exit pipe with which it is con-
nected. Each of these frames is covered on both sides with a filter cloth or bag of
suitable material, and the one cloth lies against the other without any intermediate
back of wood or metal, as is usual in other forms of filter presses. The fluid after
percolating through the said cloth finds its way between the backs of the same until
it reaches the sides of the frame, where it passes through the small holes or
perforations into the tubes and to the exit pipe, as already mentioned. The solid
material remains behind between the filter frames in the form of cakes, which
ultimately have to be taken out. For this purpose one of the ends or sides of the
filter box is made to be taken off, when the whole body of solid material which has
been formed along with the filter frames are drawn out, the cakes removed, and the
filter frames replaced for fresh operation.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is an elevation, Figure 2 is a longitudinal section, and Figure 3 is a
cross section of a filter press constructed according to my Invention.
a is the case or body of the filter press, which may be made of wood, iron, or
other suitable material, according to the nature of the liquid or semi-liquid to be
treated therein. In the arrangement represented in the Drawings the filter press
is supposed to be made of cast iron, the top and sides a being cast in one piece, and
the bottom a¹ in another, the two parts being each provided with a continuous
flange to enable the two parts to be readily connected together and disconnected
from each other by means of bolts a².
.
The top and bottom and sides of the case or body a of the filter press are when
required tied together and strengthened by the aid of bars, placed preferably at
regular distances apart on opposite sides thereof, and bolted firmly together by long
screwed bolts or rods extending across the case or body a. The bottom a¹ of the
case or body a is preferably made well shaped, as shown, and at the lower part
of the well is fixed a two-way cock b, which when the plug thereof is in the position
shown in the Drawings is used as the inlet for the material to be treated, and when
in the other position, and the object is to filter a liquid containing very little solid
matter, enables the dirty liquid outside the filter frames to be discharged from the
case or body of the press from time to time as may be found. desirable. The top of
the case or body a is provided with an air cock c to enable the air to escape from
the filter when first filling it with the material to be treated, which material is
pumped into the case or body a under pressure through the cock b. In the
bottom a of the filter press are a number of holes or sockets a³ to receive short
pipes or nozzles d' extending from the filter frames d, and to enable such filter
frames to be fixed firmly in position by means of nuts on the outside of the case
or body.
The filter frames & are arranged side by side in the interior of the case or body a
at convenient distances from each other, according to the nature of the material to
be treated. These filter frames d are formed of metal tube, connected together,.
preferably in a rectangular form, and are perforated on the inner sides thereof with
a number of small holes 3, and to the lower tube of such frame are fixed the short
pipes or nozzles d'. Each frame is entirely covered or enclosed with a bag formed
of closely woven cloth or other suitable filtering material, and the one side of such
bag lies closely against the other without any intermediate backing of wood or
other material, as is usual in other forms of filter presses. The filtering frames and
bags are somewhat less in size than the interior of the said case or body a, so that
the material to be treated may, when forced into the case or frame a through the
inlet cock b, be caused completely to surround each filter frame or bag on all sides
thereof.
I preferably forin the interior of the upper portion of the case or frame a tapered,
and I fit in the interior thereof a lining e, in order that when removing the upper
part of the case or body a from the bottom a!, the solid matter between and around
the filtering frames and bags may not adhere to such case or body a, but that the
latter may be readily removed from the bottom a¹, leaving the interior lining in
position on the bottom, and in order to facilitate the separation of the top e' of the
lining e from the top of the case or body a I fit the top of the case or body a
with screws a, to act when required upon the top e' of the lining to separate the
one from the other.
The action of the apparatus is as follows:-When the material to be treated is
forced into the case or body a it presses the sides of each filter bag close together,
and thereby forms a minute space, through which the fluid after having passed

page_text: through the pores of the filter cloth has to pass before it reaches the perforations in
the tubes forming the filter frames d. The fluid then passes by such tubes away
through the outlets or nozzles d¹.
It will be observed that according to my Invention I cause the filtering operation
to take effect from the outside to the inside of the filtering bags, and not from the
inside to the outside thereof, as has been previously the case. By these means I
retain the solid matter on the exterior of the filtering bags, thereby obviating the
necessity for opening the bags, and consequently effecting a considerable economy
in the time required for removing the solid matter from the filter press, and in re-
arranging the latter for work, and I obtain a more perfect filtration consequent on
the direction taken by the fluid passing through the bags.
When the object is to filter fluids containing only a small per-centage of solid
matter, the frames are provided with short tubes or nozzles d', and are fixed in
position, as shown, in order to secure tight joints, and thereby to prevent any of the
liquid passing away from the filter press unfiltered; but when it is desired to obtain
the solid matter from a semi-fluid material, such as china makers' " slip," I adopt
the arrangement represented at Figure 4, in which the short tubes or nozzles d'
simply rest in position, and the nuts d² are dispensed with, as the escape in such
case of a little more or less of the solid matter with the liquid is of no great
importance, whilst the ease with which the apparatus is arranged for work is
important.
When filtering any comparatively clear or limpid liquid, and purifying the same
by the aid of powdered charcoal or other purifying agent, I supply such purifying
agent to the case or body a through the tapped aperture in which the air cock c is
fixed, the latter being removed for such purpose, and I discharge such purifying
agent from the case or body a through the cock b when such purifying agent is
fouled or exhausted.
If desired the short tubes d' connected to the filter frames & may be arranged to
fit into nozzles connected to a tube in the interior of the case or body a, or on the
exterior thereof, in order to enable the filtered or separated liquid to be passed away
from the filter press through a single outlet.
Having thus described the nature of my said Invention, and the mode in which
I carry the same into effect, I would have it understood that what I claim is,-
First. The peculiar arrangement, construction, and mode of operation of a filter
press, consisting of a close filter chamber fitted with one or more filtering frames
and bags, in which the fluid is filtered or separated from the solid matter contained
therein in its passage from the outside to the inside of the bags, and is conveyed
away therefrom by a pipe leading to the outside of the filter chamber, substantially
as herein shown and described.
Secondly. I claim forming filtering frames of tubes connected together and per-
forated on the interior sides thereof, and completely covering the same with a bag,
the sides of which are not supported by any intervening diaphragm, but are pressed
closely together by the pressure of the fluid to be filtered on the exterior thereof,
the filtered or separated fluid passing from the bags into the tubular frame
and away from the filter press, in manner substantially as herein shown and
described.
In witness whereof, I, the said Frederick Ludwig Hahn Danchell, have here-
unto set my hand and seal, this Twenty-sixth day of July, in the year of
our Lord One thousand eight hundred and seventy-eight.