IMPROVEMENTS IN FILTERING APPARATUS
Year: 1878

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in the
County of Middlesex, Gentleman, for the Invention of "IMPROVEMENTS IN
FILTERING APPARATUS." A. communication from abroad by Anthony Van
Haagen, of Philadelphia, Pennsylvania, United States of America.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 14th March 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN FILTERING APPARATUS." A communication from
abroad by Anthony Van Haagen, of Philadelphia, Pennsylvania, United States of
America.
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This Invention relates to filtering apparatus which is especially applicable to the
filtration of oily and fatty matter, and it has for its object constructing a filter in
which the close packing of the filtering medium is prevented, the running of
channels in the said medium obviated, and its maintenance at such a heat assured
that the apparatus can be employed with the best results for the rapid filtering of
tallow and other fatty and oily matter.
In the operation of filtering apparatus more or less difficulty has been experienced
owing to the packing of the charcoal and other filtering mediums so tightly as to
prevent the free percolation through it of the material to be filtered, and this has
been especially the case in filtering oily and fatty matter. Another difficulty in
filtering such matter has been its maintenance in a proper fluid condition in order
to enable it to pass through the filtering bed; and a third difficulty has resulted
from the tendency of the material to be filtered to force channels through the
filtering medium, by which channels the said material is apt to escape in an
unfiltered condition.
According to this Invention the difficulties before enumerated are overcome in
the following manner.

page_text: The filtering vessel is made of a tapering form, and larger at the lower than at
the upper end, or it may be cylindrical, the vessel having double walls and an
intervening space through which steam is caused to circulate.
From the cover to the base extends a central tube, through which also steam is
caused to circulate, and from which flanges project at suitable intervals, annular
flanges being also secured to the inner wall of the casing.
In filtering fatty and oily matter it is essential that it, as well as the filtering
medium, should be maintained at a proper degree of heat, and for this purpose
vessels with steam jackets have been heretofore used, but the heat derived from
this source did not penetrate far enough into the mass of filtering material unless
the vessels were made inconveniently small, and even in this case the oily and fatty
matter would make channels nearest the casing where the filtering material was
hottest.
Attempts have also been made to overcome these difficulties by introducing steam
into the vessel, but this also had the effect of cutting channels in the filtering
material.
By combining in the filtering vessel a steam jacket in the outer casing with the
central steam chamber the mass of filtering material must be maintained at a
proper degree of heat throughout, and this is assured by the presence of the two
sets of flanges, which serve to conduct the heat of the jacket and central chamber
into the body of the filtering material. These flanges serve other useful purposes,
while they do not interfere with the proper percolation of the material to be filtered
through the mass of filtering material; they prevent the formation of channels
through the same, and they also serve to partly suspend the filtering material
within the vessel, and prevent it from being packed too closely at the bottom.
The central steam chamber and flanges may be combined with a cylindrical
filtering vessel or with a vessel of other shape; but a tapering vessel is preferred
for the reason that such of the material as descends will have a larger space to
occupy than it had above, and hence will not be packed too tightly below.
For smaller filters the central steam chamber may be dispensed with, or the
steam jacket may be dispensed with and the central chamber used.
A suitable pipe is provided in the top of the vessel for the introduction of the
material to be filtered, and a suitable outlet is also formed at the bottom; there are
also man-holes at suitable points for gaining access to the interior of the vessel.
In some cases an outer jacketed casing without internal flanges may be combined
with a central steam chamber having projections, or a central steam chamber
without projections may be combined with an exterior casing having no steam
jacket, but provided with internal flanges.
The chamber which has been termed a "central steam chamber" may consist of a
number of tubes, and may be varied in shape without departing from the main
feature of the Invention. Projections properly arranged may be also substituted
for the continuous internal flanges of the casing and for the flanges of the central
chamber; and these flanges or projections may be hollow, and may communicate
with the steam spaces.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 9th
September 1878.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN FILTERING APPARATUS." A communication from
abroad by Anthony Van-Haagen, of Philadelphia, Pennsylvania, United States of
America
The said Invention relates to filtering apparatus which is especially applicable to
the filtration of oily and fatty matter, and it has for its object constructing a filter
in such a manner that the close packing of the filtering medium shall be prevented,
the running of channels in the said medium obviated, and its maintenance at such
a heat assured that the apparatus can be employed with the best results for the
rapid filtering of tallow and other fatty and oily matter.
In the operation of filtering apparatus more or less difficulty has been experienced
owing to the packing of the charcoal and other filtering media so tightly as to
prevent the free percolation through it of the material to be filtered, and this has
been especially the case in filtering oily and fatty matter. Another difficulty in
filtering such matter has been its maintenance in a proper fluid condition in order
to enable it to pass through the filtering bed; and a third difficulty has resulted
from the tendency of the material to be filtered to force channels through the
filtering medium, by which channels the said material is apt to escape in an
unfiltered condition.
According to the said Invention the difficulties before enumerated are overcome
in the following manner, reference being had to the Drawing hereunto annexed, in
which Figuro 1 is a vertical section of a filter constructed according to one modifi-
cation of the said Invention, and Figure 2 is a horizontal section of the same
taken along the line 1-2 (Figure 1); and Figures 3, 4, and 5 are vertical sections
illustrating other modifications.
The filtering vessel is made of a tapering form, and larger at the lower than at
the upper end, as shewn in Figures 1 and 3, or it may be cylindrical, as shewn in
Figure 4, the vessel having double walls A, A', and an intervening space through
which steam is caused to circulate.
From the cover B to the base D (Figures 1 and 2) extends a central tube G,
through which also steam is caused to circulate, and from which flanges a project at
suitable intervals, annular flanges b being also secured to the inner wall A' of the
casing.
In filtering fatty and oily matter it is essential that it, as well as the filtering
medium, should be maintained at a proper degree of heat, and for this purpose
vessels with steam jackets have been heretofore used, but the heat derived from
this source did not penetrate sufficiently far into the mass of filtering material
unless the vessels were made inconveniently small, and even in this case the oily
and fatty matter would make channels nearest the casing where the filtering
material was hottest.
Attempts have also been made to overcome these difficulties by introducing steam
into the vessel, but this also had the effect of cutting channels in the filtering
material.
By combining in the filtering vessel a steam jacket in the outer casing with the
central steam chamber G the mass of filtering material must be maintained at a
proper degree of heat throughout, and this is assured by the presence of the
flanges a and b, which serve to conduct the heat of the jacket and central chamber
into the body of the filtering material. These flanges serve other useful purposes
while they do not interfere with the proper percolation of the material to be filtered
through the mass of filtering material; they prevent the formation of channels
through the same, and they also serve to partly suspend the filtering material
within the vessel, and prevent it from being packed too closely at the bottom,

page_text: The central steam chamber and flanges may be combined with a cylindrical
filtering vessel or with a vessel of other shape; but a tapering vessel is preferred
for the reason that such of the material as descends will have a larger space to
occupy than it had above, and hence will not be packed too tightly below.
For smaller filters the central steam chamber may be dispensed with, as in
Figure 4, or the steam jacket may be dispensed with and the central chamber used,
as in Figure 3.
A suitable pipe is provided in the top B of the vessel for the introduction_of
the material to be filtered, and a suitable outlet i is also formed at the bottom D ;
there are also man-holes at suitable points for gaining access to the interior of the
vessel.
In some cases an outer jacketed casing without internal flanges may be combined
with a central steam chamber having projections, or a central steam chamber
without projections may be combined with an exterior casing having no steam
jacket, but provided with internal flanges.
The chamber which has been termed a "central steam chamber" may consist of a
number of tubes, and may be varied in shape without departing from the main
feature of the said Invention. Projections properly arranged may be also substituted
for the continuous internal flanges of the casing and for the flanges of the central
chamber; and these flanges or projections may be hollow, and may communicate
with the steam spaces, as shewn in Figure 5.
Having now described and particularly ascertained the nature of the said In-
vention, and the manner in which the same is or may be used or carried into effect,
I would observe in conclusion that what I consider to bo novel and original, and
therefore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,-
First. A filtering vessel in which an outer casing provided with a steam jacket is
combined with internal flanges or projections, substantially as and for the purpose
herein-before described.
Second. A filtering vessel in which an exterior casing, with or without a steam
jacket, and having internal projections, is combined with a central steam chamber.
Third. A filtering vessel having a central tube or tubes with flanges or projections,
as and for the purpose herein-before described.
Fourth. The combination in a filtering vessel of an outer casing provided with a
steam jacket and internal flanges or projections, and of a central chamber provided
with flanges or projections, as herein-before described.
In witness whereof, I, the said John Henry Johnson, have to this my Speci-
fication set my hand and seal, the Twenty-ninth day of August, One thousand
eight hundred and seventy-eight.
J. HENRY JOHNSON. (L.S.)