AN IMPROVED FILTERING-APPARATUS.
Year: 1879

page_text: LETTERS PATENT to Johann Kroog, of Halle on the Saale, in Prussia, for the
Invention of "AN IMPROVED FILTERING-APPARATUS.'
Sealed the 28th November 1879, and dated the 1st October 1879.
COMPLETE SPECIFICATION filed by the said Johann Kroog at the Office of
the Commissioners of Patents on the 1st October 1879.
"
JOHANN KROOG, of Halle on the Saale, in Prussia. AN IMPROVED FILTERING-
APPARATUS."
This Invention relates to improvements in filtering-apparatus or filter-presses.
In the accompanying Drawing,
Figure 1 is a vertical longitudinal section on the line A, B, Figure 3, of an
apparatus constructed according to my said Invention.
Figure 2 is a vertical transverse section of the same on the line C, D, Figure 3.
Figure 3 is a plan of a frame-filter-press of six chambers constructed according
to this Invention.
Figure 4 is a view shewing the fixed head-piece hereinafter described, and parts
connected therewith.
Figure 5 is a view of a frame hereinafter described.
Figure 6 is a view of a filtering-plate hereinafter described.
Figure 7 is a plan of the feeding-pipe hereinafter described.
Figure 8 is a section through an elbow pipe hereinafter described.
Figure 9 is a view of a bar hereinafter described; and
Figure 10 is a view of two of such bars without intermediate pieces.
Like letters indicate the same parts throughout the Drawing.
The general arrangement of the said filtering apparatus or filter-press is the same
as is usual with such apparatus.
The fixed head piece 6 and standard or end piece care fastened to the foundation a.
The rods e connecting the head piece b to the standard c are arranged to support
the plates p' to 2 and the frames to in such a manner that they may be
displaced or shifted (the said plates and the frames being numbered according to
their position). The rods also support the movable head-piece f.
I will now proceed to describe the construction of the filtering-plates forming the
chief feature of the said Invention, also the peculiar arrangement of the tubes or

page_text: conduits, serving partly for effecting the feeding of the mass to be filtered, and
partly for effecting the feeding of other fluids or gases to be used in the apparatus.
Each of the filtering-plates p, p, p, p, p, p, and p, is formed by placing side
by side the narrow bars g, each of which is separated at its top and bottom end by
intermediate pieces h, as shewn in Figures 2 and 6 of the Drawing. The first and
last bars of each filtering-plate are separated in the same manner from the side-
pieces i, that is to say, by means of intermediate pieces at their upper and lower
ends. The bars g, intermediate pieces h, and side-picces i are held fast by the
beam k by means of the screws l. Thus a filtering-plate is formed furnished with
a great number of slits or openings, the said plate being smooth and level on both
sides.
The apertures m in the bars g, shewn in Figure 9, being placed in a line form
transverse or cross-tubes for connecting the said slits or openings.
In case the material used for the bars should render it desirable I may form the
slits by placing the bars side by side without any intermediate pieces and by
removing from them a portion of their substance at the point where the slit is
wanted, as shewn in Figure 10.
If it should be desired to give the filtering plates a circular or round shape I may
form them by employing concentric rings placed one within another, and separated
from each other by means of intermediate pieces.
The slits or openings are shewn very wide in Figures 2 and 6, but in practice
these slits are made so fine and narrow as to allow the liquid portion only of the
contents of the apparatus to pass through them during the filtering process, and
thence to pass out through the cocks n; any solid parts suspended in the fluid are
thus prevented from entering the said slits and cocks.
Thus the construction of the said plates permits of the filtration of fluid without
the application of the ordinary filtering-mediums, such as cloth, wool, felt, porous
plates, or the like; consequently as the construction of the plates according to this
Invention admits of arranging the width of the said slits or openings, according to
the liquid or substance to be filtered, and as every material which can be worked
into bars may be used for forming the said plates, I am enabled to produce a filtering
apparatus without employing filtering-cloth.
I do not wish it to be understood that I consider the employment of filtering-
apparatus without filtering cloth to be in all cases best and cheapest, as I am aware
that in many cases the application of filtering-mediums, and particularly of filtering
cloth, will prove to be more profitable than without the same, and in these cases
such filtering-mediums in connection with my said filtering-apparatus will afford
very great advantages.
By reason of the facility with which, according to this Invention, I may form
plates having slits of any desired width and bars of any thickness that may be
necessary and of any material, I am enabled to provide for every filtering-medium
an under-layer best suited for the purpose to which the apparatus may have to be
applied.
The cleansing of my improved plates is very easily effected for the reason that
there is complete communication through the slits or openings.
I will now proceed to describe the tubes or conduits above mentioned.
If the apparatus is to be used for filtration only all the plates are made in the
manner illustrated in Figure 6; but if the apparatus is to be used for lixiviation
also the plates pº, p², p*, and pº, will remain in communication with the outside air,
as shewn in Figure 6, that is to say, there is only one connection with the interior,
namely, the cock n. The plates p', p³, and p³, have the same connection with the
outside air, but besides this connection they are each provided with an air-valve o¹,
0, 0%, and a small pipe q. The parts o¹, o³, o, and 8¹, 8³, 8ª, correspond with the
parts p, p, p, as shewn in Figure 1.
The elbow-pipe s' is pressed tightly against the pipe o by means of a screw in
the movable bow u, shewn in Figure 8. The elbows 8, 83, 85, lead into the pipe t,
one end of which is movable in the stuffing-box, while the other end turns on a

page_text: pivot in order that when emptying the apparatus and after having turned down
the bows u the elbows 81, 83, 85, may be turned from the apparatus by means of the
handle mounted on the end of the pipe t, so that no damage will be caused to the
said elbows when moving or displacing the frames and plates.
The feeding-pipe for the mass to be filtered is composed of the length of pipe v
fastened to the foundation a, and of the lengths of pipe v², v², v³, v, v³, and v, with
cover w. The pipe is provided with pivots, as illustrated in Figure 7, connected
with rods which permit of pressing tightly together the lengths of pipe by
means of a screw passing through the cross-piece y.
The lengths of pipe v³, v², v³, v³, v³, and 6, are connected with their respective
frame by means of small pipes s¹, 22, 23, 24, 25, and 2º. The said small pipes are
made sufficiently long in comparison with their diameter to render the material of
the said pipes sufficiently elastic to ensure a tight connection of the lengths of pipe
notwithstanding any slight inexactitude which might occur.
By means of the arrangement of the tubes and conduits, as above described, a
minimum of tightening surface is attained. Whilst with the usual formation of
conduits the feeding-tube for a frame-filtering-apparatus of six chambers has twelve
tightening surfaces, the same will have, if built according to my improved con-
struction, seven tightening surfaces only (including the lid or cover). Furthermore,
the lixiviation-tube for a frame filtering apparatus of six chambers of the ordinary
construction will have twelve tightening-surfaces likewise, whilst it will have but
three according to my said Invention.
The operation of the apparatus is as follows, that is to say :-
After the same has been screwed up the mass to be filtered is poured into the
frames to through the pipe v. The fluid flows off through the said slits or
openings and the cocks n. The compact or solid particles form cakes within the
frames, and when these are formed the inlet is stopped. After the cocks of the
plates 2, 3, and p³, have been closed the fluid intended for lixiviating is let into
the said plates through the pipe t. The air contained therein passes out through
the air valves. This being effected the lixiviating fluid enters the cakes driving
the fluid contained in the said cakes into the plates p, p, p, and pº, whence it
runs out through the cocks n, the same having been left open.
After the lixiviation has been completed the influx of the lixiviating-fluid is cut
off, the elbows 8, 85, 85, are turned from the apparatus in the manner above described,
and the bow y having been loosened is placed upon the foundation a. These
proceedings having been finished the removal of the said cakes is effected by
displacing or shifting the plates and frames.
Having thus fully described my said Invention, and the manner of performing
the same, I wish it understood that I claim,-
First. The construction and application of the filtering-plates, substantially as
above described and as shewn in the Drawing, and either combined or not with
filtering-mediums for the purpose of filtration.
Second. The formation of the feeding-pipe, substantially as above described and
as shewn in the Drawing.
Third. The formation and connection of the lixiviating pipe, substantially as
above described and as shewn in the Drawing.
In witness whereof, I, the said Johann Kroog, have hereunto set my hand and
scal, this Twenty third day of September, in the year of our Lord One
thousand eight hundred and seventy nine.
JOHANN KROOG. (L.S.)