Improvements in and relating to Bone-black Filters.
Year: 1885

page_text: Improvements in and relating to Bone-black Filters.
"
I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, & Co Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS IN AND RELATING TO BONE-BLACK FILTERS
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 continuously-operating filters for decolorizing saccharine
Jiquors by the process of upward filtration through bone-black; and my invention
consists in means for mechanically compressing the bone-black in the filtering
chamber, and also, in connection therewith, of means for gradually removing the
exhausted bone-black from the bottom of the filtering chamber, and correspondingly
feeding fresh bone-black into the top of the filtering chamber.
In the accompanying drawing of a bone-black filter to which my improvements
are applied.
Figure 1 is a central vertical section of the filtering chamber, the chamber for.
receiving the exhausted bone-black, and the elevator tube.
Figure 2 is a horizontal section on the line - Figure 1.1
Figure 3 is a horizontal section on the line y-y Figure 1.
Figures 4 and 5 are vertical sections on the line z-z on Figure 1.
My apparatus consists of a metallic cylinder A, the principal portion of which is.
intended to contain bone-black in a compressed condition, and constitutes the
filtering chamber B.
•
The mass of bone-black in the filtering chamber is supported upon the top of the
horizontal rotating scraper C, in which there are radially slotted openings C¹ which
incline downwardly and backwardly from its direction of rotation.
The rim of the rotating scraper is supported upon the slightly conical rollers
d, d, & whose shafts are radially arranged and are provided with bearings in
suitably curved standards d', d¹, &, erected within the circumferential enlarge-
ment D of the cylinder A.
.
The rotating scraper C is affixed to the vertical shaft E, the lower end of which.
is stepped in the bearing E¹ on the top of the transverse beam' E', supported by the
diagonal braces E³ and E.

page_text: A transverse vertical plate F extends across the filtering chamber just above the
scraper C, and is fastened at its ends to the opposite side walls of the cylinder A.
The vertical plate F serves as a stripper, and prevents the mass of bone-black from
being bodily rotated, and thus facilitates the action of the scraper in shearing or
scraping off the bone-black from the bottom of the mass contained in the filtering
chamber.
The bone-black in the filtering chamber is compressed downward by means of the
rotating screw or compressor G, affixed to the lower end of the hollow shaft G¹
through which the shaft E passes. The shaft E, at the lower end of the hollow.
shaft G³, is surrounded by the gland. packing G³ by means of which the sugar
liquor is prevented from escaping upward into the annular space between the
shaft E and the interior wall of the hollow shaft G¹.
The compressor G may be in the form of a screw having two, three, four or more
threads or in the form of a propeller having several suitably-winding blades g, 9, 9, 9.
The adjacent opposed edges of the blades, respectively, are affixed to the lower ends
of the vertical tubes g¹, g¹, g¹, g¹ the upper ends of which are inserted in the
bottom h of the fresh-bone-black magazine H, which is affixed to the hollow shaft G¹.
As will be seen, each of the tubes g¹ in cross section has the shape of a truncated
wedge..
The shaft G¹ passes through the centre of the bone-black magazine. H,
immediately above which it is provided with a journal in the horizontal beam I,
which extends across and is supported at its ends respectively upon, the side walla
of the cylinder A.
•
The hollow shaft G₁ is provided with a fixed collar or shoulder Gʻ which bears
upon the upper end of the journal I' in the beam I.
At its upper end, the hollow shaft G¹ has affixed to it the bevel wheel G³ the
teeth of which are engaged by the teeth of the bevel pinion G*, affixed to the
horizontal driving shaft Go.
The outer ends of the screw or propeller blades g, g, g, g,, are affixed to the
interior wall of the short cylinder' g², which is the rim of the compressor G, and is
supported upon the conical rollers k, k, k, &, the horizontal shafts of which are
radially arranged, and are provided with bearings in the standards k¹ k¹, erected
within the circumferential enlargement K of the cylinder A.
The screw blades or propeller blades g, 9, 9, g are provided with numerous small
holes, J, J, J, & for the escape of sugar liquor from the filtering chamber into the
collection chamber J' above the compressor. The direction of rotation of the
compressor is indicated by the arrows J¹ in figures 2, 4. and 5, and, as will be seen,
the holes J incline downwardly and backwardly from the direction in which the
compressor is rotated, and hence are not liable to be clogged with bone-black.
Instead of the holes J in the blades of the compressor, or in addition thereto,
holes ; may be provided in the side walls of the tubes g¹, so that sugar liquor
making its way up into those tubes, will drain through the holes j into the
collection chamber J'.
At its upper end the shaft E is provided with the bevel wheel e, the teeth of
which are engaged by the teeth of the pinion e¹, affixed to the horizontal driving.
shaft e².
The bone-black in the magazine H falls through the tubes gl, and by the rotation
of the compressor is compressed in a downward direction upon the top of the mass
of bone-black contained in the filtering chamber.
By the rotation of the shaft E the scraper C is rotated, and the exhausted bone-
black is thereby sheared or scraped off the bottom of the mass of bone-black in the
filtering chamber, and falls down the inclined side wall L of the receiving
chamber L', into the bottom of the elevator tube M, from which it is elevated by
means of the chain and bucket elevator N, the buckets n, n, &o, of which are made
of wire gauze, or are perforated, in order that the sugar liquor may be drained
from the bone-black contained in them after they are elevated above the level
at which the sugar liquor stands in the elevator tube, this level being preferably,

page_text: somewhat higher than the level of the openings in the filtering cylinder through
which the decolorized and filtered sugar liquor is discharged.
At its upper end, the elevator tube is provided with the inclined chute N¹, upon
which the contents of the buckets n, n, & are discharged as they are successively
carried over the shaft of the upper wheel M¹ of the elevator..
The sugar liquor to be filtered, supplied from a suitable reservoir through the
pipe P inserted in the upper part of the elevator tube, fills the elevator chamber,
and rises by hydrostatic pressure through the mass of bone-black contained in the
filtering chamber and escapes through the perforations in the compressor G or in
the tubes g¹ into the collection chamber J, from which it is discharged, through
the perforations P¹ in the wall of the cylinder A, into a gallerý or annular trough O,
erected upon the exterior of the cylinder A, from which it is conducted off by the
pipe P..
In using my apparatus, the operations of removing the exhausted bone-black
from the bottom of the mass of bone black contained in the filtering chamber, and
of feeding fresh bone black into the upper part of the filtering chamber, may either
be performed continuously by a very slow rotary movement of the compressor G
and the scraper C, or, if desired, may be performed independently of each other or
intermittently, care being taken to remove the exhausted bone-black before the
stratum of exhausted bone black has acquired too great thickness; and similarly,
care must be taken to feed the proper quantity of fresh bone-black into the upper
part of the filtering chamber to compensate for the exhausted bone-black removed
from the lower part thereof, and to maintain the bone-black in the filtering
chamber in a compacted condition, so that the instertices between the particles of
bone-black in the filtering chamber will be comparatively minute, and no sugar
liquor can be forced through the filtering chamber without acquiring contact with
a suitable quantity of fresh or unexhausted bone-black to effectually decolorize it.
Upon consideration, it will be seen that the extent to which the bone-black in
the filtering chamber may be compacted is controllable by varying the speed of
rotation of the scraper C relatively to the speed of rotation of the compressor. The
operation may be so conducted that the stratum of fresh bone-black at the top of
the filtering chamber is that which is the most closely compacted; or by a very
slow and gradual removal of the bone-black from the bottom of the filtering
chamber the entire mass of filtering material may become closely compacted,
because, as the operation continues, the close-compacted stratum which was at the
top. of the filtering chainber gradually moves downward, and finally reaches the
bottom of the filtering chamber. Thus, if the exhausted bone-black be removed
slowly, the lowest stratum may continue in the compacted condition which it
acquired at the top of the filtering chamber.
Correspondingly, if it be desired to diminish the degree of compression of the
bone-black contained in the lower part of the chamber, the speed of rotation of the
scraper will be increased, and thus the exhausted bone-black in the bottom of
the chamber will be more rapidly removed.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed as. communicated to
me by my foreign Correspondent I declare that what I claim is..
First. In continuously-operating filters for decolorizing saccharine liquors by the
process of upward filtration through bone-black, a filtering chamber provided at
the top with a rotating compressor or screw having openings between its blades for
feeding fresh bone-black into the filtering chamber; and means for rotating the
said compressor, and thereby pressing downward and compacting the mass of
bone-black contained in the filtering chamber; in combination with means for
supporting the bottom of the said mass of bone-black and for gradually removing
the exhausted bone-black therefrom, whereby the bone-black in the filtering
chamber may be maintained in a compacted condition by feeding into and con-
pressing at the top of the filtering chamber a quantity of fresh bone-black
こ

page_text: corresponding to the quantity of exhausted bone-black removed from the bottom of
the filtering chamber.
Second. The scraper C for supporting the mass of bone-black contained in the
filtering chamber, in combination with a transverse stripping plate F, and means
for rotating the said scraper, and thereby gradually shearing or scraping the
exhausted bone-black from the bottom of the mass of bone-black contained in the
filtering chamber,
Third. The compressor G, the fresh bone-black magazine H, the tubes g¹; g¹ for
feeding the fresh bone-black from the magazine H downward through the spaces.
between the blades of the compressor, the shaft G₁ to which the compressor and
the magazine H are affixed; means for rotating the said shaft and thereby feeding
fresh bone-black downward upon the mass of bone-black contained in the filtering
chamber, and compressing it thereon; means for supporting the bottom of the mass
of bone-black contained in the filtering chamber, and means for gradually removing
the exhausted bone-black therefrom, substantially as described.
Fourth. The compressor G, provided with openings between its blades through
which fresh bone-black is fed into the top of the filtering chamber; means for
rotating the said compressor; the scraper C for supporting the mass of bone-black
contained in the filtering chamber; and means for rotating the scraper C indepen-
dently of the compressor G, and thereby regulating the degree of compactness of
the mass of bone-black contained in the filtering chamber.
Fifth. The compressor G affixed to the hollow shaft G¹ and. means for rotating
said shaft; and the scraper C, affixed to the vertical shaft E; inserted through the
hollow shaft G¹, and provided at its upper end with gearing, substantially as
shown, for effecting the rotation of the scraper C independently of the com-
pressor G, as, and for the purpose, set forth.