Improvements relating to the Manufacture or Regeneration of Carbonaceous Filtering Media.
Year: 1894

page_text: Date of Application, 1st Mar., 1894
Complete Specification Left, 3rd Dec., 1894-Accepted, 5th Jan.,
1895
PROVISIONAL SPECIFICATION.
Improvements relating to the Manufacture or Regeneration of
Carbonaceous Filtering Media.
I, JASPER WETTER, Patent Agent, of 433 Strand, in the County of London,
do hereby declare the nature of this invention, a communication to me from abroad
by Moriz Weinrich, Manufacturer, of Waverley Place St. Louis in the State
of Missouri, United States of America, to be as follows:-
In the Specification of my British Patent, No. 5375 dated 13 March 1893, I
mention as a preparatory proceeding in the regeneration of spent boneblack, the
removal of the old carbon contained in such boneblack by heating it under
admission of air until the carbon is burned and only the mineral framework left.
In order to perform this in a well regulated and automatic way, my corre-
spondent has invented a novel method and an apparatus.
The apparatus chiefly comprises a slowly revolving horizontal drum into which
air is admitted, a wall surrounding such drum, inwardly projecting (preferably
helical) ribs on the inner face of the drum, means for adjustably feeding the
boneblack to the drum, and adjustable dampers at the discharging end of the drum
to regulate the draft of air through it.
The apparatus works as follows:-
The drum is started by means of a belt and pulley, the feed hopper is filled
with boneblack, the fan for supplying the draft is set in motion, and the damper is
lifted.
The gases are drawn by the fan under the slowly revolving drum, which should
make from two to five revolutions per minute; these gases come against the
bridgewall or partition and surround the drum in the space enclosed between it and
the side wall, so as to heat the whole drum. Subsequently they are drawn off through
the fan and may be used for drying the wet boneblack.
The boneblack falls, in an equal stream, regulated by a sliding shutter, into the
interior of the drum; it is immediately heated, and is caused to move slowly and
continuously by the threads of the helix contained in the drum towards the other
end.
The heated particles of boneblack change constantly their position becoming
simultaneously exposed to the air which passes through the drum, so that the
carbon will burn off wholly or partly, as desired, without bringing the boneblack to
a red heat.
The boneblack being thus deprived of more or less of its carbon is discharged at
the lower or rear end of the drum, and is thence carried off by any convenient
means or devices. The amount of carbon desired to be burnt off can be easily
regulated; either,
1st by the amount of boneblack passing through the sliding shutter; or
2nd by the temperature of the gases drawn around the drum ; or
3rd by the amount of air drawn through the drum; or
4th by the number of revolutions of the drum, in a given time.
In place of a helix may be used a number of longitudinal ribs made of sheet iron
projecting inwardly six to 12 inches, for the purpose of lifting and dropping
constantly the heated bone black. In this case the drum should have a slight incline
sas of about one inch to six feet of its length..

page_text: It has been found that such apparatus as I have described, may be substituted
to great advantage and in quite a novel way, for the revivifying kilns for boneblack
heretofore used. As generally known to those versed in the art, the object of
revivifying kilns is to char under careful exclusion of air, the organic matters
absorbed by the boneblack during the filtration of sugar-solutions, whereby the
carbon formed by these organic matters gradually chokes and covers the pores of
this boneblack.
By a careful use of the new apparatus in the described way, these organic matters,
instead of being charred under exclusion of air, can be entirely burned off under
admission of air, thus leaving the pores of the boneblack always clean and effective,
besides requiring only a very moderate heat, by which the mineral framework of
the boneblack remains quite uninjured.
This mode of revivification is especially to be recommended if the boneblack
contains more than ten per cent. of carbon, so that its efficacy would not be impaired if
sometimes a small amount of carbon should be burned off together with the foreign
organic matters.
In the same British Patent Specification mentioned above, I have described a
new process of regenerating spent boneblack consisting in supplying it with a new
charge or coating of animal carbon, by impregnating it with a solution of organic
animal matter and then drying and charring said product.
I have made the further discovery that solutions of certain vegetable matters,
applied in substantially similar manner as described in said Patent Specification, will
also regenerate spent boneblack to such a degree that its efficiency is again equal to
that of new boneblack.
The vegetable materials I make use of in my present improvement are molasses,
(either cane, or beet-molasses), glucose, starch, and flour made from wheat, corn or
other grains.
In using molasses or glucose, I proceed as follows: The spent boneblack is
deprived first of most or all of its carbon by heating it under admission of air in any
desired way, until the carbon is burned off and only the mineral frame left, thus
freeing the pores. from the layer of the old and consequently ineffective carbon.
The decarbonized boneblack is put into an open pan provided with a double steam-
bottom or steam coil, in which pan a certain amount of hot molasses or glucose
diluted with water, has previously been put. For each one-thousand (1000) pounds
of decarbonized boneblack, I use about fifteen hundred (1500) pounds of such
solution of molasses or of glucose, containing say ten per cent. of dry matter.
decarbonized and very porous boneblack will absorb at once most of the solution.
Steam is now applied, and the mass boiled until its water contents are reduced to
such a degree that the molasses or glucose will all stick on the surface and in the
pores of the boneblack.
The
The mass is then taken out and dried on a heated surface, or by some other
suitable device or means. As soon as the boneblack thus coated with molasses or
glucose is entirely dry, it is charred in boneblack kilus in the well known way,
until all the organic matter is carbonized and covers the mineral framework with a
new coat of vegetable carbon. The burned and coated boneblack is now washed
with pure hot water and is then ready for use.
In using starch or flour, these materials require a preliminary treatment before
being brought into contact with the boneblack, in order to decompose their gluten,
thus securing a good impregnation and preventing the particles of the boneblack
from baking together during the drying of the impregnated mass.
To this end, 1 dissolve the starch or flour in cold acid water. For each one
hundred (100) pounds of starch or flour I use a thousand (1000) pounds of water
mixed with about twenty (20) pounds of muriatic acid of 22° Beaumé.
As soon as the starch or Hour is dissolved, the solution is heated up to boiling
point and kept boiling (being at the same time stirred) until it has lost all
glutinousness, and has attained a semi-transparent appearance. Lime is now added
until the solution is neutral, or only slightly acid; after which the decarbonized

page_text: boneblack is put into the solution in the proportion of one thousand (1000) pounds
of boneblack to say about twelve hundred (1200) pounds of the solution. The
subsequent treatment is exactly the same as that above described for molasses
or glucose. The price of these vegetable materials is generally cheaper than
that of gelatine or blood, besides which decarbonized boneblack coated in this
way with vegetable carbon can be used also to good advantage in industries in
which the applying of animal carbon is not advisable, as for instance the decolorizing
of cotton-seed oil.
Instead of decarbonized boneblack, other materials consisting of a porous mineral
framework, as for instance; pumice-stone, may be used. Their treatment is the
same as that of boneblack. Such filtering materials, because containing no
carbonate of lime, would be especially useful in the manufacture of tartaric acid.
Dated this 1st day of March 1894.
FAIRFAX & WETTER,
Agents for the Applicant.
Improvements relating to the Manufacture or Regeneration of
Carbonaceous Filtering Media.
I, JASPER WETTER, Patent Agent, of 433 Strand, in the County of London,
do hereby declare the nature of this invention, a communication to me from abroad
by Moriz Weinrich, Manufacturer, of Waverley Place, St. Louis, in the State
of Missouri, United States of America, and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
In the Specification of my British Patent No. 5375 dated 13 March 1893, I
mention as a preparatory proceeding in the regeneration of spent boneblack, the
removal of the old carbon contained in such boneblack, by heating it under
admission of air, until the carbon is burned and only the mineral framework left.
In order to perform this in a well regulated and automatic way, my corre-
spondent has introduced a new method and an apparatus, as shown in the
accompanying drawings.
Fig. 1 is partly an elevation and partly a longitudinal vertical section,
Fig. 2 a horizontal section along line w. of Fig. 1,
Fig. 3 is a front view,
Fig. 4 a rear end view and
Fig. 5 a section along lime x-y. of Fig. 2,
Fig. 6 shows an alternative construction of the head l.
The apparatus consists in its main part of a àrum d made of sheet irou, and
which, according to the amount of boneblack destined to be treated in a given
time, may have a length of appropriate size, say for instance, of from 12 to 30 feet,
and a diameter of from three to five feet.
The inner side of the drum is provided with a helix or Archimedean screw c.
made of sheet iron, projecting inwardly, say 4 to 6 inches, its threads or ribs
being 4 to 6 inches wide, the purpose of the screw being to move constantly the
boneblack entering at the slowly revolving drum, towards its rear end.
The drum is connected at its lower or rear end with screws or rivets to an
iron frame b, which is fastened to the short shaft or hub e.
This frame is provided
with shutters or dampers b', having adjusting screws 62 and adapted to slide in
appropriate guides 63, in order to regulate the draft of air passing through the
interior of the drum.
At its front end the drum is connected to the cast iron wheel f, which is

page_text: fastened to the hub e¹. The hubs e, e¹ rest and revolve upon the supports g, gʻ
respectively.
If the length of the drum exceeds say 16 feet, it should be further supported,
as for instance in the interior for the sake of greater firmness, by additional
wheels and which if desired, may be fixed upon a shaft extending through the
whole length of the drum, and such an additional wheel may run on its outside
upon rollers resting upon the bridge wall #.
At the end of shaft e is a cog wheel h which gears with the pinion i, whose
shaft is mounted in suitable bearings i, as shown and is set in motion or stopped
by the fast pulley k and the loose pulley & respectively. The support g' at the
front part of the apparatus is connected with the conical head I made of cast iron,
and turned smooth at the edge and around which runs closely the cast iron ring r¹,
turned smooth likewise at its edge to be mentioned again hereinafter. With the
head is connected the hopper a, provided with the sliding shutter a¹ adjustably
controlled by screw a², and sliding in guides a³. Through this hopper is fed the
boneblack, its inflow being regulated by the shutter a'. m is a pipe with a damper m²,
by which the draught of air passing through the interior of the drum is regulated
and may be connected with the pipe leading out of the fan located at s and
hereinafter mentioned. The whole drum except its ends, is walled in with brick-
work 9.
In order to prevent the air from entering between the brick wall and
the drum, the drum is provided at both ends with rings of cast iron, r r. The
rings provided with lugs, are let into the wall and turned smooth at the inner
sides, and the rings are fastened to the drum and turned smooth on their outside;
a play of only one eighth of an inch is allowed between these turned sides or faces
of the rings. The apparatus is set up in proximity to a furnace or some other
source of heat, its hot gases being led through a flue t provided. with the damper t'
and located under the rear end of the drum.
The apparatus works as follows;-
The drum is started by the fast pulley k, the hopper a is filled with boneblack,
the fan s is set in motion, and the damper t' is lifted, say by means of an adjusting
screw t².
The gases are drawn by the fan under the slowly revolving drum, which should
make from two to five revolutions per minute; and these gases come against the
bridgewall u, surround the drum in the space enclosed between it and the sidewall q,
so as to heat the whole drum. Subsequently they are drawn off through the fan's
and may be used yet for drying the wet boneblack.
The boneblack falls in an equal stream regulated by the sliding shutter a¹
into the interior of the drum; it is immediately heated and caused to move
slowly and continuously by the threads of the helix c towards the other end.
The heated particles of the boneblack change constantly their position, becoming
simultaneously exposed to the air which passes through the drum, so that the
carbon will burn off wholly or partly, as desired, without bringing the boneblack to
a red heat. In this way any excess of carbon which the boneblack has taken up
during its use, can be burned off quite evenly, thus rendering the black again very
porous and efficacious.
The boneblack being thus deprived of more or less of its carbon, is discharged
at the lower or rear end of the drum, and is thence carried off by any convenient
means or devices. The amount of carbon desired to be burnt off can be easily
regulated either,
1st, by the amount of boneblack passing through the sliding shutter; or
2nd, by the temperature of the gases drawn around the drum ; or
3rd, by the amount of air drawn through the drum ; or
4th, by the number of revolutions of the drum, in a given time.
In place of a helix may be used a number of longitudinal ribs made of sheet
iron projecting inwardly 6 to 12 inches, for the purpose of lifting and dropping
constantly the heated boneblack. In this case the drum should have a slight incline,
say of about one inch to six feet of its length.
:

page_text: Although the heated boneblack becomes in this way more thoroughly exposed
to the air, than by a helix, so that the carbon burns off more readily, I generally
prefer a helix, especially for small grain boneblack, since by its use the boneblack
is better preserved and none of its mineral framework rubbed off. It has been
found, that such apparatus as I have described, may be substituted to great
advantage and in a quite novel way for the revivifying kilns for boneblack
heretofore used. As generally known to those versed in the art, the object of
revivifying kilns is to char under careful exclusion of air, the organic matters
absorbed by the boneblack during the filtration of sugar solutions, whereby-the
carbon formed by these organic matters gradually chokes and covers the pores of
this boneblack.
By a careful use of the new apparatus in the described way, these organic matters,
instead of being charred under exclusion of air, can be entirely burned off under
admission of air, thus leaving the pores of the boneblack always clean and effective,
besides requiring only a very moderate heat by which the mineral framework of the
boneblack remains quite uninjured.
This mode of revivification is especially to be recommended, if the boneblack
cuntains more than ten per cent. of carbon, so that its efficacy would not be impaired,
if sometimes a small amount of carbon should be burned off together with the
foreign organic matters.
In the same British Patent Specification mentioned above, I have described a
new process of regenerating spent boneblack, consisting in supplying it with a new
charge or coating of animal carbon, by impregnating it with a solution of organic
animal matter and then drying and charring said product.
My correspondent has made the further discovery, that solutions of certain
vegetable matters, applied in substantially similar manner as described in said
Specification, will also regenerate spent boneblack to such a degree, that its efficiency
is again equal to that of new boneblack.
The vegetable materials I make use of in my present improvement are
molasses, (either cane, or beet-molasses), glucose, starch, and flour made from
wheat, corn or other grains.
In using molasses or glucose, I proceed as follows: The spent boneblack is
deprived first of most or all of its carbon, by heating it under admission of air in
any desired way until the carbon is burned off and only the mineral frame left, thus
freeing the pores from the layer of the old and consequently ineffective carbon. The
decarbonised boneblack is put into an open pan provided with a double steam
bottom or steam coil, in which pan a certain amount of hot molasses or glucose,
diluted with water, has previously been put. For each one thousand (1000) pounds
of decarbonised boneblack, I use about fifteen hundred (1500) pounds of such a
solution of molasses or of glucose, containing say ten per cent. of dry matter. The
decarbonised and very porous boneblack will absorb at once most of the solution.
Steam is now applied, and the mass boiled, until its water contents are reduced
to such a degree, that the molasses or glucose will all stick on the surface and in
the pores of the boneblack.
The mass is then taken out and dried on a heated surface, or by some other
suitable device or means. As soon as the boneblack thus coated with molasses or
glucose is entirely dry, it is charred in boneblack kilns in the well-known way, until
all the organic matter is carbonised and covers the mineral framework with a new
coat of vegetable carbon. The burned and coated boneblack is now washed with
pure hot water and is then ready for use.
In using starch or flour, these materials require a preliminary treatment, before
being brought into contact with the boneblack, in order to decompose their gluten,
thus securing a good impregnation and preventing the particles of the boneblack
from baking together during the drying of the impregnated mass.
To this end, I dissolve the starch or flour in cold acid water. For each one
hundred (100) pounds of starch or flour 1 use a thousand (1000) pounds of water,
mixed with about twenty (20) pounds of muriatic acid of 22° Beaumé.

page_text: As soon as the starch or flour is dissolved, the solution is heated up to boiling
point and kept boiling (being at the same time stirred), until it has lost all
glutinousness, and has obtained a semi-transparent appearance. Lime is now added,
until the solution is neutral, or only slightly acid; after which the decarbonised
boneblack is put into the solution in the proportion of one thousand (1000) pounds
of boneblack to say about twelve hundred (1200) pounds of the solution. The
subsequent treatment is exactly the same as that above described for molasses or
glucose. The price of these vegetable materials is generally less, than that of
gelatine or blood, besides which decarbonised boneblack coated in this way with
vegetable carbon can be used also to good advantage in industries in which the
applying of animal carbon is not advisable, as for instance for the decolourising of
cotton seed oil.
Instead of decarbonised boneblack, other materials consisting of a porous mineral
framework, as for instance pumice stone, may be used. Their treatment is the
same as that of boneblack. Such filtering materials, because containing no
carbonate of lime, would be especially useful in the manufacture of tartaric acid.
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. Apparatus for decarbonising and for revivifying boneblack without charring
the same, comprising in its construction a horizontal slowly revoluble drum into
which air is admitted, a wall surrounding such drum, inwardly projecting ribs on its
interior face, means for adjustably feeding the boneblack to the drum, and adjustable
dampers at the discharging end of the drum to regulate the draft of air through it,
all substantially as described.
2. The described process of regenerating and recarbonising spent boneblack,
which consists in first depriving it of all or most of its old carbon, then supplying
it with a new charge or coating of vegetable matter such as molasses, glucose,
starch or flour, and then drying and charring said product, all substantially as set
forth.
3. The herein described process for the manufacture of carbonaceous filtering
media.
Dated this 1st day of December 1894.
FAIRFAX & WETTER,
433, Strand, London, Agents.