Improvements in the Manufacture or Restoration of Filtering Media.
Year: 1893

page_text: Date of Application, 13th Mar., 1893
Complete Specification Left, 9th Dec., 1893-Accepted, 20th Jan., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture or Restoration of Filtering Media.
I, JASPER WETTER, Patent Agent, of 433 Strand, London, do hereby declare
the nature of this invention, a communication to me from abroad by Moriz
Weinrich, Manufacturer, of 1746, Waverley Place, S. Louis, United States of
America, to be as follows:-
It is well known, that bone charcoal, also known as bonechar or boneblack,
consists of about 90 per cent. of a mineral body or framework composed chiefly of
phosphate of lime and carbonate of lime. This framework which is exceedingly
porous, is covered with a thin layer of azotic carbon, originating from the organic
gelatinous matter which remains in the bones after their fat has been extracted.
In the use of bonechar for filtering purposes, this animal carbon is the only agent
in the bonechar, in which remains the color and also many mineral and organic
bodies from the sugar solutions or other solutions treated; the mineral framework
above named acting only as a support of or for the carbon.
It is further well known, that by the repeated use of bonechar in spite of the
most careful washing, treating with different chemicals, and reburning in kilns, its
carbon becomes by and by ineffective, since the foreign bodies which it had
absorbed cannot be all removed by such method of restoration, or revivification,
and they cover and choke gradually the very fine pores of the carbon.
The use of such spent bonechar has therefore to be discontinued, and it is
generally sold for fertilizing purposes at about one third of the price of new
bonechar.
The said Moriz Weinrich has found, that such spent bonechar can be completely
regenerated in the following manner:
The spent (and heretofore discarded) bonechar is put into a vessel supplied with
a false bottom and a steam coil, and carefully washed therein with pure hot water ;
and it may be treated besides with one or more of the well known purifying agents,
as for instance, muriatic acid, soda or an.monia.
The washing water is drawn off through the false bottom, and a hot solution
of crude bone-gelatine or of dissolved glue showing about 12° Beaumé at
150° Fahrenheit, is now allowed to run into the vessel on the top of the bonechar.
About 175 pounds of such a solution will be the proper quantity for 1000 pounds of
bonechar. It will penetrate the damp mass of the bonechar and just cover it a
little. Steam is now applied, the temperature brought to boiling point, and the
mass kept boiling for about half an hour. After this time, the water-contents of
the mass are reduced to such a degree, that the gelatine will all stick on the
surface and in the pores of the bonechar.
The mass is now taken out, and spread and dried upon a heated surface.
During the drying process it has to be stirred from time to time, in order to avoid
its baking together. As soon as this bonechar thus coated with gelatine, is entirely
dry, it is charred in bonechar kilns in the well known way, until all the gelatine is
turned into carbon, covering the old ineffective layer with a new coat.
The burned and cooled bonechar is now washed with pure hot water, and is then
ready for use. It will now be found to be again quite as efficacious as new
bonechar.
This process can be repeated as often as the decolourizing power of the char for
the filtering of solutions is reduced to a certain degree; none of the spent char has,
as heretofore, to be turned out of the factory because of being useless or unavailable
for filtering, and great savings can be thereby attained.

page_text: Similar results can be obtained by using a mixture of gelatine or dissolved glue
and fresh blood; or by fresh blood only. In this last named case, the fresh blood
ought to be mixed preliminarily with carbonate of potash (125 lbs. to 1000 lbs. of
blood) or carbonate of soda (280 lbs. to 1000 lbs. of blood); and the temperature,
while impregnating the bonechar with the solution, must not exceed 150 degrees F.,
in order to avoid the coagulation of the albumen contained in the blood.
When the charring of the bonechar is finished, the potash or soda has to be
extracted again by hot water and may be used in subsequent operations. I
generally prefer to use gelatine or dissolved glue alone; its application being
simpler and surer.
In using blood, great care has to be taken during the burning process, because if
too much heat be applied at the beginning of the operation, some of the organic
bodies of the blood will fuse, choke the pores, and give the char a glossy
appearance. The gases escaping from the bonechar, while being burned in the
kilns, may be used in the same way as is now practised in bonechar factories.
This process can be applied also with good advantage to other filtering materials
containing no animal carbon, as for instance, wood-charcoal, corn-cobs (crude or
charred), coke, sand etc. The method or process of treating such materials is
exactly the same as described above, and by giving them a coat of animal carbon,
they will obtain a more or less decolourizing power, thus considerably increasing
their value and range of use.
Dated this 11th day of March 1892
FAIRFAX & WETTER,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture or Restoration of Filtering Media.
I, JASPER WETTER, Patent Agent, of 433 Strand, London, do hereby declare the
nature of this invention a communication to me from abroad by Moriz Weinrich,
Manufacturer, of 1746, Waverley Place, S. Louis, 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 :-
It is well known that bone charcoal, also known as bone-char, contains about
90 per cent. of a mineral body or frame-work composed chiefly of phosphate of lime
and carbonate of lime. This frame-work which is exceedingly porous, is covered
with a thin layer of azotic carbonaceous material, originating from the organic
gelatinous matter which remains in the bones after their fat has been extracted.
In the use of bone-char for filtering purposes this animal carbon is the only agent
in the bone-char, which absorbs color and also many mineral and organic bodies
from the sugar-solutions treated; the mineral frame-work above named acting
only as a support of or for the carbon.
It is further well known, that by the repeated use of bone-char in spite of the
most careful washing, treating with different chemicals, and re-burning in kilns,
its carbon becomes by and by ineffective, since the foreign bodies which it had
absorbed cannot become all removed by such method of restoration, or revivification,
and they cover and choke gradually the very fine pores of the carbon.
The use of such spent bone-char has therefore to be discontinued, and it is
generally sold for fertilizing purposes at about one third of the price of new
bone-char.
My correspondent has made the discovery that such spent bone-char can become
completely regenerated in a very simple and cheap way.
To attain this object, the spent and heretofore discarded bone-char is put into a
vessel supplied with a double bottom, or a steam-coil, and washed therein carefully
with pure hot water; and it may be treated besides with one or more of the

page_text: well-known purifying agents, as for instance, muriatic acid, soda or ammonia. In
many cases, especially if the amount of carbon originating from the absorbed
organic matters, is large and gives the char a glossy appearance, I prefer to
remove first all or most of the old carbon in the well-known way by heating the
char under admission of air until the desired amount of carbon is burned off.
The washing water is drawn off and a hot solution of crude bone-gelatine or of
dissolved glue showing about 12° Beaumé at 150° Fahrenheit, is now allowed to
run into the vessel on the top of the bone-char. From 160 to 240 pounds of such
a solution will be the proper quantity for 1000 pounds of bone-char, according to
the size of the char. It will penetrate the damp mass of the bone-char and just
cover it a little. Steam is now applied, the temperature brought to boiling point,
and the mass kept boiling for about half an hour. After this time the water
contents of the mass are reduced to such a degree, that the gelatine will all stick
on the surface and in the pores of the bone-cbar.
The mass is now taken out, and spread and dried upon a heated surface, or dried
by some other device.
As soon as this bone-char thus coated with gelatine is entirely dry, it is charred
in bone-char kilns in the well-known way, until all the gelatine is turned into
carbon, covering the old ineffective layer with a new coat.
The burned and cooled bone-char is now washed with pure hot water, and is
then ready for use. It will now be found to be again quite as efficacious as new
bone-char.
This process can be repeated as often as the decolorizing power of the char for
the filtering of solutions, is reduced to a certain degree; none of the spent char
has, as heretofore, to be turned out of the factory because of being useless or
unavailable for filtering, and great savings can be thereby attained.
Similar results can be obtained by using a mixture of gelatine or dissolved glue
and fresh blood; or by fresh blood only. In this last named case the fresh blood
ought to be mixed preliminarily with carbonate of potash (125 lbs. to 1000 lbs. of
blood); or carbonate of soda (280 lbs. to 1000 lbs. of blood); in order to avoid
the fusing of the organic matters during the subsequent charring process.
When the charring of the bone-char is finished, the potash or soda has to be
extracted again by hot water and may be used in subsequent operations.
In place
of fresh blood, also dried blood, which has to be re-dissolved, may be used with the
same results, and instead of potash or soda some finely powdered bone-black or
wood-char (from 2 to 4 per cent. of the weight of the bone-black to be treated)
may be mixed with the blood, thus saving the expenses for the chemicals and
their tedious extraction by hot water.
The gases escaping from the bone-char while being burned in the kilns, may be
used in the same way as is now practised in bone-char factories.
This process can be applied also with good advantage to other filtering materials
containing no animal carbon, as for instance, wood-char-coal, corn-cobs (crude or
charred) coke, sand etc. The method or process of treating such materials is
exactly the same as described above, and by giving them a coat of animal carbon,
they will obtain a more or less decolorizing power, thus considerably increasing
their value and range of use.
Having now particularly described and ascertained the nature of this invention,
as communicated by my foreign correspondent, and in what manner it may be
performed, I declare, that I claim :-
1. The described process of regenerating and recarbonizing spent boue-char,
which consists in supplying it with a new charge or coating of animal carbon by
impregnating it with a solution of organic animal matter such as gelatinė or blood
as set forth and then drying and charring said product, all substantially as set
forth.
2. The described process of regenerating and recarbonizing spent bone-char,
which consists in supplying it with a new charge or coat of animal carbon, by

page_text: impregnating with a hot solution of crude gelatine and then drying and charring it,
all substantially as set forth.
3. The application of the process described above for coating other filtering
media with a layer of animal carbon, substantially as described.
Dated this 9th day of December 1893.
FAIRFAX & WETTER,
433, Strand, London, Agents.