Improved Manner and Apparatus for Nitrating Cotton, Cellulose, Straw, and similar substances.
Year: 1891

page_text: Date of Application. 24th June, 1891
Complete Specification Left, 11th Mar., 1892-Accepted, 16th Apr., 1892
PROVISIONAL SPECIFICATION.
Improved Manner and Apparatus for Nitrating Cotton, Cellulose,
Straw, and similar substances.
JOHANNES SELWIG and BRUNO LANGE, Engineers of Brunswick, Germany
address, firm, Selwig & Lange, Brunswick, Germany, do hereby declare the
nature of this invention to be as follows:-
The usual manner of removing the acid from the nitrated material is to take the
latter out of the nitrating vessel, then to put it into a centrifugal machine and to
expel in the latter the acid by centrifugal force.
The object of our invention is to avoid the incommodious transport of the
nitrated material into the centrifugal machine.
We attain this object by nitrating in the centrifugal machine itself, whose casing
forms the nitrating vessel, the perforated basket being of the usual construction.
For retaining the acid in the casing the discharging tube of the latter is closed
by a tap and for warming or cooling the acid during the nitrating, the casing is
provided with a jacket or a warming pipe of suiting shape, lying within it, through
which either warm or cold water or any other fluid circulates.
The upper journal of the shaft is so elevated, that the acid does not reach it
when the apparatus is filled.
For removing the noxious vapours arising from the process the interior of the
casing, which is closed by a cover or a top piece with a door, is connected with an
exhauster.
The nitrating and drying is effected in the following way:
The above mentioned tap being closed, the casing is filled with the acid, while
the basket is at rest, and the material to be nitrated put into the basket.
*
When the nitrating process is finished, the acid is let off to a montejus" by
opening the tap.
Now the centrifugal is put in motion and the last acid adhering to the nitrated
material is expelled by centrifugal force.
Dated this 22nd day of Tune 1901
JOHANNES SELWIG AND
BRUNO LANGE.
COMPLETE SPECIFICATION:
Improved Manner and Apparatus for Nitrating Cotton, Cellulose;
Straw, and similar substances.
JOHANNES SELWIG and BRUNO LANGE, Engineers of Brunswick, Germany
address, firm, Selwig & Lange, Brunswick Germany, do hereby declare the
nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
Up to the present when the nitrating process of cotton and similar substances.
was finished in the apparatus, the acid was first removed as far as possible from
the nitrated substance by the latter being pressed out or
the acid being
sucked off.
The substance was then taken out of the apparatus and transported to a centri-
fugal machine, in which the last adhering acid was driven out.
The transport of the nitrated substance from the nitrating apparatus to the.
centrifugal is incommodious as well as injurious to the workmen the latter being
always exposed to breathe in the noxious vapors caused by the process.
The object of our invention is to avoid this transport.

page_text: We attain this end by combining a centrifugal machine with a nitrating apparatus
in such a way as to insert in the nitrating vat the perforated revolving basket of a
centrifugal machine likewise arranging the usual mechanism for putting it in
motion such as done in an ordinary centrifugal machine.
"
In this apparatus which we call "Centrifugal nitrating apparatus we perform
at first the nitrating process by filling the vat with the acid and charging the
basket with the substance to be nitrated, and afterwards the drying of the nitrated
substance contained in the basket by putting it in motion after having let off the
acid and expelling the last adhering acid by centrifugal force.
The accompanying drawing is a vertical section of the apparatus whose general
appearance is that of a centrifugal machine with underdriven basket.
A is the perforated basket inserted in the cylindrical nitrating vat B and carried
by a cast-iron dome a upon a central shaft b, arranged with driving pulley,
footstep and neckbearing on the central bracket d, whose upper edge e lies over
the surfaces of the acid, when the vat is filled, to prevent the corrosion of the
neckbearing.
The whole is supported by the lower cast-iron part of the vat B, the conical
bracket d forming the central part of its inclined bottom. A tap Ĉ is fixed to
the discharge spout joining the bottom f.
For regulating the temperature of the acid during the nitrating, the upper
cylindrical part of the vat B is furnished with a jacket, through which cold or
hot water or any other fluid circulates when required, being the admission tap and
pipe, the overflow pipe of the fluid.
h
The jacket can be replaced by a coiled tube or a tube of any other shape
placed in the rat through which the said fluid flows during the nitrating.
On the top the vat B carries an annular rim, which prevents the substance
to be nitrated from entering the annular space, surrounding the basket A, when
charging the latter.
Above the vat a head-piece D is arranged similar to the fume-hoods used in
chemical laboratories, provided with a door m, the upper eduction pipe n of the
head-piece being connected with an exhaustor, which draws off the noxious vapours
caused by the process. The pipe joining the rim 1, which is also connected with
the exhaustor serves the same purpose; p is the inlet-pipe for the acid communi-
cating through three taps with acid tanks.
1
The nitrating and drying process is performed in the apparatus in the following
manner:
After having closed the discharge tap C the vat B is filled with the required
quantity of acid and the basket A charged with the substance to be nitrated.
Now the process is conducted in the known manner, cold or hot water flowing
through the jacket if required and the exhaustor being at work for drawing off
the acid-vapors.
When the nitrating is finished the acid is let off by opening the discharge cock C,
and the basket A containing the nitrated substance is put in motion for driving out
the last acid by centrifugal force.
This having been done the basket is stopped and the nitrated substance taken
out of it, for being washed in the usual manner.
Be it understood that the vat B may be of cylindrical or any other convenient
shape.
Likewise it does not matter how the basket A is driven.
It may be under-
driven as shown in the drawing or overdriven or suspended as for instance in
Weston's centrifugal.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
:-
1. An improved manner of nitrating cotton, cellulose, straw and similar
substances and drying the nitrated substance by centrifugal force, consisting in the

page_text: nitrating and drying of the said substances being effected in one and the same
apparatus, viz. a nitrating apparatus combined with a centrifugal machine in such
a way as to insert in the vat B nitrating apparatus the perforated basket A of the
centrifugal machine, the nitrating of the substance contained in the basket A being.
performed, while the latter is at rest and the drying of the nitrated substance
being effected by rotation of the basket, after having let off the acid, substantially
as described.
"
"Centrifugal
2. An improved nitrating and drying apparatus, called by us
nitrating apparatus consisting of a nitrating apparatus, combined with a
centrifugal machine in such a way as to insert in the vat B the perforated revolving
basket A of a centrifugal machine, which is filled with the substance to be nitrated
and can be put in motion as usual in common centrifugal machines, for expelling
the acid out of the nitrated substance by centrifugal force after the nitrating,
substantially as described.
::
3. In a Centrifugal nitrating apparatus the appliance for cooling or warming
the acid contained in the vat B consisting of the jacket h or a coiled pipe or
pipe of any other shape placed in the vat, through which jacket or pipe cold or
hot water or any other fluid circulates, substantially as described.
Dated, Brunswick, Germany, this 9th day of March 1892.
ART
LA
JOHANNES SELWIG.
BRUNO LANGE.