Improved Process and Apparatus for Tanning by the Aid of " Electricity.
Year: 1898

page_text: Improved Process and Apparatus for Tanning by the Aid of
"
Electricity.
We, NIELS PETER ANDERSEN, of Hzorth Lorentzensgade 23, Kopenhagen, Manager
for Tanning, and JOHANNES WESTENGAARD, 2, Nestervolgade, of Kopenhagen, Advocate
to the High Court of Justice, and HUGO THEODOR ZERENER, Ph.D., of 22, Dorotheen-
strasse, Berlin, Civil Engineer, do hereby declare the nature of this invention to be
as follows:
This invention has reference to an improved process of tanning which differs
essentially from those hitherto known, including so-called electric processes, in
which the action depends solely upon the active movement of the hides in the
tanning liquor, which must necessarily counteract the assumed auxiliary electric
action. The improved tanning process is based upon the transferring action of the
electric current or electrical endosmose and the apparatus employed for carrying out
such process is constructed with special regard to this electrical action.
The particular feature of this invention is the reversal at certain intervals, of the
direction of the endosmotic movement set up by the electric current, relatively to
the surfaces of the hides to be tanned, without however the continuity of such
movement and the quiescence of the tanning liquor being disturbed by the movement
of the apparatus. The endosmotic movement is of course not dependent on the
movement of the apparatus, such inovement being imparted to the apparatus only
for practical reasons and must, as is obvious, be an extremely slow one and it may be
adapted to the intervals between the reversals of the current. This movement of
the apparatus as well as the application of the electric current, is effected by using
appropriate and well known means. The surfaces of the electrodes are arranged
parallel to the surfaces of the hides, and are properly insulated and connected with
an automatic commutator.
The frequency of reversal of the direction of the current relatively to the surface
of the hides, and also the potential and the strength of the current used, depend on the
character of the hides to be heated. The reversal should, as a rule take place every
few minutes. The potential also has to be regulated according to the resistance of
the liquor employed. The apparatus requires no special attendance. As is well
known, the strength of the liquor and of the current stand in a certain relation, and
the change of direction of the direct or continuous current at definite short intervals
prevents the formation of gallic acid. The apparatus can be made of wood, stone,
metal or of a combination of these materials which however must not be such as to
form a chemical combination with tannic acid, and the rotating mechanism can be
arranged either in or outside the pit or tanning tub, or pit and tanning tub.
Fig. 1 of the accompanying drawings shows in section, partly on the line x x and
partly on the line a¹ a¹ of Fig. 2, and Fig. 2 in plan, one arrangement of apparatus
according to this invention, constructed of wood, aluminium and aluminium bronze
and designed for use in cement tanks. The apparatus shown comprises two end
frames E E¹ fixed on a shaft W and each provided with five spokes which are
connected to longitudinally arranged wooden bars b that are provided with hooks a and

page_text: are connected together at points between the end frames by three series of T irons e,
the whole forming an openwork frame of pentagonal shape in end view. On the
hooks a of the longitudinal bars b a great number of hides can be stretched out at the
necessary distances apart and head upwards, one behind the other and parallel to
the electrodes D the distance apart, which is usually about 100 m.m. depending upon
the natural form of the hides. The bearings L in which the shaft W rotates may be
arranged within the tanning tub or tank as shown, or be arranged outside of the
same. To one end of the shaft w is fixed a toothed-wheel A with which gears a worm z
fixed in a vertical shaft driven by bevel toothed-wheels 22 and 2¹ arranged above the
tanning tub or tank. These wheels are driven in the ordinary manner by shafts
and gearing. In the arrangement shown the toothed wheel z¹ is fixed upon a shaft w
mounted in bearing B and carrying a belt pulley 7 driven by a belt g. Between the
two bearings B, B is another small belt-pulley that drives through a belt f, the belt-
pulley of a current-reverser or commutator G.
It is obvious that the current reverser G (suitably constructed so as to prevent
induction sparks) can also be arranged to work automatically or electrically in any
other manner. At suitable places are also arranged the measuring instruments, viz.
an ammeter M and voltmeter V and a regulating rheostat R necessary for electrical
working, these parts being indicated diagraminatically on the drawings. The
conductors to the electrodes D, D₁ are of the usual kind and are capable of being
readily removed. They are secured to the bottom of the tank by means of strips m
of wood or other insulating material, and also by clips c. Q indicates the source of
the electric current. In treating the hides with thin liquors, movement of the
apparatus is unnecessary as the current agitates the liquor and the current reverser
effects the alternation in the direction of the current through the hides. After
strengthening the liquors however for the purpose of preventing the formation of
sediment and preserving homogeneity, the apparatus is set in slow rotation, such
that the endosmotic movement at right angles to the surfaces of the hides is not
disturbed. It is to be observed that this simple and slow rotation can also be attained
without the elaborate arrangement described. For this purpose a wooden drum
mounted on one end of the shaft w may be driven by a cord actuated by gearing
arranged above the tub.
As regards the other usual conditions of tanning and having reference to liquors,
preparing and finishing, the process in no way differs from the ordinary
processes.
Improved Process and Apparatus for Tanning by the Aid of
Electricity.
We, NIELS PETER ANDERSEN, of Hzorth Lorentzensgade 23, Copenhagen, Tanning
Manager, and JOHANNES WESTENGAARD, of 2, Nestervolgade, Copenhagen, Advocate
to the High Court of Justice, and HUGO THEODOR ZERENER, Ph.D., of 22 Doro-
theenstrasse, Berlin, Civil Engineer, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described &
ascertained in and by the following statement :-
This invention has reference to
improved nesodes
on
of tannin
which

page_text: essentially from those hitherto known, including so-called electric processes, in which
the action depends solely upon the active movement of the hides in the tanning liquor,
which must necessarily counteract the assumed auxiliary electric action. The
improved tanning process is based upon the transferring action of the electric current
or electrical endosmose, and the apparatus employed for carrying out such process is
constructed with special regard to this electrical action.
The particular feature of this invention is the reversal at certain intervals, of the
direction of the endosmotic movement set up by the electric current, relatively to
the surfaces of the hides to be tanned, without however the continuity of such
movement and the quiescence of the tanning liquor being disturbed by the
movement of the apparatus. The endosmotic movement is of course not dependent
on the movement of the apparatus, such movement being imparted to the apparatus
only for practical reasons and must, as is obvious, be an extremely slow one and it
may be adapted to the intervals between the reversals of the current. This movement
of the apparatus, as well as the application of the electric current, is effected by using
appropriate and well known means. The surfaces of the electrodes are arranged
parallel to the surfaces of the hides, and are properly insulated and connected with an
automatic commutator.
The frequency of reversal in the direction of the current relatively to the surface of
the hides, and also the potential and the strength of the current used, depend on the
character of the hides to be treated.
The reversal of the current should, as a rule, take place every few minutes.
The potential also has to be regulated according to the resistance of the liquor
employed. The apparatus requires no special attendance. As is well known, the
strength of the liquor and of the current stand in a certain relation, and the change
in direction of the direct or continuous current at definite short intervals prevents
the formation of gallic acid. The apparatus can be made of wood, stone, metal or of
a combination of these materials, which however must not be such as to form a
chemical combination with tannic acid, and the rotating mechanism can be arranged
either in or outside the pit or tanning tub, or pit and tanning tub.
Fig. 1 of the drawings filed with the provisional specification shows, in section,
partly on the line x, c, and partly on the line x¹, x³ of Fig. 2, and Fig. 2 in plan, one
arrangement of apparatus according to this invention, constructed of wood, aluminium
and aluminium bronze and designed for use in cement tanks.
The apparatus shown comprises two end frames E E¹ fixed on a shaft W and each
provided with five spokes which are connected to longitudinally arranged wooden
bars that are provided with hooks a and are connected together at points between
the end frames by three series of T irons e, the whole forming an open-work fraine of
pentagonal shape in end view. On the hooks a of the longitudinal bars b a great
number of hides can be stretched out at the necessary distances apart and head
upwards, one behind the other and parallel to the electrodes D; the distance
apart, which is usually about 100 in.m., depending upon the natural shape of the
hides.
The bearings L in which the shaft W rotates may be arranged within the tanning
tub or tank, as shown, or be arranged outside of the same. To one end of the
shaft is fixed a toothed wheel A with which gears a worm z fixed on a vertical shaft
driven by bevel toothed-wheels z² and z¹ arranged above the tanning tub or tank.
These wheels 2 z¹ are driven in the ordinary manner by shafts and gearing. In
the arrangement shown the toothed wheel is fixed upon a shaft w mounted in
bearings B, B and carrying a belt pulley driven by a belt g. Between the two
bearings B, B is another small belt-pulley that drives through a belt f, the belt-
puiley of a current-reverser or commutator G.
It is obvious that the current reverser G (which should be constructed so as to
prevent sparking) can also be arranged to work automatically or electrically in any
other manner. At suitable places are also arranged measuring instruments, viz. :--
an ammeter M and volt-meter V and a regulating rheostat R necessary for electrical
working; these parts being shewn diagrammatically on the drawings. The con-

page_text: ductors to the electrodes D, D¹ are of the usual kind and are capable of being easily
and readily removed. They are secured to the bottom of the tank by means of
strips m of wood, or other insulating material, and also by clips c. Q indicates the
source of the electric current. In treating the hides with thin liquors, movement
of the apparatus is unnecessary as the current agitates the liquor and the current
reverser effects the alteration in the direction of the current through the hides.
After strengthening the liquors however for the purpose of preventing the formation
of sediment and preserving homogeneity, the apparatus is set in slow rotation such
that the endosmotic movement at right angles to the surface of the hides is not
disturbed. It is to be observed that this simple and 'slow rotation can also be attained
without the elaborate arrangement described. For this purpose a wooden drum
mounted on one end of the shaft W may be driven by a cord actuated by gearing
arranged above the tub.
As regards the other usual conditions of tanning and having reference to
liquors, preparing and finishing, the process in no way differs from the ordinary
processes.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. The herein described process for tanning hides by means of a direct or
continuous electric current, according to which the hides, fastened at head and
feet and stretched out one behind the other, parallel to the electrodes, are placed
in an electrically fitted tanning tank or tub in such a manner that the endosmotic
movement caused by the electric current which is reversed at short intervals,
always takes place at right angles to the stretched surface of the hides, the said
hides when necessary being slowly rotated in a plane at right angles to the
direction of the current, so as to cause no alteration in the direction of the
endosmotic action, substantially as described.
2. For carrying out the process referred to in the preceding claim, apparatus.
comprising a pentagonally formed rotating frame arranged between the electrodes
and by means of which the hides suspended one behind another with their
surfaces parallel to the electrodes and at right angles to the direction of the
current can be slowly rotated in the tanning liquor in such a manner that the
endosmotic action of the electric current can be set up and maintained undisturbed,
substantially as described.
3. The improved apparatus hereinbefore described with reference to and shown.
in the drawings for tanning hides in the manner set forth.
Dated this 27th day of December 1898.