NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF EXTRACTS OF TANNIN AND APPARATUS THEREFOR
Year: 1884

page_text: PROVISIONAL, SPECIFICATION.
I WALTER ALFRED BARLOW of 6 St Pauls Churchyard in the city of London
Patent Agent and Engineer do hereby declare the nature of the said invention for
NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF EXTRACTS OF TANNIN
AND APPARATUS THEREFOR a communication to me from abroad by La Societé
Civile d'études sur les procédés, nouveaux de fabrication perfectionnée d'extraits
tannique of Paris in the Republic of France to be as follows:-
=
The price of oak bark being high tanning has of late been carried out with
extracts of tannin and these extracts are generally obtained from chestnut, oak,
or other wood containing tannin.
The tannin produced from wood is infinitely less costly than that produced from
oak bark, but the great difficulty in these extracts from wood is to remove many
products the presence of which are detrimental to the tannin process and which
moreover contain coloring matters which render the extracts improper for tanning.
The process which has hitherto given the best results is that invented by one
Paul Gondolo which consists in making a decoction at 2º Baumé which may be
treated by albumen of blood under special conditions. The extracts so mado are
of good quality but requires great attention in the manufacture.
The character of the matters to be eliminated varies from simple to complex
according to. the wood and the blood employed presents great inequalities in the
quantity of albumen' it contains and moreover there is present in the blood a
certain quantity of iron which colors the products and the price of the blood adds
to the cost of the products.
After having studied with great care the various impurities which are present
in a decoction of wood it has been found that they are for the most part in suspen-
sion but are so extremely fine that it is impossible to remove them in a practical
way by simple filtration.
It has also been essayed to separate the extracts of tannin by the phenomon
endosmose which process gives very pure products perfectly free from color but it
leaves a residuum difficult of treatment and is somewhat costly.
This invention is carried out as follows:-
After having reduced the wood to fine shavings by plancing (instead of breaking
up the wood) the shavings present the wood with all the cells well open and
consequently it will be more easy to extract the matter contained.

page_text: These shavings are placed in receptacles wherein the decoction may be made by
the introduction of steam, these receptacles may be open or be made of copper in
which the shavings will be heaped up and then the receptacle be closed. Warm
water is then introduced a small quantity of sulphuric acid be added when the
liquid may be boiled instead of using steam..
When the decoction is made it is run into a reservoir of this or that kind for
further treatment.
A certain number of the decoction receptacles are arranged together so as to
treat the shavings methodically and successively.
The liquid produced contains amylaceous, gummy, resinous, and coloring matters
as well as tannin and to obtain a good product all matters detrimental to tanning
should be removed.
For effecting this certain operations are carried out as follows:-(1) The liquid
is filtered through sheets of close felt by the filter press (2) All matters in
Buspension however fine they may be are separated by centrifugal force and for
this latter treatment there is employed the centrifugal apparatus hereinafter
described.
L-
The matters in suspension for the greater part become laid in sheets on the sides
of the apparatus where they form a bed more of less thick according to the quantity
of liquid treated. From time to time. the centrifugal apparatus will be stopped
and the deposited solid matters be removed.
By this process the matters in suspension-are-withdrawn from the liquid leaving
only matters that may be in solution this may then be by condensing apparatus,
concentrated to the requisite degree for commercial purposes.
The centrifugal apparatus consists of a frame mounted upon a base plate with
-a-central-steel-shaft working in a footstep and upper bearing of the framing said
shaft carries a cone for driving purposes from a coned wheel-driven-as-desired....
The shaft carries a cup or vessel-formed with a central_boss said vessel being of
_copper and perfectly water tight, it is also strengthened by hoops around. Above
this main centrifugal vessel is a smaller-vessel-communicating with the centrifugal
vessel by a tube and a feed tube is supplied extending through the framing from
above and an exit tube is furnished below leading into a circular box below the
centrifugal vessel. The said centrifugal vessel has a diaphragm or lining fitted
thereto concentrically so as to slide in guides (provided for the purpose of forcing
the liquid contained in the centrifugal apparatus to turn at the same speed with
the motion of the chamber). A second leading off tube is furnished from the
circular box below the centrifugal vessel. An enclosed grease box is furnished
to the foot-step. Taps are supplied to regulate the supply and draw off of the
liquid.

page_text: "
I WALTER ALFRED BARLOW of 6 St Paul's Churchyard in the city of London
Patent Agent and Engineer do hereby declare the nature of the invention for
"NEW OR IMPROVED PROCESS FOR THE MANUFACTURE OF EXTRACTS OF TANNIN
AND APPARATUS THEREFOR Communicated by "La Société Civile d'études sur
les procédés nouveau de fabrication perfectionnée d'extraits tannique" Paris and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The price of oak bark being high tanning has of late been carried out with
extracts of tannin and these extracts are generally obtained from chestnut, oak
or other wood containing tannin.
The tannin produced from wood is infinitely less costly than that produced from
oak bark but the great difficulty in these extracts from wood is to remove many
products the presence of which is detrimental to the tanning process and which
moreover contain coloring matters which render the extracts improper for tanning.
The process which has hitherto given the best results is that invented by one
Paul Gondolo which consists of making a decoction at 2° Baumé which may be
treated by albumen of blood under special conditions. The extracts so made are
of good quality but require great attention in the manufacture.
The character of the matters to be eliminated varies from simple to complex
according to the wood, and the blood employed presents great inequalities in the
quantity of albumen it contains and moreover there is present in the blood a
certain quantity of iron which colors the product and the price of the blood adds
to the cost of the products.
After having studied with great care the various impurities which are present
in a decoction of wood it has been found that they are for the most part in suspen-
sion but are so extremely fine that it is impossible to remove them in a practical
way by simple filtration.
It has also been essayed to separate the extracts of tannin by the phenomona of
endosinose which process gives very pure products perfectly free from color but it
leaves a residuum difficult of treatment and is somewhat costly.
This invention is carried out as follows :—
After having reduced the wood to fine shavings by cutting or planing against
the grain (instead of breaking up the wood) the shavings present the wood with
all the cells well open and consequently it will be more easy to extract the matters
contained.
These shavings are placed in receptacles wherein the decoction may be made by
the introduction of steam, these receptacles may be open or be copper vats or
receptacles in which the shavings will be heaped up and then the receptacle be
closed. Warm water is then introduced, a small quantity of sulphuric acid being
added and the liquid may be boiled instead of using steam.
When the decoction is made it is run off into a reservoir of this or that kind for
further treatment, and the wood shavings may if desirable be again treated to
obtain any further remaining product.

page_text: A certain number of the decoction receptacles are arranged together so as to
treat the shavings methodically and successively. The liquid produced contains
amylaceous, gummy resinous, and coloring matters, as well as tannin and to obtain
a good product all matters detrimental to tanning should be removed.
☐ For effecting this certain operations are carried out as follows (1) The liquid is 5
filtered through sheets of close felt or by the filter press. (2) All matters in
suspension however fine they may be are separated by centrifugal force and for
this latter treatment there is employed the centrifugal apparatus shown in the
drawing annexed hereto and to which reference will be made in the following
description.
The centrifugal apparatus consists of a frame A, mounted upon a base plate B,
with a central steel shaft C working in a foot step D (said footstep D being
provided with a grease box) and an upper bearing E of the framing A. The
shaft C carries a cone wheel ŕ for.driving purpose as from the wheel G driven as
required.
1
I
This shaft C, carries a basket or vessel H formed with a central boss H', said
vessel being of copper and perfectly watertight, and is strengthened around by
hoops h. Above this main centrifugal vessel H is a small annular channel or
-vessel K communicating with the vat or vessel H by a tube K¹ and a feed tube L
is provided extending through the framing A, to said channel K from above and 2
a tap R is provided to regulate the supply of the liquid, there is also a tube L¹
furnished in the bottom of the vessel H, leading into a circular box N. below the
centrifugal vessel H and a second leading off tube N' leads off from this box N.
The said centrifugal vessel has a diaphragm M fitted thereto so as to slide in
-guides m, m to serve as a stop to the liquid contained in the centrifugal apparatus 2
and to keep it at the same speed-with the motion of the vat or vessel.
The use of this centrifugal machine will be as follows:-
The diaphragm M, is drawn from its position in-tho guides and a piece of fabric
of impermeablo-texture_is_placed around the internal wall of the basket and the-
diaphragm is then replaced in position The apparatus-is-then put in rotation and 3
when a suitable speed is attained the tap R is opened and the liquid from the-
reservoir flows through the tube L into the annular channel K and from thence by
the tube K¹ it escapes to and is submitted to the action of the vessel H. The
matters held in suspension are thrown against the impermeable covering of the
walls of the vessel H and are retained upon the fabric before mentioned in sheets 3
more or less thick according to the quantity of liquid treated.
From time to time the apparatus will be stopped the liquid be drawn off and
the fabric with the deposited solid matters thereon will be removed and another
covering be introduced when the operation can be continued.
The lighter liquids accumulate towards the axle C and when the apparatus is 4
stopped will exit through tube L' into the box N from thence they can be drawn
off by means of the tube N' which will be fitted with a tap for the purpose.
By this process the matters in suspension which contain the coloring matter
injurious to the tannin are withdrawn from the liquid leaving only matter that
may be in solution this can then be by a condensing apparatus concentrated to the 4
requisite degree for commercial purposes..
Having now particularly described and ascertained the nature of the said
invention, I declare that what I claim is
Firstly. The herein described process for the manufacture of extracts of tannin
which consists in preparing the wood fibre by cutting same against the grain to 50
make the decoction which will be then filtered and then further treated in a
centrifugal vessel to separate out the matters held in suspension against the lining
of impermeable fabric material as set forth.
Secondly. The treatment of decoctions of tannin by centrifugal force as and for
the purpose herein specified,
51

page_text: Thirdly. The apparatus herein described for effecting the centrifugal treatment
of decoctions of extract matter wherein is the centrifugal vessel H provided with
the lining of impermeable fabric material which will retain the matters, held in
suspension in the liquid, when such matters are by the centrifugal action of the
apparatus terminated outward to and upon said lining.
Dated th:- 00-1 1 100