Improvements in the Method of and Apparatus for Removing Grease yor Fatty Matter from Sheep Skins and other Leather and the like..
Year: 1897

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c. Act, 1883) as required by
the decision of the Law Officer, of the 17th day of March 1898.
Date of Application, 4th June, 1897-Accepted; 10th July, 1897
COMPLETE SPECIFICATION (AMENDED).
Improvements in the Method of and Apparatus for Removing Grease
yor Fatty Matter from Sheep Skins and other Leather and the like..
We, WILLIAM SAGAR, Senior, ALFRED PARKER SAGAR and WILLIAM SAGAR,
Junior, trading, as W. and J. Sagar of Ball Grove Leather Works, Colne in the
County of Lancaster, Tanners and Leather Dressers, 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, that is to say:
In order to prepare sheep skins, hides or leather to meet certain well known
requirements it is necessary to free them of or from all grease or fatty matter, and
to do this recourse has been had to the following of many methods and the employ-
ment of varied substances and devices, chief among which perhaps have been the
employment of one or other of the many solvent substances which are easily
volatilized.
"Now in accordance with one of the methods the solvent is contained in a tank or
vessel and the hides, skins or leather are immersed therein, on which they are
raised out of the tank, allowed to drain and then they are hung in the open-air to
dry, in this case although the skins are properly and efficiently treated by the grease
removing solvent yet great waste ensues by its evaporation consequently the
is expensive.
process
According to another method most elaborate buildings and apparatus, closed to
prevent evaporation and loss into the atmosphere, with pipe connections for the
supply and withdrawal of the solvent are employed, and great expense is entailed in
their production, while the manner in which the solvent is brought into contact
with the hides or leather (which is by being forced or blown as a spray into the
room or chamber in which they are placed) does not absolutely insure all the parts
of them being properly treated or acted upon, hence, in addition to being of great
cost to install, it fails to act as efficiently as is desired.
As an alternative to spraying the solvent upon the skins or leather another
method suggested is to immerse them in the solvent and agitate or move them to
and fro therein, while the said solvent is heated above its normal temperature. It
has also been proposed to use for drying the degreased skins a separate hot air
circulating system independent of the distilling apparatus by which the spent
solvent is recovered. In this case also the cost of the apparatus is excessive while
the washing of the hides or leather in the heated solvent causes them to lose some
of their natural constituent parts and so renders them hard and harsh to the touch.
Further again, closed cylinders have been employed and arranged to contain the
solvent into which the hides or leather have been immersed, and these have been
arranged in series so that as that if one cylinder became saturated with the fatty matter
it might be drawn off and its adjoining cylinder approaching apparatus for distilling

page_text: '
it to separate the solvent as is well understood, and then water is employed to finally
remove the solvent remaining in the hides or skins thus treated, however in this case
the process is intermittent the removal of the grease being affected at one time
while on this being accomplished the removal of the solvent is commenced, and
further the use of water in any way whereby it is brought into contact with the
skins or leather being treated, we find to be very detrimental thereto either by
reason of its adding some matter or substance to these skins or leather, or removing
something from them, the resultant leather being somewhat hard or harsh to the
touch and so of less value in the market.
To avoid these losses, to produce apparatus at comparatively little outlay and to
make same thoroughly efficient in its operations so that the cost of carrying out
the process is considerably reduced and the goods treated are rendered of a higher
market value as compared with those treated by most of the processes herein before
referred to, is the object of this invention, and this object we attain by the employ-
ment of means hereinafter described and illustrated by the accompanying sheets
of drawings in which:-
Fig. 1 is an elevation showing end views of tanks and pipes connections thereto
in conjunction with apparatus for condensing and heating as hereinafter explained.
Fig. 2 is an elevation showing the parts illustrated by Fig. 1 and as seen in the
direction indicated by the arrow x.
Fig. 3 is a view of parts shown by Figs. 1 and 2 and as seen from above, and with
the covers of the condensing and heating apparatus removed therefrom.
Fig. 4 is a sectional side elevation showing the interior of one of the tanks
hereinafter described:
Fig. 5 is a view of the tank shown by Fig. 4 and as seen from above, the exhaust
and feed pipes hereinafter explained, being shown in section at a part near their
orifices in the tanks.
Figs. 6 and 7 are drawings in detail hereinafter described.
Similar letters and figures of reference indicate similar parts throughout the
several views.
In carrying our invention into effect we make use of closed tanks a b and c
arranged in suitable proximity with each other as shown, the tank a being used
for carrying one part of the process into effect during the time the other tank b
is being used for effecting the other part of the process as is hereinafter explained,
while the tank c acts as a receptacle for the solvent so that sufficient of this solvent
may at any time be supplied to the tanks a b from said tank c whence it is raised
by a pump at d which causes it to flow through the pipe e its entrance or admission
to the tanks a b being controlled or regulated by the valves f f respectively
when and as is or may be found necessary.
The discharging of the liquid or solvent from the tanks a b into the tank c is
effected through the pipe g, the flow of said liquid or solvent being controlled or
regulated in this direction by the valves g1 92.
Each of the tanks a and b has an appropriately formed air-pipe h leading into
the upper part of it from suitably constructed heating apparatus & (constructed as
hereinafter described) while leading also from the upper part of each of said tanks a
and b is a pipe m that conducts the air and its accompanying gases out of the said
tanks a b into apparatus n for cooling same and which acts as a condenser (its
construction being hereinafter explained). The air-pipes h are made to terminate
with the elongated orifice as shown at h¹ so that the currents of air and gases which
pass into the tanks a 6 through these pipes h, are spread over the entire width
of their said respective tanks while by the deflectors h³ (see Fig. 4) these currents
of air and gases are caused to travel horizontally as the positions of the skins o
within the tanks may necessitate in order such said currents of air may be split
up and caused to impinge on all the skins to an equal extent or degree; the
said deflector 2 being pivotted at its edge h³ and arranged so that the toothed
quadrant secured to its pivotal shaft h5 may be caused by the worm he

page_text: through the medium of the hand wheel h (see Fig. 7) to be adjusted and held
as desired to direct the currents of air and gases as described:
The lids q q² and upper coverings of the tanks a bare arranged at an angle
to the horizontal plane in order that the currents of air and gases may be
thereby constrained to gradually descend to pass more evenly into contact with
all the skins in said tanks a b.
The orifices of the pipes m are also of the elongated shape m² as shown, in order
that the currents of air and gases may maintain their full width until their final
exit from the ranks ab thus the skins o in all parts of the tanks are properly
dessicated thereby.
To carry out the process the skins or leather a arranged on frames p are placed in
suitable positions in the tanks, say the tank a, on which the solvent, which may be
petroleum, benzene etc., is raised by the pump d from the tanks c and caused to flow
through the pipe e and valve f (the valve fl being closed at this time) into the said
tank a entering said tank a and rising slowly therein, with as little agitation as it is
possible to impart to it during its said flow, until the said skins o are completely
immersed in it on which the valve f is closed and under these conditions they, said
skins, are allowed to remain the desired length of time for the degreasing action or
operation to be completed, during all this time the lid q being closed and held down
by the screws q' so that it is perfectly air-tight. On the completion of this action
the valve g in the pipe g is opened and the liquid solvent is allowed to flow from the
tank a back into the tank c.
During the actions of the solvent on the skins o in the tank a as above described,
the lid g of the tank 6 might have been opened or raised and a full complement of
skins placed in said tank b in order to be ready by its said lid being closed down and
held by its screws q³, to receive the solvent as it is now sent by the pump d through
the pipe e and valve f (the valve f on this occasion being closed) to fill said tank bas.
it had previously filled the tank a.
On all the liquids being withdrawn from the tank a as above described and while
this latter is still closed up (the valve g¹ being now closed) the exhausting or other
appropriate exhausting apparatus r is put into action so as to withdraw by evapora-
tion all the solvent that remains in the skins or leather, this solvent being thus.
caused to pass through the pipes m (the valves s and s¹ being at this time opened
while the valves are closed) to the condenser n where it is cooled down to again
assume its liquid form, whence it flows through the pipe t back into the tank c to
be there stored as will now be understood, while such of the gases that remain
after passing through the condenser n are carried by, the exhauster r forward by the
pipe into the heating apparatus k to be re-heated prior to their re-introduction
through the pipe h into the tank a where again they may impinge upon these
skins or leather. All these actions being thus performed without the solvent at
any time being exposed to the atmosphere by which means its escape and loss in
this direction are prevented.
During the process of extracting the solvent from the skins in the tank a referred
to; the skins in the other tank b will have been treated by the solvent, which is again
withdrawn through the pipe 9 by the valve. 92 being opened (at which time the
valve g will be closed) and passed into the tank c, on which the valve g² is again
closed so also are the valves ss', while the valves 23 are now opened for the actions
to be carried out in the tank b as they had been in the tank a, and so the process
may be continually repeated without loss of time by the operatives and without loss
of the solvent by evaporating into the atmosphere.
After the solvent has become saturated with the grease or fatty matter that it has
extracted or dissolved from the skins it is conducted away to distilling apparatus of
any well known description 'arranged in suitable proximity with the condenser n or
other condensing apparatus of any suitable construction from which it may flow
back to the tank c.
By arranging the apparatus as hereinbefore described the solvent can be kept at
a low temperature throughout the entire process since the heated or evaporated

page_text: portion of it is condensed prior to its being re-mixed with the other in the tank c
and this we find in practice to be of especial benefit since when the solvent becomes
heated other constituent parts of the skins in addition to the fatty matter are
dissolved out of them and so they are considerably, reduced in value. Still further
however, in order to prevent the possibility of the solvent becoming heated to too
high a temperature we arrange a coil of pipes within the tanks ab respectively.
through which we can cause cold water to flow, its admission into the respective
tanks ab being controlled by the valves 23, or instead of the pipes v₁ being
arranged in tanks ab they may be placed within the tank c in which latter they
would be enabled to act upon the solvent prior to its admission to said tanks a and b.
On the other hand we find that the air and gases that are caused to impinge upon
the skins to cause the solvent to evaporate has a better and more beneficial effect
on such skins by, being heated to a fair degree prior to being introduced hence we
have arranged our apparatus as before described to attain this result.
The heating apparatus k as shown in section by Fig. 6 consists of the chamber 2
through which pass the pipes 3 connecting the cavity 4 with the cavity 5. The
gases or air circulate within the chamber 2 entering same by the pipe w and leaving
by the pipe h, and so impinge in their passage upon the pipes 3 which are kept hot
by the circulation of steam through them from the cavity 4 which re-enters by the
pipe 6, to the cavity 5 from which it escapes by the pipe 7.
The condensing apparatus n is of similar construction to the heating apparatus k,
sizes and external shapes alone varying, however instead of steam being used, cold
water is circulated through the pipes 8 from the cavity 9 to the cavity 10 and the air
and gases pass through and impinge upon said pipes 8 within the chamber n.
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. In apparatus for degreasing leather, hides or skins, the combination of closed
tanks, means for supporting the leather, hides or skins within these tanks, means for
supplying a liquid solvent to said tanks without agitating or disturbing the leather,
hides or skins, and means for dessicating the contents of the closed tanks substan-
tially as herein specified.
2. In apparatus for degreasing leather, hides or skins, the combination of closed
tanks, means for supplying liquid solvent to said tanks, coiled or a series of pipes
arranged to allow the circulation of cold water for maintaining the solvent at a
normally low temperature, means for, condensing the solvent out of the air and
gases circulating in the closed tanks, apparatus for re-heating said air or gases and
means for propelling same substantially, as herein set forth.
3. In apparatus for degreasing leather, hides or skins, tanks having their lids or
upper surfaces at an angle to the horizontal plane, air delivery and exhaust pipes
with elongated orifices leading into said tanks and means for deflecting the currents
of said air and gases; in combination substantially as specified.
4. In apparatus for degreasing leather, hides or skins, the combination of tanks
formed as described, air conducting pipes with elongated orifices, leading into said
tanks, valves in connection with said pipes, means for deflecting the currents of air
and gases within the tanks and means for propelling said air and gases to cause same
to circulate substantially as herein specified.
5. In apparatus for degreasing leather, hides or skins, the combination of tanks,
formed as described, air conducting pipes with elongated orifices leading into said
tanks, valves in connection with said pipes, means for deflecting the currents of air
and gases within the tanks, worm and wheel gear for regulating and holding said
.deflector and fan or like propelling apparatus to cause the air and gases to circulate
substantially as herein specified.
6. In apparatus for degreasing leather, hides or skins, the combination of tanks
formed and arranged as described; a coil or series of pipes within said: tanks to
:enable the employment of cold water to cool the solvent, air conducting pipes with

page_text: elongated orifices leading into said tanks, means of deflecting the currents of air
circulating therein, propelling means for causing said air to circulate and heating
and condensing devices for acting thereon substantially as herein specified.
Dated this 3rd day of June 1897.
WILLIAM SAGAR SENIOR,
ALFRED P. SAGAR,
WILLIAM SAGAR JUNIOR,
Per Samuel Hey, Agent.