improvements in Futer Presses
Year: 1885

page_text: improvements in Futer Presses,
We SAMUEL HENRY JOHNSON and CHRISTOPHER CLARKE HUTCHINSON, Engineers
both of the Engineering Works Stratford in the County of Essex do hereby declare
the nature of our invention for "IMPROVEMENTS IN FILTER PRESSES ,, to be as
follows:-
This invention has for its object improvements in filter presses.
It has been found that when textile fabric either of vegetable or animal fibres is
the filtering medium in filter presses the durability of the material varies very
greatly according to the nature of the material operated upon in the filter press
and this is particularly the case when filter presses are employed on materials
undergoing putrefactive change especially in the case of the pressing of sewage
sludge. We have discovered that the organisins which cause putrefaction also
induce or cause the decomposition of the fibres of the textile fabric. Now the
object of this invention is the use in filter presses of filtering fabrics so prepared
as to prevent rapid destruction from this cause. With this object we prepare the
filter cloths with materials containing tannin such as those employed in commerce
for tanning hides. The material we prefer is the article known in commerce as
catechu cutch or terra japonica. The method we find convenient to employ for
this purpose is either to cover the cloths for some time with a strong solution of
tannin or it may be more rapidly and effectually accomplished by putting the
filter cloths into a closed tank or receptacle air tight then covering the material
with liquid and exhausting the air. By this means the tannin material penetrates
immediately into the finest pores and fibres on allowing the atmospheric pressure
again to establish itself within the closed receptacle.
Dated this 23rd day of June 1885
CARPMAEL & Co.,
Agents for the Applicants.

page_text: We SAMUEL HENRY JOHNSON and CHRISTOPHER CLARKE HUTCHINSON Engineers
both of the Engineering Works Stratford in the County of Essex 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:-
This Invention has for its object improvements in filter presses.
It has been found that when textile fabric either of vegetable or animal fibres is
the filtering medium in filter presses the durability of the material varies very
greatly according to the nature of the material operated upon in the filter press
and this is particularly the case when filter presses are employed on materials
undergoing putrefactive change especially in the case of the pressing of sewage
sludge. We have discovered that the organisms which cause putrefaction also
induce or cause the decomposition of the fibres of the textile fabric Now the
object of this Invention is the use in filter presses of filtering fabrics so prepared
as to prevent rapid destruction from this cause. With this object we prepare the
filter cloths with materials containing tannin such as those employed in commerce
for tanning hides. The material we prefer is the article known in commerce as
catechu cutch or terra japonica The method we find convenient to employ for
this purpose is either to cover the cloths for some time with a strong solution of
tannin or it may be more rapidly and effectually accomplished by putting the
filter cloths into a closed tank or receptacle air tight, then covering the material
with liquid and exhausting the air. By this means the tannin material penetrates
immediately into the finest pores and fibres on allowing the atmospheric pressure
again to establish itself within the closed receptacle.
In order that our said Invention may be fully understood and readily carried
into effect we will proceed to describe the drawing hereunto annexed.
DESCRIPTION OF THE DRAWING.
The
The Drawing shows an elevation of the apparatus we employ in preparing the
filter cloths; it consists of a cylindrical tank a with a closely fitting cover a¹. In
the tank the cloths to be treated are placed, they are first thoroughly washed in
water to remove all dressing from the fabric and they may be treated whilst still
moist from the washing. The tank being thus filled with fabric the cover is put
on and a liquor containing tannin is pumped in by means of the pump c.
tannin liquor known as catechu is suitable, if of good quality it will be suitable to
dilute it with twenty times its bulk of water. The liquor is admitted from a
reservoir into the trough d and from this the pump c draws it and forces it into
the tank a The liquor is pumped in until the tank is full and it runs out at the
cock e.
The cock is then closed and the pump is reversed so as to draw liquor out
of the tank and leave a vacuous space within it. The liquor so drawn out of the
tank is returned to the trough d. Air then escapes from the fabric and collects in
the void space at the top of the tank a. After a time the cock e is opened and the
tank is again filled with liquor, this is done about three or four times in the space of

page_text: about one hour. The cloths are now withdrawn and dried in the air; they are then
ready to take their places in the press. The cloths may be such as are at present
in use in filter presses usually they are of jute or cotton. The valves of the pump
are contained in the case c¹, the cock c² on the left side of the case has a hollow
plug and the space within the plug communicates with the space beneath the
suction valve of the pump. There is a port in the side of the plug of the cock c² and
this can be brought to correspond with one or other of two suction pipes c³ and c
the one leading into the tank a and the other into the trough d Similarly on the
other side of the valve casing c¹ a cock c³ serves to place the delivery side of the
pump into communication with one or other of two delivery pipes cc and c² one
leading into the tank a and the other into the trough d. g is a rope serving to
lift the cover a¹ for filling and emptying the tank.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
Our improvements in filter presses consisting in forming the filtering diaphragms
or partitions of such presses of textile fabric which has been treated with a liquor
containing tannin substantially in the manner and for the object herein setforth.
SAM
H. JOHNSON.
C. C. HUTCHINSON.
Carpmael & Co.,
Agents for the Applicants.
Dated 18 220da
Or March 1886.
SAM
H. JOHNSON.
C. C. HUTCHINSON.
Carpmael & Co.,
Agents for the Applicants.