IMPROVEMENTS IN FILTER PRESSES
Year: 1878

page_text: LETTERS PATENT to Eustace Carey Prentice, of Stowmarket, in the County
of Suffolk, for the Invention of "IMPROVEMENTS IN FILTER PRESSES."
Sealed the 31st May 1878, and dated the 2nd April 1878.
PROVISIONAL SPECIFICATION left by the said Eustace Carey Prentice at
the Office of the Commissioners of Patents on the 2nd April 1878.
EUSTACE CAREY PRENTICE, of Stowmarket, in the County of Suffolk. "IMPROVE-
MENTS IN FILTER PRESSES."
My Invention relates to filter presses of the kind in which fluid or semi-fluid
matter is subjected to pressure in one or more compartments for the purpose of
separating the fluid from the solid portions, the object of my Invention being to
simplify and cheapen the construction and working of such apparatus. For this
purpose I place one or more rings or frames (which may be wood, hooped with
iron) between end covers held together by bolts. The internal surfaces of the ends
are covered with a wire or wicker mat on which is laid suitable fabric constituting
the filtering medium.
When a number of rings or frames are placed between the end covers I interpose
between each ring or frame and the next a partition or mat consisting of wire fabric
or wickerwork covered on each side with the filtering inedium, the partition or
mat and the filtering medium which covers it being extended to the outer edges of
the rings or frames or beyond their inner edges sufficiently far to give free exit to
the liquid filtered out.
The compartments between the successive partitions may be supplied each by a
separate pipe, or they may communicate with each other by holes cut through the
partitions, the filtering material on the one side being stitched or otherwise tightly
fastened to that on the other side.
The press being charged with the matter to be operated on, pressure is applied by
pumping or otherwise, whereupon the fluid portion is caused to ooze through the
pores of the filtering medium and passes among the interstices of the wire or wicker-

page_text: work to the external peripheries of the joints between the ends and the rings or
frames where it escapes.
When the operation has been carried sufficiently far, the press is opened and the
solid matter is removed.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Eustace Carey Prentice in the Great Seal Patent Office on the 1st
October 1878.
EUSTACE CAREY PRENTICE, of Stowmarket, in the County of Suffolk. "IMPROVE-
MENTS IN FILTER PRESSES."
My Invention relates to filter presses of the kind in which fluid or semi-fluid
matter is subjected to pressure in one or more compartiments for the purpose of
separating the fluid from the solid portions, the object of my Invention being to
simplify and cheapen the construction and working of such apparatus. For this
purpose I place one or more rings or frames (which may be wood, hooped with iron)
between end covers held together by bolts. The internal surfaces of the ends aro
covered with a wire or wicker mat, on which is laid suitable fabric constituting the
filtering medium.
When a number of rings or frames are placed between the end covers I interpose
between each ring or frame and the next a partition or mat consisting of wiro
fabric or wickerwork covered on each side with the filtering medium; the partition
or mat and the filtering medium which covers it being extended to the outer edges
of the rings or frames or beyond their inner edges sufficiently far to give free exit to
the liquid filtered out.
The compartments between the successive partitions may be supplied each by a
separate pipe, or they inay communicate with each other by holes cut through the
partitions, the filtering material on the one side being stitched or otherwise tightly
fastened to that on the other side.
The press being charged with the matter to be operated on, pressure is applied by
pumping or otherwise, whereupon the fluid portion is caused to ooze through the
pores of the filtering medium, and passes among the interstices of the wire or wicker-
work to the external peripheries of the joints between the ends and the rings or
frames where it escapes.
When the operation has been carried sufficiently far, the press is opened, and the
solid matter is removed.
The accompanying Drawing represents a longitudinal section of a filter press
according to my Invention.
A number of rings A which are most cheaply and conveniently made of wood,
like the periphery of a wheel strengthened by an iron hoop B, but which may
be square or polygonal frames, if desired, are placed in a row between two strong
end covers C and D. Between each pair of the rings or frames A there is

page_text: interposed the partition E consisting of wire fabric or wickerwork covered on each
side with the filtering fabric. Through all the partitions there are holes F by which
the successive compartiments of the press communicate with one another, and at each
of these holes the two linings of filtering fabric are secured together by stitching or
otherwise, so that no liquid can reach the interstices of the wire or wicker
partition except through the pores of the filtering fabric.
When it is necessary to remove the linings for cleansing, that on the one
side of the partition can be gathered into puckers and drawn through the hole F.
Instead of wire or wickerwork, the partition between the linings may be made
of wood with a number of grooves sunk in both faces, these grooves extending
to the outer periphery, so as to give passage for liquid such as is afforded by the
interstices of the wire or wickerwork. When grooved wood is thus employed for
the partitions, each partition may be made in halves, being divided across the hole,
so that the linings can be readily separated from the partition by taking apart the
two halves of the latter.
The partitions and their linings extend to the outer periphery of the rings or
frames A, and they are clamped firmly between them by drawing the two end
covers C and D forcibly together by the bolts or by pressing them together by screws
or otherwise.
The partitions E may be supported against being bent by unequal strains on their
opposite sides by fillets or cross bars G extending across the rings or frames.
When the rings or frames A with their lined partitions E are firmly clamped
together, the fluid or semi-fluid material to be operated on is admitted into the press
by the supply pipe H; and when all the compartments are filled, pressure is applied
by a pump or otherwise, so as to cause the liquid portion of the material to ooze
through the pores of the linings, and find its way by the interstices or grooves of
the partitions to the periphery where it escapes, the solid portion being left behind
in the compartments between the partitions.
The filtration having been thus effected, the pressure is relieved, the end covers C
and D are released, the rings or frames A are separated and the blocks of solid or
pasty material loft in the successive compartments are removed. In this manner,
substances, such as sewage liquid, can be partially dried by squeezing out a large
portion of the moisture, the solid ingredients being retained in the compartments of
the press from which they are removed in blocks.
Also liquors or solutions can be thus extracted from semi-fluid substances, such
for example, as result from the treatment of phosphates with acid, or of superphos
phates with water. And generally, a filter press such as is herein described is
applicable for the separation of the liquid from the solid ingredients of various
substances, and particularly in cases where it is necessary to provide a very
extended filtering surface at moderate cost for dealing with large quantities of
material.
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I claim the construction of filter press consisting of rings or
frames separated by channelled partitions lined on both sides by filtering fabric, the
said partitions and their linings being extended to the exterior of the rings or frames
so as to allow escape of the liquid of filtration, substantially as herein described.
In witness whereof, I, the said Eustace Carey Prentice, have hereunto set
my hand and seal, this Twenty-eighth day of September, in the year of our
Lord One thousand eight hundred and seventy-eight.