Improvements relating to Filtering Apparatus for Saccharine and other Liquors.
Year: 1892

page_text: Date of Application, 9th May, 1892
Complete Specification Left, 24th Feb., 1893-Accepted, 8th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements relating to Filtering Apparatus for Saccharine and
other Liquors.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by William Price Abell, of L'Union House, Essequebo, British Guiana
and Tooley Park, Hinckley, England, Whitworth Scholar and Engineer) to be as
follows:-
This invention relates to improvements in apparatus for filtering thick, muddy
and glutinous liquids such as sugar liquor subsidings, and has for its chief object to
provide means whereby a large self-clearing continuous working filtering surface is
afforded in a comparatively small space.
In carrying out my invention as applied to a filter press I employ a hermetically
closed vessel of any suitable form provided with a number of filtering plates
or diaphragms wrapped in filtering cloths or other suitable filtering medium.
Through the centre of these plates or diaphragms, passes a shaft carrying a
series of arms or scrapers one of which revolves between each pair of adjacent
plates. The liquor to be filtered percolates through these plates in the usual
manner but instead of the spaces between the plates becoming choked with the
residue it is scraped away by means of the arms while working the residue or thick
deposit dropping onto a screw, plunger or other suitable conveyor which carries it
to an outlet through which it passes either in an unconsolidated condition or into
the ordinary plate filters to be caked.
For operating the scrapers I employ a ratchet wheel worked by the pump
supplying the filter.
In some cases the scrapers are fixed and the filtering diaphragms are revolved the
shaft carrying them having an outlet at one end or the scrapers may be caused to
reciprocate.
When I apply my invention to bag or stocking filters I cause a ring scraper to
traverse and clean their whole length while working.
Dated the 9th day of May 1892.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to Filtering Apparatus for Saccharine and
other Liquors.
I, GEORGE FREDERICK REDFERN, of the firm of G. F. Redfern & Co., The
General Patent Office, No. 4, South Street, Finsbury, in the County of Middlesex,
Patent Agents, do hereby declare the nature of this invention (a communication
to me by William Price Abell, of L'Union House, Essequebo, British Guiana
and Tooley Park, Hinckley, England, Whitworth Scholar and Engineer) and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
This invention relates to improvements in apparatus for filtering thick, muddy
and glutinous liquids such as sugar liquor subsidings, and has for its chief object

page_text: to provide means whereby a large self-clearing continuous working filtering surface
is afforded in a comparatively small space.
In carrying out the invention as applied to a filter press I employ a hermetically
closed vessel of any suitable form provided with a number of filtering plates or
diaphragms wrapped in filtering cloths or other suitable filtering medium.
Through the centre of these plates or diaphragms passes a shaft carrying a
series of arms or scrapers, one of which revolves or is reciprocated between each
pair of adjacent plates. The liquor to be filtered percolates through the surfaces
of these plates in the usual manner but instead of the spaces between the plates
becoming choked with the residue it is scraped away by means of the arms while
working, the residue or thick deposit dropping onto a screw, plunger or other
suitable conveyor which carries it to an outlet through which it passes. If the
residue be required to be caked, it is passed through an ordinary plate filter.
For operating the scrapers I employ a ratchet wheel worked by the pump
supplying the filter.
In some cases the scrapers are fixed and the filtering diaphragms are revolved,
the shaft carrying them having an outlet at one end.
To enable my invention to be fully understood I will describe how it can be
carried into practice by reference to the accompanying drawings, in which :-
Figures 1 and 2 are respectively a side and end elevation of a filter-press con-
structed according to my invention :
Figures 3 and 4 are respectively longitudinal sections of the left and right hand
ends of the apparatus:
Figure 5 is a transverse section on the line 5-5, Figure 1:
Figure 6 is a longitudinal section drawn to an enlarged scale of one of the outlet
nozzles hereinafter described; and,
Figure 7 is a plug or valve adapted to fit within the same:
Figure 8 is an elevation shewing my filter-press arranged in combination with a
pump for supplying the liquor to be filtered, and an ordinary plate filter-press for
caking the residue :
.
Figure 9 is a longitudinal section of a modified form of my filter-press; and,
Figure 10 is a transverse section of the same on the line 10-10, Figure 9.
Similar reference letters indicate similar or corresponding parts throughout the
drawings.
a is the hermetically closed vessel provided with the inlet pipe 6 for the liquor
to be filtered, outlet nozzles c, c for the filtered liquid and an outlet d for the
residue. e, e are the filter plates or diaphragms arranged side by side in the said
vessel and wrapped in filtering cloth or other suitable filtering medium. The said
plates are each formed with two lugs e, e¹ through the medium of which they are
supported on ledges e, in the vessel a, the outlet e from each plate passing
through one of the lugs e¹, e' to one of the outlet nozzles c, c, one of which is shewn
detached in Figure 6. Each of the said nozzles is provided with a screw-valve c¹
and passes through a stuffing box f (having packing rings f¹, f) on one side of the
vessel a and into one of the outlets e, a packing ring being employed to make a
joint therein. f, fare bolts for tightening the nozzles against the rings f¹,f*,f³,
and is a trough into which the nozzles c, c discharge.
g, g are the arms or scrapers for the filter plates, the said arms or scrapers
being mounted on the shaft h, the said shaft being carried in bearings h', h¹ and
passing through an opening or slot in each of the plates e. One of the said
arms or scrapers revolves between each pair of plates and in close proximity
thereto, as clearly indicated in Figures 3, 4 and 5.
i is the screw conveyor (or a plunger can be used) arranged longitudinally
beneath the plates in bearings, , the said screw being rotated by means of a
ratchet wheel and pawl j. k is a pump for forcing the liquor to be filtered
through the press, as clearly indicated in Figure 8. The said pawl is mounted on
a lever loose on the shaft of the conveyor i and operated preferably from the

page_text: pump k through the medium of a rod m from a lever n connected to any recipro-
cating part of the pump, such as the piston or valve rod. Movement is transmitted
to the shaft h from the conveyor shaft by the spur-wheels o, o'. Or the conveyor
shaft may obtain its movement from the shaft h, in which case the said latter shaft
is extended outside the vessel a and the ratchet wheel; applied thereto.
By this construction it will be seen that the liquor to be filtered percolates
through the surfaces of the plates e, e in the usual manner, but instead of the spaces
between the plates becoming choked with the residue, the latter is scraped away by
means of the arms or scrapers g, g and falls onto the conveyor by which it is
conveyed to the outlet d through which it passes to an ordinary plate filter
(Figure 8) if it be required to be caked; or it may be simply discharged and left
in the unconsolidated condition.
To enable the filtering cloths to be cleaned I provide a channel q longitudinally
of the vessel a aud communicating with the interior of the nozzles c, c by holes q¹, 9',
the inlet to the said channel being governed by a valve r. By closing the outlet
valves c', c' and the inlet valve 61 and opening the valve clean water can be passed
into the channel q and through the filter plates and cloths in the reverse direction
to that taken by the filtered liquid.
+
In case any one of the filter plates should become defective I provide a screwed
plug or valve s, Figure 7, adapted to screw within the female thread of the nozzle c
of the defective plate so as to fit against a seating s' and prevent the unfiltered
liquor from passing through the said plate into the channel 2 and through the outlet
nozzle in connection with the said plate.
Instead of revolving the arms or scrapers they can be oscillated or reciprocated.
In the modified form of filter press shewn in Figures 9 and 10 the filter plates
are constructed of corrugated discs t, t enveloped in filter cloths and clamped side
by side (with distance pieces or washers t¹ between them) on a bar น, which bar
may be advantageously fluted or of the section shewn in Figure 10 so that the
filtered liquor will pass away from the corrugations of the plates to the outside of
the filter through the hollow shaft v, which shaft, together with a shaft vt serves to
clamp the filter plates together, the said shafts being carried in bearings at the ends
of the vessel a. , are openings connecting the corrugations of the discs t, t
with the flutes on the bar u. The arms or scrapers g in this case are fixed as shewn
clearly in Figure 10. Instead of the bar u a hollow shaft can be employed.
For cleaning the filter cloths in this arrangement I provide a hollow screw-
threaded shaft w passing through a nut w' in a branch pipe w and in axial alignment
with the hollow shaft v. The shaft to has its end w³ so formed that when it is
rotated by the wheel it will seat itself against the open end of the shaft v.
When in this position by opening a cock a clean water can be allowed to flow
through the pipe w³, shafts w and v and through the filter plates.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that
what claim is :-
1. In a filter of the kind in which filter plates are employed, scrapers or arms
working over and removing the residue from both sides of the said plates whilst the
filter is in operation, substantially as described.
2. A filter comprising one or a series of revolving filter plates in combination
with fixed scrapers for removing the residue, substantially as described.
3. A filter comprising one or a series of corrugated filter plates or discs revolving
in the fluid to be filtered and covered with a porous or filtering medium, the said
plates or discs being mounted on a fluted bar or hollow shaft for conducting the
filtered liquor outside the filter in combination with fixed scrapers, substantially as
described.
4. The improved filtering apparatus hereinbefore described and illustrated in
Figures 1 to 8 of the accompanying drawings.

page_text: 5. The modified form of filtering apparatus hereinbefore described and illustrated
in Figures 9 and 10 of the accompanying drawings.
Dated the 24th day of February 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.