Improvements in or appertaining to Apparatus for. Filtering Saccharine or other Liquids, and Method of Working the same.
Year: 1892

page_text: Date of Application, 12th Mar., 1892
Complete Specification Left, 12th Dec., 1892-Accepted, 21st Jan., 1893
:
.**
PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Apparatus for. Filtering
Saccharine or other Liquids, and Method of Working the same.
We, THOMAS OGILVY EASTON and ALEXANDER WATT, both of 34 Moorfields
in the City of Liverpool, Sugar Refiner and Analytical Chemist respectively and
JAMES BUCHANAN the Younger, of Caledonian Foundry in the City of
Liverpool, Engineer, do hereby declare the nature of this invention to be as
follows:-
Bag filters, such as those known as Taylor's filters, in use at the present time,
consist of a casing or tank, generally rectangular in form, having a fixed top plate
jointed on to a flange usually projecting from the inside surface of the casing at a
lower level than the top of the casing, thus forming a shallow upper tank into which
the sugar or other liquor to be filtered is run. A series of bags open at one end and
closed at the other is fastened on to nozzles or "bottles," as they are technically
termed, which bottles are secured into the fixed top plate itself, or into nats, fixed
into the top plate; the bags are in this way suspended vertically with the closed
end down, in the interior of the chamber or casing, and the liquor run into the top
or shallow tank then runs through the openings in the bottles and filters through
the bags. The casings are provided with manholes or doors for access to the
interior of the chamber, and for the purpose of fixing in position the nozzles with
clean bags attached, and also for removal of the same when the filter has finished
operation, and requires replenishing with clean bags for succeeding operations.
The disadvantages, of this system are numerous, and obvious, taking a long time
After a
to filter the liquor, besides being severe and laborious work for the men.
time, the bags become inoperative from their pores being choked, and the filtering
surface of the bags being quickly, reduced, and towards the end, even before the
bags are quite choked, the liquor only filters through very slowly, and eventually
the supply of the liquor has to be stopped. The pores of the bags being choked,
the liquor will not filter out, and a large quantity of unfiltered liquor remains in the
bags.
i
At present, in order to drive out the remaining liquor, hot water is run into the
top tank and into the bags, but it takes a long time, and requires a very large
quantity of hot water to drive out the remaining liquor, and the resultant liquor is
so dilute as to greatly deteriorate the 'product and increase the cost of obtain-
ing it.
Now our invention is designed to obviate these evils generally, to largely increase
the quantity of liquor filtered through an equal number of bags, or equivalent
filtering surface, in a given time, to use a less quantity of hot water, to save dilution
of the liquor, thus preventing deterioration of the product, facilitate the operations
of working the filters, economise space, reduce manual labour, and to expeditiously
transfer the unfiltered liquor remaining in the bags into the chamber of the filter in
use, or into another filter direct, or into a suitable tank or vessel provided for the
purpose, without dilution of the liquor, in which it can be re-treated and
subsequently pumped or run out again for subsequent filtration.
In place of the ordinary filter casing with a fixed and jointed bottle plate as
before described, we use a casing or chamber, preferably rectangular in shape, (to
economise space over a circular or other shape) having a portable top or bottle
plate made in the form of a shallow tank which rests on the top edges of the casing
or machined surfaces only, or the edges of the casing may be provided with a groove
'

page_text: into which is fixed india rubber or suitable material to make a steam tight joint, or
a projection may be cast or fixed on the underside of the portable top, entering a
groove in the top edges of the casing sealed with. water or liquor. In the former
case, the portable top may rest only by its own weight or may be held down by
hinge bolts or other fixings, if preferred. The portable top is also provided with
projections to guide the top into its correct position, and has screwed openings or
screwed, nuts, fitted in for the attachment of the bottles, in the manner hereafter
described.
One, of
In place of the ordinary bags closed at one end and fastened to the bottle at the
other, we use bags of about twice the length (enclosed in the usual form. of sheath
also about twice the length) and having a bottle; fastened at each end.
these bottles is attached to the top in the usual manner, the other end is attached to
the top by screwing, (or otherwise, fastening) on to the neck of the bottle,,a tube
from the top side, which tube has a conical end to fit and joint into a conical hole.or
nut, in the plate, and which tube rises above the level of the bottom of the top plate,
or, shallow tank, consequently above the level of the liquor, which is regulated by
an,overflow, and acts as a nut to hold the bottle in its place, without the bottle being
screwed into the plate..
!.
The bag fixed in this manner forms a loop, and the advantage of this arrangement
is that, when the liquor is run into the shallow tank in the first instance, it enters
the bags through the opening not provided with the tube, consequently, the air can
at once rapidly escape through the other opening to which the tube is attached
above, the level of the liquor in the tank and no liquor enters through the end of
the bag to which this tube is attached.
By this means, the liquor descends through the one half of the looped bag and
ascends the other half, until it reaches its own level; moreover, as the liquor to be
filtered passes down one side or half of the looped bag and up the other; the tendency
is for the slimy matter, which chokes the pores of the filtering bags, and retards
filtration, to deposit on the down half of the bag and at the bottom, and so leave the
up bag comparatively clean, and consequently a greater quantity of liquor is filtered
through equal surface. and in a given time.. When the filter has been running such
a length of time as to make it practically inoperative for the purpose of efficient and
economic filtration, the discharge valve or cock in the bottom of the casing, which
runs the filtered liquor into a gutter or pipe, can be shut off, and, by screwing off
the tube, one end of the bag will at once fall down and allow the unfiltered liquid
contents to escape into the filter chamber, from which it can be run off by another
outlet into a pipe or gutter leading to a suitable. receptacle or tank provided for the
purpose. The result is our bags begin filtering and are emptied of the unfiltered
liquor at the end of the operation, in an extremely short time. The other
advantages previously described are obtained by filling the casing with hot water.
The sweet or sugar liquor can be washed 'out with a small quantity of water, prior
to the bags going to the final washing or scum, room.; or the bags may be emptied
of their contents, and washed as hereafter described.
The mode of working the apparatus may, be described as follows:-
The filters generally stand on a floor in rows (or may he suspended, as positions
demand) touching each other at the top and jointed together between the rows, a
second flooring of metal trays or flat troughs is arranged near the top of the filter
casings, covering the entire space not occupied by the filters. This flooring or
troughing preferably slopes slightly to the end where the washing apparatus is
placed, and is arranged so that it can be washed down into the latter or into a
liquor tank and thus spilling on the floor is prevented and the splashes and drips
are recovered.
J. 1 *
Above the rows of filters is placed a travelling crane or other equivalent
arrangement for the purpose of lifting off and on the portable tops from the
casings of the filters, and for conducting the operations of working, as will be here-
after described.

page_text: At the beginning of the operations, the shallow tank forming the top of the filter
is placed in a convenient position by the crane, the bags are attached thereto, the
first row of holes being supplied with bottles screwed in, in the usual way; and to
the next row,
the other bottles of the same set of bags are attached by screwing
the tube on to the top of the bottle from the top side of the shallow tank. This is
continued until the entire sets of bags are fixed in position.
The cover or top of the filter with all its bags attached is now carried by the
travelling crane and lowered into position on the top of the filter casing, the
machined surfaces or the india rubber joint or seal making it tight.
The crude liquor is then run into the shallow tank and descends through the
opening into the bags to which no tubes are attached; at the end of the filtering
operation the tubes are screwed off the bottles at the other end, and the 'bags fall
down, into the chamber as before described.
The filter top is then attached by chains to the travelling crane, and hoisted off
the casing, the bags hanging down vertically discharging their contents into the
casing of the filter as before described. To effect this and to raise the now
unlooped bags to a height free from the casing, the travelling crane has
preferably a lift a little more than twice the height of the filters, and the filter top
with the bags hanging from it is carried away to the washing room by the aforesaid
travelling crane.
When the top and bags are travelling over the other filters, to prevent drippings
from the bags falling into another filter in operation, a tray is placed on the next
filter to the one being emptied; the top and bags when raised are travelled over
this tray, which is then hooked to the top already suspended from the crane and
the whole travelled to a liquor tank into which is emptied the thick liquor in the
tray. The top and bags then pass on to the washing tank. By this arrangement,
the tray retains the drippings from the bags while passing over the other filters,
and thus liquor of inferior class is prevented from falling into the other filters,
which might be working a superior class of liquor.
A slight variation of the method of working and of emptying the unfiltered
liquor from the bags producing the same results in even a more perfect manner and
applicable where the head room is somewhat deficient,
as follows:
-
The top with the bags looped up may be lifted out of the filter casing and
travelled by the crane over another filter, the tubes being unscrewed, the bags fall
down, and discharge their contents directly into the shallow tank of this filter,
which is in operation, the top is then lifted, the tray attached as before described
and the whole travelled to the washing room; or
The top with the bags looped up may be lifted out of the filter casing, and, with
or without the tray attached, travelled by the crane over a liquor tank, into which
the bags would be lowered, the tubes being unscrewed, the ends of the bags fall
down, and the thick liquor emptied into the tank.. The top is then hoisted up and
travelled over another tank, where the liquor would be washed out of the bags,
prior to their subsequent removal to the scum room.
The bags, instead of being attached to the top as before described, forming a
single loop, may be of longer length and have multiple loops, the inlet of the
liquor and the tube end, as before described, being common to the lot, or again,
instead of the bags being looped up as before described, single length bags may be
used, open at both ends, the upper end fastened to a bottle and attached to the top
or shallow tank by the tubes being screwed on from the top side, and the lower end
fastened on to a nozzle or bottle attached to a pipe or even a shallow box, this pipe
or box being common to a row of bags.
The upper end, of one of the bags would be attached by the bottle to the top in
the usual way, and thus form the inlet for the unfiltered liquor which would pass
down this bag into the canal or pipe to which it is attached at the bottom, which
pipe would supply all the other bags with liquor, the liquor ascending these said
bags to a common level. By unscrewing a plug at either end; or other equivalent
means, the unfiltered liquor can readily be emptied out of all the bags into the

page_text: casing, into the tray, directly over another filter into the tank of the next filter, or
into a tank separately provided for the purpose.
Dated this 11th day of March 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in or appertaining to Apparatus for Filtering
Saccharine or other Liquids, and Method of Working the same.
We, THOMAS OGILVY EASTON and ALEXANDER WATT, both of 34 Moorfields,
in the City of Liverpool, Sugar Refiner and Analytical Chemist, respectively, and
JAMES BUCHANAN the Younger, of Caledonian Foundry, in the City of Liverpool,
Engineer, 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 :-
Bag filters, such as those known as Taylor's filters, in use at the present time,
consist of a casing or tank, generally rectangular in form, having a fixed top plate
jointed on to a flange usually projecting from the inside surface of the casing at a
lower level than the top of the casing, thus forming a shallow upper tank into
which the sugar or other liquor to be filtered is run. A series of bags open at
one end and closed at the other is fastened on to nozzles or "bottles," as they are
technically termed, which bottles are secured into the fixed top plate itself, or into
nuts, fixed into the top plate; the bags are in this way suspended vertically with
the closed end down, in the interior of the chamber or casing, and the liquor run
into the top or shallow tank then runs through the openings in the bottles and
filters through the bags. The casings are provided with manholes or doors for
access to the interior of the chamber, and for the purpose of fixing in position the
nozzles with clean bags attached, and also for removal of the same when the filter
has finished operation and requires replenishing with clean bags for succeeding
operations.
The disadvantages of this system are numerous and obvious, taking a long time
to filter the liquor, besides being severe and laborious work for the men. After a
time, the bags become inoperative from their pores being choked, and the filtering
surface of the bags being quickly reduced, and, towards the end. even before the
bags are quite choked, the liquor only filters through very slowly, and eventually
the supply of the liquor has to be stopped. The pores of the bags being choked,
the liquor will not filter out, and a large quantity of unfiltered liquor remains
in the bags.
At present, in order to drive out the remaining liquor, hot water is run into the
top tank and into the bags, but it takes a long time and requires a very large
quantity of hot water to drive out the remaining liquor, and the resultant
liquor is so dilute as to greatly deteriorate the product and increase the cost of
obtaining it.
Now our invention is designed to obviate these evils generally, to largely
increase the quantity of liquor filtered through an equal number of bags, or
equivalent filtering surface, in a given time, to use a less quantity of hot water, to
save dilution of the liquor, thus preventing deterioration of the product, facilitate
the operations of working the filters, economise space, reduce manual labour, and
to expeditiously transfer the unfiltered liquor remaining in the bags into the
chamber of the filter in use, or into another filter direct, or into a suitable
tank or vessel provided for the purpose, without dilution of the liquor, in which
it can be re-treated and subsequently pumped or run out again for subsequent
filtration.
Referring to the drawings
:-
Kuro 1 is an elevation partly in section of an apparatus :

page_text: Figure 7, plan view partly with cover removed of the filter:
Figure 8, an alternative arrangement of filter; and
Figure 9, sectional view of a bag and its attachment.
A A, are a series of filtering chambers arranged preferably in two rows, side
by side:
B B, shallow tanks above these filters, the bottoms of which tanks consist of the.
bottle plates:
C, a tray sometimes used hooked on to the top tank when transporting a tank
with all its tubes attached to it over the line of filters, this tray C being employed
to catch the drip from the bags and prevent them falling into the various filters
en route:
DD, the filtering bags:
E E', the bottles :
F, a travelling crane running on a rail road suspended from the ceiling by
brackets G:
H. metallic troughs, placed between lines of filtering chambers and between
them and the walls, acting both as a floor and to catch any splashings or drip.
This floor is preferably arranged with a slight downward slope to the end where.
the washing tank is situated.
The tank B, having for its bottom the bottle plate b, shown in detail in Figures 3, 4-
and 5, rests on the top edges of the casing A. Preferably, however, we groove the
top of the casing with longitudinal groovings and thereon fix an india rubber plate 1,.
having a longitudinal ridge on the top as shown.
j
Casing A is fitted, at the corners, with swivelling eye bolts J to tighten down
the tank B in place, and tank B is fitted with eye bolts in order to be more easily
suspended to the travelling crane.
The object of the india rubber plate is to form a syrup-tight seal. It is,..
however, not indispensable, and, in place of this arrangement, the top tank B could
be provided with projections to guide it into its correct position, and could simply
rest on the chamber A. In place of the ordinary bags closed at one end and
fastened to the bottle at the other, we use bags D. Figures 1 and 3, about twice
the length, enclosed in the usual form of sheath, which is also about twice the
ordinary length and has a bottle E E' fastened at each end. One of these
bottles E is attached to the top in the usual manner, the other E' is attached to.
the top by screwing or otherwise fastening on to the neck the tube K, from the top
side, which tube has a conical nut to fit and joint into a conical hole or cut in the-
bottom plate of tank B. This tube rises above the level of the liquor in the
shallow tank B, which is regulated by an overflow. The tube acts as a nut to hold
the bottle in its place without the bottle being screwed into the bottom plate of
tank B.
It will be obvious that this device could be varied in numerous ways; thus the-
tube could be fixed and the bottle unscrewed by means of a key, or the tube
could be a continuation of the bottle.
The bag fixed in this manner forms a loop, and the advantage of this arrange--
ment is that, when the liquor is run into the shallow tank in the first instance, it
enters the bags through the opening not provided with the tube, consequently, the
air can at once rapidly escape through the other opening to which the tube is.
attached above the level of the liquor in the tank and no liquor enters through the
end of the bag to which this tube is attached.
By this means, the liquor descends through the one half of the looped bag and
ascends the other half, until it reaches its own level; moreover, as the liquor to.
be filtered passes down one side or half of the looped bag and up the other, the
tendency is for the slimy matter, which chokes the pores of the filtering bags and.

page_text: retards filtration, to deposit on the down half of the bag and at the bottom, and so
leave the up bag comparatively clean, and, consequently, a greater quantity of
liquor is filtered through equal surface in a given time. The bags can also be
arranged in a group with one or more inlets for liquor, the remaining bags all
forming ascension filters as shown in Figures 8 and 9 and hereafter described.
When the filter has been running such a length of time as to make it practically
inoperative for the purpose of efficient and economic filtration, the usual discharge
valve or cock in the bottom of the casing, shown at S in Figure 8, which runs the
filtered liquor into a gutter or pipe, can be shut off, and, by screwing off the tube,
one end of the bag will at once fall down and allow the unfiltered liquid contents
to escape into the filter chamber, from which it can be run off by another outlet
into a pipe or gutter leading to a suitable receptacle or tank provided for the
purpose. The result is our bags begin filtering and are emptied of the unfiltered
liquor at the end of the operation in an extremely short time. The other advan-
tages previously described are obtained by filling the casing with hot water. The
sweet or sugar liquor can be washed out with a small quantity of water prior to the
hags going to the final washing or scum room; or the bags may be emptied of
their contents, and washed as hereafter described.
The mode of working the apparatus may be described as follows-
The filters generally stand on a floor in rows (or may be suspended, as positions
demand) touching each other at the top and jointed together between the rows,
the second flooring of metal trays H or fat troughs is arranged near the top of the
filter casings, covering the entire space not occupied by the filters. This flooring
or troughing preferably slopes slightly to the end where the washing apparatus is
placed, and is arranged so that it can be washed down into the latter or into a
liquor tank and thus spilling on the floor is prevented and the splashes and drips
are recovered.
The travelling crane F above the filters is employed for lifting the portable
tops off and on the casings A, and, when these double bags are used, the crane
should be of sufficient height above the filter to allow the tank, a set of double
bags with their ends released, and a tray C, hooked on to the bottom of these bags,
to clear the filters.
In the drawing, Figure the bags are shown already lifted up, ready to com-
mence operations, the tray C being shown in dots, and another shown in full on
the top of filter B.
At the beginning of the operations, the shallow tank, forming the top of the
filter, is placed in convenient position by the crane, the bags are attached thereto,
the first row of holes being supplied with bottles screwed in, in the usual way;
and, to the next row, the other bottles of the same set of bags are attached by
screwing the tube on to the top of the bottle from the top side of the shallow
tank. This is continued until the entire sets of bags are fixed in position.
The cover or top of the filter, with all its bags attached, is now carried by the
travelling crane, as shown in Figure 1, and lowered into position on the top of
the filter casing, the machined surfaces or the india rubber joint or seal making
it tight.
The crude liquor is then run into the shallow tank and descends through the
opening into the bags to which no tubes are attached; at the end of the filtering
operation, the tubes are screwed off the bottles at the other end, and the bags fall
down, into the chamber as before described.
The filter top is then attached by chains to the travelling crane and hoisted off
the casing, the bags hanging down vertically discharging their contents into the
casing of the filter as before described..
The filter top with the bags hanging from it is carried away to the washing room
by the aforesaid travelling crane.
Previous to its being carried away, however, the tray C is suspended by chains
to the tank B immediately under the lower bottles, so as to catch the drip and
prevent the latter from falling into. the other tanks while travelling over these.

page_text: The whole is then travelled over the other tanks B, and the thick liquor in the
tray emptied into a liquor tank, the top and bags then pass on to a washing tank.
In some cases, however, in place of allowing the bags to empty into their own
case A, the top with the bags looped up is lifted out of the filter casing and
travelled by the crane over another filter, the tubes are then unscrewed and the
bags fall down and discharge their contents into the tank B of this second filter,
the top is then still further lifted, the tray attached, as before described, and the
whole travelled to the washing room; or the top with the bags looped up may be
lifted out of the filter casing, and, with or without the tray attached, travelled by
the crane over a liquor tank into which the bags would be lowered, the tubes
being unscrewed, the ends of the bags falling down, and the thick liquor emptied
into the tank. The top is then hoisted up and travelled over another tank where
the liquor would be washed out of the bags prior to their subsequent removal to
the scum room.
The bags, instead of being attached to the top, as before described, at each
end only, forming a single loop, can be of longer length and have multiple loops,
the inlet of the liquor of the tube end, as before described, being common to
the lot.
Figures 8 and 9 show the arrangement of bags in a group.
The bags, instead of being attached to the top, as before described, at both
ends, forming a loop, are attached at one end only to the top and their lower ends
fastened to bottles m attached to a pipe N at the bottom. In this case, the liquor
enters the end bag D' or possibly two end bags, the bottles of the remaining bags
having the pipes K on top so as to prevent the liquor entering them. By this
means, all but one or two bags in a row receive the liquor at their lower ends from
their bottles on the pipe N, the liquor ascending these bags to a common level.
By unscrewing a plug P at their end, the whole of these bags can be discharged
at a single operation into the tank B of the next filter, or into any other tank
that may be desired.
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. A bag filtering device comprising a filtering chamber and a series of
substantially U-shaped bags or bags joined at bottom by a liquid passage, the
upper extremities of said bags being provided respectively one or more with an
air escape passage, the other or remainder with an inlet for the liquid substantially
as described.
2. The process of bag filtration of sugar syrup and the like which consists in
causing the liquor to descend to the bottom through one portion of the system and
rise up and the air escape through another portion of the system, whereby the
bags are more rapidly filled and, as regards the portion through which the liquor
rises, its pores continue open and it is capable of rapid filtration for a longer period.
3. The combination of a bag filter of the type set forth in Claim 1 with means
for hoisting up the top of the filter with all the bags attached and travelling it
over the other filters to the washing tank, means for intercepting the drip and
means for emptying the bags while still suspended from the filter top, substantially
as described.
4. The arrangement of filters placed side by side with double floors substantially
as described and illustrated in Figures 1 and 2.
5. The special arrangement and construction of bag filters substantially as
described and illustrated in Figures 3, 4 and 5 and in 8 and 9 respectively.
Dated this 10th day of December 1892.
WM. P. THOMPSON & Co.,
Of Liverpool, Manchester, Nottinghan, and London, Patent Agents.