IMPROVEMENTS IN BAG FILTERS AND IN THE MEANS OF CLEANSING THE SAME
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I EDWARD PERRETT of 8 Victoria Chambers in the City of Westminster Civil
Engineer do hereby declare the nature of my said invention for IMPROVEMENTS IN
BAG FILTERS AND IN THE MEANS OF CLEANSING THE SAME to be as follows:-
My Invention relates to improvements on a former Invention in respect of which
I obtained Letters Patent dated the 22nd August 1882 No 4028 and it has for
its object the production of a bag filter in which the cleansing is more readily
effected and in a simpler manner than beretofore..
In carrying out my Invention in order to effect this object I so arrange the
filter that the process of filtration shall take place from the exterior to the interior
of the filter bags, that is to say, I introduce the fluids to be operated on outside
the bags the sides of each of which are allowed to close against and mutually
support each other without any internal distending plate or body, the filtered
liquid passing off from the inside. For this purpose I suspend the bags from a
plate or piston capable of reciprocating motion and attach them at their lower ends
to suitable "bells" or nozzles carried on a fixed plate, the whole heing contained in
a suitable vessel, in which the piston is capable of moving. In the process of
filtration the fluid to be filtered is introduced into the said enclosing vessel, and
passes through the sides of the several bags leaving its impurities adhering to the.
outside of the bags, the clear liquid escaping through the lower "bells" or nozzles.
When it is required to cleanse the bags water or other suitable clean liquid is let.
into the case and the piston being put in reciprocating motion from without by
means of hand power, a steam cylinder directly attached or other suitable method,
the dirt on the outside of the bags is disturbed and run off with the water or other
cleansing liquid. The cleansing operation may be expedited by the simultaneous
introduction of air or other elastic fluid under pressure into the interior of the bags
which distends them and escapes through the interstices of the bags during the
operation of cleansing.
.

page_text: COMPLETE SPECIFICATION.
I EDWARD PERRETT of 8 Victoria Chambers in the City of Westminster Civil
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
BAG FILTERS AND IN THE MEANS OF CLEANSING THE SAME," and in what manner
-the-same-is-to-be-performed,-to-be-particularly-described_and_ascertained_in_and_
by the following statement:
My Invention relates to improvements on a former invention in respect of which
I obtained Letters patent dated the 22nd August 1882 No 4028 and it has for its.
object the production of a-bag-filter-in-which-the-cleansing is effected more readily
and in a simpler manner than heretofore.
In carrying-out-my-Invention in order to effect-this-object, I-so-arrange-the-
filter that the process of filtration shall take place from, the exterior, to the interior
of the filter bags, that is to say, I introduce the liquids to be operated-on-outside
the bags the sides of each of which are allowed to close against and mutually,
support each other without any internal distending plate or supporting body, the
filtered liquid passing off from the inside. For this purpose, I suspend the bags,
from a plate or piston capable of reciprocating motion, and attach them at their
lower ends to suitable "bells" or nozzles carried in a fixed plate, the whole_being
contained in a suitable vessel in which the piston is capable of moving. In the
process of filtration, the liquid to be filtered is introduced into the said enclosing
vessel and passes through the sides of the several bags leaving its impuritics
adhering to the outside of the bags, the clear liquid escaping through the lower
bells" or nozzles. When it is required to cleanse the bags, water or other suitable
liquid is let into the case and the piston being put in reciprocating motion by
means of hand power, a steam cylinder directly attached or other suitable method,
the dirt on the outside of the bags is disturbed and run off with the water or other
cleansing liquid. The cleansing operation may be expedited by the simultaneous
introduction of air or other clastic fluid under pressure into the interior of the bags,
which distends them and escapes through the interstices of the bags during the
operation of cleansing.
And in order that the said Invention may be perfectly understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the accompanying sheets of drawings the same letters of
reference indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings reprosents a vertical section of a filtering
apparatus constructed and arranged according to my said, Invention, a steam
cylinder being represented as employed for imparting motion during the cleansing
operation to the plate or piston from, which the filter bags are suspended.
Figures 2 and 3 are similar views illustrating arrangements in which air or other
elastic fluid under pressure acting directly on the said plate or piston is used for
a like purpose to the steam cylinder shewn in Figure 1 a special sack or flexible
chamber being employed in the arrangement Figure 2 for the reception of the
elastic fluid, whilst in the modification Figure 3 the bags themselves are. utilized

page_text: for the reception of the elastic fluid which imparts motion to the plate or pistori
during the cleansing operation.
A are the filter bags which are suspended by means of screw nozzles a from a
plate or piston B capable of reciprocating motion, and are attached at their lower
ends to nozzles b screwed to a fixed plate C, the whole being contained in a
vessel D in which the plate or piston B is capable of moving.
In the process of filtration the plate or piston B is maintained in its elevated
position shown in the drawings and the liquid to be filtered is introduced into the
vessel D at o and passes through the sides of the several bugs leaving its impurities
adhering to the outside of the bags, the clear liquid escaping through the nozzles b
into a chamber d and being run off at e.
The process of filtration thus takes place from the exterior to the interior of the
filter bags, the liquids to be operated on being introduced outside the bags, the
sides of each of which are allowed to close against and mutually support each other
as shewn in Figure 1 and 2 without any internal distending plate or supporting
body, and the filtered liquid passing off from the inside.
When it is requiried to cleanse the bags, the cocks at ce are closed and water or
other suitable liquid is let 'into the vessel D, and the plate or piston B being put in
reciprocating motion the dirt on the outside of the bags is disturbed and run off
with the water'or other cleansing liquid.
In the drawings, I have represented the pipe E which conveys the cleansing
liquid to the filter as connected by a cock with the interior of the vessel D and
by a cock g with the chamber d, so that such cleansing liquid may, if desired,
obtain access to both the outside and inside of the bags, the waste liquid or "wash-
out" carrying away the impurities which adhered to the outside of the bags, being
run off at h.
F, G, represent a pipe and cock for the introduction of air or other elastic fluid
under pressure into the interior of the bags, which expedites the cleansing
operation by distending the bags and escaping through their interstices during the
operation of cleansing.
The reciprocating motion of the plate or piston may be obtained in various ways
several of which I have illustrated in my drawings.
In Figure 1 I have shewn a single acting steam cylinder H as fitted over the
filtering apparatus with the rod k of its piston I directly attached to the plate or
piston B from which the filter bags are suspended. By the act of operating the
valve K, steam is admitted beneath the piston I so as to raise the same with the
plate or piston B and is then exhausted, the plate or piston descending again by
gravitation.
Figures 2 and 3 illustrate arrangements in which air or other elastic fluid under
pressure acting directly on the plate or piston B is employed for raising the same,
the return stroke of the plate or piston being effected by gravitation as before.
In the arrangement Figure 2 a special sack or flexible chamber L is employed, into
which the air or other elastic fluid under pressure is introduced through a cock G',
whilst in the arrangement Figure 3, the air or other elastic fluid under pressure is
shewn admitted to the filter bags A to expedite the cleansing operation and is
utilized in raising the piston, and the sack L is dispensed with. It will be under-
stood that when for the cleansing operation the plate or piston B is to be put in
motion it is simply necessary to remove the cotter and allow the plate or piston B
to descend and then by alternately opening and closing the cock G¹ (Figure 2)
or G (Figure 3) the requisite reciprocating motion of the plate or piston B is
obtained. In the case of the apparatus illustrated in Figure 2 the cock G is a two
way one, so as to provide when the plate or piston B descends, an exit for the
compressed fluid which has been admitted; and the cock G (Figure 3) may also if
necessary be a two way cock as shewn in the drawings.
It should be understood that although I have described my method of cleansing
the filter bags in connection with the arrangement of bags in which there is no
distending plate or internal supporting body, yet such method of cleansing is

page_text: equally applicable when the sides of the bags are kept from closing in, say. for
example by rings placed at intervals or by equivalent means which do not interfére
with the movement of the plate or piston and the crumpling up of the bags.
"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
I claim is
1st A. bag filter, in which the process of filtration takes place from the exterior
to the interior of the filter-bags, without the employment in such bags of any
distending plate or supporting body, substantially as herein before described.
2nd Cleansing filter bags by the movement of a plate or piston which alternately.
extends and crumples up the bags longitudinally substantially as hereinbefore
described.
3rd The introduction of air or other elastic fluid under pressure, into the interior
of filter bags during the cleansing operation, substantially as hereinbefore described.
300K