IMPROVEMENTS IN FILTERS AND IN THE MODE OF AND APPARATUS FOR CLEANSING THE SAME
Year: 1882

page_text: "C
LETTERS PATENT to Edward Perrett of Victoria Chambers in the City of
Westminster Civil Engineer for an Invention of IMPROVEMENTS IN FILTERS
AND IN THE MODE OF AND APPARATUS FOR CLEANSING THE SAME
"
PROVISIONAL SPECIFICATION left by the said Edward Perrett at the Office
of the Commissioners of Patents on the 22nd August 1882.
EDWARD PERRETT of Victoria Chambers in the City of Westminster Civil
Engineer "IMPROVEMENTS IN FILTERS AND IN THE MODE OF AND APPARATUS
FOR CLEANSING THE SAME
ور
The first part of this invention relates to an improved mode of and apparatus
for cleaning the filtering medium in the class of filters wherein the grosser
impurities held in mechanical suspension in water or other liquids are removed by
causing the impure liquid to percolate through the mass of filtering material such
as sand, charcoal, asbestos, sponge or other well known filtering media and consists
in effecting the cleansing of the said filtering medium whilst inside the filtering
vessel by causing a body of water to be moved or forced alternately in opposite
directions through the said medium whilst it is in a free, loose, or expanded con-
dition thereby disturbing the impurities lodged therein. The said body of water
is moved by a plunger or displacer working in a separate barrel or cylinder and
actuated by hand or by power. The filtering medium when in action is maintained
in a close or compressed condition between two perforated metal
or other
diaphragms inside any convenient vessel or tank one of the said diaphragms being
fixed and the other capable of adjustment by one or more screw spindles or
otherwise towards or from the fixed diaphragm or both diaphragms may be rendered
capable of adjustment towards or from each other. The liquid to be filtered
preferably enters by a pipe and cock at the bottom of the vessel so as to flow
upwards through the filtering medium whilst the filtered liquid flows out by a
discharge pipe and cock at the top of the tank. The water for disturbing the
impurities in the filtering medium is moved through a pipe at the bottom of the
vessel communicating with any suitable plunger or displacer. When the filtering
Price G/1

page_text: medium is to be cleansed the diaphragm or diaphragms are first separated more or
less to allow it to loosen or expand and the displacer is then started thereby at
one stroke forcing a powerful rush of water through the loose or expanded filtering
medium in one direction and at the next or reverse stroke drawing back the water
again. During this pulsation or alternating movement of the said body of water a
small supply of clean water may be run in at the top of the filtering medium to
carry away through a pipe and cock at the bottom of the filter the impurities which
have been disturbed by the movement of the main body of water. If desired a
small supply of clean water may be brought directly into the displacer barrel in
order to ensure as far as practicable the plunger working in clean water.
several filters are employed they may be cleansed in succession by connecting the
displacer barrel with each filter as required or a number of branch pipes may be
employed provided with stop cocks and communicating between the displacer barrel
and each one of the series of filters so that by simply opening or closing the cocks
any one of the series may be brought under the action of the displacer.
When
The Second part of the said invention relates to the class of filters known as
Bag Filters and consists in dispensing with the usual cases or stockings by so
arranging a number of bags inside a case or vessel common to the lot as that
they shall mutually support each other. With a view to facilitate the cleaning of
the said bags they have each secured at their lower ends a weight preferably of a
spherical form and the containing vessel is mounted on trunnions at opposite sides
so as to be capable of rotation on its transverse axis. When it is desired to clean
the several bags the containing vessel is slowly rotated and the weights move by
gravitation from end to end of the filter at each revolution thereby alternately
crumpling and extending the bags. This action disturbs. the dirt on the inner sides
of the bags which is then carried away through outlets at each end of the vessel
by a small supply of cleansing liquid introduced for that purpose.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Perrett in the Great Seal Patent Office on the
22nd February 1883.
EDWARD PERRETT of Victoria Chambers in the City of Westminster Civil
Engineer "IMPROVEMENTS IN FILTERS AND IN THE MODE OF AND APPARATUS
FOR CLEANSING THE SAME
"
My said invention relates first to an improved mode of and apparatus for
cleaning the filtering medium in that class of filters wherein the grosser impurities
held in mechanical suspension in water or other liquids are removed by causing the
impure liquid to percolate through the mass of filtering material such as sponge
asbestos sand charcoal or other well known filtering media. Secondly to improve-
ments in the construction and arrangement of what are known as "bag-filters" and
to the mode or method of cleaning the bags.
And in order that my said invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the explanatory sheets of drawings hereunto annexed the
same letters of reference indicating corresponding parts in all the corresponding
figures.
Figure 1 (Sheet 1) of my drawings represents a vertical section and Figure 2 a
corresponding plan of a filter and accessory parts specially arranged with a view
to the cleansing of the filtering medium (in this case sponge or other like com-
pressible and expansible material or substance) in accordance with the first part of
my said invention.
A is the filtering vessel of any convenient size and shape closed at the top by
a lid or cover B and provided with a perforated fixed diaphragm C and a perforated
adjustable diaphragm D or both diaphragms may be adjustable towards and from
each other. E is a rod or spindle secured to the adjustable diaphragm and passing
through a stuffing box F in the cover the upper end of the spindle being screwed
so as to be raised or lowered by the nut in the boss of the hand wheel G. Or the
vertical adjustment of the moveable diaphragm or diaphragins may be effected by
any other suitable mechanical contrivance. H is the filtering medium (in this
case spouge or other compressible and expansible material or substance) contained
between the two diaphragms. I is the inlet pipe and cock preferably at or near
the bottom of the vessel for the entrance of the liquid to be filtered but in some
cases it may be advantageous to place the inlet at the top. K is another pipe and
cock at or near the top of the vessel or in the cover thereof for the outflow of the
filtered liquid. L is a pipe connected with the bottom of the filtering vessel and
with a barrel or cylinder M containing any suitable reciprocating plunger or
displacer N actuated either by hand or by power in any suitable manner,
in my
drawings I have shown as an example the application of a well known arrangement
of steam pump O for this purpose. P is a pipe and cock for the escape of the
impurities and washing water. Qis a pipe and cock for allowing a supply of
clean water to be run in at the top of the filtering medium during the operation
of cleaning the same and R is a pipe and cock for supplying clean water to the
displacer barrel M. I effect the cleansing of the filtering medium H whilst it is
contained inside the filtering vessel A, by causing a body of water to be moved or
forced alternately in opposite directions or to-and-fro through the said medium
whilst it is in a free loose or expanded condition thereby disturbing the impurities
lodged therein. The said body of water is moved by the plunger or displacer N
working in the barrel or cylinder M. The filtering medium if of an expansible

page_text: nature such for example as sponge is maintained when in action in a close or
compressed condition between the two perforated metal or other diaphragms C, D,
inside the vessel or tank A one of the said diaphragms C being fixed and the
other D capable of adjustment by one or more screw spindles E or otherwise
towards or from the fixed diaphragm C or both diaphragms may be rendered
capable of adjustment towards or from each other.
The liquid to be filtered preferably enters by the pipe and cock I at the bottom
of the vessel so as to flow upwards through the filtering medium H whilst the
filtered liquid flows out by a discharge pipe and cock K at the top of the tank.
The water for disturbing the impurities in the filtering medium is moved through
the pipe L at the bottom of the said tank or vessel communicating with any
suitable plunger or displacer N. When the filtering medium is to be cleansed the
diaphragm or diaphragms are first separated more or less to allow it to loosen or
expand if it be of an expansible nature and the displacer N is then started thereby
at one stroke forcing a powerful rush of water through the expanded or loose
filtering medium H in one direction at at the next or reverse stroke drawing
back the water again. During this alternating movement of the said body of
water a small supply of clean water may be run in at the top of the filtering
medium by the pipe Q to carry away through the pipe and cock P beneath the
filter the impurities which have been disturbed by the movement of the main
body of water if desired a small supply of clean water may be brought directly
into the displacer barrel M by the pipe and cock R in order to ensure as far as
practicable the plunger working in clean water.
Figure 3 represents a vertical section of a filter adapted for cleansing in the
manner herein before described the filtering medium when composed of a bed of
sand charcoal or the like. As this medium is not expansible or compressible like
sponge the use of an adjustable diaphragm may in some cases be dispensed with
the said medium H simply reposing upon a fixed perforated diaphragm C and the
top of the filtering vessel A may be left open or uncovered, and the water to be
filtered may be passed downwards through the filtering medium the filtered water
passing away from the bottom of the filter. The rest of the parts corresponding to
those already described with reference to figures 1 and 2 are marked with similar
letters of reference. In this filter after the impurities in the filtering medium have
been disturbed by the action of the displacer N as before described and allowed to
flow off along with the dirty water at P the filtering medium is allowed to settle
again or to compact itself upon the diaphragm C after which the operation of
filtration can be resumed as before.
When several filters are employed as shown in the diagram plan Figure 4 they
may be cleansed in succession by connecting the displacer barrel M with each
filter A as required or a number of branch pipes L' from the pipe L may be
employed provided with stop cocks and communicating between the displacer
barrel M and each one of the series of filters so that by simply opening or closing
the cocks L¹ any one or more of the series of filters may be brought under the
action of the displacer.
Figure 5 Sheet 2 of my drawings is a vertical section figure 6 is an elevation and
figures 7 and 8 enlarged details in horizontal and vertical section of a bag-filter
constructed and arranged so that the several bags shall afford a mutual support to
each other without the necessity for the usual cases or stockings the said drawings
also illustrating the mode of facilitating the cleansing of the said bags as comprised
under the Second head of my invention.
A is the vessel containing the filtering bags a' such vessel being of any convenient
form and dimensions preferably cylindrical and mounted so as to be balanced or
nearly so upon trunnions B B turning in the standards or supports C C the vessel
being thus capable of rotation in a vertical plane on the axis of the trunnions by
any suitable arrangement of gearing for the purpose hereinafter described. D is a
disc or diaphragm (shown also at figures 7 and 8) having as many openings b therein
as there are bags in the filter. This disc is secured by screws c or otherwise into

page_text: Each
one end of the vessel A and is connected by the tie rods d with a second disc E
fitting inside the opposite end of the vessel A. The mouths of the several bags
may be secured round the openings b in any suitable manner but I have found the
following to answer well in practice. Round each aperture b there is fitted in a
suitable recess a packing ring e of india rubber or other suitable material.
bag is passed through one of these apertures and is secured in position by turning
outwards the mouth of the bag over the rubber packing ring e and holding it in
place by a metal ring falso carrying a rubber packing ring g on its under face such
ring being held firmly down by washers and nuts g' on the upper ends of the
several rods d each rod occupying the space between three adjacent bags so that
the washer and nut will serve to pinch the edges of three rings fat one time as will
be clearly seen on referring to figures 7 and 8. A cover F is secured to each end
of the vessel a cock i being provided thereon for the exit of the water used in
washing, the bags. It will be seen that the several bags are in actual lateral contact
with each other although guided or kept in position by the rods d and that
consequently when in filtering action they will mutually support each other
laterally.
With a view to facilitate the cleansing of the said bags they have each secured
at their lower ends a weight k preferably of spherical form so that when the con-
taining vessel A is rotated at a moderate speed the said weights will move from
end to end of the vessel at each half revolution and will thereby effect the alternate
crumpling up and extension of the bags in a longitudinal direction which action
disturbs the dirt on the sides of the bags and renders it capable of being readily
carried away through the cocks ii at each end of the vessel by a supply of
cleansing liquid introduced for that purpose through the pipes or passages ll,
are the inlet and outlet pipes for the liquid to be filtered. These pipes l'
communicate with the pipes or passages m m' which open direct into the hollow
trunnions B B the pipe m serving at one time for the inlet of the liquid to be
filtered and at another time for the inlet of the cleansing liquid whilst the pipe m¹
serves for the outlet of the filtered liquid as well as for the inlet of the cleansing
liquid. Branch pipes or passages n n from each trunnion lead to the opposite ends
of the vessel A or to perforated pipes contained therein which discharge the liquid
to be filtered into the mouths of the several bags or the perforated pipes may be
dispensed with and the liquid to be filtered may pass through openings in the
plate o into the bags. The filtered liquid passes out through perforations in the lower
plate or disc E and thence by the exit passage n. When the bags are to be cleaned
the cleansing liquid is introduced through the pipes and finds its way through
the pipes m m trunnions B B and pipes or passages nn to the opposite ends of the
vessel A which is at the same time caused to rotate gently the washing liquid
acting on both the interior and exterior of the bags access being afforded to the
exterior thereof through the perforations in the disc or plate E. The water con-
taining the impurities disturbed by the alternate crumpling and extension of the
bags produced by the revolution of the vessel A flows away through the exit
openings and cocks l. l. This crumpling and extending of the bags however may
be effected if desired by other means such as strings or rods connected to the ends
of the bags and passing through the filter covers and actuated from the outside so
that the bags may be moved without the rotation of the vessel.
Having now described and particularly ascertained the nature of my said
invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the invention secured to me by the herein before in part
recited Letters Patent is:
--
First. The mode or method of cleansing a filtering medium preferably whilst in
a free loose or expanded condition inside the filtering or containing vessel by
causing a body of water to be moved by any suitable displacer through the said
medium to-and-fro or in opposite directions alternately whereby the impurities are

page_text: disturbed and the cleansing of the medium is effected substantially as hereinbefore
described.
Second, The so arranging or disposing the bags in the containing vessel or
casing of what is commonly known as a "Bag-filter" as that the several bags shall
mutually support each other laterally thereby dispensing with the usual cases or
stockings substantially as described.
Third. The mode or method of disturbing the impurities adhering to the filtering
bags of bag-filters by causing the said bags to be alternately crumpled up and
distended longitudinally whilst in contact with water or other cleansing liquid
inside the containing vessel or casing substantially as hereinbefore described.
Fourth. Imparting a rotary motion in a vertical plane to the vessel containing
the bags of a bag filter for the purpose of causing the said bags to be alternately
crumpled up and distended longitudinally by the action of gravity and thereby
disturbing the dirt adhering thereto substantially as hereinbefore described.
In Witness whereof I the said Edward Perrett have hereunto set my hand and
seal this twelfth day of February in the year of our Lord one thousand
eight hundred and eighty three.