Improvements in and relating to Filtering Apparatus.
Year: 1893

page_text: Date of Application, 26th Jan., 1893
Complete Specification Left, 26th Oct., 1893-Accepted, 6th Jan., 1894
Improvements in and relating to Filtering Apparatus.
I, HEINRICH JÜRGEN ERNST JENSEN, of 11 Schauenburgerstrasse, Hamburg, in
the Empire of Germany, Manufacturer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to a filtering apparatus comprising filter cells or plates with
layers of asbestos or cellulose serving as a filtering agent. The object of this
invention is to distribute the liquid to be purified over the whole filtering surface
at disposal so as to prevent the filtering agent being partially washed from the
several filtering surfaces.
In carrying my said invention into practice I provide an open vessel in which
filtering plates or cells are arranged below horizontal tubes, their interior
communicating through apertures with the interior of these tubes. The liquid to
be purified coming from a reservoir above flows over a channel into the said vessel
in which it is compelled by a transverse partition not extending quite to the bottom
of the vessel to move from the bottom upwards.
In order to utilize the layers of filtering material on the surface of the several
cells in a uniform manner and to prevent currents which would partially wash away
the layers of cellulose or asbestos, and also to render possible a uniform deposition
of the latter when the apparatus is set in operation, the outflow of the purified
liquid is regulated in a peculiar manner.
I provide in each of the aforesaid horizontal tubes, communicating with the cells
and connected with an equal number of collecting tubes, a tube which, extending
the entire length of the cell, leaves between itself and the outer tube an annular
space shut off from the collecting tube by a disc. One end of the interior of each
inner tube is in communication with a collecting tube but its other end is closed and
supported by a central rod and a bridge-piece fastened to the outer tube. As each
inner tube is provided with apertures at its upper side, the outer tubes and also the
cells suspended from the under side of these outer tubes communicate through the
said apertures with the collecting tube. The apertures establishing communication
between the cells and outer tubes are of equal width and arranged at equal
distances from each other, but the apertures in the inner tube are so distributed.
that the sectional area for the admission of liquid to the inner tube decreases
towards the said collecting tube. If with filters of this kind the cleaning of the
filtering surfaces is to be effected by a counter current I put the ends of the outer
tubes which are opposite to the collecting tube in communication, through bells
provided with branch tubes, with a tube which is common to all the cells and in
the interior of which is arranged a tube acting like the plug of a cock. This
latter tube in accordance with the number and the distance of the said branch
tubes has apertures so arranged that the common tube communicates with only one
branch tube at a time. To the common tube is joined a tube through which the
liquid used for the washing is introduced under pressure.
Such a filtering apparatus is operated in the following manner. When the
lateral surfaces of the cells are to be covered with filtering material the latter is
generally mixed with a portion of the liquid to be purified which is contained in
the reservoir for the same, and the mixture is conducted through a tube adapted to
be closed by a valve over the above-mentioned channel into the filtering vessel.
In consequence of the peculiar arrangement of the aforesaid inner tubes and the
siphon action caused by the collecting tubes the filtering material is uniformly
deposited at all parts of the cells, the liquid moving at a uniform velocity in the

page_text: vessel, because the portions of the liquid passing into the inner tube in the vicinity
of the collecting tubes are kept somewhat back by the decrease in the sectional
area at this point, so that the portions of the liquid entering at remoter points gain
time to unite with the others. If the layers of filtering material are to be cleaned by
a counter current the collecting tubes are closed, the tube which acts like a plug in
the aforesaid common tube being put in such a position, after the opening of a cock
included in the tube coming from the reservoir, that the liquid used for the washing
is conducted under pressure to one after the other of the outer tubes and the layer
of filtering material is washed from the several filter plates.
In a modified arrangement of the apparatus the above-mentioned horizontal
tubes, and therefore also the cells, are arranged not in the longitudinal direction
but in the transverse direction of the vessel. In this case the outlet of the filtered
liquid takes place from the middle of the said tubes towards both sides, to each of
their two ends being joined a collecting tube arranged in the longitudinal direction
of the said vessel. The two collecting tubes communicate through bent tubular
pieces and a T piece with the outflow tube proper, this tube being adapted to be
closed. The tubes inserted into the outer tubes and held in discs are in this case
provided with apertures decreasing in sectional area from the middle towards both
sides, care being moreover taken that the number of these apertures shall, without
interfering with the above mentioned relation, progressively diminish towards the
outflow tube. The apertures leading from the interior of the outer tubes to the
cells have also in this arrangement everywhere the same sectional area.
The introduction of the liquid to be purified takes place through a tube terminating
in the middle of the bottom of the vessel. In order that the liquid may not move
directly upwards I place over the orifice of the said tube a cap arranged at the
bottom of the vessel and which has the necessary apertures on the upper side for
distributing the liquid.
To obtain a uniform distribution of the liquid in the vessel it has been found
expedient to decrease the sectional area of these apertures from the tube in the
middle to both sides. When currents are to be obviated altogether in the vessel
this provision is however not alone sufficient and it is advisable to put above the
cap a plate which in transverse section forms an arc of a circle with the cavity
downwards and with the ends turned upwards. The guide surfaces thus constituted
form, in conjunction with the suitably shaped bottom of the said vessel, gradually
increasing channels leading to the cells so that the liquid to be purified approaches
these cells at a gradually diminishing velocity. The liquid used for the washing
is let out through openings in the wall of the vessel which terminate in a common
outlet pipe.
In the modified arrangement the several cells are provided with a recess which
is open below, in order to make room for a horizontal shaft arranged in the central
plane of the vessel. On this shaft I fix vanes between two neighbouring cells.
Owing to the action of these vanes when the filter is set in operation, the filtering
fibre mixed with the liquid is distributed uniformly over the perforated surfaces of
the cells or, when the cleaning is necessary, the layers of filtering material are
washed from the perforated surfaces of the cells. To this end each separate vane
is formed in such a manner that one-half of its surface, which is nearest to the
periphery throws the liquid used for the washing to one side, while the other half,
which is turned towards the rotary axis, throws the liquid to the other side, so
that two opposite filtering surfaces will be acted upon at the same time. The
form of the vanes is however based on the assumption that the surfaces of one
vane are so placed relatively to that of the other vane as to enable all the layers
of fibre deposited upon the filtering surfaces to be peeled off. The position of the
vanes relatively. to their rotary axis is such that in their rotary movement in one
direction they will throw the liquid used for the washing at an acute angle against
the filtering surfaces and will thereby sever the layers of filtering material. When
they are turned in the opposite direction, which has to be done when putting
on a fresh layer of filtering material, the vanes act chiefly as stirrers and cause

page_text: the filtering materials, which are placed in the liquid used for the washing, to
float about.
Instead of providing the inner tubes with apertures as hereinbefore set forth
may also form them with one or more slots decreasing in width from one end
towards the other or from the middle to both ends.
I
Dated this 26th day of January 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in and relating to Filtering Apparatus.
1, Heinrich JÜRGEN ERNST JENSEN, of 11 Schauenburgerstrasse, Hamburg,
in the Empire of Germany, Manufacturer, 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 :-
My invention relates to a filtering apparatus comprising filter cells or plates
with layers of asbestos or cellulose serving as a filtering agent. The object of this
invention is to distribute the liquid to be purified over the whole filtering surface
at disposal so as to prevent the filtering agent being partially washed from the
several filtering surfaces.
In the
drawings twee constructional forms are represented of this

page_text: communicate through the said apertures with the collecting or outlet tube h. The
apertures b, c¹ establishing communication between the cells and outer tubes are
of equal width and arranged at equal distances from each other, but the apertures i
in the inner tube are so distributed that the sectional area for the admission of
liquid to the inner tube i decreases towards the said collecting or outlet tube h.
If with apparatus of this kind the filtering surfaces are to be cleaned by a
counter current I put the ends of the outer tube which are opposite to the
collecting or outlet tube in communication, through bells furnished with branch
tubes in, with a tube n which is common to all the cells and in the interior of which
is arranged a tube o acting like the plug of a cock. This tube o in accordance
with the number and the distance of the branch tubes m has apertures o¹ so
arranged that the tube n communicates with only one branch tube m at a time.
To the tube n is joined a tube p through which the liquid used for the washing
is introduced under pressure.
Such a filtering apparatus is operated in the following manner. When the
lateral surfaces of the cells c are to be covered with filtering material the latter is
generally mixed in the reservoir with a portion of the liquid to be purified and
the mixture is conducted through a tube e adapted to be closed by a valve over the
channel d into the filtering vessel a.
In consequence of the peculiar arrangement of the tubes i and the siphon action
caused by the collecting or outlet tubes h, the filtering material is uniformly
deposited at all parts of the cells, the liquid moving at a constant velocity in the
vessel, because the portions of the liquid passing into the inner tube i in the vicinity
of the collecting or outlet tubes are kept somewhat back by the decrease in the
sectional area at this point, so that the portions of the liquid entering at remoter
points gain time to unite with the others. If the layers of filtering material are to
be cleaned by a counter current the tubes h are closed, the tube o being put in such
a position after the opening of a cock included in the tube p coming from the
reservoir, that the liquid used for the washing is conducted under pressure to one
after the other of the tubes b, and the layer of filtering material is washed from the
several filter plates and discharged through the outlet a¹ close to the bottom of the
vessel.
In the modified arrangement of the apparatus shown in Figures 6 to 8 the
tubes band also the cells c are arranged not in the longitudinal direction, but in
the transverse direction of the vessel a. In this case the outlet of the filtered
liquid takes place from the middle of the tubes towards both sides, to each of
their two ends being joined a collecting tube arranged in the longitudinal
direction of the vessel a. The two collecting tubes communicate through bent
tubular pieces 2 and a T piece h' with the outlet tube proper which is adapted
to be closed. The tubes i inserted into the outer tubes and held in discs k are in
this instance provided with apertures decreasing in sectional area from the
middle towards both sides, care being moreover taken that the number of these
apertures, shall, without interfering with the above mentioned relation, pro-
gressively diminish towards the outlet tube h. The apertures 6' c¹ leading from
the interior of the outlet tubes 6 to the cells c have also here everywhere the same
sectional area. The introduction of the liquid to be purified takes place through a
tube terminating in the middle of the bottom of the vessel a. In order that the
liquid may not move directly upwards I place over the orifice of the tuber a cap s
arranged at the bottom of the vessel a and which has the necessary apertures &¹ at
its upper side for distributing the liquid.
To obtain a uniform distribution of the liquid in the vessel a it has been found
expedient to decrease the sectional area of these apertures s¹ from the tuber to
both sides, as shown in Figure 9. When currents are to be obviated altogether in
the vessel a this provision is however not alone sufficient, and it is advisable to put
above the caps a plate t which in transverse section forms an arc of a circle with
the cavity downwards and with the ends turned upwards. The guide surfaces t¹
thus obtained form, in conjunction with the suitably shaped bottom of the

page_text: vessel a, gradually increasing channels leading to the cells so that the liquid to be
purified approaches these cells at a gradually diminishing velocity. The liquid
used for the washing is let out through openings a³ in the wall of the vessel which
terminate in a common outlet pipe a'.
In the arrangement represented in Figures 6 to 8 the several cells c are
provided, with a recess which is open below, in order to make room for a
horizontal shaft v arranged in the central plane of the vessel a. On this shaft
I fix vanes w between two neighbouring cells c. Owing to the action of these
vanes when the filtering apparatus is set in operation, the filtering fibre mixed with
the liquid is distributed uniformly over the perforated surfaces of the cells c, or,
when the cleaning is necessary, the layers of filtering material are washed from the
perforated surfaces of the cells. To this end each separate vane is formed in such
a manner that one half of its surface, which is nearest to the periphery, throws the
liquid used for the washing to one side, while the other half, which is turned
towards the rotary axis, throws the liquid to the other side, so that two opposite
filtering surfaces will be acted upon at the same time. The form of the vanes
is however based on the assumption that the surfaces of one vane are so placed
relatively to that of the other vane, as to enable all the layers of fibre deposited
upon the filtering surfaces to be peeled off. The position of the vanes relatively to
their axis is such that in their rotary movement in one direction they will throw
the liquid used for the washing at an acute angle against the filtering surfaces
and will thereby sever the layer of filtering material. By turning them in the
opposite direction, which has to be done when putting on a fresh layer of filtering
material, the said vanes act chiefly as stirrers and cause the filtering materials,
which are placed in the liquid used for the washing, to float about.
Instead of providing the tubes i with apertures I may also form them with one
or more slots & Figures 10 and 11, decreasing in width from one end towards the
other or from the middle to both ends.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a filter, the combination, with a filtering cell and a vessel receiving the
same, of a collecting tube (b), carrying at its under side the filtering cell (a) and
communicating with the interior of the cell through a series of apertures (6¹ c¹) of
equal width, a discharge pipe (1) leading to the outlet tube or tubes (h or h¹) of the
filter and provided in its periphery with passages (1 or 2) for the liquid, the
discharge pipe (i) being held within the collecting tube so as to leave an annular
space between them and the sectional area of the said passages being designed to
decrease towards the said outlet tube or tubes, substantially as and for the purpose
set forth.
2. In a filter the combination with one or more filtering cells each of which
being suspended from the under side of a collecting tube (b) within a vessel (a), of
an inlet tube (r) and a cap (s) arranged at the bottom of the said vessel having
apertures (s) at its upper side, the sectional area of which decreasing from the
tube (r) to both sides of the cap, substantially as and for the purpose set forth.
3. In a filter, the combination, with one or more filtering cells each of which
being suspended from the under side of a collecting tube (6) within a vessel (a), of
an inlet pipe (r) and a cap arranged at the bottom of the said vessel, and above
the said cap a plate (t) which in transverse section forms an arc of a circle with
the cavity downwards and with the ends turned upwards, substantially as and
for the purpose set forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.