Improvements in Filtering Apparatus.
Year: 1893

page_text: Date of Application, 2nd Nov., 1893
Complete Specification Left, 31st July, 1894-Accepted, 1st Sept., 1894
Improvements in Filtering Apparatus.
I, LEONARD HUGH BRISTOWE of Albany Buildings 47 Victoria Street in the
County of London, Gentleman do hereby declare the nature of this invention to be
as follows:
This invention relates more particularly to that description of filtering apparatus
known as the "Riddell" filter (but is not restricted thereto) in which the liquid to
be filtered is caused to pass through perforated radial arms or passages into and
through the filtering medium, the arms or passages radiating from a hollow hub
communicating with the passage through which the liquid to be filtered passes.
The pressure of the fluid through the perforations nearest the hub where the fluid
enters the arms is greater than at the outer ends of the said radial arms and con-
sequently' the liquid passing through the perforations near the outer ends of the
arms does not penetrate the filtering medium so readily as does that which passes
through the perforations nearer to the hollow hub whilst some parts of the filtering
material in proximity to the outer ends of the radial arms remaining untouched by
the liquid passing through the perforation. The object of my invention is to
provide means whereby the force of the jets of liquid passing through the per-
forations near the outer ends of the radial arms or passages will be greater than
that of the jets which pass through the perforations nearer to the hollow hub and
consequently a more uniform penetration of the filtering medium by the liquid is
ensured. According to my invention there is provided in each radial arm or
passage a longitudinal partition extending from that end of the arm where it joins
the hollow hub to within a short distance from the opposite or outer end of the
said arm, the said partition dividing the perforated part of the arm from the
unperforated part. The incoming liquid is caused by the partition to travel along
the unperforated part of the arm to the outer end thereof and then over the end
of the partition into the perforated portion of the said arm it passing thence through
the perforations into the filtering medium. The pressure of the incoming liquid is
greatest at this outer end of the arm, and will pass through the perforations at
this end with great force, the said pressure gradually reducing towards the end
where the said arm is connected to the hollow hub so that the liquid passes through
the perforations near the cuter end of the arms with greatest force, where most
required, the force of the jets gradually diminishing towards the ends of the arms
where they join the hollow hub and where less force is required. The liquid is
thus more efficiently distributed throughout the filtering medium than is the case
with hollow arms constructed as heretofore.
Dated this 2nd day of November 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, Agents.

page_text: Improvements in Filtering Apparatus.
I, LEONARD HUGH BRISTOWE of Albany Buildings, 47 Victoria Street, in the
City of Westminster, Gentleman, 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 :-
This invention relates more particularly to that description of filtering apparatus
known as the "Riddell filter" (but is not restricted thereto) in which the liquid to
be filtered is caused to pass through perforated radial arms or passages into and
through the filtering medium, the arms or passages radiating from a hollow hub
communicating with the passage through which the liquid to be filtered passes.
In apparatus of this kind as hitherto constructed the pressure of the fluid through
the perforations nearest the hub where the fluid enters the radial arms, is greater
than at the outer ends of the said radial arms and consequently the liquid passing
through the perforations near the outer ends of the arms does not penetrate the
filtering medium so readily as does that, which passes through the perforations
nearer to the hollow hub whilst some parts of the filtering material in proximity to
the outer ends of the radial arms remain practically untouched by the liquid
passing through the perforation. The object of my invention is to provide means
whereby the force of the jets of liquid passing through the perforations near the
outer ends of the radial arms or passages will be greater than hitherto or than
that of the jets which pass through the perforations nearer to the hollow hub
whereby a more uniform penetration of the filtering medium by the liquid is
ensured.
I will describe my invention with reference to the accompanying drawings
Figure 1 of which is a longitudinal vertical section of one of the radial arms
detached.
Figure 2 is a vertical section on the line 1-2 Figure 1, and
Figure 3 is a horizontal section on the line 3-4 Figure 1.
Figures 4, 5, 6 and 7 are transverse sections taken along the lines 5-6, 7-8,
9-10, and 11-12 respectively in Figure 3.
Figure 8 is a part elevation and part vertical section of the hub from which the
arms radiate and Figure 9 is a plan of the same.
According to my invention there is provided in each hollow radial arm A a
longitudinal partition A² extending from that end of the interior of the arm where
it joins the hollow hub B to within a short distance from the opposite or outward
end of the said arm, the said partition A² dividing the perforated part d² from the
unperforated part 2 of the arm. The hollow hub B (as shewn in Figure 8) is also
divided into two compartments by a partition B2 which, when the arms are fixed
in position, form a continuation of the partitions A2. Holes or passages c d are
formed in the sides or wall of the hub B and communicate respectively with the
chambers c² d² in the arms A. The liquid to be filtered enters, by a suitable
conduit, the hollow hub B above the partition B2 and passes thence through the
holes or passages c into and along the chamber on the upper side of the
partitions A2 in the radial arms to the outer ends of the said arms which outer
ends are preferably inclined from the top downwards, and outwards, as shewn at b,
so as to direct the liquid with great force through the perforations near the said
outer ends which perforations are made to radiate, or incline, outwardly, so that
the liquid is efficiently distributed over, or through, the filtering medium in proximity
to the said outer ends of the arms. Liquid passes from the chamber above the
partitions Around the outer end of the said partition into the chamber d² below,
and thence through the perforations 9 and h, the pressure of the liquid gradually

page_text: diminishing as it flows along the chamber towards the hollow hub B and con-
sequently issuing through the perforations 9 and h with gradually diminished force
but sufficient to spread the liquid efficiently over or through the filtering medium
the area of which is gradually less towards the hub B. Any of the liquid entering
the lower chamber k in the hollow hub B will pass therefrom by the perforations
into the filtering medium. Although I prefer the arrangement of partitions in the
radial arms as hereinbefore described and illustrated, I do not restrict myself
thereto, as it is obvious that pipes or passages for the liquid from the hollow
hub to the outer ends of the arms may be arranged either inside or outside the said
arms.
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 or for apparatus for filtering liquids in which the liquid to be filtered is
caused to pass through perforations in hollow arms, means whereby the liquid is
caused to pass through the perforations at the outer ends of the arms with greatest
force and with gradually diminished force through the perforations towards the
inner ends of the arms substantially as hereinbefore described.
2. In or for filtering apparatus in which the liquid to be filtered is caused to
flow through perforations in hollow arms, a partition in each hollow arm by means
of which the liquid is caused to flow to the outer ends of the arms before it can
pass through the perforations in the said arms substantially as hereinbefore
described.
3. In or for apparatus for filtering liquids the combination with a hollow hub
into which the liquid to be filtered is admitted, of hollow perforated arms pro-
jecting from and communicating with the interior of the hollow hub and partitions
in the hollow arms by which the liquid to be filtered is caused to flow from the
hollow hub to the outer ends of the radial arms before it can pass through the
perforations therein substantially as hereinbefore described.
4. In or for filtering apparatus the construction and arrangement of hollow
perforated arms and hollow perforated boss as hereinbefore described and shewn in
the accompanying drawings."
Dated this 31st day of July 1894.
JOHNSONS & WILLCOX,
Agents.