Matters from the Liquids in which they are Suspended.
Year: 1887

page_text: Date of Application, 28th May, 1887.
Specification Accepted, 28th June, 1887.
Matters from the Liquids in which they are Suspended.
We WILLIAM MACNAB Senior Engineer and WILLIAM MACNAB Junior Analytical
Chemist both of 74 Windsor Road Forest Gate in the County of Essex and JAMES
DONALD of Paisley in the County of Renfrew North Britain 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 :-
This Invention is designed to effect the rapid clarification of liquids holding solid
matters in suspension by an efficient and easily constructed apparatus of but small
size compared to the work which it is capable of performing.
It is well known that the rate of subsidence of solids from the liquids in which they
are suspended depends on the vertical depth of the layer of liquid through which the
solid particles have to fall and on the density and size of these particles and also when
the turbid liquid is in motion on the speed of the current.
Having regard to these considerations we construct our apparatus in the following
manner and as illustrated by the example_shewn in the accompanying drawings
wherein Figure 1 is a longitudinal section Figure 2 a cross section on the line 1-2
of figure 1 and Figure 3 a transverse section, one half of which shews the inclined-
plates in the forward part of one of the compartments of the part A' and the other
half shewing the plates in the backward part of the same compartment. Figure 4
is an enlarged detail shewing in cross section the passages, below the compartments,
by which the mud is drawn off.
The apparatus is formed of a horizontal tank near one end of which there is a
vertical transverse partition A' separating the tank into parts A and A². In this
partition A¹ there are openings a a providing communication between the parts A

page_text: and A of the apparatus. Into the part A the liquid to be treated is introduced.
The said part A has vertical divisions a¹ a¹ so arranged as to cause the liquid to pass
downwards and by the central space and by openings a² beneath the central partitions
upwards and then again downwards on its way to the part A2 and thus become
thoroughly mixed (when useing reagents) before entering the part A' which constitutes
the clarifying portion of the tank. In the said part A³ are fixed inclined flat shelves
or plates B B parallel with each other and placed at increasing distances apart as
they approach the outlet e the first third and fifth extending from within a short
distance of the top right to the bottom to which they are also fixed and the second
and fourth from the top to within a certain distance of the bottom so that a
liquid admitted from the first part A of the apparatus takes alternately an upward
and downward direction in its passage through the part A³ to the point of discharge
and owing to the disposition of these shelves the current becomes gradually slower
as it approaches the outlet.
In the channels formed by these shelves B B we place a series of moveable
shelves or plates CC parallel to the others the distance apart of these moveable
shelves being greatest in the narrowest channel less in the next and so on, being
at the least distance apart in the widest channel viz.:-that nearest the outlet from
the part A². The lower ends of these moveable shelves as well as those of the
fixed ones B which do not reach the bottom of the part A² are provided with
narrow spouts or shoots and the edges of these shoots are turned up so as to
guide and conduct the deposit which takes place on the shelves and which owing
to their angle of inclination slides down to the bottom of the tank. The partially
clarified liquid in its passage from the downward to the upward channels passes
through the spaces between these shoots or spouts without disturbing or being
contaminated by the deposit which is falling from the ends of these shoots to the
bottom of the tank A which is so constructed that the deposited matter can easily
be drawn off through outlets terminating in pipes to which cocks or valves are
attached. The outlets as shewn consist of castings D fixed to the ends of the
plates as a and B between which is a space for the passage of the mud through
openings d into the castings through which it flows to the outlet at d³ and can
thence be drawn off by opening the valves or cocks secured to the outlet d³.
In this manner we construct an apparatus which presents the most favourable
conditions for clarifying turbid liquids by subsidence for when a liquid containing
solid particles in suspension is allowed to stand at rest or only kept in gentle motion
the greater portion of the solid matter consisting of the coarser and denser particles
settles out comparatively easily and rapidly whilst the finer and lighter particles
remain longer in suspension. In our apparatus the most favorable conditions for
subsidence viz. the slowest current and shallowest layers of water are formed at the
end where the lightest and finest particles will also be and less assistance is given at
the beginning where the bulk of the deposit composed chiefly of the heavier and
coarser particles takes place.
The rate of flow of the turbid liquid into the apparatus is so adjusted that the
effluent liquid is always clear. It will be evident that we are not limited to the
precise number of channels and plates therein as illustrated.
Having now particularly described and ascertained the nature of our said Invention
and in what manner the same is to be performed we declare that what we claim is :-
First In apparatus for separating solids from liquids by subsidence passages
forming channels increasing towards the outlet and provided with plates which are
nearer together in the channels towards the outlet than they are in the channels
towards the inlet substantially as herein before described and illustrated.
Second-In apparatus for separating solids from liquids by subsidence passages
forming channels increasing towards the outlet and provided with removable plates
which are nearer together in the channels towards the outlet than they are in the
channels towards the inlet substantially as hereinbefore described and illustrated.
Third In apparatus for separating solids from liquids by subsidence the

page_text: combination of the parts A and A³ the former constituting a chamber in which the
mixing can be effected and the latter a subsidence tank provided with channels and
plates arranged substantially as hereinbefore described and claimed by the preceding
claiming clauses.
Fourth- -In apparatus for separating solids from liquids by subsidence a tank or
chamber A provided with partitions so that the liquid passes in reverse directions
therethrough in combination with the subsidence portion A2 provided with channels
and plates substantially as herein before described and illustrated.
:
Fifth In apparatus for separating solids from liquids by subsidence channels or
passages provided with plates which are nearer together in the channels towards the
outlet than they are in those towards the inlet substantially as herein before described
and illustrated.
Sixth-In and for apparatus for separating solids from liquids. by subsidence
plates to receive the deposited matter the said plates having spouts or shoots at their
lower parts with spaces between substantially as and for the purpose hereinbefore
described and illustrated.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C.,
Agents.