Improvements in Apparatus for Accelerating the Passage of Liquids. through Filter Beds.
Year: 1888

page_text: Improvements in Apparatus for Accelerating the Passage of Liquids.
through Filter Beds.
I, WILLIAM DUNSMORE BOHM, of 51 Avenue Road, Acton in the County of
Middlesex, Engineer do hereby declare the nature of this invention to be as
follows:-
My invention relates to apparatus employed for the separation of liquids from
solid matter or slime with which they may be mingled, such as solutions of metal
from their crushed ore, by drawing them through filter beds, and consists of an
improvement in the construction of a pump which, whilst drawing the liquid through
the filter bed by suction, shall at the same time produce a reflux action sufficient to
keep the said filter bed from choking with the slime.
It is well known that where moisture has to be separated from finely pulverised
material or slime by a filter bed, slime so rapidly chokes the filter bod as shortly to
prevent further passage of the liquid. To prevent this injurious effect, I construct
a suction pump as follows:-The main cylinder of the suction pump is constructed
with a bucket receiving rectilinear motion from any convenient shafting by an
eccentric or crank in the usual way, the pump being provided with the ordinary
suction and delivering valves.
My improvement consists in the addition thereto and combination therewith of a
second pump barrel of smaller dimensions than the first of say, about one quarter
the area, which is provided with an ordinary bucket piston and receives a recipro-
cating movement from any convenient source. The barrel of this auxiliary pump
communicates by a suitable pipe with the suction pipe of the main suction pump
between the suction valve of the latter and the filter bed.
Both the
There are no valves between the auxiliary pump and the filter bed.
main and the auxiliary pump make their suction stroke together, thus jointly with-
drawing liquid through the filter bed. On the return stroke the main pump delivers
its withdrawn charge of liquid into a delivery pipe for further treatment or collection;

page_text: but the auxiliary pump delivers back its charge once more into the main suction
pipe, and thence back through the filter bed in a reverse direction to the former
travel.
This has the effect of lifting and agitating the slime and pulverised material upon
the filter bed, and thus of freeing the same sufficiently to cause an accelerated flow
through the filter bed on the following suction stroke of the pumps.
The charge of the auxiliary pump may be adjusted by altering the throw of the
eccentric controlling the piston.
Dated th: 90th of ML 1000
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Apparatus for Accelerating the Passage of Liquids
through Filter Beds.
I, WILLIAM DUNSMORE BOHM, of 51 Avenue Road, Acton, in the County of
Middlesex, 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 stateinent :-
My invention relates to apparatus employed for the separation of liquids from
solid matter or slime with which they may be mingled, such as solutions of metals
from their crushed ore, by drawing them through filter beds, and consists of a
combined suction pump, which, whilst drawing the liquid rapidly through the filter
bed by suction, shall also produce a reflux action sufficient to keep the said filter bed
from choking with the slime.
It is well known that where moisture has to be separated from finely pulverised
material or slime by a filter bed, the slime or material so rapidly chokes the filter
bed as shortly to prevent further passage of the liquid.
To prevent this consequence, 1 construct my combined suction pump as follows,
reference being had to the drawing hereunto annexed and to the letters and figures
marked thereon.
A is the main suction pump provided with an ordinary single acting piston or
bucket, receiving rectilinear motion from any convenient shafting by an eccentric
or crank in the usual way. This pump is provided with the ordinary suction and
delivery valves B and C. This pump draws the moisture or liquid in its up-suction
stroke through the suction valve B and suction pipe D D, through the filter bed E,
and delivers it in the down stroke through the ordinary delivery valve C and delivery
pipe O.
F is an auxiliary or combined single acting bucket or piston pump but entirely
without valves. It also receives reciprocating movement from any rotary shaft by a
suitable eccentric or crank, being timed to make its up and down strokes similarly
with the main suction pump A. The effect then of the auxiliary combined pump
is to draw a charge of liquid by suction from the filter bed E, either by a branch
pipe G from the main suction pipe D or by an independent suction pipe H; and on
the return stroke when the suction pump proper A is delivering through the delivery
valve C and delivery pipe O, the auxiliary pump F returns its cliarge direct under the
filter bed either through the distinct suction pipe H or the pipe G connected to the
main suction pipe D. "In this latter case, in order to ensure that the reflux charge
from the auxiliary pump F is returned to the filter bed, and does not lift the suction
valve B and thus deliver into the delivery pipe O, I provide a plug cock K or sluice
or other convenient valve in the main suction pipe. Where a plug cock is used, it
has a straight through passage and stands fully open as shown, during the suction
stroke of the two combined pumps, and is closed during the downward delivery stroke
of both pumps. This ensures that the reflux charge of the pump F must return
under the filter bed.

page_text: To automatically effect the opening and closing of this plug valve, I employ the
following appliance :-A rod M is fitted so as to have the same reciprocating move-
ment as that of the bucket of the pump F, and this rod is provided with two
tappets N N. The plug cock K is provided with an arm L with a spring tongue P
fitted thereon, which will bend in one direction, but is rigid in the other. Another
similarly fitted lever is pivotted at another convenient point above, and they are
connected by a rod Q. As illustrated in the drawing, the suction stroke has been
just completed, the cock K standing with its passage full
open. The rod M is about
to descend, and the tappet N at the top is about to strike the end of the top lever L,
thereby closing the cock K, and throwing the lever L in such a position that the
lower tappet N will come in contact with it in the course of its movement. The
lower tappet N in completing its downward movement however strikes the spring
pressed pivotted tongue P in that direction in which it gives way, and thus passes
the lever in its downward stroke without producing any consequent movement. On
the return stroke however, the tappet N strikes the spring pressed pivotted tongue P
in its ascent in that direction in which it cannot pivot, and thus raises the lever L
once more reopening the cock K in the suction pipe.
The effect of the reflux charge upon the filter bed is that it agitates and lifts the
slime and pulverised material upon the filter bed, and thus frees the same sufficiently
to permit the maintenance of a rapid flow through the filter bed by the suction action
of the main pump A. The reflux charge of the auxiliary pump may be adjusted by
.altering the throw of the eccentric.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declaro that what I
claim is
1st. The combination, with an ordinary suction pump drawing liquid by suction
through a filter bed of an auxiliary or combined single acting pump without valves
and connected to the suction pipe of the main pump or by a distinct pipe to the filter
bed, substantially as and for the purposes described.
2nd. The combination with the pumps A and F and connected suction pipes D
and G of a valve K with levers L L and tappet rod M, by which the said valve is
automatically worked, substantially as and for the purposes described.
Dated this 90th day of December 1000
FELL & WILDING,
1, Queen Victoria Street, London, E.C.,
Agents for the Applicant.