Year: 1899

page_text: I, GEORGE MACDONALD, of 40, Dalmeney Road, Tufnell Park, in the County
of Middlesex, Mechanical Engineer, do hereby declare the nature of this inven
tion to be as follows;-
These improvements in filter presses enable me to produce sludge cakes from
sewage in a natural or treated condition or from other liquids or semi-liquids,
such, for instance, as china clay, whiting or peat in a convenient and expedi-
tious manner. I employ a cylinder closed at the ends and provided on its cir-
cumference with small perforations so as to constitute a strainer. In the
cylinder I fit another cylinder or lining which is removable on taking off an end
cover, this lining has also small strainer perforations and is fitted with a piston.
The inner cylinder and, if desired, also the outer cylinder may be wrapped round
with cloth, felt, horse hair cloth, or perforated sheet metal. By pipes provided
with cocks or valves I connect the cylinder ends with a pipe leading to a pump
which serves to force the sewage or other liquid or semiliquid under a high pres-
sure into one end or the other of the cylinder. The valves or cocks may be
operated separately or be connected by toothwheel gearing or otherwise in such a
manner that the opening of a cock to one end of the cylinder closes a cock to
the other end of the cylinder. Assuming the piston to be at what I may call the
left end of the cylinder, I admit sewage under pressure to the opposite or right
end of the cylinder and continue this until no more will conveniently enter, the
thin liquid parts of the sewage escaping meanwhile through the perforations in
the inner cylinder or lining, and the outer cylinder. I then reverse the position
of the cocks, and admit sewage under pressure to the left hand end of the cylin-
der, whereby the piston is forced to the other or right hand end and compresses
the partly solid matter contained in the cylinder into a solid or hard cake.
When the operation is finished an end cover is taken off and the cake pushed out.
The lining as well as the cylinder are cleaned occasionally as required. In order
to produce a continuous manufacture I prefer to employ more than one such
cylinder, so that a man or men can be usefully employed all the time. The
valve or cock gear of two or more cylinders may be connected.
The pressure
employed for forming the cake may be higher than that for the straining opera-
tion and may for this purpose provide the pump with quick and slow clutch
gear. In order to free the lining so that it can be readily removed I may provide
means for giving it a turning motion. Or the lining may be cut open for making
it elastic. This press may also be used for moulding the cake into certain shapes,
for which purpose the piston at each end would be made to form one half of the
mould while the other half would be placed loose in 'the lining at each end.
Dated this 17th day of October 1899.

page_text: COMPLETE SPECIFICATION.
Improvements in Filter Presses and Moulding Presses.
I, GEORGE MACDONALD, of 40, Dalmeney Road, Tufnell Park, in the County
of Middlesex, Mechanical Engineer, do hereby declare. the nature of this inven
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement:
71
The improvements when applied to filter presses 'enable me to produce sludg
cakes from sewage in a natural or treated condition or from other quids or sem
liquids such for instance as china clay whiting or peat, in a convenient and expe
ditious manner. 1 employ a cylinder closed at the ends and provided on it
circumference near each end with small periorations so as to consutute a straine
In the cylinder I fit another cylinder or ning near each end; this lining has als
small strainer perforations, a piston is provideu capable of moving from one end
the cylinder to the other. The liner and if desired also the outer cylinder ma
be wrapped round with cloth, felt, horsehair, cloth or perforated sheet meta.
Each liner with its compressed filtrate cake is removable on taking off the cylin-
der cover at that end. By pipes provided with cocks or valves 1 connect the
cylinder ends with a pump which serves to force the sewage or other liquid or
semiliquid under a high pressure into one end or the other of the cylinder. In
order to tree the lining so that it can be readily removed I may provide means for
giving it a turning motion or the lining may be cut open for inaking it elastic.
Fig. of the accompanying drawings is a plan view partly in section of such
a filter press or moulding press. Fig. 2 is a side view of a somewhat similar press
mounted in trunnions.
A is a double ended filter press cylinder having strainer perforations near each
end, where linings C are fitted having also strainer perforations. B is a piston
with leather packing B¹ near each end. Between the liner and cylinder is
wrapped cloth, felt, horsehair cloth, or perforated sheet metal or both the latter
and cloth or the like. C is a leather packing. A sluice valve D at each end
serves to shut off the entry of sewage from the pipes E, the threeway cock F and
This latter is to force sewage
the sewage supply pipe G from the forcing pump.
into the cylinder ends with gradually increased pressure until the filter becomes
filled with so dense a filtrate that the liquid in the sewage will not pass through
the same except at a higher pressure. In the operating of this filter press the
piston B will be driven forward at a gradually decreasing speed and finally squeeze
the solid matter in front of it into a cake which can be taken out by undoing the
screw H of the bailshaped clamp I and by undoing other screws in case of a
large diameter of cylinder, and then swinging the body of the sluice valve round
the centre of the pipe E the end flanges of which are provided with hydraulic
joint packing. F is a threeway cock.
For larger diameters or for ensuring a more perfect action the press cylinder
may as shown in Fig. 2 be mounted in trunnions in bearings M, whereby the
weight of the piston gives an additional squeeze when it is let fall from the top
to the bottom position, the cylinder being then in a vertical position. N is a
spoke wheel for turning the cylinder round by. K and L are additional screws for
securing the sluice valves I). The cake is removed when the cylinder has been
brought into the horizontal position or thereabouts.
Assuming the piston to be at what may call the left end of the cylinder,
admit by the threeway cock F sewage under pressure to the opposite or right end
of the cylinder and continue this until no more will conveniently enter, some of
the thin liquid part of the sewage escaping meanwhile through the filter at the

page_text: a
right end. I then reverse the position of the cock F and admit sewage under
pressure to the left end of the cylinder whereby the piston is forced to the right.
end and compresses the partly solid matter there into a hard cake. The lining
as well as the cylinder are cleaned occasionally as required. In order to produce
continuous manufacture I prefer to employ more than one such cylinder so that
a man or men may be usefully employed all the time. The valves or cocks of two
or more cylinders may be connected. The pressure employed for forming the cake
may be higher than that for the straining operation, and L may for this purpose
provide the pump with quick and slow clutch gear. When such a press is used
adapted for moulding the cake (say of paper pulp) into certain shapes the piston
ends would be formed to the desired design, or the cylinder covers or both.
or
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. A filter press or moulding press in which a piston is impelled by the sewage
or other liquid or semi liquid under pressure on one side of the piston for the
purpose of straining or filter pressing the sewage enclosed in the previous opera-
tion on the other side of the piston, the action being alternating.
2. The construction of apparatus described with reference to rig. 1.
3. The construction of apparatus described with reference to Fig. 2.
Date the Sevantaouth
2000
this Sevantoon l
1000.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.