Improvements in Filters for Artesian Wells.
Year: 1895

page_text: Date of Application, 21st Dec., 1895-Accepted, 14th Mar., 1896
Improvements in Filters for Artesian Wells.
I, FRIEDRICH PEALKE of Sierpe in the Empire of Russia, Brewery Proprietor,
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 :-
In artesian wells the tube which acts as a filter has hitherto according to the.
nature of the ground been perforated for a certain length, and said perforations
occupied about to of the circumferential area of the entire filter tube, so that.
thus to of the surface of the tube remained unutilised. After the holes had
been bored in the tube, the latter were entirely and firmly covered with brass or
tinned copper wire net, that is to say the network was pressed directly on to the
surface of the tube and as a consequence when subsequently used in the well, the
unperforated part of the tube surface, that is to of the whole tube became.
stopped up by the inflowing layer of fine sand. Thus the perforations alone remained
for the passage of the water into the tube, that is into the well. Even this scanty
water supply lasted only so long as the filter was not sanded up by the fine sand
held in suspension in the water.
In view of the small filter surface amounting to about to of the circumference
of the filter tube, and in order not to reduce the flow of water into the well to a
minimum, it was not deemed advisable to select such a fine mesh as would keep
back the finest sand and as a consequence the filter was naturally completely sanded
up in a very short time.
In order to avoid the above drawback in the most certain manner, the filter
which forms the object of this invention has been designed and is so constructed
that the whole pipe so far as it is intended to act as a filter remains always fully
capable of filtering.
In the accompanying drawings,
Figures 1 and 2 are vertical sections of the old and new filter pipes respectively;
and
Figure 3 is a transverse section on the linea of Figure 2.
As shown in Figure 2, increased filtering capacity is attained by spirally
wrapping the pipe a with galvanised brass wire d at a pitch or distance apart of
about 25 millimetres after the boring of the holes (which latter in any case may be
bored further apart) and by soldering on these wire spirals longitudinally of the
tube, strips of galvanised metal c about 12 millimetres in breadth and 1 millimetre
in thickness at distances apart of 25 millimetres. A tinned copper netting or
gauze d through which the finest sand cannot penetrate, is then soldered over the
metal strips and the bottom end of the filter is firmly closed by means of an iron
stopper.
The great advantage of the form of construction just described consists in the
network or gauze being held off the tube surface and consequently the flow of
water into the well pipe is in no way impeded. It must further be noted that
hitherto pipes of large diameter, for instance 160 millimetres were used to form
the whole well, and, as shown in Figure 1, the finished filter a was let into said well
pipe B down to the bottom and the whole well pipe then drawn so far up that
almost the entire filter was exposed. The joint between the filter and the end of
the well pipe was however very often defective in this arrangement, because the
said operation was carried out under water without any means of control. In the

page_text: present filter, this danger is however entirely avoided, because I, in consequence of
the 4 or 5 fold greater inflow of water, can make use of considerably smaller pipes
and can screw the filter a directly on to the well pipe B*, so that any deleterious
influence, whether of surface water or sand is thus excluded from the well.
In using the filter herein before described, a boring to the full depth is first made
with a larger pipe B° and the pipe B with a filter already screwed therein, is then
let down into it, and after this has suitably descended to the bottom, the pipe B°
is again drawn out.
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 :-
:-
A filter for artesian wells consisting of a perforated pipe (a) directly screwed
onto the well pipe (B) and surrounded by a wire spiral (b) and provided with
metallic strips (c) adapted to keep at a distance from the surface of the pipe the
wire gauze (d) which is fastened on said strips and to admit of a free inflow of
water to the well pipe substantially as described.
Dated this 20th day of December 1895.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.