Improvements in Power-plants for Raising Water and other Liquids from Mines.
Year: 1897

page_text: Date of Application, 15th Mar., 1897-Accepted, 29th May, 1897
COMPLETE SPECIFICATION.
Improvements in Power-plants for Raising Water and other Liquids
from Mines.
1, LUDWIG KAUFMANN, of Aachen, in the Province of the Rhine, German
Empire, 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 refers in general to power-plants for raising liquors (water, brine,
and the like) from mines, and in particular to that kind of such plants, in which
the motor driving the pump is located below the surface whereas the generator of
the power requisite for that motor is located above the surface. Plants of this
kind have up to now been operated either only by steam, or by steam and water;
when using only steam the engine and the mine-pump are both located below the
surface, and the steam is thus led down by a pipe from the boiler to said engine;
but when using steam and water the engine and a pump are arranged above the
surface, and the water which is put under pressure within said pump is led down
by a pipe to a water-motor which in its turn drives the mine-pump proper.
Arranging the steam-engine below the surface is connected with the drawback of
necessitating a large room and a strong foundation, which in many cases renders
the erection of the plant circumstantial as well as expensive. Moreover, the long
steam pipe causes a great loss of heat, and the hot water of condensation resulting
from the exhaust-steam raises in an unwished for degree the temperature of the
water or other liquor to be pumped out of the mine. Finally, other drawbacks,
such as incrustations and chemical reactions necessitate frequent repairs of such
plants.
Employing a water-motor instead of a steam-motor within the mine allows of
doing with a smaller room, it is true, but there is requisite a pipe-line more for
leading the waste-water of the motor up to the surface, and the pressure within
that pipe-line as well as within the other one (for leading the water from the upper
pump down to the motor) is very great. For instance, in a pipe-line having a
length of 600 meters the pressure amounts to 60 atmospheres. Further, in moving
so long columns of water there arise very violent and dangerous shocks, which
require the pipe-lines to be constructed with extreme care, and the places of
abutment or connection of the pipes to be excellently tightened or packed.
The frictional resistance offered by such pipe-lines is enormous, the more, as the
quantity of water to be moved through the line is oftentimes very great. For instance,
a water-motor of 500 H.P. located in a depth of 600 meters requires pipes of a
diameter of 150 millimeters; the weight of the water amounts then to about
24000 kilogrammes, and, finally, in water pipes as well as in steam-pipes the metal
is affected by the water.
Thus, steam power plants as well as water power plants are not well suited for the
purpose in question, i.e. for raising water from mines.
A third kind of power plauts, that is to say, air-power plants or pneumatic plants
have in this specification not yet been treated, and it may seem that such kind of
plant may easily be substituted for any of the two above dealt with. In fact,
however, the systems that have become known up to now are far from being suited
for mines. Compressed air has up to now been used only in connection with
expansion-engines, but these engines must be furnished with fly-wheels and require
Price adl

page_text: in consequence thereof large spaces. Furthermore, to prevent the formation of
icc the engines should be combined with heating devices, which in their turn
necessitate a steam pipe line.
These and other drawbacks are avoided in the system forming the subject-matter
of the present invention. The compressed air is led in or through a circuit, in such
a way, that the air which has been compressed by a compressor located above the
surface is led back to this compressor after it has worked within the air motor
located below the surface. An important feature of my invention resides however,
in letting the compressed air not completely expand within said motor, but letting
it escape from the same with a comparatively high tension, in a similar manner as
is the case with steam working within the high pressure cylinder of a compound-
or multiple-expansion-engine. If, for instance, the compressed air enters the motor
with a tension of about 9 atmospheres 1 let it escape from the motor with a
tension of about 6 atmospheres; if the inlet-tension amounts to about 11 atmospheres,
then the outlet tension is to amount to about 8 atmospheres, and so on. Thus, the
working pressure proper (within the air-motor) is a difference between two different
pressures, the higher of which is produced by the compressor, whereas the air
baving the lower pressure is either led back to the compressor, or is led to the
boring apparatus or other mine-machines for driving the same. A pneumatic power
plant constructed after the principle just revealed has all the advantages of the
pneumatic plants known, but is free of the disadvantages of the same.
The com-
paratively low useful tension allows of employing degrees of filling of from
75-80% The higher the inlet-pressure is, the higher degrees of filling may be
used. The air-motor may work nearly without any expansion at all, and there may
thus be employed comparatively small fast running engines without fly-wheels and
with the simplest valve-arrangements imaginable. Owing to the slight expansion
the cooling of the compressed air is also so slight that any formation of ice is
perfectly prevented. Suppose, the air motor be located in a depth of 600 meters
and the power requisite for driving the mine pump amount to 500 H.P., and the free
section of the pipe-line be double as large as in the example above spoken of, then
the compressed air present within the pipe-line at any given time will amount to
no more than 500 kg., whereas with water the weight amounted to not less than
24000 kg.
Another advantage offered by my novel system resides in the following:
There is in nearly every recently established mine-plant an air-power plant
which serves for operating the boring-apparatus and other machines in the mine.
This plant which generally works with a pressure of about 6 atmospheres may very
well be combined with the pumping-plant by adding to the already existing air-
compressor another compressor which increases the teusion of the compressed
air produced by the first compressor; only then the compressed air is led down to
the air-motor in the mine, and the exhaust-air of this motor is led over into the
feed-pipe for the boring-apparatus or other machines employed within the mine.
Thus, the combination of the existing air-power plant with my novel arrangement
necessitates only one pipe line more, as the existing pipe-line which up to then was
used for feeding the boring apparatus and the like may now be used for leading
any surplus of the exhaust air back to the second compressor.
In order to make my invention more clear, I refer to the accompanying drawing,
in which:
Figure 1 is a diagrammatical view of a vertical section through a part of a nine
furnished with an air-power plant constructed according to my invention, and
Figure 2 is a similar view showing only the lower part of the plant, but with
some changes which will be referred to in the further course of the specification.
The air is first compressed within the compressor A up to about 6 atmospheres
and the compressed air is then led down to the boring apparatus and other
mine-machines through the pipes a and a¹.
The parts A a a¹ exist, of course, in any mine where the boring apparatus and
the like are operated by means of compressed air. When enlarging such a plaut

page_text: according to my system another compressor B is provided, and the inlet port of this
compressor is connected with the pipe a of the first compressor by means of a
pipe b. The compressed air produced by the compressor A flows over also into the
pipe and into the compressor B, and is further compressed within the same up to
about 9 atmospheres. Then the compressed air is delivered into the pipe c and is
led down to the air-motor m which in its turn operates the pump W. The exhaust
pipe d of the air motor is connected with the pipes a a', as shown, so that
consequently the exhaust air is compelled to pass over into one or the other of
these pipes.
The manner of operation of this air-power plant may easily be understood.
The piston of the air-motor m is on one side exposed to a pressure of 9 atmospheres
(produced by the compressor B), but on the other side of said piston there is a
counterpressure of 6 atmospheres (produced by the compressor A.). Therefore,
the useful tension is comparatively low, in that it amounts to 3 atmospheres only.
The motor m may thus work with a degree of filling of from 75-80% which
allows of employing a fast running engine without fly-wheel and with a very
simple arrangement of valves.
The exhaust air issuing from the pipe d flows either into the pipe a or into the
pipe a', or into both these pipes. If, for instance, the boring apparatus and other
machines within the mine do not consume as much air as is delivered by the pipe d,
then the excess of air flows upwards through the pipe a and b into the compressor B,
so as again to be compressed up to 9 atmospheres. If, on the other hand, the
apparatus M are able to consume all the exhaust air of the motor m, then there
will be no flow of air at all within the pipe a between the pipes a¹ and . If,
finally, the apparatus require a greater quantity of air than is exhausted by the
motor, the necessary air is taken out of the pipe a.
The arrangement before described allows of using very simple air-motors which
require no attendance at all, and may run perfectly automatically, so that they may
be regulated from above the surface by causing alterations of pressure within the
pipes a or c. The regulation of the tension of the compressed air may well be
effected by aid of accumulators inserted into the pipes a and c, or into one of these
pipes. By affording the possibility of operating the valves of the motor from a
distant plane, for instance from the engine house above the surface, there is attained
the great advantage that in case of the mine getting flooded the power plant
remains perfectly operative and is able to pump the water out of the mine.
In the modified form of construction shown in Figure 2 the pump W is not the
mine-pump proper, but is connected with a water motor W₁ by means of pipes w w'.
The water motor W₁ drives the mine pump proper W 2 and is driven itself from
the pump W by aid of the water streaming to and fro through the pipes w w¹.
I prefer to make use of this arrangement in cases where it must be expected that a
frequent flooding of the mine will occur. The air motor m and the pump W are
located in a height up to which the water cannot rise. The co-operation of the
air-motor with the two compressors and with the boring-apparatus and the like of
the mine is just the same as above described.
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 a power plant for raising liquids from mines, the combination with a pump
located below the surface, of an air-pressure motor also located below the surface
and arranged to drive said pump; an air-compressor located above the surface, and
pipes adapted to lead the compressed air from said compressor to said motor,
and the exhaust-air of the latter back to the compressor, the compressed air being
caused to work within the motor with either no fall of tension at all or with but a
slight fall, substantially and for the purpose as described.
2. In a power plant for raising liquids from mines, the combination with a pump
located below the surface, of an air-pressure motor also located below the surface,

page_text: and arranged to drive said pump, an air-compressor located above the surface; a
pipe adapted to lead the compressed air from said compressor to said motor;
another pipe adapted to lead the exhaust air of the motor back to the compressor;
mine engines of any description located within the mine, and a pipe or pipes
connecting said exhaust pipe with the inlet ports of the cylinders of said
mine-engines; the compressed air working within the said motor with either no
fall of tension at all or with but a slight fall, so that the air exhausted from the
motor has a tension sufficient to operate said mine-engines, substantially as
described.
3. In a power plant for raising liquids from mines, the combination with a pump
located below the surface, of an air-pressure motor also located below the surface
and arranged to drive said pump; an air-compressor located above the surface;
another air-compressor also located above the surface; a pipe connecting the
outlet-port of said first compressor with the inlet port of said second compressor;
another pipe connecting the outlet-port of the second compressor with the
inlet-port of said motor; and a third pipe connecting the exhaust-port of the
motor with the said first pipe, substantially and for the purpose as described.
4. In a power plant for raising liquids from mines, the combination with a pump
located below the surface of a water-motor also located below the surface and
arranged to drive said pump; another pump also located below the surface; pipes
connecting said other pumps with said water-motor; an air-pressure-motor also
located below the surface and arranged to drive the other pump; an air-pressure
motor located above the surface, and pipes for leading the compressed air to said
air-pressure motor, and the exhaust air of the latter back to said compressor,
substantially and for the purpose as described.
Data: 11
1 1007
LUDWIG KAUFMANN,
By Geo. Thos. Hyde,
No. 1, Broad Street Buildings, Liverpool Street, E.C.,
Agent for the Applicant.