Improvements in or relating to Pumps.
Year: 1891

page_text: Date of Application, 19th Nov., 1891-Accepted, 2nd July, 1892
COMPLETE SPECIFICATION.
Improvements in or relating to Pumps.
I, JAMES STEVENSON of Gray's Inn Chambers, 20 High Holborn, London,
W.C., Civil Engineer and Patent Agent, communicated to me by Pierre Metayer
of Paris, in the Republic of France, 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:-
My invention has for its object the construction of a pump for clevating liquids
and compressing gases by means of a quantity of very dense liquid, which liquid
returns to its starting place under the pressure of the compressed gases or of the
raised column of liquid.
In the accompanying drawings
Figure 1 is a perspective view of my improved pump; and
Figure 2 is a sectional enlarged view of the sleeve end (hereinafter referred to)
thereof.
Figure 3 is a perspective view of a modification of my invention.
Figures 4 and 5 are respectively a side and an end elevation of another
modification.
My improved pump consists of a cylinder a surrounded by preferably three
convolutions of a spiral coil the end of the last convolution joining the central
tube c. This tube is mounted on and extends down to near the pivot d thence
returning near the centre of the cylinder a in order to communicate with the first
convolution of the coil. The upper part of the tube c passes through the centre
of the cylinder a and rises above the apparatus where it enters a sleeve e a second
tube is connected at one end with the sleeve e and at the other with the suction
pipe h. The elevating pipe y is connected with the central tube e in the sleeve e.
The apparatus is inclined at an angle of about 30°, being supported by a shaft i
provided with a suitable bearing and held by the sleeve e mounted upon a support.
The spiral tube extends to a point, determined so as to receive its overflow, an
opening & being provided at this point for the purpose.
Through the opening is inserted a certain quantity of mercury such for example
as is sufficient to fill half of the three convolutions of the coil and about of the
tube c; the opening is then closed.
At the beginning, the mercury assumes its natural equilibrium. The suction
tube is placed in communication with the liquid to be raised (water for example)
placed at a depth of at least 10 in. and the apparatus is caused to rotate. As there is
no pressure at first, fluctuation of short duration will result until the pipes and the
pump itself are entirely filled with water. After this, the apparatus being left at
rest, the mercury will occupy practically a vertical position within the convolutions
of the coil between certain points, the remaining portion of the said coil being
filled with liquid while the mercury contained in the pipe g is forced back by the
existing pressure. Upon the apparatus being set in motion again, each revolution
of it causes the first convolution of the coil to discharge its contents into the next,
and similarly the contents of the latter to be discharged into the third convolution
which in its turn discharges the mercury and water it contained into the pipe :
the water is then forced into the central tube c and elevating pipe and issues at
the orifices of the latter while the mercury drops by its own weight into the same
pipe. This fresh quantity of mercury breaks the equilibrium and causes an equal
amount of mercury to reascend in the first convolution and in the space forming
a reservoir for the mercury in excess; the first convolution thus at each turn is
half filled with mercury and-half with water.
9
The height of elevation is in proportion to the diameter and to the number of

page_text: convolutions of the coil; and, the quantity of liquid raised is equal to one half of
the contents. The convolutions are here supposed to be three in number and if the
diameter of each be 0.07 c. the three combined together will produce a pressure of
three atmospheres; but, the better to ensure uniformity in the working of the pump,
it is suggested that the water should only be raised about 25 metres; if the
capacity of each convolution' be 1 litre, litre is raised at each turn. Slow motion
in no way interferes with the proper working of the pump and is therefore prefer-
able, as too rapid a motion would prove disadvantageous on account of the
centrifugal force.
In order to compress gases by means of the same apparatus, the gases are
admitted into the suction pipe h, and the elevating pipe is placed in communi-
cation with a receiver. The size of the successive convolutions of the coil in this
case decreases there being a difference of about two-thirds between the first and
third convolutions to suit the decrease of the volume of the compressed gas which
will thus reach the receiver at a maximum degree of pressure of four atmospheres
including the surrounding atmosphere. If a second coil be connected with the
first, having the same circumference but only one fourth of the capacity of the
first, though similar in shape and provided with the same proportion of mercury,
the connection is formed by means of a pipe forming half a circle in the vicinity
of the sleeve and joining the first convolution of the second coil (shewn in dotted
lines in Figure 1) while the second pipe of this coil takes the position of the pipe
within the sleeve e. The air compressed in the first coil is at each revolution of
the pump forced into the second convolution where it is further compressed and
from whence it passes into the receiver at a pressure about three atmospheres in
excess of that attained in the first coil, in other words at a total pressure of about
seven atmospheres.
By thus coupling together a number of coils and always decreasing their
capacity in proportion to the diminishing volume of the gas, the degree of a
pressure eventually obtained may be increased as required; or, a vacuum may be
produced.
In the construction of pump illustrated in Figure 3, the mercury return pipe is
connected to the coil by sleeves and the water-pipe forms a rising circle so as to
prevent the mercury from descending. The elevating pipe rises vertically from
the apparatus.
In the modified construction of apparatus shown in Figures 4 and 5, a pipe m
is arranged upon the felly of a light wheel n. The ends of this pipe are curved
so as to form a smaller coil and are fitted within a hollow journal o supporting the
wheel. This journal is connected with the vertical pipe provided with two
curved branches, one of which is immersed into the liquid to be elevated, while
the other conveys the water into any suitable reservoir q. This wheel may be set
in motion by means of a crank or hand wheel and two pinions s and 3. The
operation is, substantially, identically the same as that of the apparatus herein
first described the only difference being that instead of having three equal con-
volutions, there are three convolutions of unequal size namely one convolution.
formed by the tube m fixed to the elly of the wheel and the other convolutions
formed by the curved branches of the pipe p.
The effect of these modifications is to render the pump more readily applicable
in practice and more efficient, as said modifications enable a greater yield to be
obtained with the same amount of mercury. The yield. would be the same if the
coil were inclined, and the number of its convolutions diminished, while increasing
its diameter.
This apparatus may be applied both for elevating liquids and compressing gases.
By increasing the size of the pipes and the diameter of the wheel upon which it
is arranged and by substituting water for mercury, it may be converted into a
very powerful and simple air-pump, suitable for mining purposes for example.
The apparatus may also, if required, be used as a vacuum-pump and as such
utilized in the construction of incandescent lamps.

page_text: In short whatever the modification of size and form and the nature of the dense
liquid employed, this improved apparatus is equally applicable, both in laboratories
and manufactories as an air vacuum-pump, or for elevating water or compressing
gas.
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:-
The improved pump and its modifications arranged, constructed, and operating
substantially as and for the purposes herein described and shown in the accom-
panying drawings.
JAMES STEVENSON.