IMPROVEMENTS IN APPARATUS FOR COMPRESSING AIR OR OTHER ELASTIC FLUID
Year: 1876

page_text: "
LETTERS PATENT to Peter Brotherhood, of No. 25, Ladbroke Gardens, Notting
Hill, in the County of Middlesex, for the Invention of IMPROVEMENTS IN
APPARATUS FOR COMPRESSING AIR OR OTHER ELASTIC FLUID."
PROVISIONAL SPECIFICATION left by the said Peter Brotherhood at the
Office of the Commissioners of Patents on the 10th August 1876.
PETER BROTHERHOOD, of No. 25, Ladbroke Gardens, Notting Hill, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR COMPRESSING AIR OR
OTHER ELASTIC FLUID."
My Invention relates to a construction and arrangement of apparatus consisting
of successive pumps for the purpose of compressing air or other elastic fluid by
stages.
In order that the nature of my Invention may be better understood I will
describe the node in which I apply it for compression of air by four successive
stages, it being understood that a similar construction is applicable for another
even number of stages. I fix two inverted cylinders side by side parallel to one
another, and I fit them with trunk pistons provided with suitable packing, the
trunks passing through packed glands. The first cylinder is larger than the second
in any desired proportion, and the two pistons are attached to, one cross head
caused to reciprocate by a steam engine or other suitable power, so that the two
pistons always travel together. The first cylinder has a suction valve at the top,
by which air enters during the down stroke. At the up stroke this valve is closed,
and the air is discharged through a valve in the piston into the annular space
round the trunk. Thence at the next down stroke the air is led by a pipe to a
suction valve at the top of the second cylinder, which it supplics, and at the
following up stroke it is delivered through a valve in the piston into the annular
space of the second cylinder, whence at the next down stroke it is discharged
through a delivery valve into the receiver, being thus by the successive diminution
of areas in the cylinders and their annular spaces compressed by stages up to the
final pressure required.

page_text: In order to keep the pumps cool I supply a little water at the first suction, and
I also immerse the cylinders in a water tank, which keeps their outer surfaces cool.
In order to cool the interior of the trunks I pass into cach through a hole in the
cross head a fixed pipe open at the upper end into the trunk, and communicating
at the lower ond with a box containing a suction and delivery valve, so that
as the pistons reciprocate water is drawn by these pipes into the interior of
the trunks, and discharged therefrom into the tank in which the cylinders are
immersed.
By the construction and arrangement which I have described above I am
enabled to simplify the apparatus, using two trunk cylinders to act as four separate
cylinders; and I am further enabled to cool effectually the air as it is compressed
by causing it to expose a large surface in a thin layer in the annular spaces of the
cylinders.
Although I have described inverted cylinders as a convenient arrangement it is
obvious that the cylinders could be placed upright, horizontal, or at any desired
angle, the operation being similar to that described above.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Brotherhood in the Great Seal Patent Office on the 10th
February 1877.
PETER BROTHERHOOD, of No. 25, Ladbroke Gardens, Notting Hill, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR COMPRESSING AIR OR
OTHER ELASTIC FLUID."
My Invention relates to a construction and arrangement of apparatus consisting
of successive pumps for the purpose of compressing air or other elastic fluid by
stages.
In order that the nature of my Invention may be better understood I will
describe the inodo in which I apply it for compression of air by four successive
stages, it being understood that a similar construction is applicable for another even
number of stages. I fix two inverted cylinders side by side parallel to one another,
and I fit them with trunk pistons provided with suitable packing, the trunks
passing through packed glands. The first cylinder is larger than the second in
any desired proportion, and the two pistons are attached to one cross head caused
to reciprocate by a steam engine or other suitable power, so that the two pistons
always travel together. The first cylinder has a suction valve at the top, by which
air enters during the down stroke. At the up stroke this valve is closed, and the
air is discharged through a valve in the piston into the annular space round the
trunk. Thence at the next down stroke the air is led by a pipe to a suction valve
at the top of the second cylinder, which it supplies, and at the following up stroke
it is delivered through a valve in the piston into the annular space of the second
cylinder, whence at the next down stroke it is discharged through a delivery
valve into the receiver, being thus by the successive diminution of areas in the
cylinders and their annular spaces compressed by stages up to the final pressure
required.
In order to keep the pumps cool I supply a little water at the first suction, and
I also immerse the cylinders in a water tank, which keeps their outer surfaces
cool. In order to cool the interior of the trunks I pass into each through a hole
in the cross head a fixed pipe, open at the upper end into the trunk, and com-
municating at the lower end with a box containing a suction and delivery valve,
so that as the pistons reciprocate water is drawn by these pipes into the interior
of the trunks, and discharged therefrom into the tank in which the cylinders are
immersed.

page_text: By the construction and arrangement which I have described above I anı
enabled to simplify the apparatus, using two trunk cylinders to act as four separate
cylinders; and I am further enabled to cool effectually the air as it is compressed
by causing it to expose a large surface in a thin layer in the annular spaces of the
cylinders.
Although I have described inverted cylinders as a convonient arrangement it is
obvious that the cylinders could be placed upright, horizontal, or at any desired
angle, the operation being similar to that described above.
by causing it to expose a large surface in a thin layer in the annular spaces of the
cylinders.
Although I have described inverted cylinders as a convonient arrangement it is
obvious that the cylinders could be placed upright, horizontal, or at any desired
angle, the operation being similar to that described above.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents a vertical section through a set of compressing pumps arranged
according to my Invention.
A is a cross head caused to reciprocate vertically by any suitable power; it may
be from a crank on a shaft driven by direct acting engines, an arrangement of which
kind I will presently describe. To the cross head A are fixed two trunk pistons,
a larger B and a smaller C, which work respectively in the cylinders D and E.
In the cover of the larger cylinder D is fitted the inlet valve F, which is kept
seated by a spring f. In the piston B is a valve G, by which communication is
opened or closed from the upper end of the cylinder D to its lower annular space;
H is a valve governing the passage h from the lower end of cylinder D to the
upper end of E; G₁ is the valve in the passage from the upper end of E to its
annular space; and I is the discharge valve from the lower end of cylinder E in
a passage i leading to a coil of pipe J enclosed in a water tank j. The trunks of
the pistons B and C are tubular, and through packing at the end of each passes
a stationary tube K communicating with a vessel L having a suction valve
opening into it and discharge valves in pipes leading to the tank j. The two
pistons B and C are shewn at Fig. 1 at the top of their stroke; as they descend
together air enters by the inlet valve F (preferably along with a little water
allowed to trickle into the aperture of the valve) to fill the cylinder D, whilst the
air previously contained in the annular space of that cylinder under the piston
passes by the passage h and valve H to the cylinder E. Also the air in the
annular space of E is discharged by the valve I and passes through the coil J to
the receptacle for the condensed air. The pistons having completed their down
stroke ascend, and the air above the pistons in the cylinders D and E passes by
the valves G and G¹ to the annular spaces below them respectively. During the
ascent of the pistons water from the vessel L is drawn into their interior by the
tubes K to cool them, and during the descent of the pistons water is discharged
from their interior and passes by the pipes to the tank j, whence it is discharged
by an overflow pipe.
·
Figs. 2, 3, 4, and 5, represent respectively a side view, a cross section, an end
view, and a plan of a set of pumps such as I have described above combined on
the same framing with a pair of steam cylinders M and N for working them.
The pistons of these cylinders are connected to cranks on the main shaft O,
a crank a on which works the pump cross head A.
Having thus described tho nature of my Invention, and in what manner the
same is to be performed, I hereby declare that I make no general claim to the
method of condensing air or other gas by stages, that is to say, by means of
pumps of successively decreasing capacities, each discharging into the one smaller
than itself, but I claim for effecting condensation of air or other gas in this
manner
First. The use of two or other number of pump cylinders fitted with trunk or
differential pistons, so that each cylinder is rendered equivalent to a pair of single-
acting pumps, of which the one lias less capacity than the other, substantially as
lierein described.
Second. The method, substantially as herein described, of cooling the trunk

page_text: pistons of pumps such as are referred to in the preceding claim by causing them
to work over stationary tubular plungers communicating with a supply of water.
In witness whereof, I, the said Peter Brotherhood, have hereunto set my
hand and seal, this Thirtieth day of January, in the year of our Lord One
thousand eight hundred and seventy-seven.