Improvements in Compressing Air or other Gaseous Fluid and Apparatus for that Purpose.
Year: 1890

page_text: Date of Application, 23rd Jan., 1890
Complete Specification Left, 24th Nov., 1890-Accepted, 23rd Apr., 1891
PROVISIONAL SPECIFICATION.
Improvements in Compressing Air or other Gaseous Fluid and
Apparatus for that Purpose.
I, REINHARD MANNESMANN, of Landore, R.S.O. South Wales, Engineer, do
hereby declare the nature of this invention to be as follows
My invention relates to means for compressing air or other gaseous fluid by the
application of heat. In what follows I shall speak of air as the fluid to be com-
pressed, but it is to be understood that other elastic fluid may be compressed in a
similar manner. I provide a cylinder fitted with a displacing piston and I make a
passage from one end of that cylinder with communications to a number of strong
vessels or reservoirs, preferably in the form of closed tubes. These communications
are governed by a rotary or other slide valve or by a set of separate valves worked
by connections from the displacing piston, which may itself be worked by any con-
venient motor. The displacing cylinder has connected to it means of heating the
air in it and preferably also means of cooling the air; both the heating and the
cooling may be effected by causing the air to pass from the one end of the cylinder
to the other through a heater and regenerator, having hot and cold zones, such as
is employed in certain hot air engines. In explaining the operation of this
apparatus I shall assume that the reservoirs, which we may number 1, 2, 3 &c. in
order, already contain air at various pressures increasing from the 1st to the 2nd,
from the 2nd to the 3rd and so on, to the last, which contains air compressed to the
pressure required. Supposing the displacing piston to be at the top of its stroke
and beginning to descend, I first admit to the cylinder above the piston a quantity
of fresh cool air, blowing off a corresponding quantity below. I then admit a
quantity of air from reservoir 1, then from 2 and from the others in succession, thus
by steps raising the pressure of air in the cylinder, up to that of the air in the last
reservoir when the piston has completed its down stroke. As the piston makes its
upstroke, of this high pressure air, having its volume increased by the heating, a
portion goes back to the last reservoir, thus by expansion reducing the pressure in
the cylinder, and then the communications to the successive reservoirs being opened
in reverse order, a portion goes from the cylinder to each, the pressure in the
cylinder being thus reduced by steps until finally the pressure equals that in the
1st reservoir. The principal part of the contents of the cylinder are now blown out
at this low pressure and a corresponding charge of fresh cool air is taken in as
already described, and the action is repeated. The additional quantity of fresh air
thus taken in at each stroke determines the equivalent quantity of compressed air
that may be taken from the last reservoir at high pressure for working an engine or
for other purposes.
Instead of employing a displacing cylinder and piston as above described, a vessel
may be used with means such as a fan or other blower of circulating the air
through the heating and cooling zones of the heater and regenerator. Or circu-
lation, heating or compressing may be at the same time effected by directing a jet
of high pressure steam or a flame burning under pressure into the air.
When a displacer piston is used, the timing of the admission of the air at the
higher pressures may be so arranged as to make the displacer self acting or even
capable of giving off power.
Dated this 23rd day of January 1890.
ABEL & IMRAY,
Agents for the Applicant

page_text: the communication with the reservoirs is cut on.
By this means the air will pass from the lower end of the cylinder into the upper
part, passing on its way through the regenerative heater A (which is heated by
any suitable means) whereby the air is heated to a high degree, for example
to 300° Cent.
The pressure in the cylinder rises at such temperature to double that which it
was before, namely 20 atmospheres.
When arrived in its highest position, the slide S establishes a communication by
its channel between the cylinder, through passages e, f, ƒ³, s and i, and a
passage, closed by a check valve or similar device ; this valve remains closed
until by the heating of the charge as described the pressure in cylinder C exceeds
that existing in passage k beyond the valve, whereupon this will open, and air under
pressure will pass from the upper end of the cylinder back through the regenerator A
into passage k, which conducts it into a pressure main, to be utilised in any desired
manner, such discharged air being however cooled down again before its escape by
its passage back through the regenerator, to which it gives off its heat.
FOURTH PERIOD (Figs. 4, 4*).
The piston having nearly arrived at the end of its down stroke while slide S is
moving downward, the latter is made to establish a communication between
passages ef and reservoir 3. The pressure in the cylinder being now higher than
that in this reservoir, a certain quantity of air passes into the latter until the pressure
in the two is nearly equalised; by the further descent of the slide, reservoir 2 is
now put in communication with the cylinder, whereby the pressure in the former
will be raised to a certain degree, and the same will then take place with reservoir 1.
On the completion of the down stroke of the slide, this will put the cylinder in
communication with the atmosphere through fs and g, so that the remainder of the
pressure in the cylinder will escape into the atmosphere. The greater the number
of the reservoirs, the smaller will be this loss of pressure.
The above described operation No. 1 will now be repeated, that is to say the
piston rises while the slide remains in its lowest position, and so on.
Thus at each up and down stroke of the piston D the pressure in the cylinder will
first be gradually increased from the charges in the reservoirs 1, 2 and 3, the charge
will then be heated, and lastly air under pressure will pass from the same into the
pressure main h, assuming that the pressure attained after heating exceeds that in
the main.
D
Fig. 5 shews an enlarged section of the slide S and its several ports and
passages.
The pressure obtained by the above described means is dependent :
1. Upon the number of the reservoirs the greater the number the higher will be
the pressure in the pressure main.

page_text: 2. Upon the size of the reservoirs; the larger these are in comparison to the
volume of air which alternately passes into and out of the same, the greater will be
the pressure in the cylinder before heating in consequence of the decrease of the
reduction of pressure in the reservoirs, and consequently, the greater will be the air
pressure in the pressure main.
3. From the degree of heating; as the available pressure of course rises with the
temperature attained.
4. Upon the extent of the dead space in the regenerative heater. The smaller
this space is, the higher will be the pressure in the cylinder before heating, and
also, the greater will be the rise in pressure in the cylinder on heating to a certain
temperature.
This influence of the dead space can be maintained comparatively small by the
employment of a large number of reservoirs and by heating to a certain
temperature.
The body of air contained in the heater will, on starting, already have a corre-
sponding high temperature.
.
The piston D and slide S can either be driven by cranks placed at or about
right angles to each other, as described, or they may be driven by any other known
mechanism.
When using crank motions as described the opposite movements of the piston and
slide will not be sharply defined, the slide S will during period 1 begin to move
upward before piston D has completed its upstroke, and so on; but this will only
slightly affect the above described result.
For heating, a regenerator heated in any suitable manner can be used, or the
heating can be effected from the outside, or again, it may be effected by a flame
burning under pressure.
Instead of transferring the air by means of a displacer from one end of the
cylinder to the other, this can also be effected by an injector, Roots blower or other
suitable appliance.
The circulating, heating, and the compression can be simultaneously effected by
blowing a jet of high pressure steam, or a flame burning under pressure in a suitable
manner into the air.
the
If a displacer is employed the connection of the lower part of the cylinder with
upper, instead of being constantly open, can be intermittently opened or closed
and the displacer can be automatically moved, or it can even give off power. For
example it is only necessary in the compression period during which the reservoirs
deliver air to the cylinder to lead this air to that side of the piston which is moving
forward. The same object is attained if, during the period when the cylinder
delivers air to the reservoirs, the air is taken to that end of the cylinder towards
which the piston is at the time tending to move.
:
Having now particularly described and ascertained the nature of this inven
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The method of compressing air or other gases by means of heat, wherein the
waste air is successively charged into a series of reservoirs each of which has a
greater pressure than the preceding one, such stored air being led back to the com-
pression space before heating, in order to serve for the next compression period,
substantially as described.
2. The herein described method of raising, by heating, air and other gases at
once to a degree of pressure which is considerably higher than if the volume of air
or gas introduced were heated to the same degree in an entirely closed space.
3. In caloric apparatus for compressing air and other gases the method of
obtaining to a certain extent automatically increasing pressure, by storing up the
waste air in reservoirs for increasing the pressure of the following charge before the
heating, substantially as described.
4. The method of compressing air or gases by storing the air or gas under

page_text: pressure remaining after heating a quantity of air or gas in a closed space and after
discharging the pressure into the pressure main, in a series of air or gas reservoirs
with decreasing pressure, and then using such stored pressure for the following
charge of the compressing cylinder, whereby the air or the gas is compressed before
the heating, thus effecting, in combination with the following heating of the air or
gas an automatically increasing pressure which is higher than if the volume of air
or gas employed were heated in a closed space to the same degree, substantially as
described.
5. The utilisation of the pressure of the waste air or gases of one charge in caloric
air or gas compressing apparatus, for the compression of a fresh charge in a cold
condition, substantially as described.
6. The herein described construction of apparatus for carrying out the method of
compression referred to in the preceding claims.
7. The combination of vessels for the reception and caloric compression of air or
other gases with one or with one or more storage reservoirs which at each
compressing operation store up a portion of the waste air or other gas which is
otherwise lost, and supply the same to the compressing apparatus again before the
following operation, substantially as described.
Dated this 22nd day of November 1890.
ABEL & IMRAY,
Agents for the Applicant.