mprovements in the Utilization of Air or other Gas for the Production of Motive Power, and in Apparatus therefor.
Year: 1892

page_text: Date of Application, 8th Jan., 1892
Complete Specification Left; 6th Oct., 1892-Accepted, 12th Nov., 1892
PROVISIONAL DIEVIT
mprovements in the Utilization of Air or other Gas for the
Production of Motive Power, and in Apparatus therefor.
I, ALBERT KRANK, of Taipale, Finland, Engineer, do hereby declare the nature
f this invention to be as follows:-
My invention has for its object to utilize more effectively and economically than
eretofore the power produced by the heating and consequent expansion of air or
ther permanent gas, and in carrying out my invention I compress the air or other
as previous to heating the same, abstracting the heat which is produced during
he compression, so that the air is delivered to the heater in a cool condition,
whereby it is capable of taking up more heat and thus of greater expansion than
f delivered to the heater in a warm state, and I thus practically reduce to a
minimum the power necessary for effecting the compression.
The heat may be imparted to the compressed air in various ways such for
example as,
(1) by passing it through a coil or heater directly heated by a furnace :
(2) by passing it through a steam-heater, or
(3) by causing the compressed air to mingle with steam.
In a suitable arrangement for carrying out my invention I employ an engine
of ordinary construction and an air-pump or compresser advantageously operated
from the engine and, in order to abstract the heat from the air during the com-
pression thereof as hereinbefore stated, the cylinder of the air-compresser is
surrounded by water-jackets and the cylinder-covers and the piston are constructed
so as to have very large conducting surfaces; for example I find it advantageous
to provide the piston and the cylinder-covers with wedge-shaped grooves, so that
the said piston in central section is of a zig-zag form. The ribs between the
grooves may be hollow or solid and are made of a good conducting material such as
brass.
In some cases I arrange in conjunction with the engine a condenser into which
the exhaust is delivered and from which the air for supplying the pump is with-
drawn. In practice I advantageously maintain a pressure in this condenser which
serves for starting the engine, or I may provide means whereby the engine may, in
In the case where the air is heated by
the first instance, be started by steam.
mingling with steam, the air serves to condense the steam and at the same time to
absorb its latent heat.
It will be understood that the relative areas and strokes of the piston of the
engine and the piston of the pump must be proportioned according to the difference
5 in volume between the necessary quantity of air in its heated and its cool
condition.
Dated the 8th day or ợ
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Utilization of Air or other Gas for the
Production of Motive Power, and in Apparatus therefor.
I, ALBERT KRANK, of Taipale, Finland, 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 to utilize more effectively and economically than
heretofore the power produced by the heating and consequent expansion of air or
other permanent gas (hereinafter referred to as air only).
In carrying out my invention I compress the air previous to heating the same,
such compression being done, so that the heat produced during the compression is
abstracted, whereby the air is rendered more capable of taking up the heat than if
delivered to the heater in a warm condition, and whereby the power expended for
the compression is practically reduced to a minimum, the pressure of the air and
consequently also the resistance to the movement of the piston of the compressing
pump being less at a low temperature than at a high one.
The air which I use may have a higher initial pressure than that of the
surrounding atmosphere, and for such purpose I advantageously confine such air in
a closed circuit, one part of which contains compressed air and the other part
expanded air, that is to say, the air exhausted from the cylinder in which it is
utilized. The compressing pump takes its supply from that part of the circuit
containing the expanded air and delivers it to the part containing the compressed
air where it is heated and its volume and working capacity thus increased. The air
after it is exhausted from the cylinder is cooled before it is again compressed.
In some cases however, air of atmospheric pressure is used and in this case the
air is not confined in a closed circuit the air for compression being drawn from the
surrounding atmosphere.
The heat may be imparted to the compressed air in various ways, such for
example as :-
1. By passing it through a coil or heater directly heated by the combustion of
fuel, or indirectly by means of steam.
2. By causing the compressed air to mingle with steam, or other hot vapour.
Previously to being so heated, however, the compressed air is advantageously
partly heated in what I term a preliminary heater by the heat remaining in the
expanded air or by the gases escaping through the funnel or chimney thus effecting
economy of fuel.
To enable my invention to be fully understood I will describe how it can be
carried into practice by reference to the accompanying drawings, in which :-
Figure 1 is an elevation partly in section shewing an arrangement of apparatus
in which the air is heated directly by the combustion of fuel.
Figure 2 is an elevation shewing an arrangement wherein the air is heated by a
steam heater.
Figure 3 shews an arrangement of apparatus where the compressed air is mingled
with steam.
Figure 4 is a sectional elevation to an enlarged scale of the air compressing pump,
which I advantageously employ; and of two other pumps hereinafter described.
Figure 5 is a side elevation of one of the pumps shewn in Figure 4.
Figure 6 is an elevation of the engine of the apparatus detached.
Similar letters of reference indicate corresponding parts in the several figures.
a indicates a vertical engine of ordinary construction, 6 being the cylinder
thereof and indicates the air-compressing pump. The piston-rods of the
cylinder b and the pump c are connected to a beam d in a well known manner so
that both move at the same time. e, f are small pumps placed at the sides of the
compressing pump c, and worked from the ends of the cross-head c¹ of the same

page_text: as shewn in Figure 4, the pump e serving for circulating the cooling water and
the pump for charging the circuit with air in case there should be any
leakage. When air at atmospheric pressure is used the pump f naturally is
not necessary. The said pump f may also be used to create the initial pressure
in the circuit or a special hand or donkey pump may be used for the purpose.
In order to prevent the charging pump from gradually raising the pressure
in the circuit above the desired point, the piston or plunger of the said pump f
is adapted to be adjusted relatively to the end of the cylinder in which it works
so that the pump f compresses up to any pressure desired, but so that as soon as
the pressure behind the delivery valve y reaches the predetermined limit no more
air will pass through the valve, the compressed air finding sufficient space in the
pump and expanding again during the outstroke of the piston or plunger. In order
to effect this adjustment of the piston or plunger, I advantageously connect the
piston rod f' of the pump f to the crosshead c by means of a stirrup f' as shewn
in Figures 4 and 5, the said piston rod being screw-threaded and provided with
nuts f, for adjusting it relatively with the stirrup.
9 indicates the preliminary heater which is connected with the air-compressing
pump by a pipe h, and i is the main heater into which the partly heated air from
the preliminary heater passes through a pipe i, a pipe connecting the main
heater with the valve-chest of the engine. The said preliminary heater (as shewn
in the drawings) is provided with a series of internal tubes j, j through which the
compressed air delivered from the pump c passes, but an ordinary coil may be used
for the purpose of heating the air. The space around the heater g is connected by
a pipe with the exhaust of the engine and is provided with a series of baffle
plates 1, for causing the heated exhaust air to travel in a circuitous course over
the tubes j, j and so give up as much heat as possible.
m is a cooler into which the partly cooled exhaust air from the preliminary
heater is led through a pipe m¹ to be further cooled, a pipe m³ serving for the
return of the air to the pump c; this cooler, as shewn, is of similar construction
to the preliminary heater g, the air to be cooled passing around tubes j, j and
cooling water through the said tubes. This second cooler is not necessary when
air at atmospheric pressure is used.
When the air is to be heated directly by the combustion of fuel, the heater i is
advantageously located as represented in Figure 1 so that the heat can be shut off
when the apparatus is at rest. For this purpose I have shewn two dampers n, o
the former being in a flue for conveying the products of combustion from the
furnace to the heater, and the latter in a flue through which the products of
combustion may escape directly to the chimney.
When the apparatus is at work, the damper n is opened and the damper o
closed so that the gases pass over the heater; when, however, the apparatus is not
at work, the damper n is closed and the damper o opened so that the products of
combustion are conducted directly to the chimney.
When a steam heater is used (as shewn in Figure 2) the steam is conducted from
a boiler p through a pipe to the heater i and the water of condensation is returned
to the boiler by the pipe r.
The heated gases pass from the heater through the pipe and the valve i to
the cylinder b, and having done their work therein they pass through the pipe k,
the preliminary heater 9 and the pipe m¹ into the cooler m where they are cooled
before again passing to the pump c through the pipe m².
When the compressed gases are heated by causing them to mingle with steam
(as shewn in Figure 3) the partly heated air from the preliminary heater 9 is
conducted through the non-return valves and the pipes' to the steam pipe ³,
leading from the steam boiler p to the cylinder b. The steam should be of about
the same pressure as the compressed air and, if higher temperatures are desired
for the steam or the air they may be super-heated before reaching the junction of
the pipes with the pipe. In order to mingle the air properly with the stean in
the pipe it is advantageous to have the pipe enlarged at the point where the

page_text: air enters and to admit the air into the steam through a perforated pipe placed in
the enlarged part so that the air enters into the steam in small jets. By expansion
of the mixture of steam and air in the cylinder b, the steam is condensed giving
off its latent heat to the air. The quantity of steam admitted should naturally
not be more than can be condensed by the air during the expansion. The
quantity of the steam admitted is practically regulated by the proportions of the
pump cand of the cylinder b, that is to say, the pumpe must be so proportioned
as to deliver at each stroke a quantity of air which is insufficient for the stroke but
which with the addition of the required quantity of steam for heating the air will
make up the quantity of motive fluid necessary for the stroke of the engine.
When the air is confined in a closed circuit the particles of hot water, exhausted
with the air from the cylinder b, are separated from the air in the trap‍t from
which they are returned to the boiler by an ordinary feed-pump.
The dried air passes from the trapt to the preliminary heater 9 and thence
through the cooler m again to the compressing pump c. If air of atmospheric
pressure is used the trap t is not necessary.
In order to abstract the heat from the air during the compression thereof as
hereinbefore stated, the cylinder of the compresser is surrounded by water-
jackets u, u (see Figure 4); as, however, such water-jackets would not be sufficient
to effectually reduce the temperature, I provide the cylinder with very large con-
ducting surfaces. As shewn in Figure 4, the piston which is indicated by the
letter v, is provided with several wedge-shaped grooves and on the cylinder-covers
I arrange corresponding ribs adapted to enter the grooves in the piston during the
reciprocation thereof, as will be readily understood. As shewn in Figure 4, the
ribs on the covers are made solid and a corresponding cooling surface is provided
on the back side of the covers, but where space allows the said ribs may be
made hollow so as to allow the cooling water to enter nearer to the surface of the
ribs.
Although I have described my invention as applied to a single acting engine it
is to be understood that it is also applicable for use in connection with compound
engines, and in such case I advantageously arrange for the gases after leaving
one cylinder to pass through an auxiliary heater before reaching the next cylinder
and so on.
It is to be understood that I do not confine myself to any particular arrange-
ment for carrying out my invention, those shewn in the drawings being simply
given as illustrations of suitable means for carrying the invention into practice.
For instance, instead of using a single air-compresser, I may use a series of such
compressers. which may be either single or double acting, and such compresser or
compressers may be driven by auxiliary engines independent of the main engines,
the said auxiliary engines operating by a part of the heated gases.
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. The method of utilizing air or other gas as a motive power consisting in
first compressing such air or gas and at the same time abstracting the heat
produced during such compression, and then passing the cool compressed air
through suitable heaters or otherwise heating the same before using it in the
engine to be driven, substantially as described.
2. In apparatus for utilizing air or other permanent gas as a motive power, the
combination of the following elements arranged in an open or closed circuit, viz. a
motor in which the power generated is to be employed, an air-compresser and
means for heating the air or other gas compressed by the pump before passing to
the motor and when a closed circuit is used for cooling the air or gas before it
again returns to the pump, all substantially as described.
3. In apparatus for utilizing heated compressed air or gas as a motive power, an
air-compressing cylinder and piston constructed with ribs and grooves; substantially

page_text: in the manner and for the purpose described and illustrated in Figure 4 of the
accompanying drawings.
4. The several arrangements of apparatus for utilizing heated compressed air
or gas as a motive power constructed and operating substantially as described
and illustrated in Figure 1, in Figure 2 and in Figure 3 respectively of the
accompanying drawings.
CO 1000
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.