IMPROVE- MENTS IN CALORIC APPARATUS FOR CHANGING THE VOLUME AND PRESSURE OF AIR, APPLICABLE FOR THE PRODUCTION OF AIR BLAST, AND FOR OTHER PURPOSES
Year: 1880

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN CALORIC APPARATUS FOR CHANGING THE VOLUME AND PRESSURE
OF AIR, APPLICABLE FOR THE PRODUCTION OF AIR BLAST, AND FOR OTHER
PURPOSES." A communication from abroad by Nicholas Yagn, of St. Petersburg,
Russia, Mechanical Engineer.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abol at
the Office of the Commissioners of Patents on the 2nd April 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane,
in the County of Middlesex. "IMPROVEMENTS IN CALORIC APPARATUS FOR
CHANGING THE VOLUME AND PRESSURE OF AIR, APPLICABLE FOR THE PRODUCTION
OF AIR BLAST, AND FOR OTHER PURPOSES." (A cominunication from abroad by
Nicholas Yagn, of St. Petersburg, Russia, Mechanical Engineer.)
The present Invention relates to the production of air blast or suction by the
alternate expansion and contraction of air by heating and cooling, such operations
being effected by the direct application of heat, and practically without the aid
of mechanical power, by means of apparatus which I will now proceed to
describe.
A cylinder containing a piston working easily up and down therein com-
municates at one end with an air chamber heated externally by fire, which
chamber also communicates with the other end of the cylinder by a conduit or
second chamber filled with loose material that, while allowing air to pass more or
less freely through it, will readily take up beat therefrom or give off heat thereto,
which second chamber I will term a regenerator. The said other end of the
cylinder is also provided with an inlet valve by which air can enter the cylinder,
and an outlet valve, by which such air can escape. This apparatus operates as
follows:-Assuming the piston to be at that end of the cylinder which communicates
with the air heater, and which I will term the lower end, then on the upstroke of
the piston the comparatively cold air situated above it in the cylinder will be caused
to pass through the regenerator and air heater into the lower end of the cylinder
below the piston: The air on its passage becomes heated, and consequently expands
Го

page_text: to a corresponding extent, so that as the piston travels upward a portion of the air
above it will be forced to escape through the escape valve owing to its increase of
volume as it flows into the lower end of the cylinder, and this escape of air under
pressure due to the heat applied may be utilised either as air blast or for any
other purpose, such as for working a motor engine.
On the piston commencing its down stroke it causes the heated air below it to
pass back through the air heater and regenerator into the upper part of the cylinder;
in so doing the air gives off the greater portion of its heat to the regenerator, and
consequently contracts to a corresponding extent, so that as the piston descends a
partial vacuum will be formed above it, causing the air to be drawn in through the
inlet valve either from the outer atmosphere or from any locality from which it is
-desired-to-remove the air. On the re-ascent of the piston the air so introduced,
together with that already in the cylinder, is again caused to pass through the-
regenerator, taking up heat therefrom, and through the air heater into the lower
end of the cylinder, whereupon the above described action will be repeated..
Instead of allowing the fresh air to enter the cylinder freely during the whole of
the downstroke of the piston, it is preferred for a purpose to be presently stated to
prevent such free entrance until the last part of the stroke. For this purpose there
is provided above the inlet valve a throttle or equilibrium valve, the spindle of
which carries a weighted arm that keeps it closed, but which is acted upon by a
stud on the piston rod towards the end of the downstroke, so as to open the valve
and let the air enter freely. The piston of the cylinder is by preference mado
hollow with a filling of slag wool, baked clay, or other non-conducting substance.
-As-during-both-strokes the pressure above and below the piston is always equal, it
does not require to work tight in the cylinder, and it requires but very little-force-
to impart to it the reciprocating notion.
This power may be derived from any convenient source; thus the suction
produced during the downstroke of the piston may be utilised to drive cither a
small air turbine or other motor engine serving to work the engine. For this
purpose there is provided a branch pipe on the suction valve box leading to the
said motor engine, through which the air drawn into the displacing cylinder is
caused to pass until the above mentioned equilibrium valve.is opened. One such
small motor engine may conveniently be made to work a number of such caloric
apparatus, the suction pipes of all of these being connected to a main pipe lending
to the engine, the piston of which works a shaft having a crank connected by chains
or other gear to the piston rods of the several apparatus; the connections are so
arranged that the pistons are all made to perform their strokes consecutively, so
as together to produco a continuous suction and blast.
The filling in of the regenerator of the apparatus is by preference formed of
very thin corrugated bands of copper coiled spirally and piled one above the
other.
The air heating chamber is constructed by preference in a similar manner to a
tubular steam boiler, the flames from the fire being caused to pass first through the
tubes and then through flues surrounding the shell.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Soal Patent Office on the 1st
October 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN CALORIC APPARATUS FOR CHIANGING
THE VOLUME AND PRESSURE OF AIR, APPLICABLE FOR TILE PRODUCTION OF AIR
BLAST, AND FOR OTHER PURPOSES." A communication from abroad by Nicholas
Yagn, of St. Petersburg, Russia, Mechanical Engineer.
The present Invention relates to the production of air blast or suction by the
alternate expansion and contruction of air by heating and cooling, such operations
being effected by the direct application of heat, and practically without the
aid of mechanical power by means of apparatus which I will now proceed to
describe.
A cylinder containing a piston working easily up and down therein cominunicates
at one end with an air chamber heated externally by fire, which chamber also
communicates with the other end of the cylinder by a conduit or second chainber
filled with loose material, that while allowing air to pass more or less freely through
it, will readily take up heat therefrom or give off' heat thereto, which second chamber
I will term a regenerator. The said other end of the cylinder is also provided with
an inlet valve by which air can enter the cylinder, and an outlet valve by which
such air can escape. This apparatus operates as follows:-Assuming the piston to
be at that end of the cylinder which communicates with the air heater, and which
I will term the lower end, then on the upstroke of the piston the comparatively
cold air situated above it in the cylinder will be caused to pass through the
regenerator and air heater into the lower end of the cylinder below the piston.
The air on its passage becomes heated and consequently expands to a corresponding
extent, so that as the piston travels upward a portion of the air above it will be
forced to escape through the escape valve, owing to its increase of volume as it flows
into the lower end of the cylinder, and this escape of air under pressure due to the
heat applied may be utilised either as air blast or for any other purpose, such as for
working a motor engine.
On the piston commencing its downstroke it causes the heated air below it to
pass back through the air heater and regenerator into the upper part of the cylinder;
in so doing the air gives off the greater portion of its heat to the regenerator, and
consequently contracts to a corresponding extent, so that as the piston descends a
partial vacuum will be formed above it, causing the air to be drawn in through the
inlet valve either from the outer atmosphere, or from any locality from which it is
desired to remove the air. On the re-ascent of the piston the air so introduced
together with that already in the cylinder is again caused to pass through the
regenerator taking up heat therefrom, and through the air heater into the lower
end of the cylinder, whereupon the above described action will be repeated.
Instead of allowing the fresh air to enter the cylinder freely during the whole
of the downstroke of the piston, it is preferred for a purpose to be presently stated
to prevent such free entrance until the last part of the stroke. For this purpose
there is provided above the inlet valve a throttle or equilibrium valve, the spindle
of which carries a weighted arm that keeps it closed, but which is acted upon by
a stud on the piston rod towards the end of the downstroke, so as to open the
valve and let the air enter freely. The piston of the cylinder is by preference made
hollow with a filling of slag wool, baked clay, or other non-conducting substance.
As during both strokes the pressure above and below the piston is always equal, it
does not require to work tight in the cylinder, and it requires but very little force
to impart to it the reciprocating motion.
This power may be derived from any convenient source; thus the suction

page_text: the regenerator, by means of which heat is absorbed from the air passing up through
it from the air heater to the upper end of the cylinder, such heat being imparted
again to the air passing down from the upper end of the cylinder to the air heater.
The air heater D consists of a metal cylindrical chamber, through which pass a
number of tubes, similar to those of a tubular boiler, the chamber being heated by
a fire, the flames and hot gases from which pass first through the tubular flues, and
thence through the flues formed in the surrounding brickwork on their way to the
chimney. This chamber communicates firstly with the regenerator C by means of
the branch d, as before stated, and secondly, with the cylinder A, by the branch c.
Thus the space within the cylinder A beneath the piston B communicates with
the space above the piston through the air heater D and regenerator C, so that on
motion in an upward or downward direction being imparted to the piston, the air
on the one side thereof in the cylinder will be caused to pass freely through the air
heater and regenerator to the other side thereof, the action of the apparatus being
as follows:-
Assuming the piston B to be at the bottom of its downstroke, then on its per-
forming its upstroke, the air above it will be caused to pass through the regenerator
C and heater D into the lower end of the cylinder. The air in becoming
heated on its passago will tend to expand, and the consequent increased pressure in
being transmitted back through the heater and regenerator to the upper part of the
cylinder will cause the outlet valve v¹ to open, so that on the continued upward
motion of the piston only a portion of the air above it will pass to the lower end of
the cylinder, the other portion being discharged through the outlet valve into the
conduit pipe, thus creating an air blast. On the downward motion of the piston,
the air below it will be caused to pass back through the heater and regenerator into
the upper part of the cylinder. In so doing it will in passing through the heater
D become still further heated, but on passing through the regenerator C, it will
give up the greater portion of its heat to its filling, so that it will enter the
cylinder above the piston in a comparatively cool state. In being thus cooled, the
volume of the air entering the cylinder at top will be less than that of the air
displaced by the piston at bottom, and owing to the resulting decrease of pressure,
cold external air will be drawn in through the suction valve v. On the next
upstroke of the piston, the air above it in passing again through the regenerator,
will take up the heat previously deposited therein, and the operation above
described will be repeated; the heating of the air at each upstroke being mainly
effected by the heat deposited in the regenerator during the downstroke, an
additional amount of heat being however taken up from the heater D. Thus at
each upstroke the piston B will cause a certain quantity of air to pass into the
blast pipe, which quantity will be proportionate to the degree of heat imparted to
the air on entering the cylinder below. As this temperature can be carried to
660° Fahr. without injury to the cylinder, it follows from calculations that when
the piston has performed about one ninth part of its upstroke, the pressure of the
air will be about one eighth in excess of the atmospheric pressure, so that during
the remaining 8/9ths of the stroke, air will pass out of the cylinder as blast into
the blast pipe, and this will take place to the extent of about one half of the
volume of the air contained in the cylinder. It will be seen that this blast is
produced without any corresponding pressure being exerted by the piston during
its upstroke, as the air pressure is practically always in balance on each sido
thereof, both during the up and the downstroke, so that its motion will be effected,
with only such slight expenditure of power as is necessary to overcome the friction
of the air in motion, and that of the moving parts. Owing to the balance of air
pressure existing on both sides of the piston, there will be little or no tendency of
the air to leak between it and the cylinder, and consequently there is no need for
the packing to fit tight. By this means any friction due to such packing will be
reduced to a minimum, and any lubrication thereof will be unnecessary, which
circumstance is of great importance, as the burning off and drying in of lubricating

page_text: oils are the principal inconveniences occurring in caloric engines of known
construction.
It will be evident then from the foregoing that according to the essential feature
of this Invention the function of the piston is only to effect the circulation of the
air from the one end of the cylinder to the other and back again, the blast being
produced by the heat actually expended in the alternate heating and cooling of the
circulating air. Thus the power required to work the piston being comparatively
very small may be produced either by a small separate motor engine, or it may be
derived from a small portion of the work performed by the engine itself, making
use for this purpose of either a portion of the air blast produced by the upstroke, or
of the suction or air current entering the cylinder during the downstroke. For the
latter purpose it would only be necessary to cause the air current on its way to the
_ cylinder to pass through a turbine or other suitable motor, the motion of which
would be communicated by any suitable mechanism to-the-piston rod. As for this.
purpose the air current would act with more advantage if caused to operate with
increased speed during a short period of the stroke than if it were produced during
the entire stroke with a proportionately less speed, it is preferred to keep the suction
valve closed during the greater part of the downstroke, so that during this time the
nir pressure within the cylinder will sink considerably below that of the atmo-
sphere. Upon then opening the suction valve the outer air will rush into the
cylinder with a velocity corresponding to the difference of pressure produced.
It has been ascertained that a pressure of about 1/2 lb. per square inch is sufficient
to overcome the resistance of the piston, whereas the pressure produccable by the
suction of the blast engine is about 7 lbs. per square inch.
The above described action is produced by the balance valve K and lever K¹ acted
upon by the piston rod S, as hereinbefore described, the opening of the valve-being
so timed that by the time the piston has arrived at the end of its downstroke the
air pressure within the cylinder will have become equal to that of the atmosphere.
As the cold atmospheric air entering through the suction valvo will considerably
reduce the temperature of the air passing in from the regenerator, which will still
be comparatively hot, the temperature of the air issuing through the pressure
valve during the upstroke will not exceed that of the atmosphere by more than
about 122° Fahr.
Various arrangements for actuating the pistons of the above described apparatus
may be adopted. Thus Fig. 6 shews a plan, and Fig. 7 an elevation of an arrange-
ment in which a series of four blowing cylinders A, A, with their heating apparatus
and regenerators, are placed side by side, and all have their pistons actuated by one
and the same motor engine worked by the current of air produced by their suction.
L is the suction pipe common to all the cylinders; M² is the blast pipe, also common
to all the cylinders; v are the suction valve boxes, which are here placed in the
branches leading to the suction pipe, instead of on the cylinder as at Fig. 1. The
levers K¹ and counterweights Z actuating the throttle valves are omitted in Fig. 7
for the sake of clearness. B2 is a motor engine consisting of a cylinder with piston
and a slide valve at w; this valve is so arranged as by its motion alternately to put
the suction pipe L in communication with the one or the other end of the cylinder,
while the other end is put in communication with the atmosphere. Thus by the
partial vacuum alternately produced on each side of the piston while the air enters
freely on the other side, the piston receives a to and fro motion, which it imparts
by its piston rod, working in the guide m, to the slide valve w, and by a crank to
the spurwheel n, which thus receives rotary motion. The wheel n gears with the
large spur-wheel Q, on the shaft of which is a crank 7, the pin of which carries 4
loose rings a provided with eyes. To these eyes are attached the ends of ropes or
chains which pass round pullies R, R', and are connected by their other ends to the
piston rods S of the blast cylinders. Thus it will be seen that at each revolution
of the wheel Q the crank will cause each of the piston rods S to be first drawn
upwards, causing the pistons B to perform their upstrokes, and will then allow the

page_text: pistons to descend again by their own weight, thus performing their downstrokes.
It will also be seen that by the action of the crank these motions of the pistons
will take place in succession in the four cylinders, thereby dividing the work
uniformly over the entire revolution of the crank r, and producing a continuous
uniform flow of air into the blast pipe. It will be evident that instead of actuating
the pistons B in the manner described this may be effected in various other ways,
such as by an overhead shaft having cranks, by the rotation of which both the up
and downstrokes may be imparted to the piston rods.
Also, as before stated, any other description of motor engine may be employed
for the above purpose.
The blast engine above described is principally. adaptable for metallurgical
purposes; for instance, for blast-furnaces, fineries, large forges, & etc., and generally
in all cases where the ordinary blast-engines require a great expenditure of
mechanical force. It is proved by calculation that in employing the air pressure
obtained by the direct heating thereof, instead of mechanical compression, the con-
sumption of fuel in the caloric blast-engine amounts only to about 1/6th of the
quantity of fuel required by the most improved cylindrical blast-engines of known
construction.
Lastly, it is to be observed that the air furnished by the caloric blast-engine
having a greater pressure than the atmosphere can be employed not only for pro-
ducing a blast, but also for performing any other kind of work. For the latter
purpose it suffices to conduct the air from the blast-engine into the cylinder or any
other receiver of a motor of any system whatever. The air furnished by the
caloric blast-engine being of a temperature comparatively not high, the use of the
present caloric blast-engine as a motor offers an advantage heretofore not practically
obtainable by caloric-engines, viz., that the moving power is consisting of com-
paratively cold air. It is, however, easily understood that in caso of employing a
strong blast for doing mechanical work, it is of advantage to bring the air to the
highest possible degree of pressure, and this is obtained without any difficulty by
letting the air escape from the cylinder at the very moment when the piston B has
reached its highest point in the cylinder. Then the pressure of the air will amount
to more than 2 atmospheres. The admission of air into the cylinder must in that
case take place when the piston has arrived at its lowest point, at which time
the pressure of the confined air in the cylinder will be less than one half
atmosphere.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent,
I claim,―
First. The method, substantially as herein described, of producing air blast by
alternately heating and cooling confined air, and thus causing its alternato
expansion and contraction as it is made to travel alternately from one enclosed
space into another of about the same capacity, a portion of the air being caused to
escape as blast during the timo of expansion, and a fresh quantity of air being
drawn in during the time of contraction.
Second. The construction of caloric apparatus, wherein a piston travelling to
and fro in a cylinder alternately causes the air to flow froin the one end of the
cylinder through a regenerator and a heater to the other end thereof, so as to take
up heat during its transit, and then to flow back again through the heater and
regenerator, so as to give up the greater part of its heat to the latter before
re-entering the cylinder, substantially as herein described.
Third. In caloric apparatus for producing air blast, the combination of a
cylinder and piston with a heating apparatus and a regenerator, and with valves
for the inlet and the outlet of air, arranged and operating substantially as herein
described.
Fourth. The combination of one or more caloric apparatus, such as are referred
to in the preceding claims, with a motor engine worked by the suction or the blast

page_text: produced by the apparatus, and serving to operate the pistons of such apparatus,
substantially, as herein described.
Fifth. The combination of one or more caloric apparatus, such as are referred to
in the preceding claims, with a motor engine worked by the air blast produced by
the said apparatus, substantially as herein described.
In witness whereof, I, the said Charles Denton Abel, have hereunto sot my
hand and seal, this first day of October, in the year of our Lord One
thousand eight hundred and cighty.
CHA³. D. ABEL. (L.S.)