AN IMPROVED CONSTRUCTION OF COMBINED STEAM AND HOT AIR GENERATOR
Year: 1883

page_text: LETTERS PATENT to William Turnbull, of 2 School Road Villa New Hampton
in the County of Middlesex Engineer-for an Invention of "AN IMPROVED
CONSTRUCTION OF COMBINED STEAM AND HOT AIR GENERATOR
"
PROVISIONAL SPECIFICATION left by the said William Turnbull at the
Office of the Commissioners of Patents on the 31st October 1883.
WILLIAM TURNBULL of No 2 School Road Villas New Hampton in the County
of Middlesex Engineer "AN IMPROVED CONSTRUCTION OF COMBINED STEAM AND
HOT AIR GENERATOR"
The object of this Invention is generating Hot Air for subsequent heating or
power producing purposes by a combination of tubular receptacles flues and pumps
in which a portion of the heat or the waste heat from the furnace of a Steam
Boiler is utilized for heating air in a second receptacle or vessel combined or
connected with the said Steam Boiler such second Vessel or receptacle being
supplied with compressed air forced therein by suitably arranged pumps.
When carrying my Invention into practice the air before entering the compressing
pumps worked by Steam or manual power is partially moistened by a jet of cold
water sprayed thereon or the air may be cooled after leaving the compressing
pump or pumps by passing it into a receptacle containing tubes having cold water
flowing through them.-Again the air after leaving the compressing pump or cooler
is first heated by passing it into the receptacle containing tubes before mentioned
and then further heated if required to a higher temperature or volume by passing
it from the tubular receptacle into tube coils worms or other suitably arranged
pipes conveniently placed in or connected with the furnace or combustion chamber
of the Steam boiler, or if desired the Air may first pass from the pumps or cooler
into and through tubular coils worms or pipes and then finally into the tubes
contained in the receptacles before mentioned. The air in this compressed and

page_text: heated condition flows through suitable thoroughfares to be used separately or in
conjunction with Steam for Heating purposes or into the Cylinder or Cylinders of
a Steam and Hot Air Engine for power producing purposes the hot air or hot air
and Steam combined is exhausted into the furnace of the Steam boiler to aid and
improve combustion.
SPECIFICATION in pursuance of the conditions of the Letters Patent, and of an
Order of the Lord Chancellor, filed by the said William Turnbull in the
Patent Office on the 15th May 1884.
WILLIAM TURNBULL of 2.School Lane Villas New Hampton in the County of
Middlesex "AN IMPROVED CONSTRUCTION OF COMBINED STEAM AND HOT AIR
GENERATOR
"
The object of this Invention is generating Hot air for subsequent heating or
power producing purposes by a combination of tubular receptacles Aues and pumps
in which a portion of the heat or waste heat from the furnace of a Steam Boiler is
utilized for heating air in a second receptacle or vessel combined or connected with
the said Steam Boiler such second Vessel or receptacle being supplied with
compressed air forced therein by suitably arranged pumps.
When carrying my Invention into practice, the air before entering the compressing
pumps, worked by steam or manual power is partially moistened by a jet of cold
water sprayed thereon or the air may be cooled after leaving the compressing
pump or pumps by passing into a receptacle containing tubes having cold water
Howing through them, again the air after leaving the compressing pumps or cooler
is first heated by passing it into the receptacle containing tubes before mentioned
and then further heated if required to a higher temperature or volume by passing
it from the tubular receptacle into tube coils, worms, or other suitably arranged
pipes conveniently placed in or connected with the furnace or combustion chamber
of the Steam Boiler or if desired the air may first pass from the pumps or cooler
into or through tubular coils, worms or pipes and then finally into the tubes
contained in the receptacle before mentioned The air in this compressed and
heated conditions flows through suitable thoroughfares to be used separately or in
connection with Steam for heating purposes or into the Cylinder or Cylinders of a
Steam and Hot Air Engine for power producing purposes, the hot air or hot air
and steam combined is exhausted into the furnace of the Steam boiler to aid and
improve combustion.
In order that the Invention may be well understood and explained in detail
I have hereunto annexed three sheets of Drawings representing as examples the
application of my Invention to three different classes of generators viz: to Marine
Locomotive and Stationary Boilers, letters of reference being made on corresponding,
parts on all the Fig' alike On Sheet 1 Fig. 1 represents a transverse sectional

page_text: elevation of a Marine Boiler- of the Flue and Multitublar class having applied
thereto my improvements,
Fig 2 represents a longitudinal section of the same.
In these-Figs a is the shell of the boiler b the furnace c the boiler tubes d.the.
combustion chamber e the hot air generator f. are tubes which forms passages or,
thoroughfares through the hot air generator, these tubes may be placed in a
horizontal position as shawn, or they may be placed in any other convenient
position and the cylinder or receptacle containing them should be placed
immediately above or near the steam boiler a the flue or chimney for the escape
of the unconsumed gases is shewn at g, the hot gases as they leave the furnace b,
and combustion chamber & pass through the tubes c into the smoke box d¹ from
whence the heated gases, pass through the tubes f of the hot air generator e.into
the chimney g The heated gases whilst passing through this generator which is
filled with compressed air, heats and expands such air to a high degree of
temperature, if the heat of the waste gases is not sufficient for the purpose I
provide a thoroughfare between the combustion chamber d and the flue e' of the
hot air chamber, and this thoroughfare I close in with dampers the object of
which regulates and governs the passage of the heated gases from the combustion
chamber, so as to allow a portion of such heat to pass direct into the flue e¹ where
it mingles with the waste gases in the smoke box d thereby increasing the heat
in such Gases before passing through the tubes of the hot air chamber, Such
passage of hot gases from the combustion chamber in the case of vertical tubes
being used may pass direct into and through the same without the necessity of
entering the smoke box. The waste gases in this case mingle with each other and
escape up the chimney or such gases may be otherwise directed and utilized. It
will be understood that the air in the generator is applied thereto and compressed
therein by a pump or pumps through the pipes k preparatory to its "being heated
and expanded by the waste gases of the furnace as described
it
After the air in the hot air chamber e has received its full heat and expansion,
passes off from such chamber through the pipes . to be employed as an Agent
for motive power purposes, or as a hot blower, or for other uses."
On sheet 2 my improvements are illustrated as applied to Locomotive, portable,
or semi-portable Boilers, Fig: 3 being an end elevation Fig 4 a longitudinal section,
and Fig: 5 a plan In these Figs: a is the Boiler b the furnace or fire box c the
tubes through the boiler d the combustion chamber, e the hot air Generator
f the hot air tubes g the chimney h the thoroughfare between the fire box and
combustion chamber i the regulating dampers & the pipe from the pump feeding
the chamber e with compressed air, is the pipe by which the hot air escapes to
the cylinders of the Engine, to be used in conjunction with Steam for giving
motive power n is the dome from whence the steam is taken to the Cylinders.
The various parts comprising the steam and hot air generators are similar in their
functions and character to those herein before described, in connection with the
Marine boiler, shewn on Sheet 1. I provide the combustion chamber with a
door or cover & which when the engine standing can be opened for the free
escape of the hot gases.
On Sheet 3 my Invention is shewn applied to an ordinary stationary boiler, of
vertical type, Fig 6 being a vertical section and Fig 7 a sectional plan, the part
comprising the boiler and hot air generator are similar in their construction and use
to those already described with this slight difference that I prefer to close the
thoroughfure leading to the hot air generator during the time steam is being got
up by the damper p which allows the waste gases from the furnace to pass off
direct into the chimney but so soon as steam is up, the damper p is opened and
the damper q closed under which condition the hot gases from the furnace pass
direct into and through the tubes of the hot air generator for the purpose of
heating the compressed air therein in the manner hereinbefore described. In the
case of the air compressed and expanded by heat in the generator e being used for
driving purposes I prefer to direct the exhaust into the ash pit of the furnace by

page_text: the pipe thereby effecting a more thorough and economical combustion of the
fuel supplied to such furnace.
Having now described the nature of my said Invention together with the means
of carrying the same into practical effect I wish it to be understood in conclusion
that what I claim as new and as of my Invention is
First Utilizing the waste gases from the furnace of a steam Boiler for heating
and storing compressed air in a hot air Receiver in the manner and for tho
purpose as herein substantially described and setforth in the Drawings.
Secondly. Using a portion of the heat of the furnace of a Steam boiler which
has not been utilized in conjunction with the waste heat escaping from such
.furnace for the purpose of increasing the temperature of the waste gases
transmitting heat to the compressed air in the hot air receiver in the manner
as berein substantially described and setforth in connection with the drawings
annexed.
In witness whereof I the said William Turnbull have hereunto set my hand
and Seal this, the twelfth day of May in the year of our Lord One thousand
eight hundred and eighty four.