Improvements in Combined Steam and Hot-air Motors.
Year: 1889

page_text: Date of Application, 28th Nov., 1889
Complete Specification Left, 18th Aug., 1890-Accepted, 18th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in Combined Steam and Hot-air Motors.
I, WILHELM SCHMIDT, Civil Engineer of 8, Plantagen Strasse, Halberstadt, German
Empire, do hereby declare the nature of this invention to be as follows:-
My invention relates to a combined steam and hot air engine in which the fire is
made to serve a double purpose, viz. first to generate steam for the steam cylinder and
then to superheat the mixture of steam and air for the motor. My motor further
distinguishes itself for the peculiar manner in which the mixture of steam and
air is formed. The generation of the mixture is effected by bringing compressed
air in contact with water so that the latter is evaporated. At the same
time the water is continually warmed by the steam from the steam cylinder
exhausting into it and this together with the compressed air causes energetic vapori-
sation. The double use of the fire and the manner of generating the mixture of steam
and air form the principal features of my present invention, the result of which is
great economy of fuel whilst the engine combines the advantages of a steam engine
with those of a hot air motor.
In order to make my invention more clear, I refer to the accompanying drawings,
which form part of this Specification and shows a vertical section through the apparatus.
Steam is generated in the boiler a and passes to the steam cylinder through pipe a¹.
c is the air pump for compressing the air for the hot air and steam motor. The com-
pressed air passes along pipe d and enters the water holder from underneath. The
water in this holder is heated from the coil e¹ into which the steam from the steam
cylinder exhausts through pipe e². The air is forced through the warmed water in
finely divided particles by which the water is energetically evaporated.
The mixture of steam and air which has nearly attained its saturation point, passes
along pipe g to the superheater h, heated by the combustion gases from the fire box of
the steam engine. In the superheater the mixture will be superheated to a high degree
and passes then along pipe k to the cylinder for hot air and steam mixture or the power
cylinder.
It will be seen from the foregoing description that the boiler fire first serves to
heat water in the boiler a and generate steam which is used in the steam engine, that
the heat in the exhaust steam is not wasted but is used to heat the water in the water
holder which is constantly being cooled by evaporation and whereby the volume of the
steam and air mixture for the motor is increased, and lastly that the combustion gases
from the fire-box are used to heat the superheater for the mixture, increasing the
volume of the same. The fuel is thus burned in the most economical manner possible
and the machine combines the advantages of a steam and steam and hot air motor.
Dated this 26th day of November 1889.
WILHELM SCHMIDT.
By Rayner & Cassell,
37, Chancery Lane, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Combined Steam and Hot-air Motors.
I, WILHELM SCHMIDT of 8 Plantagen Strasse, Halberstadt in the German Empire,
Civil Engineer, do hereby declare the nature of my said 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 relates to a combined steam and hot air engine in which the fire is
made to serve a double purpose, viz. first to generate steam for the steam cylinder

page_text: and then to superheat the mixture of steam and air for the motor. My motor further
distinguishes itself for the peculiar manner in which the mixture of steam and air is
formed. The generation of the mixture is effected by bringing compressed air in
contact with water so that the latter is evaporated. At the same time the water is
continually warmed by the steam from the steam cylinder exhausting into it and this
together with the compressed air causes energetic evaporisation. The double use of
the fire and the manner of generating the mixture of steam and air form the
principal features of my present invention the result of which is great economy
of fuel whilst the engine combines the advantages of a steam engine with those of a
hot air motor.
In order to make my invention more clear, I refer to the drawing sent in with
Provisional Specification, and which forms part of this Specification and shows a
vertical section through the apparatus.
Similar letters denote to similar parts throughout the drawing.
Steam is generated in the boiler a and passes to the steam cylinder 6 through pipe a¹.
c is the air pump for compressing the air for the hot air and steam motor.
The com-
pressed air passes along pipe d and enters the water holder from underneath. The
water in this holder is heated from the coil c¹ into which the steam from the steam
cylinder exhausts through pipe 2. The air is forced through the warmed water in
finely divided particles by which the water is energetically evaporated.
The mixture of steam and air which has nearly attained its saturation point, passes
along pipe g to the superheater h, heated by the combustion gases from the fire-box
of the steam engine. In the superheater the mixture will be superheated to a high
degree and passes then along pipe k to the cylinder for hot air and steam mixture or
the power cylinder.
It will be seen from the foregoing description the boiler-fire first serves to heat
water in the boiler a and generate steam which is used in the steam engine, that the
heat in the exhaust steam is not wasted but is used to heat the water in the water
holder which is constantly being cooled by evaporation and whereby the volume of the
steam and air mixture for the motor is increased, and lastly that the combustion gases
from the fire-box are used to heat the superheater for the mixture, increasing the
volume of the same. The fuel is thus burned in the most economical manner possible
and the machine combines the advantages of a steam and hot air motor.
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 :-
In combined steam and air motors:
The method of heating by a firing the steam boiler as well as the superheater,
through which a mixture of steam and air passes, and of producing the mixture of
steam and air by guiding compressed air into a reservoir and bringing it therein
thoroughly in contact with water, which is heated by the exhaust steam of a steam
engine, for the purpose as described.
Dated this 18th day of August 1890.
WILHELM SCHMIDT.
By Rayner & Cassell,
Agents for the Applicant.