IMPROVEMENT IN COMPOUND STEAM ENGINES
Year: 1885

page_text: I, ROBERT HARKNESS TWIGG of 30 Great George Street Westminster in the
County of Middlesex Civil Engineer do hereby declare the nature of my invention
for AN IMPROVEMENT IN COMPOUND STEAM ENGINES to be as follows:-
My Improvement in Compound Steam Engines consists of a method of heating
the exhaust steam that passes from the High pressure cylinder to the Low pressure
cylinder or cylinders of such engines, and the means by which I do this are as
follows:-The exhaust steam from the High pressure cylinder, or when three or
more cylinders are used, then the exhaust steam from all the cylinders but the one
connected with the condenser I lead into the steam jacket or steam jackets of the
Low pressure cylinder or cylinders and there heat it by passing it around a metal
tube or tubes placed in the said steam jacket or steam jackets. The tube or tubes are
supplied with steam direct from the boiler or boilers or communicate with the
jacketed cylinder covers which are supplied direct with boiler steam. These tubes
are arranged circumferentially round the cylinder or cylinders and may be parallel
with its axis or their axes or be in the form of a spiral or may take the form of
rings connected together by short straight pieces of tube.
By the above described method of heating the steam used in Compound Engines
a more economical result will be obtained than is done with the ordinary jacketed
cylinders or with the separate receiver commonly known as the "hot pot."

page_text: I, ROBERT HARKNESS TWIGG of 30 Great George Street Westminster in the
County of Middlesex, Civil Engineer do hereby declare the nature of my invention
for AN IMPROVEMENT IN COMPOUND STEAM ENGINES and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
My improvement in Compound Steam Engines consists of a method of heating
the exhaust steam that passes from the High pressure cylinder to the Low pressure
cylinder or cylinders of such engines, and the means by which I do this are as
follows: The exhaust Steam from the High pressure cylinder, or when three or
more cylinders are used, then the exhaust steam from all the cylinders but the one
connected with the condenser, I lead into the steam jackets of the Low pressure
cylinder or cylinders and there heat it by passing it around a metal tube or tubes
placed in the said steam jacket or steam jackets. The tube or tubes are supplied
with Steam direct from the boiler or boilers or communicate with the jacketed
cylinder covers which are supplied direct with boiler steam. The tubes are
arranged circumferentially around the cylinder or cylinders and may be parallel
with its axis or their axes, or be in the form of a spiral or may take the form of
rings connected together by short straight pieces of tube.
By the above described method of heating the steam used in Compound Engines
a more economical result will be obtained than is done with the ordinary jacketed
cylinders or with the separate receiver commonly known as the "hot pot."
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
The heating of exhaust steam from the cylinders of Compound Engines sub-
stantially as described.