Improvements relating to the Exhaust of Gas Engines..
Year: 1898

page_text: Date of Application, 7th Dec.,
1898
Improvements relating to the Exhaust of Gas Engines..
We, HENRY NIELD BICKERTON, and HENRY WENTWORTH BRADLEY, both of
Wellington Works, Ashton-under-Lyne, Engineers, do hereby declare the nature
of this invention to be as follows:-
The improvements relate to the exhausting of the cylinders of large gas engines,
or of those engines wherein the products of combustion attain a very high tem-
perature, and wherein the great heat thus generated tends to damage or burn
the exhaust valve and its seating when such valve is opened for the escape of
the gases.
To remedy this drawback, and to effect our improvements, we form at a suit-
able part of the engine cylinder, and in addition to the ordinary exhaust port, a
special outlet or passage of a restricted character and provided with an external
water jacket or other means for cooling purposes.
This special outlet or passage is made to lead into a chamber or passage of
larger area than itself, the object being to subject the escaping gases, during
their passage from the engine cylinder to the secondary chamber or passage
aforesaid, to a throttling action.
The chamber or passage is provided with an auxilliary exhaust valve, and
preferably of smaller size to that of the engine proper.
When the engine is running, and at the commencement of the first outward
stroke of the piston, this secondary chamber or passage contains moderately cool
gas from the previous exhaust, and the new charge of gas and air is drawn in,
compressed, and fired in the ordinary manner.
After expansion, and at or about the time the main exhaust valve would be
opened under ordinary conditions, the auxilliary exhaust valve is opened, while
the main exhaust is, for a short time, kept closed.
The release of pressure causes a portion of the hot gases in the cylinder to rush
through the special outlet formed therein, and into the secondary chamber; but
in doing so the gases part with a portion of their heat by reason of the sudden
expansion, and thus reach the auxilliary exhaust valve in a thermal condition
which will not deteriorate the valve or its seating.
By the consequent expansion of the gases left in the engine cylinder, these
also are brought to a lower temperature, and may be allowed to escape through the
main exhaust at the desired moment without the evil results herein before
referred to.
Variations in detail may be made, such as the relative times of opening the
two exhaust valves, and the periods during which they are opened; and more
than one auxilliary exhaust valve, chamber, and outlet may be provided for each
cylinder; and other variations in detail may be made without departing from the
peculiar character of the invention.
1000
WILLIAM GADD, C.E.,
64, Barton Arcade, Manchester,
Agent for Applicant,

page_text: We, HENRY NIELD BICKERTON, and HENRY WENTWORTH BRADLEY, both of
Wellington Works, Ashton-under-Lyne, Engineers, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
The improvements relate to the exhausting of the cylinders of large gas engines,
or of those engines wherein the products of combustion attain a very high tem-
perature, and wherein the great heat thus generated tends to damage or burn
the exhaust valve and its seating when such valve is opened for the escape of
the gases.
To remedy this drawback, and to effect our improvements, we form at a suit-
able part of the engine cylinder, and in addition to the ordinary exhaust port, a
special outlet or passage of a restricted character and provided with an external
water jacket or other means for cooling purposes.
This special outlet or passage is made to lead into a chamber or passage of
larger area than itself, the object being to subject the escaping gases, during
their passage from the engine cylinder to the secondary chamber or passage
aforesaid, to a throttling action.
The chamber or passage is provided with an auxilliary exhaust valve, and
preferably of smaller size to that of the engine proper.
When the engine is running, and at the commencement of the first outward
stroke of the piston, this secondary chamber or passage contains moderately cool
gas from the previous exhaust, and the new charge of gas and air is drawn in,
compressed, and fired in the ordinary manner.
After expansion, and at or about the time the main exhaust valve would be
opened under ordinary conditions, the auxilliary exhaust valve is opened, while
the main exhaust is, for a short time, kept closed.
The release of pressure causes a portion of the hot gases in the cylinder to rush
through the special outlet formed therein, and into the secondary chamber; but
in doing so the gases part with a portion of their heat by reason of the sudden
expansion, and thus reach the auxilliary exhaust valve in a thermal condition
which will not so greatly deteriorate the valve or its seating.
By the consequent expansion of the gases left in the engine cylinder, these
also are brought to a lower temperature, and may be allowed to escape through the
main exhaust at the desired moment without the evil results herein before
referred to.
But that the improvements may be better understood we will, with the aid
of the accompanying drawing, proceed more fully to describe means employed
by us.
DESCRIPTION OF DRAWING.
The figure shows a longitudinal section of the end portion of a gas engine
cylinder arranged according to our improvements. The same letters indicate
corresponding parts wherever they occur.
a is the cylinder end which is formed with a restricted passage b leading into a
chamber or passage c of larger area. A space, or spaces, external to the passage b
and chamber c is provided, as at d, to form a water jacket about such passage
and chamber. The chamber c is shown provided with an auxilliary exhaust
valve c, which valve is preferably of smaller size to the main exhaust valve e.
f is the ordinary air valve. After expansion of the fired gases in the engine

page_text: cylinder, and at or about the time the main exhaust valve e would be opened under
ordinary conditions, the auxilliary valve c¹ is opened, while the main exhaust
valve is kept closed. The release of pressure causes a portion of the hot gases
within that part of the cylinder marked X to rush through the passage b into
the chamber c, but in doing so the gases lose some portion of their heat by reason
of the sudden expansion. By the consequent expansion of the gases remaining
in that part of the cylinder marked X these also are brought to a lower tem-
perature and may be allowed to escape through the main exhaust by the opening
of the valve e. Variations in detail may be made, such as the relative times of
opening the two exhaust valves, and the periods during which they are opened:
and more than one auxilliary exhaust valve, chamber, and outlet may be pro-
vided for each cylinder; and other variations in detail may be made without
departing from the peculiar character of the invention.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:-
The formation in connection with gas engine cylinders of a restricted passage
combined with and leading into a larger chamber or other passage which is pro-
vided with a special or auxilliary exhaust valve, the said restricted passage being
situated between the main exhaust valve and the beforementioned auxilliary
chamber and exhaust valve, for the purpose and in manner substantially as
herein shown and described.
Dated this 5th day of September 1899.
WILLIAM GADD, C.E.,
64, Barton Arcade, Manchester,
Agent for Applicant.