Improvements in Steam Engines.
Year: 1897

page_text: Improvements in Steam Engines.
We, SAMUEL CHATWOOD, of 76, Newgate Street, in the City of London. Banker's
Engineer, and SAMUEL RAWSTHRONE CHATWOOD, of the Lancashire Safe and Lock
Works, Bolton, in the County of Lancaster, Manager, do hereby declare the
nature of this invention to be as follows:-
-
Or
This invention relates to engines in which the steam is expanded in several
cylinders, is repeatedly superheated, and is finally returned to the boiler.
the engine may be worked with a condenser, or the steam may pass away uncou-
densed.
In the arrangement whch is preferred there are three cylinders one above the
other, the pistons are on one rod and by a connecting rod they drive a crank.
The steam in a highly superheated state is admitted to the uppermost or high
pressure cylinder, it operates during the down stroke upon the upper side of the
piston therein and is expanded more or less as is determined by the operation
of a shaft governor which controls the admission valve.
On the upstroke the steam is ejected from the high pressure cylinder and is
made to pass through a second superheating system. The steam next passes to
the upper end of the intermediate cylinder. The piston in this cylinder is
furnished with a trunk, the high pressure piston being at the upper end of the
trunk. The steam is admitted to the annulus between the trunk and the walls
of the intermediate cylinder, it operates during the down stroke of the piston and
in doing so is more or less expanded. During the up stroke the steam is ejected
from the upper end of the intermediate cylinder, it is again passed through a
superheater and then is admitted beneath the intermediate piston. The steam
During
operates on the piston during the up stroke and is more or less expanded.
the down stroke the steam is ejected and is passed into a receiver. The receiver
supplies the low pressure cylinder which is double acting, steam being admitted
to the upper side of the piston during the down stroke and to the under side of
the piston during the up stroke.
The low pressure cylinder also serves to compress the steam which remains in
the cylinder at the end of the stroke. By the return of the piston this steam
is compressed to the boiler pressure and when this pressure is obtained it makes
its way past a non return valve into a receiver and through a second non-return
valve into the boiler. During this compression a certain amount of heat is
generated, this may be utilized to heat the incoming steam by the employment
of suitable regenerative devices. The cylinder walls absorb part of the heat
generated during compression and give it up in heating the incoming steam.
Regenerative devices may also be employed for this purpose. They may also
be employed for the purpose of abstracting heat from the compressed steam
to do part of the superheating of the steam between the first and second and
between the second and third pistons. For example the compressed steam may

page_text: be delivered into a receiver communicating with the boiler through suitable non
return valves. Through this receiver tubes may pass conveying the steam from
the first piston to the superheater and also tubes conveying the steam from the
second piston to the superheater. In place of returning the exhaust steam to
the boiler it may be passed to a condenser or allowed to escape in which case it
is preferred that the steam should again be superheated in its passage from the
intermediate to the low pressure cylinder.
It is preferred to arrange the valves in connection with the upper and lower
end of the intermediate cylinder upon the same rod and to actuate them by an
eccentric on the main shaft. The valves of the low pressure cylinder may also
be upon the same rod and worked by the same eccentric but it is preferred to
provide a separate eccentric and rod. The valves which are employed are
preferably of the piston type.
The expansions and the superheating are so controlled that the steam in the
high pressure and intermediate cylinders shall remain dry throughout whilst the
steam issuing from the low pressure cylinder passes from the receiver to the
boiler as saturated steam.
The glands are arranged that the heat may not affect them injuriously.
We, SAMUEL CILATWOOD, of 76, Newgate Street, in the City of London, Banker's
Engineer, and SAMUEL RAWSTHRONE CHATWOOD, of the Lancashire Safe and Lock
Works, Bolton, in the County of Lancaster, Manager, do hereby declare the
nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:
This invention relates to engines in which the steam is expanded in several
cylinders, is repeatedly superheated, and is finally returned to the boiler. Or
the engine may be worked with a condenser, or the steam may pass away uncon-
densed.
The arrangement which is preferred is represented by the annexed drawings.
Figure 1 is a vertical section. Figure 2 is an end elevation.
There are three cylinders a b and c one above the other, the pistons a' and c'
are on one rod and by a connecting rod d they drive a crank e. The steam in a
highly superheated state is admitted to the uppermost or high pressure cylinder,
it operates during the down stroke upon the upper side of the piston a therein
and is expanded more or less as is determined by the operation of a shaft
governor which controls the admission valve g.
On the upstroke the steam is ejected from the high pressure cylinder and is
made to pass by hand h¹ through a second superheating system. The super-
heaters and the connecting pipes are not shown in the drawings. The steam
next passes by the valve i to the upper end of the intermediate cylinder. The
piston b in this cylinder is furnished with a trunk 3, the high pressure piston a¹
being at the upper end of the trunk. The steam is admitted to the annulus
between the trunk and the walls of the intermediate cylinder b, it operates
during the down stroke of the piston and in doing so is more or less expanded.
During the upstroke the steam is ejected from the upper end of the intermediate

page_text: cylinder, it is again passed through a superheater by the passages k and kand
then is admitted beneath the intermediate piston b. The steam operates on the
piston during the up stroke and is more or less expanded. During the down
stroke the steam is ejected and is passed into a receiver . The receiver supplies
the low pressure cylinder c which is double acting, steam being admitted by the
valve m to the upper side of the piston during the down stroke and to the under-
side of the piston during the upstroke.
The low pressure cylinder also serves to compress the steam which remains
in the cylinder at the end of the stroke. By the return of the piston this steam
is compressed to the boiler pressure and when this pressure is obtained it makes
its way past a nou return valve n into a receiver and through a second non-
return valve (not shown) into the boiler. During this compression a certain
amount of heat is generated, this may be utilized to heat the incoming steam
by the employment of suitable regenerative devices. The cylinder walls absorb
part of the heat generated during compression and give it up in heating the
incoming steam. Regenerative devices may also be employed for this purpose.
They may also be employed for the purpose of abstracting heat from the com-
pressed steam to do part of the superheating of the steam between the first and
second and between the second and third pistons. For example the compressed
steam may be delivered into a receiver communicating with the boiler through
suitable non return valves. Through this receiver tubes may pass conveying
the steam from the first piston to the superheater and also tubes conveying the
steam from the second piston to the superheater or conversely the compressed
steam may pass through the pipes whilst the steam passing from the cylinders
to the super heaters circulates around them.
Such an arrangement is shown by the Figures 3, 4 and 5. Figure 3 is a plan,
Figure 4 is a vertical section, and Figure 5 à transverse section of the regenerator
or temperature interchanger. The compressed steam enters at 0, passes through
the pipes to 01 and thence through a non return valve into the boiler.
The steam from the passage in Figure 1 enters the regenerator at H and
leaves it at H similarly the steam from the passage k in Figure enters the
regenerator at K and leaves it at K¹.
In place of returning the exhaust steam to the boiler it may be passed to a
condenser or allowed to escape in which case it is preferred that the steam should
again be superheated in its passage from the intermediate to the low pressure
cylinder.
It is preferred to arrange the valves i in connection with the upper and lower
end of the intermediate cylinder upon the same rod and to actuate them by an
eccentric on the main shaft as the drawing shows. The valves in of the low
pressure cylinder may also be upon the same rod and worked by the same eccentric
The valves which
but it is preferred to provide a separate eccentric and rod.
are employed are preferably of the piston type.
The expansions and the superheating are so controlled that the steam in the
high pressure and intermediate cylinders shall remain dry throughout whilst
the steam issuing from the low pressure cylinder passes from the receiver to the
boiler as saturated steam.
The glands are arranged that the heat may not affect them injuriously.
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:-
-A multiple cylinder engine having superheaters to reheat the steam after
expansion and means for finally compressing the steam and returning it to the
boiler.
2. A multiple cylinder engine having superheaters to reheat the steam after
expansion, means for compressing the steam and returning it to the boiler and

page_text: a regenerator or temperature interchanger to transfer the heat of the compressed
steam to the steam entering the superheaters.
3. A triple cylinder engine having cylinders arranged one over the other on
the same axial line, and superheaters to heat the steain after its expansion and
the terminal cylinder arranged to compress the steam and return it to the boiler.
4.—An engine substantially represented by the annexed drawings.
Dated this 22nd day of September 1898.
SAMUEL CHATWOOD
SAM. R. CHATWOOD.