Improvements in Steam Boilers.
Year: 1892

page_text: Date of Application, 4th Aug., 1892
Complete Specification Left, 15th Feb., 1893-Accepted, 8th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Steam Boilers.
I GEORGE CAWLEY of Grangethorpe Manor Road, Beckenham in the County
of Kent Civil and Mechanical Engineer do hereby declare the nature of this
invention to be as follows:-
are
The tubes or
My present invention has more particular reference to boilers such as
described in the Specification of Letters Patent No. 10540 granted to me and
dated 29th June 1889. It has for one of its objects to provide for a very effective
circulation of the water in the boiler. To effect this I provide a tube or passage
or tubes or passages which opens or open at one end into the water space of the
boiler a little below the lowest working level of water therein and at the other end
near to the lowermost portion or portions of the water space.
passages may be arranged in various ways for instance they may take the form of
tubes which are external to the boiler or they may be tubes which pass into the
water spaces through the skin of the boiler enclosed within the casing which
surrounds the annular space between the upper and lower parts of the boiler the
tubes being joined together by lengths of tubing situated in the said space. Or
tubes may be led from the upper water space below the lowest working water level
and between the upper small tubes into a small central globe or junction chamber
from which a tube or tubes descends or descend into the lower part of the central
or side water space or both. The upper ends of the said tubes or passages should
have their openings situated in as quiescent a part of the water as is practicable.
In the Specification of my aforesaid Patent I describe a feed water heater con-
sisting of a tubular arrangement through which the products of combustion pass on
their way to the chimney and I describe a cone or valve which allows the products
to pass partly through a central large tube when desired and so less to pass through
the smaller tubes of the tubular arrangement. According to my present inven-
tion I provide an arrangement which will allow the hot gases to be passed not
only entirely through the small tubes or partly through them and partly through
the large central tube, but also entirely through the large central tube if so desired.
With this object I make the valve of an annular form corresponding to the lower
side of the plate through which the said small tubes pass, so that when this valve
is moved up close to this plate it closes the openings of the small tubes and the
hot gases pass through the large central tube by a central opening in the plate
corresponding therewith. A convenient arrangement is to secure the annular
plate to an inner tube sliding in the large central tube and to connect the said inner
tube to a lever by which the valve is operated. When the valve and its tube are
lowered its central opening will be closed by coming against a surface beneath
which may be a dome shaped piece resting on the boiler plate beneath and covering
the man-hole door if there be one at this part. The said tubular arrangement
may convert into a superheater for the steam by making a communication therewith
from the steam space so that the steam passes therethrough around the tubes and
therefrom by the steam outlet pipe and in order to direct the steam so that it
comes in contact with all the tubes throughout their length I may arrange a baffle
plate or baffle plates so that the steam passes backwards and forwards or from side
to side of the space between the tubes before it leaves by the steam outlet pipe.
1
C
1000
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London.

page_text: COMPLETE SPECIFICATION.
Improvements in Steam Boilers.
1, GEORGE CAWLEY, of Grangethorpe, Manor Road Beckenham in the County
of Kent Civil and Mechanical Engineer, 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 :-
My present invention has more peculiar reference to boilers such as are described
in the Specification of Letters Patent No. 10540, granted to me, and dated
29th June 1889. It has for one of its objects to provide for a very effective
circulation of the water in the boiler. To effect this I provide a tube, or passage,
or tubes, or passages, which opens or open at one end into the water space of the
boiler a little below the lowest working level of water therein and at the other end,
near to the lowermost portion, or portions of the water space.
In order that my invention may be well understood I will refer to the accom-
panying drawing which shows in vertical section in Figure 1 and in section on the
line 1-2 (Figure 1) in Figure 2 a boiler like that shown in Figures 3 and 4 of the
drawings accompanying my Specification of the aforesaid Patent No. 10540 of 1889
but with arrangements according to my present invention applied thereto.
The aforesaid tubes or passages may be arranged in various ways, for instance
they may take the form of tubes which are completely external to the boiler as
shown at Z or they may be tubes which pass into the water spaces through the
skin of the boiler enclosed within or above and below the casing I which surrounds
the annular space H between the upper and lower parts of the boiler, the tubes
being joined together by a length of tubing situated in the said space. This
is shown at Z2. Or tubes may be led as shown at 7 from the upper water space
below the lowest working water level and between the upper small tubes G into
a small central globe or junction chamber Y from which a tube, or tubes, descends
or descend into the lower part of the central water spaces as at y or of the side
water space as at y' or both. The upper ends of the said tubes or passages should
have their openings situated in as quiescent a part of the water as is practicable.
Where the tubes or passages are inside the water space they may be complete
tubes or be formed by bent strips rivetted to the inside of the skin of the boiler
so that one side is formed by the said skin as shown at the lower part of 7. In
the Specification of my aforesaid Patent No. 10540 of 1889 I describe a feed
water heater consisting of a tubular arrangement (L ) through which the products
of combustion pass on their way to the chimney and I describe a cone or
valve () which allows the products to pass partly through a central large tube l
when desired and so less to pass through the smaller tubes of the tubular
arrangement. According to my present invention I provide an arrangement which
will allow the hot gases to be passed not only entirely through the small tubes or
partly through them, and partly through the large central tube, but also entirely
through the large central tube if so desired. With this object I make the valve
of an annular form corresponding to the lower side of the plate through which
the said small tubes / pass so that when this valve is moved up close to this plate
(as shown in full lines) it closes the openings of the small tubes and the hot gases
pass through the large central tube 1 by a central opening in the annular valve
corresponding therewith. A convenient arrangement is to secure the annular
valve or plate to an inner tube sliding in the large central tube and to
connect the said inner tube to a lever l by which the valve is operated. When
the valve and its tube are lowered its central opening will be closed by coming
against a surface beneath which may be a dome shaped piece X resting on the
boiler plate beneath and covering the manhole door, if there be one at this part, as
at f. The said tubular arrangement (L 1) I may convert into a superheater for
the steam by making a communication therewith as at w from the steam space so

page_text: that the steam passes therethrough around the tubes and therefrom by the steam
outlet pipe and in order to direct the steam so that it comes in contact with all
the tubes throughout their length I may arrange a baffle plate or baffle plates so
that the steam passes backwards and forwards or downwards and upwards through
the space between the tubes before it leaves by the steam outlet pipe such baffle
plates being arranged so that they leave an opening at opposite places alternately
for the steam which is thus compelled to pass in an upward and downward or back-
ward and forward or zigzag manner through the superheater. I have shown two
baffle plates at with openings below and there will be baffle plates extending
from either side of the central tube to the inside of the vessel L with an opening
above the said baffle plates so that the steam passes under the first baffle plate
over the next ones (not seen in the drawing as they are behind and before the
tube) and under the last baffle plate.
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 :-
1. In steam boilers of the kind referred to tubes or passages opening at their
one end into the water space a little below the lowest working water level of water
therein and at their other end opening into the lower part of the water space
substantially as hereinbefore described.
2. In steam boilers having a tubular feed water heater or steam superheater an
annular valve which can close all the tubes so that the products of combustion can
be caused to pass only through the central space or partly through the said space
and partly through the tubes substantially as herein before described.
3. In steam boilers having the tubular feed water heater or steam superheater
an annular valve attached to a tube sliding in the central space and a bearing
surface beneath so that the products of combustion can be caused to pass only
through the central space or only through the tubes or partly through the said
space and partly through the said tubes substantially as herein before described.
4. In steam boilers having a tubular steam superheater the arrangement of
baffles between the tubes so that the steam passes through the superheater in a
circuitous manner substantially as hereinbefore described.
5. The arrangement and combination of parts constituting a steam boiler substan-
tially as herein before described and shown in the accompanying drawing.
Dated this 15th day of February 1893.
J. H. JOHNSON & Co.,
Agents.