Improvements in Steam Generators for Superheating the Steam.
Year: 1899

page_text: Date of Application, 4th Oct., 1899
CL
2000
0th Cont
4000
PROVISIONAL SPECIFICATION.
Improvements in Steam Generators for Superheating the Steam.
I, JOHN EDWARD SLACK, of Chester Road, Manchester, in the County of
Lancaster, Mechanical Engineer, do hereby declare the nature of this invention
to be as follows:-
-
This invention relates to heaters applied to steam boilers for the purpose of
raising the temperature or superheating the steam generated therein. It is
intended primarily for boilers of the water-tube type but may also be applied to
Lancashire and other types of boilers.
In superheaters as at present constructed the outlets from the boiler usually do
not give an equal distribution of steam to the heater-tubes and they are so placed
or arranged as to carry over a quantity of water and frequently one or more of
the joints are exposed to the action of the furnace gases.
This invention consists essentially in constructing the apparatus with a separato
steam box or drum placed at each side of the steam drum or cylinder of the
boiler and a number of heater-tubes passing under the drum into the flue con-
nected at one end direct to the steam drum and at the other end to one or other of
the separated steam chests or drums placed alongside.
In carrying out the invention the main structure of the boiler is constructed in
the usual way and in the case of water tube boilers with a steam drum or
cylinder above the water tubes.
At one or both sides preferably both sides I place a steam box or drum of
cylindrical rectangular or other form to which are connected the superheated
tubes. These tubes at one end are connected or attached direct to the shell
plate of the steam drum or cylinder and at the other end to the additional steam
boxes or drums. They are of curved or other looped form preferably approxi-
mately semicircular and are arranged singly or in pairs or in sets alternately
to pass from one side of the steam drum to the steam box or drum at the opposite
side thereof extending underneath into the flue below.
The additional steam boxes or drums and the junction of the superheated
tubes are above the water level and above the furnace walls out of contact with
the furnace gases thus no joint is exposed to the action of the furnace gases.
The steam boxes or drums are connected together with a suitable steam outlet
and are also provided with outlets for blowing off water when the superheater is
out of use.
When
Although two additional steam boxes or drums are preferred one only may be
employed placed either above or at one side of the main steam drum.
placed above the tubes the tubes may be arranged alternately as described.
Applied to Lancashire boilers the superheater tubes are passed down below the
boiler into the bottom flues.
By this arrangement a number of small tubes are connected with the steam
space and direct the flow of steam from the generator which being equally

page_text: divided amongst a number of tubes the liability of priming or of water being
carried over into the tubes is reduced to a minimum.
Dated this 3rd day of October 1899.
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
Improvements in Steam Generators for Superheating the Steam.
I, JOHN EDWARD SLACK, of Chester Road, Manchester, in the County of
Lancaster, 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:―
This invention is designed to provide an improved arrangement of tubes for
superheating steam in the ordinary Lancashire water tube and other steam
boilers.
Hitherto it has been customary to carry the superheating tubes in different
ways from specially constructed or arranged side boxes or steam tubes into the
path of the heated gases but I consider it is better to draw the steam direct to
the boiler or steam drum and I therefore expand the superheated tubes into the
boiler shell of a Lancashire boiler and into the steam drum of a water tube
boiler above the water level in either case the joint being above or out of contact
with the heated gases.
My invention will be fully described with reference to the accompanying
drawings in which sufficient of a steam boiler is shown to illustrate the invention.
Fig. 1. Transverse section of Lancashire boiler.
Fig. 2. Transverse section of steam drum of water tube boiler.
Fig. 3. Side elevation of same.
In a Lancashire boiler A such as shown in Fig. 1, at a point above the water
level I expand or otherwise attach a number of superheater tubes B which
are carried down in a curve beneath the shell of the boiler through the flues CD
and E and up to a steam pipe or small drum F running longitudinally of the
boiler.
There are two sets of superheater tubes B one set attached to the right side of
the boiler and passing to a steam pipe at the left and the other attached to the
left side of the boiler and passing round the bottom to steam pipe F at the
right. The steam. passes from the pipe F through the steam outlet valve G.
As applied to a water tube boiler as shown in Figs. 2 and 3 the superheater
tubes Bare at one end expanded or otherwise attached into the steam drum H
above the water level and are carried down in a curve below the drum through
the combustion chamber K into which the heated gases pass and then up to the
steam pipe F running longitudinally of the steam drum.
There are preferably two sets of the heater tubes B one set attached to the
drum at one side and the other set at the other side both sets passing beneath
the drum and connecting with the steam pipe F at the opposite side to that to
which they are attached to the steam drum. A steam outlet valve is provided
as before to which the steam pipes F are connected.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that
what I claim is: -
1. A steam boiler constructed with superheater tubes attached at one end direct

page_text: to the shell of the boiler or steam drum curved down beneath the boiler or drum
into the heated gases and extending upwards to a steam pipe substantially as
described.
2.
A. steam boiler with superheated tubes constructed and arranged in combina-
tion substantially as described and shown either in Fig. 1 or in Figs. 2 and 3
of the drawings.
Dated this 27th day of July 1900.
WM. P. THOMPSON & Co.,
Manchester, Liverpool, London & Birmingham,
Patent Agents.