Improvements in Steam Boilers.
Year: 1889

page_text: Date of Application, 20th Aug., 1889
Complete Specification Left, 16th May, 1890-Accepted, 28th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in Steam Boilers.
I, GUSTAV LENTZ, of Dusseldorf, in the Empire of Germany, Civil Engineer, do
bereby declare the nature of this invention to be as follows:-
My invention relates to locomotive and other steam boilers having internal fire
boxes or flues.
In such boilers the fire boxes are generally secured by means of stay bolts and the
like, thereby often rendering the boilers costly and difficult to repair. My invention
has for object to obviate this objection.
For this purpose I make the outer shell of the boiler with plates having the shape
of truncated cones so arranged that the ends of the boiler are of smaller diameter
than the middle portion thereof, and the top is inclined from the said middle portion
towards the ends, the steam space being thereby located towards the middle of the
boiler.
A steam dome is fitted to the rear end of the boiler and is connected with the said
steam space by means of a pipe; or it can be made integral with the pipe.
The fire box, which is by preference made of corrugated plates, is connected at its
inner end with the boiler tubes or flue and forms a rigid stay for the shell of the boiler
in the direction of its axis, thus dispensing with the use of stay-bolts for that purpose.
The end plate of the boiler consists of a flat iron ring which serves to hold the fire
box in position.
Dated the 20th day of August 1889.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Boilers.
I, GUSTAV LENTZ, of Dusseldorf, in the Empire of Germany, Civil 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 invention relates to locomotive and other steam boilers having internal fire
boxes or flues.
In such boilers the fire boxes are generally secured by means of stay bolts and the
like thereby often rendering the boilers costly and difficult to repair. My invention
has for object to obviate this objection.
For this purpose I make the outer shell of the boiler with plates having the shape
of truncated cones so arranged that the ends of the boiler are of smaller diameter
than the middle portion thereof, and the top is inclined from the said middle portion
towards the ends, the steam space being thereby located towards the middle of the
boiler.
A steam dome is fitted to the rear end of the boiler and is connected with the said
steam space by means of a pipe, or it can be made integral with the pipe.
The fire box, which is by preference made of corrugated plates, is connected at its
rear end with the boiler tubes or flue and forms a rigid stay for the shell of the boiler
in the direction of its axis, thus dispensing with the use of stay-bolts for that purpose.
The end plate of the boiler consists of a flat iron ring which serves to hold the fire
box in position.
In order to enable my invention to be fully understood I will describe how it can be
carried into practice by reference to the accompanying drawings, in which―

page_text: Figure 1 represents a longitudinal section of a locomotive engine for narrow gauge
railways and having a boiler constructed according to my invention.
Figure 2 is a cross section partly on the line A B and partly on the line CD;
and
Figure 3 is an end view of the same.
Figure 4 is a longitudinal section; and
Figure 5 is an end view half in section on the line A B of figure 4 shewing my
invention applied to a locomotive engine for a broader gauge railway.
Figure 6 is a longitudinal section; and
Figure 7 an end view of a heavy locomotive engine showing my invention applied
thereto.
Figure 8 is a longitudinal section; and
Figure 9 is an end view half in section on the line A B of figure 8 of another
form of heavy locomotive engine illustrating the application of my improvements
thereto.
Figures 10, 12, 14, 16, 18, 20 and 22 are longitudinal sections shewing the
application of my invention to stationary boilers.
Figures 11, 13, 15, 17, 19, 21 and 23 are respectively cross sections of the same.
I will first describe my invention by reference to figures 1, 2 and 3.
The boiler consists of two plates a and b of tension equilibrium and each having
the form of a truncated cone, the two cones being connected together at their bases,
so that the upper part of the boiler-shell inclines downwards from the middle portion
towards the ends, while the underpart of the boiler-shell is straight, but, slanting, in
longitudinal section, as clearly shewn in figure 1. The end plate of the boiler is
formed of a flat iron ring f and serves to hold the fire-box c, the latter being made
slanting and having a plate d to cause the ashes while travelling to slide down into
the ash-panthereby leaving the air space underneath the grate always clear.
The fire-box is provided with a hollow cast iron plate e to assist the passage of air to
the grate.
With the exception of the said flat iron ring the fire-box is only supported by the
boiler tubes s and is nevertheless quite reliable and strong and as no perforation for
the reception of stay-bolts, screws or the like are. necessary it is not liable to
leak.
It will be obvious that the stay formed by the fire-box c combined with the boiler
tubes s is quite sufficient to secure the boiler ends.
In the examples shown in figures 4 and 5, the plates a and b have a conical form
and the fire-box is arranged and fitted in a manner similar to that before described
with reference to figures 1, 2 and 3 but the bases of the cones are connected to a
cylindrical middle plate m.
g is a pipe forming the steam dome which I fit at the rear end of the boiler and
which is formed integral with the pipe which serves to connect it with the middle
steam space of the boiler.
In the heavier form of 'ocomotive engines illustrated in figures 6, 7, 8 and 9 four
conical plates are employed marked a, a, b, b1, the plates a¹ and 6' are connected to
the cylindrical middle plate m which carries the steam dome i. As in the engines
shewn in figures 4 and 5 a small or auxiliary steam dome g is fitted over the fire-box
and is connected with the highest part of the steam space of the boiler.
By reason of the inclined form of the upper part of the boiler-shell the steam always
rises towards the middle part and into the dome i and the regulator, whether the
locomotive might run up or down an inclined way, and the water is entirely prevented
from adhering as the steam space is large and the water is not near to the dome. The
result is that perfectly dry steam is obtained and a saving in feed water and fuel
thereby effected. The boiler can be kept cleaner than an ordinary boiler as it is easily
accessible from above as well as from below and for periodical inspections when the
other boiler tubes are taken out, no stay-bolts or the like need be destroyed or taken
out, it being only necessary to remove the rivets in the flat iron ring and perhaps in
the bottom ring.

page_text: In figures 6 and 7 the end ring f is similarly to the Belgian locomotive, connected
to a bottom ring f¹, f having a cross-piece f³ in order to keep the ash-pan in the
usual place. The after part c of the fire-box is therefore not cylindrical but is jointed
at the lower end to the part f¹ of the bottom ring and only the fore part C of the
fire-box is cylindrical.
In figures 8 and 9 is shewn another form of end ring which might be required for
altering existing boilers where no space is provided for the air current through the
ash-pan. In this case the end ring is of an inclined form as indicated by dotted
lines so as to leave the casting or frame z carrying the draw-bolt intact. This would
of course cause the fire-grate to be rather smaller but I can obviate this, if necessary,
by using a bent ring as shewn in full lines in section instead of the straight ring
shewn in dotted lines, the fire-door then retaining its usual position.
The hereinbefore described auxiliary steam dome connected by a pipe with the
middle steam space of the boiler is especially advantageous when applied to the
boilers of locomotive, torpedo boat, steam road roller, and other travelling engines.
In the small stationary boiler shown in figure 10 which is a longitudinal section
and in figure 11 which is a transverse section on the line A B of figure 10 the upper
part is formed, as hereinbefore described, inclined downwards from the middle towards
the ends. The same remark applies to the different types of stationary boilers with
inside flues illustrated in figures 12 to 23. With regard to the latter type of boilers
having outer shells of various forms, the flue forms the longitudinal stay for the boilers
and all end or corner stays are unnecessary. In all of the boilers the outer shell forms
so to speak an arch or roof in which the fire-box in combination with the boiler-tubes
or the flue serves as a stay while the corrugated fire-box or flue affords the necessary
elasticity.
Instead of the corrugations, especially in small fire-boxes, plain tubes or other tubes
could be used in the stationary boilers shewn in figures 12 to 23, but the corrugated
form of fire-box is preferable.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. In a steam boiler having an internal fire-box or flue, forming the outer shell of
the boiler with plates having the shape of truncated cones arranged in such a manner
that the ends of the boiler are of smaller diameter than the middle portion thereof
and the top is inclined downwards from the said middle portion towards the ends the
steam space being thereby located towards the middle of the boiler, the fire-box being
connected with the boiler tubes or the internal flue so as to form a rigid stay for the
ends of the boiler, substantially as hereinbefore described.
2. The use in combination with a steam boiler constructed in the manner referred
to in claim 1, especially when such boilers are employed for locomotive, torpedo boat,
steam road roller and other travelling engines, of an auxiliary steam dome fitted upon
the rear end of the boiler and connected by a pipe with the steam space in the middle
of the boiler, substantially as herein before described.
3. The improved steam boilers hereinbefore described with reference to the various
figures of the accompanying drawings.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.