IMPROVEMENTS IN STEAM BOILERS
Year: 1880

page_text: LETTERS PATENT to Carl Pieper, Civil Engineer and Patent Agent, resident
at 109-110, Gneisenaustrasse, Berlin, S.W., Prussia, for an Invention of
"IMPROVEMENTS IN STEAM BOILERS." A communication from Adolf Knaudt,
Manufacturer, of Essen on the Ruhr, Kingdom of Prussia.
COMPLETE SPECIFICATION filed by the said Carl Pieper at the Office of the
Commissioners of Patents on the 21st April 1880.
CARL PIEPER, Civil Engineer and Patent Agent, resident at 109-110,
Gneisenaustrasse, Berlin, S.W., Prussia. "IMPROVEMENTS IN STEAM BOILERS." A
communication from Adolf Knaudt, Manufacturer, of Essen on the Ruhr, Kingdom
of Prussia.
This Invention consists in an improvement in the construction of steam-boilers
by which the difference of strains in different parts of the boiler arising from
unequal heating or from other causes is compensated.
It is well known that every steam-boiler is subject to unequal and varying strains
when in use, as those parts of the same upon which the flames or combustion gases
act directly are heated in a higher degree than other parts not thus exposed.
Unequal strains may however also be caused in a boiler by an irregular settling of
the brickwork in which it is enclosed, or by other circumstances.
In consequence of such unequal and varying strains the boiler is apt to become
leaky, and when it is of cylindrical shape its peripherical seams will first of all show
such defect.
This disadvantage [may be obviated by constructing the shell of the boiler of
corrugated plates, and thereby rendering it to a certain degrce elastic. When a
strain acts on any part of such boiler transversely to the corrugations, each
corrugation of this part will yield more or less to the pressure to which it is
exposed, whereby the injurious effects which may otherwise be caused under the
said circumstances are averted. The seams of the boiler will therefore present a
greater durability than in boilers made of smooth (ie., non-corrugated) plates.
As regards details of construction the edges of the plates for the seams must
necessarily in some cases be left smooth or uncorrugated, whereas in other cases the
corrugations may extend over these edges or not, as may be preferred. It is also
advantageous to provide for smooth strips in the plates where brackets or stay-
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plates are to be fixed, and some parts of the boiler, such as the ends of cylindrical
boilers, may be made altogether without corrugations. The boilers are provided
with stays as usual.
When the boiler is heated from the outside the corrugation of its shell presents in
addition to the advantage already mentioned, the further favourable feature that
its heating surface is increased, and moreover the same causes a better utilization
of the heat contained in the combustion gases. The reason of this is that every
corrugation gives rise to an eddy in the gas-current striking against it, whereby the
different layers or particles of gas are mixed and stirred, and other hot particles
continuously brought in contact with the plate.
The third advantage of the described Invention is that the corrugations prevent
the plates exposed to the action of the fire from becoming incrusted by deposits.
Having thus described the nature and object of this Invention, and the mauner
in which it is to be carried out in practice, as communicated to me by my
correspondent, I hereby clain as new and important feature of the same,-
-
In a steam boiler which has to sustain an inside pressure, the use of corrugated
plates for the shell of such boiler, substantially as described.
In witness whereof I have hereunto set my hand and seal, this Nineteenth
day of April, in the year of our Lord One thousand eight hundred and
eighty