Improvements in Steam Generators.
Year: 1897

page_text: Date of Application, 16th Mar., 1897-Accepted, 12th June, 1897
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
We, GEORG NIEMEYER, 17 Neuhofer-Strasse, Hamburg-Steinwarder, Manufacturer,
and GEORG FRIEDRICH SCHRÖDER, of 53 Eppendorferweg, Hamburg-Eimsbuttel,
Machinist, 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 :-
The object of our invention is to produce a continuous circulation of the water
in steam generators and we accomplish this object by exhausting or drawing off
the water in the lower part of the generator, say under the fire tubes, and subsequently
readmitting it at a higher part preferably near to the water level.
According to our invention we utilize the feed water supplied to the generator
as the means for giving the continuous circulation aforesaid.
The feed-water is, by means of any suitable arrangement, such as an ejector or
the like, caused to exhaust the water at the lower part of the generator and, after
being admixed therewith, to inject or discharge it into the generator, by means of
an inner feed pipe, at or near to the water level.
The exhaust pipe is preferably arranged inside the generator and the part of
the pipe into which the water first enters is arranged along the bottom in a line
parallel to the shell of the generator. The exhaust pipe may extend the whole
length of the generator and be provided with small openings or perforations so that
the water can be exhausted all along the bottom of the generator. In large
generators several such perforated exhaust pipes may be arranged along the bottom
and below the fire tubes and be made to communicate with one pipe leading to
the ejector apparatus.
And in order that our said invention may be properly understood we have
hereunto appended two explanatory sheets of drawings.
On the drawings the same reference letters wherever repeated indicate the same
parts.
Figs. 1 and 2 are longitudinal sections of a portion of a marine boiler showing,
by way of example, different forms of our water circulating apparatus.
Figs. 3 and 4 show modifications of the apparatus.
In Fig. 1, a is the suction pipe which is laid along the inside of the boiler shell
under the fire box. A second pipe b connects the pipe a with the ejector apparatus d,
by means of which the colder water at the lower part of the boiler is drawn off and
mixed with the feed water which is conveyed under pressure from the feed pumps
driven by the main engine in the usual way to the boiler through the pipe e and the
feed valve c. The mixture of exhaust boiler water and fresh feed water is delivered
from the ejector d by means of a pipe f, which latter may be arranged so as to
discharge the water at any desired part of the boiler.
The apparatus d is preferably constructed in the same manner as an ordinary
ejector or injector as shown. It may consist of a nozzle part h which projects into a
bell mouthed part i. Any other suitable and well known contrivance capable of
performing the work may however be used instead of the ejector d.
It is not absolutely necessary that the ejector d and pipe be arranged within
the boiler.
In Fig. 2 the perforated pipe a is dispensed with the water being drawn off
through the pipe b which is suitably bent as shown.

page_text: Fig. 3 shows a slightly modified construction of the apparatus.
Fig. 4 shows another modified construction of the apparatus.
By adapting our invention to steam generators the circulation of the boiler water
is constantly maintained so long as the main engine is working as the feed water
pumps are usually coupled thereto. When the main engine is not used for driving
the feed water pumps they may be operated and the circulation maintained by
means of an auxiliary engine.
Auxiliary feed pipes can, if so desired, be fitted in connection with the circulating
apparatus, so that, should the main engine be stopped, the circulation could still
be maintained within the boiler. This would be useful when the boiler was only
required for supplying steam to auxiliary engines or for other purposes other
than driving the main engine.
This method of circulating water in steam generators is found to give very
beneficial results and to supply a long felt want.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
consider novel and desire to claim is :-
1. The method of promoting a continuous water circulation in steam generators by
causing the feed water to draw up the comparatively cold water at the bottom of the
generator and then discharge it again at a higher level, substantially as hereinbefore
described.
2. The apparatus for carrying out the method of water circulation described in
Claim 1 consisting of an ejector apparatus d which, by the action of the feed water, is
caused to suck up the water at the bottom of the generator, substantially
hereinbefore described with reference to the drawings annexed.
.as
3. The combination with the ejector d of the exhaust pipe a extending along the
bottom of the generator and provided throughout its length with perforations,
substantially as and for the purpose set forth.
Dated this 15th day of March 1807
H. D. FITZPATRICK,
70 Wellington Street, Glasgow, Agent.