Improvements in or connected with Feed-water Heaters.
Year: 1896

page_text: Date of Application, 29th Apr., 1896-Accepted, 6th June, 1896
COMPLETE SPECIFICATION.
Improvements in or connected with Feed-water Heaters.
A communication by JOHANN FRIEDRICH HAUSER, of No. 26 Martin
Richterstrasse, Nuremberg, in the Empire of Germany, Engineer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6, Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham,
in the County of Warwick and 322 High Holborn in the County of Middlesex,.
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 :-
In the feed-water heaters hitherto employed the water could only be preliminarily
heated up to a temperature of 100° C., and a large part of the exhaust steam, if no-
other employment for the same existed, was lost.
This invention has for its object to obtain a better and more complete utilization
of the heat contained in the waste steam by withdrawing heat from the waste
steam by means of the surrounding water, even when the latter has already been
heated to a temperature of 100° C. and above. This object the inventor endeavours
to obtain by employing a well known physical law in the following way, namely,
by securing in a feed heater by artificial means a difference of temperature even
above 100° C. between the two mediums of which one circulates (in pipes, or the
like) through the other, and which are always separated one from another by
means of vessel walls. So long as such a difference of temperature exists an
exchange of heat between the two mediums takes place.
This arrangement of feed heater is shown in the accompanying drawing, in
which
Figure 1 is an elevation, and
Figure 2 a plan view.
In order to produce this difference of temperature, the pressure of the waste
steam is regulated to that of the water in the feed heater, and this is done by
means of spring valves R, columns of liquid, the differential action of two pumps,
or the like, in such a way that the pressure of the waste steam is always higher
than that of the water which is to be heated. The boiling point of the latter
stands therefore at 100° C., and over, according to the pressure, and the water still
absorbs beat over that temperature. If, for instance, the water contained in the
feed heater be weighted with atmosphere, it may be heated up to 105° C. before
it evaporates. If theu the waste steam be weighted with about atmosphere,
which pressure corresponds to a temperature of 110° C., the difference of
temperature necessary for the exchange of heat will be established.
The arrangement hereinbefore described of pressure regulators in the feed
heaters renders it possible to carry out a cycle of processes in steam engines by
expanding in the machine the steam developed in the boiler, and then condensing
it in the feed heater. The water of condensation together with the additional
feed water is again conveyed into the feed heater, there again heated, and fed to
the boiler.
The feed heater shown in the accompanying drawings is arranged in the manner
hereinbefore described, that is to say, the feed heater with steam apparatus
contains pressure regulators and has the following constitution.
The high pressure steam evolved in the boiler K is conveyed through pipe a to

page_text: the steam engine D, from which it is discharged after expansion as waste steam
through the pipe c. The waste steam then passes into the feed heater V in which
the above described exchange of heat between the two mediums takes place. The
condensed fluid is then conveyed through a condenser g in which the last remaius
of steam is deposited as water, and is cooled to 100° C. This water flows through
the pipe of the pump i and is returned to the feed heater from said pump by
means of a pipe k. The condensed fluid may, however, be conveyed directly to the
pump together with the necessary supplementary water withdrawn from the
tank w and conveyed by the said pump to the feed heater.
The water heated in the latter flows, as already stated, away at e and is
conveyed by means of a pipe m to a second pump n from which it is forced through
the pipe o into the boiler.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
In feed-water heaters which are heated with the waste steam, the arrangement
of pressure regulators to maintain the water at a lower pressure than the waste
steam, with the object of producing a constant difference of temperature between
the two mediums, thereby causing heat to be imparted from the waste steam to
the feed water even at 100° C. and over substantially as described.
Dated this 28th dor of April 1806
WM. P. THOMPSON & Co.,
Agents.