Improvements in Superheaters for Steam Generators.
Year: 1895

page_text: Date of Application, 26th Mar., 1895-Accepted, 4th May, 1895
COMPLETE SPECIFICATION.
Improvements in Superheaters for Steam Generators.
I, JAMES HERMANN ROSENTHAL, Director of Babcock and Wilcox (Limited)
147 Queen Victoria Street, in the City of London, Steam Boiler Manufacturers,
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 has for its object to provide in connection with steam generators a
simple and efficient apparatus for superheating and drying the steam which is
passed through it, a feature of the improved apparatus in which it differs from
superheaters of a similar type being the provision of means whereby water may
be supplied to circulate through the heating tubes of the superheater and thus
render them part of the boiler system when steam is being raised in order that
the tubes may not be injured by the impingement on them, while dry, of the fire
gases.
In the accompanying drawings which illustrate the invention,
Figure 1 is a vertical section of a water tube boiler of the well-known
Babcock & Wilcox type to which the improved superheating apparatus is shown
applied.
Figure 2 is a sectional end elevation of the same and
Figure 3 is a vertical section corresponding to Figure 1 but showing only part
of the boiler and a modification of the superheater hereinafter referred to.
The
The improved superheater is composed of two cross boxes A A', of wrought iron
or steel or other suitable material fitted in or across the combustion chamber C of
the boiler and connected together by a number of long tubes a expanded in them
and doubled or bent to U-shape or other shape, arranged in the combustion
chamber as shown in order to present a large surface for absorption of heat.
upper one A of the cross boxes has connected to it a vertical pipe B passing into the
steam space of the boiler drum D and terminating in a perforated cross pipe B¹. The
lower cross box A' is connected by vertical tubes A2 with a third cross box A³
resting on the top of the boiler drum D and which supports the weight of the
apparatus and serves as a collector for the superheated and dry steam.
delivery pipe E provided with a stop valve F is attached to the collector A³. The
ends of the tubes A2 are expanded into the cross boxes A' and A³, flanged and
bolted joints being avoided in the construction of the improved superheater.
A steam
The steam collecting in the boiler drum D passes through the perforated pipe B'
and pipe B into the cross box A, thence through the bent tubes a into the cross
box A from which it passes upwards by the tubes A2 into the collector A³ being
highly heated and dried in its course.
The cross boxes, A, A', are each connected by pipes g, g², to a pipe G attached to
the drum D, and the lower end of which is open or connected to a steam trap.
A two-way cock is provided at the junction of the pipes 9 and G and a three-way
cock at the junction of the pipes g', G, a stop valve I being also provided on the
pipe G. By opening these cocks water is admitted into the cross boxes A, A¹, and
tubes a of the superheater and water circulation maintained in them while steam is
being raised so that risk of the tubes becoming damaged by the action of the fire is
avoided, and the superheater is rendered more durable than would be the case were
the pipes left empty during steam raising. The arrangement permits of the
superheater being drained by means of the valves referred to when it is desired to
nass steam through it.

page_text: Furthermore the water circulating through the tubes a and exposed to the fire
passes into the drum D and facilitates the rapid raising of steam, the superheater
then acting as auxiliary boiler heating surface.
In the modification shown at Figure 3, the perforated steam collecting pipe B'
within the steam space of the drum D is provided with a valve casing b fitted
with a ball b¹ or other valve which in the event of the superheater bursting is
by the rush of steam automatically pressed against a valve seat at 62 and
prevents the further outflow of steam. A separate pipe connection J provided
with a stop cock J is in this case attached to the upper side of the steam drum D
to convey steam which has not been superheated to the steam pipe E. In other
respects this superheater is of the same construction and operates in the same way
as that shown at Figures 1 and 2.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that
what I claim is :-
1. The combination with a steam generator, of a superheater composed of two or
more cross boxes A A¹, communicating with the steam space of the boiler and
connected together by tubes a of U or other suitable shape extending through the
combustion chamber, and an upper cross box or collector A³ connected thereto by
tubes A' and resting
on the boiler drum so as to support in large measure the weight
of the apparatus, pipes such as g, g', and G, having suitable valves, being provided
to connect the superheater with the boiler drum so that water may be circulated
through the superheater when raising steam, substantially as described.
2. In combination with steam superheating apparatus the provision of pipes, such
as g, g', and G, having suitable valves, connecting the superheater with the boiler
drum so that water may be circulated through the superheater when raising steam,
and drained off when steam is raised, substantially as described.
3. In combination with steam superheating apparatus the provision of an
automatically acting valve adapted to close and shut off steain from the superheater
in the event of the latter bursting, substantially as described.
Dated this 25th day of March 1895.
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62, St. Vincent Street, Glasgow, Agent for the Applicant.