IMPROVEMENTS IN THE GENERATING OF STEAM, AND IN THE MEANS OR APPARATUS EMPLOYED THEREFOR
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by William Hamilton at the Office
of the Commissioners of Patents, with his Petition, on the 23rd
April 1868.
I, WILLIAM HAMILTON, of the City of Glasgow, in the County of
Lanark, North Britain, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE GENERATING OF STEAM, AND IN THE
MEANS OR APPARATUS EMPLOYED THEREFOR," to be as follows, that is to say:―
This said Invention consists essentially in the use of superheated
steam as a direct heating medium or agent for the raising or production
of steam within steam boilers or generators under pressure for the use
of motive-power engines, and other purposes for which. the steam from
such generators is used generally, and which in many positions and
circumstances is of great advantage in the saving of fuel, the number
and size of said boilers employed, and consequently the space or ground
room required therefor over the means heretofore used for the said
purpose of generating steam; and, stated more minutely or particularly,
consists under one form or modification in superheating. a part or the
whole of the steam generated in a close boiler by conducting it, fromi
.

page_text: the upper or steam space thereof through or into a very hot chamber or
vessel, or it may be a range or coil of undulating close piping placed
adjacent to the boiler or boilers to which it is connected, either heated
within a main flue of one of the steam boilers or generators or a furnace
of its own, or it may be within a chamber formed in the brickwork.
heated by the flame and gases in the flues leading from the boiler or
boilers to the chimney; from which superheating steam vessel the steam
after it has been surcharged with heat is conducted into the lower part
or water space of the same, or one or more other close steam generator
or generators, by preference forced or injected from the outlet conduit
and orifice of the superheating vessel directly into the body of the
water, to which it immediately imparts all its surcharged heat, thus
producing great or active ebullition in the water with increased and
free evaporation, and consequently the production of a greatly increased
quantity of steam as the superheated and newly formed steam spreads
and rises to the surface or steam space within the generator or
generators into which the superheated steam is thus injected or forced
to pass through, all by preference in addition to the steam being
raised in the said generator in and by the usual means and modes of
doing so..
The steam boilers or generators and their furnaces and heating
arrangements may otherwise generally or in addition to these improve-
ments as described be of any of the usual forms and constructions, and
the superheating vessels or chambers may be of various shapes and sizes
to suit the available space and other circumstances near the arrangement
of boilers to which these improvements are to be applied, premising
however that the heating vessel ought to have sufficient heating surface
without being heated above a low red heat to burn it, that it will
superheat the quantity of steam passing through it properly so as to
produce the regular amount of ordinary steam within the generator
required for use.
The form of the superheating vessel preferred is that of the arched
range of undulating pipes as used for the heating of air for blast
furnaces, placed in a convenient heating chamber, by preference rather
higher than the level of the water within the generator into which the
superheated steam is to be forced; and the pressure within the said
generator should, when possible, be lower than that within the heating
vessel and first steam boiler; which may be smaller in size than the

page_text: former when two or more generators are used. The orifice of the
superheating discharge pipe is by preference perforated with small holes
in the form of a long horizontal rose pipe for the superheated steam to
pass through into the water, and also the pipe itself is fitted with a
check valve or valves; and a small hole may be perforated in the pipe
above the water level, this pipe being, by preference, inserted through
the crown or upper steam space of the generator for that purpose so
as to equalize the pressure above the water in the boiler and in the
pipe so as to prevent the water from being forced back into the heating
chamber should the pressure within the generator at any time by
accident or otherwise be greater than that within the superheater. When
more than one steam generator is supplied from the same superheater
a corresponding number of branch pipes with cocks or valves may be
employed to regulate the amount of superheated steam to be injected
into each generator; and in some cases a cock or valve may be fitted
also to the induction pipe leading to the superheater so as to prevent
the superheated steam from blowing back into the steam space of the
boiler supplying the moist steam to the superheater.