IMPROVEMENTS IN GENERATING STEAM
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Matthew Piers Watt Boulton at
the Office of the Commissioners of Patents, with his Petition, on the
15th June 1865.
I, MATTHEW PIERS WATT BOULTON, of Tew Park, Oxfordshire, Esquire, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
GENERATING STEAM," to be as follows:-
Ordinarily steam is generated by applying heat externally to, the part of the
boiler in contact with the water. This method is attended with disadvantage
when the water deposits in the boiler earthy or saline matter. To obviate
this disadvantage, it is proposed in the present plan to employ the heat of the
furnace to superheat steam, and to generate steam in the boiler by causing the
steam thus heated to pass through the water in the boiler; the steam may be
superheated in the ordinary manner, or by injecting into it heated liquid.
It is forced through the superheating apparatus with such a pressure as is
requisite to overcome the pressure of the water in the boiler; this be
may
done by a pump propeller or forcing apparatus. The superheated steam may
be made to pass through the water in the boiler in numerous small streams.
It may be made to pass through perforations in plates; it may be made to
take a zig-zag course through the water in the boiler by means of plates or
surfaces suitably disposed; it may be made to pass through interstices between

page_text: moveable bodies, such as balls in the water of the boiler, which moveable
bodies may float in the water, or may be suspended in it, or otherwise may
find their own position by weight. The heated steam rising through the
water in the boiler, and generating steam in its passage through it may
carry along with it into the upper part of the boiler particles of water
in a state of spray or of minute division. It is not desirable that such
particles of water should pass into the superheating apparatus as they
might cause deposit there. To prevent this a portion of the superheated
steam may be caused to pass through the water in the boiler, while a portion
of it is caused to mix with the steam which has issued from the water
in the boiler and which contains the particles of water mixed with it. The
heated steam may mix with the watery steam either in the upper part
of the boiler or in a chamber or chambers communicating with this, mixing
with it, it turns into steam the particles of water suspended in it. In this
way it may be secured that the steam which passes to the cylinder to
perform work, and also the steam which passes into the superheating apparatus
and is used as a heating agent shall be pure steam, not having particles of
water suspended in it. Supposing the above action to be brought into play,
all the heat required for the generation of steam may be imparted to the
steam in the superbeating apparatus, and no other source of heat need be
employed. In the first instance before steam is generated, air may be heated
in the same apparatus in which the steam is subsequently superheated; this
heated air being forced through the water in the boiler and raising its tem-
perature, and when steam begins to be generated, this steam mixed with air
may be heated in like manner, and passed through the water generating more
steam. Again, in the first instance, the water may be raised to the boiling tem-
perature and steam generated by the application of external heat. The inside
of the boiler in which the water is heated in the manner previously described
may be coated with deposit, and it may not be desirable to apply external heat
to this boiler, accordingly another vessel constituting an auxiliary boiler
may be used for this purpose. To prevent incrustations in this vessel it may
be supplied with distilled water, or with water which has been freed by heat,
or by heat and filtration from all matters which it is capable of depositing.
Otherwise this auxiliary boiler may be kept free from deposit by frequent
cleaning, which as it is only occasionally used can be done without difficulty;
otherwise the following method may be adopted :-Products of combustion
are caused to pass, through the vessel, used as auxiliary boiler, heating its
interior.. The vessel may contain in its interior bodies which absorb heat and
which are heated by the products of combustion passed through it. The

page_text: interior of this vessel having been thus heated, the passages through which
the products of combustion passed are closed, and water is injected into it,
which water is converted into steam by the heat in the interior. Steam
having been generated in the auxiliary boiler, the action of the superheating
apparatus previously described is brought into play, and when this is done the
auxiliary boiler is no longer needed.