Year: 1886

page_text: Date of Application, 28th Aug., 1886.
Complete Left, 23rd Nov., 1886.
Complete Accepted, 12th July, 1887.
I HUGH MONTGOMERIE Marine Engineer East Boldon Newcastle on Tyne do
hereby declare the nature of this invention to be as follows:-
1st. An Air holder filled with Tubes is placed in the uptake through which the
heat from the Boiler passes.
2nd. A portion of the bottom of the Boiler is also Tubed round which the feed
water enters.
3rd. An Engine drives air into the holder which is taken to the Fires and to the
feed heater in the Boiler bottom the whole being regulated by Valves.

page_text: COMPLETE SPECIFICATION.
Collecting and Using the Waste Heat from Steam Boilers.
I HUGH MONTGOMERIE of East Boldon Newcastle on Tyne in the County of Durham,
Marine Engineer do hereby declare the nature of my invention for COLLECTING AND
USING THE WASTE HEAT FROM STEAM BOILERS and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to collecting the waste heat of steam boilers on its passage to
the chimney into a receiver or holder in which it is made to traverse through or
around tubes or flues on the other sides of which atmospheric air is caused to circulate by
mechanical means, preferably by the action of a Fan or Blower, and is heated by contact
with the heated surfaces, leaving the receiver at a greatly increased temperature and
entering the furnaces in regulated quantity to effect the combustion of the fuel,
entering also a series of tubes below the furnaces to heat the dead water and cause it
to circulate the feed water entering the boiler at that part being also heated. The
heated air may also be used to warm the cylinder jackets or to impart fresh beat to
the partly spent steam in the valve chests or passages from one cylinder to another or
to warm the saloons and cabins.
I propose to use furnaces much smaller in diameter than now used, as no fire bars
are required, the fuel lying on the bottoms of the furnaces the mouths of which are
entirely closed except the inlet for the heated air and a small opening to admit a
regulated quantity of air from the stoke hold and allow of the introduction of a firing
tool to manipulate the fuel when required. In case of existing boilers the area of the
furnace may be contracted by lining them with fire bricks on their bottoms and sides.
Each furnace door is so hinged that when it is opened to charge with fresh fuel the
supply of hot air is cut off automatically and the air to each furnace is also regulated,
by a valve, to its requirements independently of all the other furnaces. The supply
of hot air to the tubes in the bottom of the boiler is also regulated or shut off
altogether by separate valves and in addition adjustable shutters or dampers are fitted
at the back end in combustion chamber to regulate the passage of the hot air through
the centre and side groups of tubes. When so fitted the supply of hot air to cylinder
jackets &c. and to the saloons is adjustable or may be entirely shut off by valves.
The furnace door is only required to be opened for any length of time when fires are to
be cleaned which will be at long intervals as I anticipate the combustion of the fuel
will be much more complete than with ordinary furnaces and less ashes left.

page_text: to heat the air for supplying the furnaces heating and circulating the water in bottom
of boiler and for the other purposes named but I do not bind myself to either
particular form of air heating apparatus as many other modifications may be adapted.
Fig. 1 is an end view, the left side in section.
Fig. 2 is a longitudinal section.
A A A are the furnaces six in number three into each combustion chamber B B¹
from which the tubes C, which are longer than in ordinary boilers, return to the
smoke box D in the upper part of which is placed the receiver or apparatus for heating
the air consisting of 2 end boxes E E' connected by tubes F which are entirely
surrounded by the hot gases on their way to the chimney. The air enters the box E
from a Fan G, driven by the main or an auxiliary engine, passes through the upper
rows of tubes into the box E and returns through the lower rows of tubes into the
box E from which it is taken to the furnaces and other parts as required.
Underneath the furnaces in the bottom of the boiler are a number of tubes H which
run from the front into the two combustion chambers B B in which are fitted
adjustable shutters or dampers J each worked by a rod K passing through a tube
to front.
The hot air from the heating apparatus is conveyed to the furnaces and circulation
tubes from the shut off valve L through a pipe M to a valve N one branch of
which leads to the furnaces the other to a valve O which regulates or shuts off
the supply of air through the pipe P to the casing Qover openings of circulation
tubes H. A valve 1 regulates or shuts off the bot air from receiver to the
cylinder jackets &c. and the saloons. The supply of hot air to cach furnace is
separately controlled by the valves S S S from which the air passes through the
furnace doors when they are closed but is shut off when they are opened.
Fig. 3 shews to a reduced scale another method of constructing the apparatus
for transferring the heat of the waste gases to the air to be used for combustion
and heating purposes, the hot waste gases passing through 3 series of tubes before
reaching the chimney provided with soot boxes and doors for cleaning and the air
entering from the Fan G making several courses outside the tubes before it escapes
at the valve at T the full and dotted arrows indicate respectively the courses of
the hot gases and of the air to be heated. The air may by such an apparatus be
heated to very high temperatures.
Figs. 4 & 5 shew details of the construction of one of the automatic furnace doors
when closed and the passage for air into furnace open, also the grated adjustable
opening for cold air, inspection of the fire and introduction of a firing rod.
The principal advantages I expect to realise by my invention are:-
1st. Great economy of fuel by the introduction of air at high temperatures say
300° Faht. driven amongst and over the burning fuel by the Fan.
2nd. Increased strength of the furnaces from their smaller diameter, owing to the
absence of fire bars, small charges of coal being admissable and the more completo
combustion of the fuel.
3rd. Intense combustion in flame box and the possibility of using tubes of greater
length and proportionately smaller diameter to the current of heated air and the tube
surfaces can be effectually cleared of soot by blowing thom through with a concentrated
current of air.
4th. Obtaining rapid circulation of water from first lighting of fires by the intro-
duction of heated air through the tubes traversing the bottom of boiler and heating
the cold water lying there and the entering feed when the boiler is in full work.
5th. The prevention of straining by the unequal expansion of the boiler when steam
is being raised.
My invention is specially adapted for the use of oil or liquid fuel now engaging so
much attention as the ash or residuumn of of coal has not then to be dealt with. When
oil is used any of the approved burners may be fitted and the heated air introduced in
such a way as to cause the oil to be distributed as a spray as is now effected by steam
or by compressed air.

page_text: Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed whilst I make no claim for heating
air by the waste gases of the boiler nor for the application of such heated air
under either forced or natural draft to ordinary furnaces, I declare that what I
claim is :-
First. The application of air, heated by the waste gases of the Boiler in any suitable
apparatus, in regulated quantity to the coal or other fuel in closed furnaces into the
front of which the air is delivered under pressure direct from, or induced by, a fan
blower or equivalent appliance to effect rapid combustion and great ovaporative
officiency substantially as described and shewn.
Second. The application of air so heated and delivered under pressure to tubes in
the bottom of boiler to heat the colder water lying there, or entering as feed water,
and produce uniform temperature and circulation and increasing the evaporation
of the boiler and applying such heated air to other purposes substantially as described
and shewn.
Third. The furnace door so constructed as to automatically shut off the supply of
air when opened for firing or cleaning fires and to open the supply of air when closed,
arranged and operating substantially as described and shewn.
Fourth. The combination of heating apparatus, fan or blower, pipes and valves to
convey and regulate the supply of heated air to furnaces, tubes in bottom of boiler,
cylinder jackets and saloons and the automatic furnace door, arranged and operating
substantially as described and shewn.