Improvements in or connected with Steam Boilers and other Evaporating Apparatus.
Year: 1891

page_text: Date of Application, 18th Aug., 1891
Complete Specification Left, 18th May, 1892-Accepted, 18th Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Boilers and other
Evaporating Apparatus.
I, JOSEPH ELTON BOTT, of Eyam, in the County of Derby, Metallurgist, do
hereby declare the nature of this invention to be as follows:-
It is a well known fact that present methods of evaporating water and other
liquids are far from perfect, and that the amount of fuel required to evaporate a
given quantity of liquid is far in excess of what is theoretically necessary, even with
the best constructed appliances.
At present liquids are evaporated in steam boilers and other evaporating
apparatus by the conduction of heat through the metal plates of the boiler or other
receptacle containing the liquid to be evaporated.
According to my invention I avail myself of the fact that the caloric contained
in heated atmospheric air is readily utilized by bringing it into direct contact with
water or other liquids and, taking, for example, an ordinary steam boiler, the
peculiar character of my invention is as follows.
With either the direct or waste products of combustion, I heat a stream of air,
which may be passed or forced through suitable tubes fixed in the fire box or in the
flues of a steam boiler or elsewhere; the said air becoming heated is passed through
the water contained in the boiler and, by coming into direct contact with the water,
evaporation commences and is carried on with much greater freedom and efficiency
than if the available heat had been wholly transmitted through metal plates, as is at
present usual.
I am aware that air and steam have heretofore been mixed for the purpose of
superheating the steam, but my invention consists in passing streams of air heated
by the products of combustion (either directly or by heated flues) into water or
other liquids to be evaporated either under pressure or in open vessels, whereby
hot air is caused to give off caloric to the water or other liquid and thereby
evaporate the same, thus increasing the evaporative efficiency of a steam boiler or
other evaporating vessel or apparatus and at the same time saving a large amount
of fuel.
Dated this 18th day of August 1891
COMPLETE SPECIFICATION.
Improvements in or connected with Steam Boilers and other
Evaporating Apparatus.
I, JOSEPH ELTON BOTT, of Eyam, in the County of Derby, Metallurgist, 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 :-
It is a well known fact that present methods of evaporating water and other
liquids are far from perfect, and that the amount of fuel required to evaporate a
given quantity of liquid is far in excess of what is theoretically necessary, even
with the best constructed appliances.
At present liquids are evaporated in steam boilers and other evaporating
[DQ77

page_text: Figure is a longitudinal sectional elevation of a steam boiler constructed with
the necessary apparatus for utilizing my invention and carrying the same into
effect.
Figure 2 is an end elevation of same and
Figure 3 is a plan.
Similar letters of reference indicate like parts in all the figures.
The boiler A is in this instance of a marine type, in the flue B of which are a series
of air pipes C C. A suitable pump conducts air, at a pressure slightly in excess of
that at which the boiler works, through the pipe D, check valve E, and heating
pipes C C. The products of combustion in furnace B heat the compressed air to a
high temperature, and the heated air is conveyed through the syphons F F; through
check valves G G, into the water space of the boiler A. Any excess of heat
contained in the air over and above the temperature of the water in the boiler, acts
by intimate contact in further raising the temperature of the water, whilst the air
itself passes off with the steam generated to the engine in which it is intended to be
used, and in consequence of each molécule of air being in intimate mechanical
contact with the molecules of steam at the same temperature, the steam is kept
perfectly dry, and consequently condensation in the cylinder is prevented, thus
enabling a much greater duty to be obtained from a given weight of steam.
"
I am aware that hot air has been admitted into the steam chest or cylinder of
steam engines for the purpose of drying steam, but as the use of hot air “per se
inevitably results in the deterioration of the metal of which the steam chest or
cylinder may be constructed, such use of hot air is attended with many
disadvantages.
In my invention however, the air and steam, being intimately mechanically
mixed, and of the same temperature and pressure, are admitted direct through the
steam chest or cylinder of any ordinary steam engine, no special valve or gearing
being required as in other cases, whilst at the same time all excess of heat
contained by the air as it comes from the heaters is utilized in evaporating the
water.
.

page_text: Although I have only shown in the drawings herewith my invention as applied
to steam boilers, it will be readily seen that it is equally applicable to other kinds
of boilers or evaporating apparatus.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. The pre-heating of air at a pressure equal to, or slightly in excess of, that
contained in the boiler to which it is to be applied, and passing the same by suitable
pipes into the water contained in the boiler, whereby the surplus heat of the air
evaporates its quota of water, and passing off in intimate contact with the generated
steam, causes the compound of air and steam to be perfectly dry and the whole of
its expansive powers to become utilized.
2. In steam boilers and other evaporating apparatus, the forcing of heated air
into the water to be evaporated, for the purpose explained.
3. The combination with steam boilers and other evaporating apparatus, of air
heating tubes, a supply pipe connected with such air heating tubes, a force pump
and check valve connected with the supply pipe, one or more syphon connections
between the air heating tubes and the water space, and a check valve on each of
such syphon connections, substantially as herein shown and described and for the
purpose stated.
4. The combination with steam boilers and other evaporating apparatus, of air
heating tubes, air supply pipe, air forcing apparatus, and check valve, for the
purpose explained.
5. The combination with steam boilers and other evaporating apparatus, of means
for forcing heated air into the water for the purpose explained.
1000
J. ELTON BOTT,
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.