Improvements in Apparatus for the Production of, Electricity from the Waste Heat of Gas, Steam, or other Heat Engines.
Year: 1896

page_text: Improvements in Apparatus for the Production of, Electricity from
the Waste Heat of Gas, Steam, or other Heat Engines.
HERBERT JOHN. DOWSING 24 Budge. Row London E.C. Engineer, do..hereby
declare the nature of this invention to: be as follows:-
My invention relates to improvements in, and the application of, electrical
appliances known as thermopiles, for the direct production of electricity from the
waste heat of explosive or other heat engines, and it is particularly applicable to
motors used on self propelled carriages.
The present, means adopted for cooling the cylinders of small engines driven; by
explosive gasses,, are to obtain an enlarged surface for radiation by deeply ribbing
or corrugating the outsides of the cylinders, but in the case of larger engines a
water jacket is employed in which the waste heat is absorbed and carried off by, the
circulation of water.which in turn is itself cooled in. a larger vessel. The waste
heat, from the engine is by these means carried off and dissipated.
By my invention I.apply to the cylinders and other suitable parts of the engine
where waste heat is available, and where it is desirable, to reduce the temperature,
a number of elements to form an electrical apparatus known as a thermopile, the
action of which is to produce electricity when one part of the thermopile is heated
by the waste heat, and the other part, is cooled by contact with the air, or by, other
means.
I sometimes utilise the waste gasses, given off from the exhaust of the engine
which are heated to a high degree. These gasses I cause to pass through the
elements of the thermopile in such a manner. that they produce the required effect.
The electricity obtained from the thermopile may be used to charge storage
batteries, or it may be used direct for firing the charge in the cylinder of the
engine, producing light, or for other purposes. The power of the, thermopile may
be varied by diverting the heating effect or altering the combination of the
elements.
0.Improvements in Apparatus for the 'Production of Electricity from
5
the Waste Heat of Gas, Steam, or other Heat Engines.
I, HERBERT JOHN DOWSING, of 24 Budge Row, London, 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.:-
My invention relates to the application of appliances known as thermopilés for
the direct production of electricity from the waste heat of explosive or other heat
⚫engines.

page_text: Some of the waste heat developed in engines driven by explosive gases is carried
off, according to present arrangements, by radiation from deeply ribbed or corru-
gated parts, or by being transmitted to water circulated through water-jacket, or
otherwise, whichever of these two methods is employed the waste heat is dissipated
and lost. According to my invention instead of allowing the whole of the waste
heat heretofore carried off by radiation or by transmission to water to be dissipated
and lost, I utilise more or less thereof for the purpose of generating a current of
electricity by means of a thermopile, the well known action of which is to produce
electricity when one part of elements composing the pile is heated and the other
part is cooled by contact with air or other cooling medium.
And in order that my said invention may be fully understood I will proceed to
describe the same with the aid of the accompanying sheet of drawings, in which
Figure 1 is a diagrammatic sectional elevation showing the invention applied by
way of example to part of the exhaust pipe of a gas or oil engine, and Figure 2 is
a plan of same.
A represents part of the exhaust pipe of the engine, B a cylinder of porcelain,
fireclay or other suitable fire resisting material which is a bad conductor of
electricity and having formed therewith the flanges B' between which are placed
the elements C of the thermopile. The inner ends of these elements touch or are
brought into close proximity with the cylinder B so as to be heated by the heat
transmitted thereto from the exhaust pipe A through which the hot products of
combustion pass on their way to the outer atmosphere. The outer ends of the
elements C are freely exposed to the cooling effect of the outer atmosphere, the
difference of temperature between the inner and outer ends of the elements C causing
a current of electricity to be generated in them in the manner well understood in
connection with thermopiles.
$ 1.
The arrangement of thermopile above described and shown in the drawings is
given only by way of example as any other suitable arrangement of thermopile may
be employed.
It will be obvious that instead of applying the thermopile to the exhaust pipe it
may be applied in a similar manner to the chimney of the burner employed to heat
the ignition tube of a gas, oil, or other explosive engine or to the flue or chimney
of a steam boiler, in order to utilize more or less of the waste heat escaping from
such burner, flue, or chimney; and that by suitably shaping and arranging the parts
of the thermopile they may be adapted to any part of the engine giving off waste
heat, as for example to the external surface of the working cylinder, especially in
cases where they can be so applied as to absorb as much of the waste heat as it is
necessary to take off. In some cases, however, the thermopile may be employed in
conjunction with the means usually employed to dissipate the waste heat, that is to
say the thermopile may be employed to take off and utilise part of the waste heat,
and the usual means for taking off the remainder.
The thermopile may be used in connection with the exhaust pipe or other part
of a steam engine giving off waste heat; but the effect will not be so good as with
explosive or hot air engine, because the temperature of such waste heat is not so
great in the steam engine as in explosive or hot air engines.
The electricity obtained from the thermopile may be used to charge storage
batteries for producing light or other purposes, or it may be used direct for firing
the explosive charge in the cylinder of the engine or for other purposes. The
power of the thermopile may be varied by diverting part of the heating effect, or
by altering the number or combination of the elements forming the thermopile.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
First. The combination of a thermopile with any part of a gas, steam or other
heat engine giving off waste heat, for the purpose of utilising more or less of such
waste heat for the production of electricity, substantially as described.

page_text: Second. Apparatus for the production of electricity from the waste heat of gas,
steam, or other heat engines, arranged and operating substantially as described.
Dated this 2nd day of April 1897.
H. J. DOWSING,
Per W. H. Beck,
115 Cannon Street, London, E.C., Agent.