Year: 1886

page_text: Date of Application, 16th July, 1886.
Complete Left, 18th Apr., 1887.
Complete Accepted, 20th May, 1887.
I WILLIAM THOMPSON of 58 Fenchurch Street in the City of London Marine
Engineer do hereby declare the nature of this invention to be as follows:-
In steam engines as they are usually worked the greatest portion of the heat passed
into the water in the boiler and used to raise steam escapes either in the form of
vapour as in high pressure engines or in the condensing water as in condensing
engines.
The object of this invention is to avoid this Joss by returning the whole of the
exhaust steam back to the cylinder so as to work again and again without condensation
or escape of any kind so as to form a completely closed cycle.
Plans of apparatus working in this direction may be found scattered through various
patents and especially in a patent granted to Mr. Imray on May 30th 1880. None of
these attempts however went to the extent of absolutely closing the cycle and none
have in practise been successfully carried out and I found that an apparatus
constructed and worked as described in the afore mentioned specification failed to give
useful results.
By the present arrangements an engine is obtained in which I am able absolutely
to close the cycle so that no heat is carried off by water of condensation, nor by the
escape of exhaust steam and every precaution is taken to avoid loss by radiation the
only loss of heat being limited to that arising from unavoidable radiation and from
actual work done.

page_text: This is effected in the following manner.
The exhaust steam from the engine I conduct into a vessel which I call (coefficient
of equilibrium) or equaliser and which in the working of the engine keeps at such a
temperature that steam does not condense therein.
Preferably I form it with large surface as compared with its capacity and keep it
immersed in a body of water which without assistance from new steam from the boiler
remains at a temperature at or below the boiling point of water. Its purpose is
simply to act as an equaliser of temperature of the exhaust steam.
From this equalizer I draw the exhaust steam by a pump or by an aspirator so as to
maintain a partial vacuum in the equalizer. This pump delivers the exhaust steam
into a vessel which I call the accumulator and from this it is withdrawn by an aspirator
or battery of aspirators acting by steam from the boiler-preferably I superheat this
steam from the boiler to a high temperature. These aspirators deliver it into a third
vessel which I call the recipient and preferably a further aspirator which I call an
aspirator of intensity and which in detail is slightly different from the others injects it
into the steam pipe leading to the cylinder of the engine.
The small quantity of steam required for working the aspirators can easily be heated
to 500° F. or higher and by its use the utmost economy is gained.
Steam heated to this temperature could not be used in the ordinary way on account
of the difficulty arising from the destruction of packings and the impossibility of
obtaining proper lubrication but in this system the superheated steam does its work in
heating up the far larger volume of steam from the equalizer with which it is caused
to mingle so that the mixed steam passing forward to the engine may enter it at a
temperature which is not injurious to the parts.
There is found in the equaliser and in the accumulator a certain quantity of
condensed water being in fact that arising from radiation and work done this is
pumped back into the boiler in the ordinary way and apart from leakage the exact
measure of the quantity required to keep up the level of water therein.
The aspirator referred to is in the nature of an injector but being used solely for
the action of steam of one pressure upon vapour of a lower pressure and in large
volumes and against and producing high pressure it necessarily differs from injectors
in its construction as these all depend on the condensation of the steam or exhaust
steam in the liquid to be injected and also from blowers or the ordinary means of
producing currents of air or vapour.
This efficient action depends upon its being so formed that the greatest possible
surface action shall be exposed of the acting steam to the recipient vapour and that
they shall be thoroughly mingled in the process.
In its simplest form consists of a jet of steam issuing from a conical aperture and
acting in a tube one end of which is connected with the accumulator and the other is
a channel pipe slightly larger than itself.
But as experiments prove that this cannot be used of larger diameter than
6-7 millimetres I use one formed with a circular aperture of any given diameter
reduced to a breadth of 3-4 millimetres by the use of an internal spindle terminating
in a conical point not as it has been used by others as a regulating spindle but as an
essential part of the apparatus and by another arrangement I use a cylindrical jet with
the central spindle in the same way.
The central spindle projects much below the jet its function being to gradually
reduce and then maintain the area of the delivery pipe to a size larger than but in
due proportion to the area of the jet.
Or in other ways I so form the aspirator as to impart the maximum velocity
practicable to the lower pressure steam.
A non return valve is placed on the suction side of the aspirator and though not
essential I use occasionally a valve also on the delivery side.
In the aspirator of intensity the jet is prolonged further into the channel of
delivery.
I find the greatest advantage by the use of this system in rotary engines. In a

page_text: rotary engine of the ordinary system the loss of steam through leakage at the joints is
so great that practically they are out of the market and also there is in them no
possibility of using expansion.
But under this system this loss is not felt or certainly in an enormously diminished
degree. All steam or vapour leaking past the joints being returned to the steam side
and also the value of expansion is gone where the loss of heat is limited to the work
done I am thus enabled to make use of the simplicity of these engines.
.
In a compound engine I place an aspirator in the passage between the cylinders
thereby diminishing materially the back pressure in the high pressure and adding to
the pressure of the low pressure cylinders.

page_text: I, WILLIAM THOMPSON of 58 Fenchurch Street in the City of London Marine
Engineer (a communication to me from abroad by Felix Alexandre Testud de
Beauregard of 162 Rue Lafayette Paris, in the Republic of France Engineer) 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 :-
In steam engines as they are usually worked the greatest portion of the heat passed
into the water in the boiler and used to raise steam escapes either in the form of
vapour as in high pressure engines or in the condensing water as in condensing
engines.
The object of this invention is to avoid this loss by returning the whole of the
exhaust steam back to the cylinder so as to work again and again without con-
densation or escape of any kind so as to form a completely closed cycle.
Plans of apparatus working in this direction may be found scattered through various
patents and especially in a Patent granted to Mr. Imray on May 30th 1880. None of
these attempts however went to the extent of absolutely closing the cycle and none
have in practice been successfully carried out and I found that an apparatus constructed
and worked as described in the afore-mentioned specification failed to give useful
results.
By the present arrangements an engine is obtained in which I am able absolutely
to close the cycle so that no heat is carried off by water of condensation, nor by the
escape of exhaust steam and every precaution is taken to avoid loss by radiation the
only loss of heat being limited to that arising from unavoidable radiation or leakages,
and from actual work done.
This is effected in the following manner and as is illustrated in Figure 1 of the
drawing hereunto annexed which shows the arrangement applied to a marine engine
of the ordinary construction.
The exhaust steam from the engine is conducted into a vessel A which I call
(coefficient d'equilibre) or equaliser and which in the working of the engine keeps at
such a temperature that steam does not condense therein.
Preferably I form it with large surface as compared with its capacity and I keep it
immersed in a body of water which without assistance from new steam from the boiler
remains at a temperature equal to or very slightly differing from the boiling point of
the water in the interior of the coefficient under the vacuum existing therein. Its
purpose is simply to act as an equaliser of temperature of the exhaust steam.
In the drawing it is shown as being constructed like and taking the place of an
ordinary tubular surface condenser with horizontal tubes the pump for maintaining
a flow of water through the casing around the exterior of the tubes being removed
and the casing simply kept filled with water.

page_text: The heat of the water surrounding the equaliser can be carried to the last point of
temperature of water at the boiling point under the vacuum existing. If the
temperature tends to exceed this it will part with the excess to the condensed water
in the coefficient and so increase the volume of vapour and the heat to be returned to
the steam.
From this equalizer I draw the exhaust steam by a pump B or by one or more
aspirators C or by both so as to form and maintain a partial vacuum in the equaliser.
This pump delivers the exhaust steam into a vessel D which I call the accumulator
and from this it is withdrawn by an aspirator or battery of aspirators E acting by
steam from the boiler H which may be of any system or type and these aspirators
deliver it into a third vessel F which I call recipient and from this vessel a tube
conveys it to the cylinder of the engine. Or a further aspirator which I call an
aspirator of intensity and which is not shewn in the drawing may be used to inject it
into the steam pipe.
Any water collecting at the bottom of the vessel D can be drawn off by the feed
pump of the engine and returned to the boiler.
I superheat the steam from the boiler before it acts in the apparatus by passing it
through a superheater I to a very high temperature. This superheater may be of the
form shown in Figure 2.
The small quantity of steam required for working the aspirators can easily be heated
to 500° F. or higher and by its use the utmost economy is gained.
Steam heated to this temperature could not be used in the ordinary way on account
of the difficulty arising from the destruction of packings and the impossibility of
obtaining proper lubrication but in this system the superheated steam does its work in
heating up the far larger volume of steam from the equaliser with which it is caused
to mingle so that the mixed steam passing forward to the engine may enter it at a
temperature which is not injurious to the parts.
There is found in the equalizer and in the accumulator a certain quantity of
condensed water being in fact that arising from radiation and work done this is
pumped back into the boiler H in the ordinary way and is apart from leakage the
exact measure of the quantity required to keep up the level of water therein.
The aspirator referred to is in the nature of an injector but being used solely for tho
action of steam of one pressure upon vapour of a lower pressure and in large volumes
and against and producing high pressure it necessarily differs from injectors in its
construction as these all depend on the condensation of the steam or exhaust steam in
the liquid to be injected and also from blowers or the ordinary means of producing
currents of air or vapour.
This efficient action depends upon its being so formed that the greatest possible
surface action shall be exposed of the acting steam to the recipient vapour and that
they shall be thoroughly mingled in the process.
In its simplest form it consists of a jet of steam issuing from a conical aperture and
acting in a tube is connected with the accumulator so that the jet is surrounded by
vapour from the accumulator which it carries forward and delivers into a channel tube
slightly larger than itself.
But as experiments prove that this cannot be used of larger diameter than
6-7 millimeters I use one formed with an annular aperture of any given diameter and
I use an internal spindle terminating in a conical point not as it has been used by
others as a regulating spindle but as an essential part of the apparatus.
The central spindle projects much below the jet its function being to gradually
reduce and then maintain the area of the delivery pipe to a size larger than but in due
proportion to the area of the jet.
Or in other ways I so form the aspirator as to impart the maximum velocity
practicable to the lower pressure steam.
•
By preference a non return valve is placed on the suction side of the aspirator D
and though not essential I use occasionally a valve also on the delivery side.
In the aspirator of intensity if such an aspirator be used-the jet is prolonged
further into the channel of delivery.

page_text: I find the greatest advantage by the use in this system of rotary engines. In a
rotary engine of the ordinary system the loss of steam through leakage at the joints is
so great that practically they are out of the market and also there is in them no
possibility of using expansion.
But under this system this loss is not felt or certainly in an enormously diminished
degree. All steam or vapour leaking past the joints being returned to the steam side
and also the value of expansion is gone where the loss of heat is limited to the work
done I am thus enabled to make use of the simplicity of these engines.
In a compound engine whether of two or more cylinders I place one or more
aspirators in the passages between the cylinders thereby diminishing materially the
back pressure in the high pressure and adding to the pressure of the low pressure
cylinders.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I declare that what I claim is :-
1. The combination substantially as herein described forming a closed cycle that is
a cycle in which there is no passing off of heat except by radiation unavoidable
leakage or work done.
2. The employment in this cycle of steam superheated to a high temperature.
3. The combination of a rotary engine and parts forming therewith a closed cyclo
substantially as described.
CARPMAEL & Co.,
Agents for the Applicant.