Applying, and Keeping Up Extreme Temperatures.
Year: 1885

page_text: Applying, and Keeping Up Extreme Temperatures.
I, ERNEST SOLVAY of Brussels in the Kingdom of Belgium, Manufacturer 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:-
I produce high temperatures by making a series of consecutive compressions of
gas and by forcing the heat resulting from each compression and pervading the
compressed gas to systematically concentrate itself in quitting the apparatus upon
a special body acting as recuperator, such heat being subsequently continued also
systematically and in an opposite direction, by the incoming gas intended for tho
following compression.
I produce low temperatures by making a series of successive expansions of gas
by mechanical power and by forcing the cold resulting from each expansion and
itself pervading the expanded gas to concentrate itself on leaving the apparatus,
upon a special body acting as recuperator, such cold being subsequently continued
also systematically and in an opposite direction by the incoming gas intended for
the succeeding expansion.
In the annexed drawings, Figure 1 is a longitudinal section, and Figure 2 a plan
view of a pump embodying the invention. A is the piston; B the appendix ;
C the cylinder; D an extension of the cylinder; E open space between the
appendix and the cylinder extended; F packing; G iron plate; H inlet of the
gas; J standards; M cock and L L foundation plates. The outlet valves are
preferably placed at the point marked H'.
The apparatuses which I preferably make use of are ordinary simple acting
compression and expansion pumps to which I merely add the following organs :
the cylinder is lengthened and this lengthening I call "sheath" which is attached
to, and is generally much longer than the former and which merely increases
directly its capacity; the piston is likewise lengthened by what I call the
"appendix" which is attached thereto and is of the same length as the inside of
the sheath which too merely increases directly the length of the piston, but the
addition has however a diameter somewhat smaller than that of the piston so as to
have a small annular interval free between the sheath and the appendix when the

page_text: latter is therein introduced, and in such a way that when the piston is at the
bottom of its course the appendix completely fills the sheath, and that when
it is at the top of its course, there exists at the lower part of the sheath a free
space equal to that of the cylinder less the volume of the piston proper.
PUMP FOR THE COMPRESSION AND PRODUCTION OF HEAT.
The foregoing being explained, and if we take the vertical compression pump,
we see that if the piston rises with its appendix, the gas drawn in instead of
entering at the lower part of the cylinder as is usually the case with ordinary
simple acting compression pumps, must come in the free space at the bottom of the
sheath, by first passing through the space existing around the appendix of the
piston; and if the piston afterwards descends, always with its appendix, the gas
will first be compressed in that space with disengagement of heat, and then as soon
as the repulsion valves open, it will be discharged therefrom and forced to again
pass through the round space existing between the sheath and appendix upon
the sides of both of which it will necessarily and gradually deposit its heat.
On the second rising of the piston, the incoming gas will take up in passing
through the said round space the heat produced by the foregoing operation and
will thus, loaded with this heat, arrive in the space of the foot of the sheath where
it will, in its turn be compressed. The heat disengaged by such second compression
will add itself therefore to that produced by the first compression and lodge itself
with same upon the recuperating sides during the second discharge and so on,
so that after a certain number of compressions, the bottom of the sheath and of
the appendix will be at as high a temperature as is desired, in as much as their sides
will have collected practically the whole of the heat evolved during all the
successive compressions.
It is obvious that owing to the systematic working of the recuperating sides of
the round space the deposit as well as the removal of the heat at each operation,
may be complete or nearly so; so that the discharged gas can quit the apparatus
and reach the valves at its initial temperature. This however depends on the
concentrating faculty of such sides which must consequently have a sufficient
surface as it is obvious that at each inspiration less weight of gas enters than on
the previous inspiration, the volume remaining the same by reason of the pro-
gressive rise of temperature of the gas on its reaching the space from the bottom
of the sheath, it follows from this that the mass of the incoming gas, at any
particular inspiration, will always be incapable of absorbing the whole of the heat
evolved by the foregoing discharge, consequently there must be each time a certain
surplus which added to any preceding surplus would eventually have the effect of
carrying the higher temperature quite up to the outlet valves, if one did not place
between them and the compression room a sufficient regenerating mass, which is an
easy thing to do. If notwithstanding the concentration of such heat upon the sides
was not complete, it might be advisable to cool the gas before it enters the valves
in order to avoid injuring the latter.
The round space existing between the appendix and the sheath having a much
larger capacity in consequence of its being necessary to give to the two latter more
power which it is very advisable to do when it is desired to attain very high
temperatures, and this round space being an inconvenience in a compression pump
which it is advisable to obviate I have sought to do away with it by giving the
sheath of the cylinder, and the appendix of the piston a somewhat conical form, so
that when the latter is fully introduced into the former, it completely fills same
without any vacant space at all, the discharge is then complete.
The expelled compressed gas can be conducted into a reservoir or a gasometer to
be utilized in any particular way, for instance in an expansion pump which might
do part of the compression work itself, or in any other manner.
The same gas
can, at pleasure be made use of indefinitely. The intensity of the compression
is optional, the system allowing very high temperature to be attained without

page_text: going beyond the limits of compressions currently employed in many branches of
industry.
In the case of high temperatures, those for instance required for the fusion of
metals and minerals, it is indispensable to line the sheath and the appendix with
refractory materials. For that purpose any of the substances usually employed or
recommended may be used and especially magnesia the moulding faculty of which
is particularly suitable to the making of the appendix of the piston. Carbon can
likewise be used provided the gas used does not attack it. In addition to this
refractory lining it is advisable to surround the sheath with nonconducting
materials in order to avoid as much as possible any waste of caloric, the sheath is
therefore preferably formed of a metallic case, hermetically fastened to a cylinder
and having in the first place in the interior a very thick lining of non-conducting
material and after that of refractory materials.
The recuperation of the heat can be divided in two as regards the materials to
be employed for this operation, that is to say one can employ refractory materials
only at the part where high temperatures exist, and make use of metals at the part
where the temperature is not high enough to destroy same, one can make use for
this purpose of metallic wire gauze by employing same, for instance in the manner
indicated by Prieson for hot air machines either inside or outside such round
interval.
I make use of the high temperatures produced by this system of successive
compressions, to effect the fusion of metals and minerals, and thus obtain substances
in a pure or crystallized state or otherwise; to effect chemical decompositions of
composite or organic materials, to produce chemical combinations between substances
of difficult fusibility, etcetera, I use according to circumstances air, hydrogen, oxide
of carbon, water stean, nitrogen or any other gas or vapour; or also mixtures of
different gases or vapours. I place the materials to be used in the compression
vessel into a space arranged for that purpose or in an adjoining reservoir. The said
space or reservoir may be the space D; in this case the stroke of the piston is
arranged so as to leave always at the bottom of the cylinder a space between.it and
the end of the piston. Or the space or reservoir may be placed laterally and in
communication with the space D. I withdraw the products when the operation is
completed either by letting same escape through an outlet K or by removing &
part of the sheath arranged for the purpose and easily removable. For this purpose
the end of the cylinder marked E in the drawing may be constructed to take off,
having a collar projecting beyond the non-conducting envelope held to the body of
the apparatus by screw bolts.
One may judge of the temperature attained in the reaction department by
ordinary means, such as pyrometers, or else by the quantity of gas which enters
the apparatus at every inspiration, or which leaves it after every compression, the
temperature being so much the higher as the quantity of gas is less. I arrange
the pump in such a manner as to compress from top to bottom or from bottom to
top according to the object in view.
PUMP FOR EXPANSION AND PRODUCTION OF COLD.
This apparatus is almost identical in its arrangement to that just described,
being also characterized as stated before by a cylinder which we will suppose
vertical, bearing a sheath wherein is placed a piston bearing an appendix, the whole
being arranged and disposed as has just been explained, only that the gas instead
of entering expanded and escaping compressed, enters on the contrary compressed
and leaves expanded, larger and larger quantities by weight of gas enter, and it is
the cold and not the heat that concentrates itself in the recuperating sides of the
round space. It results from this that all the sides may simply be inetallic, that of
the sheath only being surrounded by non-conducting materials of a thickness
sufficient to avoid any loss of cold. The appendix may be hollowed out and filled
with non-heat-conducting materials. I groove if necessary the recuperating sides,

page_text: or I corrugate the same in order to better induce the cold of the outgoing gas to
remain thereon and to be absorbed subsequently by the incoming gas, or else
I employ metallic wire gauze as described by Ericson as hereinbefore stated.
I employ the cold produced in this expansion department for all known processes,
but particularly to liquefy any gas whatsoever and more especially atmospheric
air. The gas used and which arrives compressed, partly liquefies itself at every
stroke when the temperature has become sufficiently low. It is collected throug
an orifice arranged for the purpose at the bottom of the sheath and is replaced by
air in the gaseous state at the following aspiration.
If a gas somewhat uncondensable such as hydrogen for instance, be used for the
dilatation any other more condensable gas can be liquefied by causing same to
circulate outside the recuperating part of the sheath and quite close thereto; with
that view I put round the sheath a second sheath a little larger forming a round
space with the former along the whole length of which the gas to be condensed
must run, in an opposite direction to that of the discharge of the expanded gas
that is to say from top to bottom the gas to be condensed thus being continuously
in contact with a colder surface. The liquefied gas is drawn off at the bottom of
the second sheath by means of an orifice arranged for the purpose.
I keep any liquified gns by introducing same into ordinary reservoirs, at the top
of which I leave open a very small orifice covered by a cap and which I carefully
surround in every direction and more particularly at the top by a very thick layer
of non-conducting material, preferably pulverulent bodies. Avoiding in this way
almost entirely the action of the outside heat the vaporization and waste of liquefied
gas is prevented almost entirely.
The process described and the results obtained differ from the usual mode of
compression and expansion from the form or kind of compression and expansion
apparatuses in use; from the form or kind of recuperating linings in use which
may be simple tubes or metallic wire gauze directly employed on or in the cold
producing pump, the latter being then devoid of a sheath or an appendix to the
piston.
The arrangement I show appears to me the best, but the object would be more
or less attained, once there are successive compressions and dilatations whatever
they may be, by observing the principle set forth in the two first paragraphs of
this specification which together with the foregoing one in reality constitute the
exact resume of the invention.
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:
1st. The process consisting in obtaining high temperatures by means of successive
compressions of any kind of gas and the systematic concentration of the caloric so
obtained.
2nd. The process consisting in obtaining low temperatures by means of successive
expansions of any kind of gas and the systematic concentration of such low
temperatures.
3rd. The system of the recuperation of the heat produced, consisting in causing
the gas intended to be compressed to pass through a contracted space existing
between a cylinder and a piston, both lengthened, and whose sides have been
heated by previous compressions, in such a way that at every fresh passage of the
gas there is a fresh deposit of all or part of the heat released by the previous
compression,
4th. The system of recuperation of the cold produced consisting in causing the
gas intended to be expanded to pass through a contracted space existing between a
cylinder and a piston, both lengthened, and whose sides have been cooled by
previous expansion in such a way that at every frosh passage of the gas, there is a
fresh deposit of all or part of the cold produced by the previous expansion.

page_text: 5th. The application of the principle above described whatever may be the kind
of apparatus employed as also the materials composing same and the nature of the
gas employed for all purposes and specially for the fusion of metals and of minerals
for producing chemical compositions or effecting combinations between substances
of difficult fusibility for the cooling or liquefaction of gas and the like.
6th. Preserving liquefied gas in any reservoirs devoid from any extraneous
pressure by the use of a cover which is a bad heat conductor combined with a
small orifice at the top of the reservoir closed by a cap.
The whole substantially as described and shown in the accompanying drawings.
Dated this 5th day of November 1885.
WP. THOMPSON & Co.,
Patent Agents for the Applicant.