Improvements in or relating to a Process and Apparatus for the Preparation of Aldehydes.
Year: 1896

page_text: Date of Application, 21st Feb., 1896-Accepted, 1st Aug., 1896
Improvements in or relating to a Process and Apparatus for the
Preparation of Aldehydes.
A communication from GUSTAV BARTHEL, Chemist, in Dresden-Striesen, Enpire
of Germany.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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 :-
The present invention relates to a process for preparing aldehydes from the
vapour of alcohol by the incomplete oxidation of this vapour by means of a flame
playing round a stream of such vapour. The apparatus for carrying out this
process consists of a portable receptacle for the alcohol with a vaporising chamber
from which the vapours pass into an oxidising chamber for the production of
aldehydes. From the main stream of vapour a branch-stream is diverted and
ignited. The flame produced must be directed in such manner as not to be liable
to be blown out by the main stream, but to play round it so as to produce aldehyde
gas or vapour without the admission of a sufficient quantity of oxygen for complete
oxidation of the vapours of alcohol.
In the processes used hitherto for the production of aldehydes by oxidation
from vapours of alcohol, which were led over glowing surfaces, success was
uncertain, especially so in apparatus provided with glowing platinum surfaces or
coils of wire; this uncertainty prevented the general introduction of that process.
In the accompanying drawings,
Figure 1 is an elevation, partly in central section of one construction of
apparatus according to this invention, and
Figure 2 is a similar view of an alternative construction.
This apparatus consists of the portable receptacle a for receiving the alcohol,
which is vaporised in the chamber 6 by the heat of the metallic parts, heated by
the flame c. The vapours produced pass into the pipe d and find in ic two
outlets d d one of which (the right-hand one in Figure 1, and the lower one in
Figure 2) is small and lets out the stream of vapours, serving for formation of the
flame c, in the direction opposite to that of the main stream, of vapour which
issues by the orifice d 2. The flame c strikes against the back wall e of the
cylindrical chamber of combustion and is attracted by the main stream of
vapours, round which it then plays and in this manner produces its oxidation
preventing at the same time the admission of too much oxygen.
When the lamp is first lighted both the small as well as the larger vapour-
streams coming out from both of the orifices buru, namely the larger one through
the burning-tube straight forward, the smaller one on the other hand is directed
backwards against the fixed wall against which it strikes and theu being enlarged
by the draught produced in the tube is drawn forward. The burning smaller
vapour-stream thus completely surrounds the larger one, prevents the admission of
oxygen to it and as a natural consequence causes its extinction. The gases
escaping from it (the admission of oxygen to the larger vapour-stream being
prevented) are thereby only exposed to a partial decomposition and it is only in
this manner possible to produce "formaldehydes." The oxygen is fed to the
smaller vapour-stream through air-holes in the burning-tube.

page_text: The whole arrangement, owing to its simplicity, assures certain success and
enables the apparatus to be placed and used anywhere, where it is desired to
produce aldehydes; the apparatus can also be placed in any position without
affecting the process.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent, and in what manner
the same is to be performed; I declare that what I claim is :-
1. A process for producing aldehydes from the vapour of alcohol by means of a
flame, consisting in diverting a part of a stream of alcohol vapour from a main
stream and utilizing it to generate flame round the main stream in such a manner
as to prevent the admission of an excess of oxygen substantially as and for the
-purpose described.
2. An apparatus for carrying out the process herein before described consisting
of a combustion chamber (f) closed at one end and a vaporising chamber (b)
separated from the combustion chamber, the outlet pipe (d) of the vaporising
chamber being led into the combustion chamber and therein provided with openings
substantially as and for the purpose described.
Dated this 21st day of February 1896.
BOULT & WADE,
Agents for the Applicant.