IMPROVEMENTS IN CONDENSING THE VAPOURS ARISING FROM FLUIDS EVAPORATING IN CLOSED VESSELS, WHICH INVENTION IS ALSO APPLICABLE TO THE CONDENSATION OF THE VAPOURS OF VOLATILE FLUIDS DURING THE PROCESS OF DISTILLATION, & FOR IMPROVEMENTS IN APPARATUS TO BE EMPLOYED FOR THE PURPOSE
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by James John Field at the Office
of the Commissioners of Patents, with his Petition, on the 1st October
1860.
I, JAMES JOHN FIELD, of Holloway Place, Holloway, in the County of
Middlesex, Analytical and Manufacturing Chemist, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN CONDENSING THE VAPOURS
ARISING FROM FLUIDS EVAPORATING IN CLOSED VESSELS, WHICH INVENTION IS ALSO
APPLICABLE TO THE CONDENSATION OF THE VAPOURS OF VOLATILE FLUIDS DURING THE
PROCESS OF DISTILLATION, & FOR IMPROVEMENTS IN APPARATUS TO BE EMPLOYED
FOR THE PURPOSE," to be as follows:-
My Invention relates to the condensation of the vapours that arise during
the evaporation (in close vessels) of saccharine solutions & other fluids, &
also to the condensation of the vapours that arise during the distillation of
volatile fluids.
My Invention consists in effecting the condensation of the vapours aforesaid
within the covered vessels in which the evaporation or distillation is going on,
instead of as heretofore passing the vapours out of such vessels through a tube,
neck, or similar contrivance into a seperate condenser.
My Invention also consists in the employment of a condenser placed within
the space between the surface of the evaporating liquid & the head or cover of
the vacuum pan for the purpose of condensing the vapours that arise during
the evaporation of saccharine & other solutions & fluids in vacuo.

page_text: The form of condenser that I prefer to employ consists of a number of ver-
tical plates, hollow in the interior, & so arranged that there may be a con-
tinuous flow of cold fluid through their interior, by which means their external
surfaces which are surrounded by the vapours to be condensed are kept
sufficiently cooled to admit of their condensing the said vapours.
These condensing plates have each a channel at the lower end which
receives the fluid condensed upon their surfaces, & these channels communicate
with a tube passing out of the pan cover, & terminating in a receiving vessel,
the interior of which vessel is kept in the same state of exhaustion as the
vacuum pan itself. By this means all the fluid condensed upon the surfaces
of the internal hollow plates aforesaid passes into the receiving vessel, & by
constantly refrigerating the hollow plates by the transmission of cold fluid
through their interior, the condensation of the vapour arising from the con-
tents of the pan may be carried on continuously until the required evaporation
has been completed.
My Invention also consists in refrigerating such portions of the external
surface of the vacuum pan & cover as admit of being cooled without interfering
with the effectual heating of the contents of such vacuum pan; & in employ-
ing such refrigerated surface either in combination with or in substitution for
the internal condenser aforesaid, for the purpose of condensing the vapours that
arise during the evaporation of fluids in vacuo; the refrigeration being
effected by a constant flow of cold fluid over the surface to be cooled. I also
employ within the closed evaporating vessel a channel, so placed as to receive
the fluid condensed upon the cooled surface of the pan head & upon such other
parts of the vacuum pan as are refrigerated, the condensed fluid being after-
wards conducted by means of a pipe from the channel into the seperate
receiving vessel before mentioned.
The employment of this means of condensation in the process of distillation
is similar to the method herein-before described as applied to the evaporation
of fluids in vacuo, the internal condenser being placed within the still head, &
the still head itself being refrigerated in a similar manner, the condensed fluid
being collected in channels & conveyed by a pipe or pipes to a seperate
receiving vessel as fast as it is condensed.