Improved Process for Preserving Substances.
Year: 1897

page_text: Date of Application, 8th Mar., 1897-Accepted, 8th May, 1897
COMPLETE SPECIFICATION.
Improved Process for Preserving Substances.
I, HANS HUMBSER, of 26 Bäumenstrasse Fürth, Bavaria, 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 :-
This invention relates to a process for preserving substances, more particularly
those of the plant kind, which contain aromatic oils that are easily volatilised
under heat (such as hops) and that are to be preserved in the substance by the
process, without decomposition or being rendered of a resinous character.
For this purpose according to my invention the moisture is abstracted from the
substance to be preserved without thereby causing the volatilisation of the aromatic
constituents thereof. As these constituents volatilise already at tolerably low
temperatures it is necessary to keep the substances so cool that the said volatilisation
cannot take place, and this is effected by drying the same by means of air having
the said low temperature.
The air can be dried in various ways before it passes among the substances to be
preserved. But as in the present case only low temperatures can be dealt with, it
is advisable to effect the drying of the air by means of cold, and then to increase
its power of absorbing moisture by warming it again.
This is effected by means of apparatus which is shewn diagrammatically on the
accompanying drawing in such manner that air is first forced into a very cold
chamber where its moisture will be deposited; it is then warmed so as to enable it
to take up moisture again after which it is conveyed into the storage chamber
containing the substances to be preserved, where it takes up moisture from the
latter, and whence it is then made to pass away.
Fig. 1 of the drawings shews a horizontal section through the preserving
apparatus;
Figs. 2 and 3 shew sections on lines 1-I and II-II of Fig. 1.
Ris the chamber for containing the substance to be preserved.
The air charged with moisture contained therein is forced from the same through
a channel by means of an air propeller into a cold chamber K. In this
chamber the air is dried by causing its moisture to be deposited on the walls.
From this chamber the air passes into the warming chamber W where it is
warmed to the requisite degree for enabling it to take up moisture again.
Of course such warming must not reach the limit determined by the temperature
at which the volatile constituents of the substances begin to volatilise. From the
warming chamber W the dry warmed air passes through the channel ¹ back into
the chamber R.
It will be readily understood that the drying of the air in the chamber K can be
accelerated by providing hygroscopic substances. The warming of the air can be
effected by a stove pipe, or by passing it through a thin coiled pipe exposed
externally to the open air, so that the heat of the atmosphere serves to raise the
circulating air to the required temperature.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A process for preserving substances, in particular those of the plant species,

page_text: containing aromatic oils that are easily volatilised under heat (such as hops)
wherein dry air the temperature of which is below that at which the said aromatic
substances volatilise, is led through the substances to be preserved, substantially
as described.
2. In the process for preserving substances referred to in the first claim causing
the air to be passed through the materials to be preserved, to be first cooled to a
low temperature and then warmed again for increasing its power of absorbing
moisture, substantially as described.