IMPROVED MEANS OF AND APPARATUS FOR OBTAINING EXTRACTS OR INFUSIONS FROM VEGETABLE OR OTHER SUBSTANCES AND FILTERING OR CLARIFYING LIQUIDS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by William Joseph Curtis at the
Office of the Commissioners of Patents, with his Petition, on the
2nd August 1871.
I, WILLIAM JOSEPH CURTIS, of Holloway, in the County of Middle-
sex, Civil Engineer, do hereby declare the nature of the said Invention
for "IMPROVED MEANS OF AND APPARATUS FOR OBTAINING EXTRACTS OR INFUSIONS
FROM VEGETABLE OR OTHER SUBSTANCES AND FILTERING OR CLARIFYING LIQUIDS,"
to be as follows:-
The object of my Invention is to facilitate the obtaining of extracts
from or infusions of various substances, and is effected by causing a
circulation of the water to be maintained through the mass until all
the useful properties are extracted from the substance under operation.
The Invention is particularly applicable for obtaining infusions of tea
or coffee, but it is equally applicable for extracting dyeing or coloring
matters from various substances, or for obtaining aqueous extracts from
drugs or chemicals.
Vegetable infusions have usually been obtained by steeping the
substance in water of suitable temperature and thus dissolving out the

page_text: soluble matters. I have discovered that by causing the water or other
liquid to flow continuously through the substances to be operated upon,
the extractive matter can be more effectually separated and with greater
facility than heretofore. The constant circulation of the water required
for effecting the extraction of the soluble matters may be produced in
various ways.
In carrying out the Invention on a large scale, as for obtaining
extracts from dyeing materials or from malt and hops in brewing, the
requisite circulation of the water may be effected by means of a pump
or by causing an artificial ebullition of the liquid by blowing in air, but
when operating upon small quantities of vegetable matter, as, for instance,
in making extracts of tea or coffee, the required circulation may be pro-
duced by the use of a very simple apparatus, which consists of a vertical
cylinder made by preference of metal and divided about its middle into
two compartments by means of a perforated metal diaphragm, on which
the substance to be operated upon is placed. The sides of the cylinder
immediately above this diaphragm are also perforated. Upon placing
this cylinder in a vertical position in the infusion pot and filling the
latter with hot water, the water will rise up in the cylinder and will
pass through the substance on the perforated diaphragm, and will flow
out through the perforated sides of the cylinder. The circulation takes
place automatically and naturally in consequence of the water in the
cylinder being slightly warmer than that which is outside, and this
circulation will continue as long as there is any difference in temperature
in the different parts of the apparatus. An artificial circulation may be
kept up by applying heat to the central part or by blowing into the
central part of the apparatus, but for ordinary domestic purposes this
will not usually be required. The filtration or clarification of liquids is
effected by causing a circulation of the liquid to take place in a
similar manner, the flow of liquid always being upwards through the
fillering medium. The construction of the apparatus for filtering is
substantially the same as that for obtaining infusions or extracts.