IMPROVED MEANS OF AND APPARATUS FOR OBTAINING EXTRACTS OR INFUSIONS FROM VEGETABLE OR OTHER SUBSTANCES, AND FILTERING OR CLARIFYING LIQUIDS
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by William Joseph Curtis at the
Office of the Commissioners of Patents, with his Petition, on the
1st February 1872.
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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 dis-
solving out the soluble matters.

page_text: 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 circu-
lation may be produced 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 per-
forated. 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 air 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 upward through the filtering medium. The
construction of the apparatus for filtering is substantially the same as
that for obtaining infusions or extracts.