An Improvement in the Method of and Apparatus for Roasting Coffee and Cocoa.
Year: 1889

page_text: Date of Application, 9th Nov., 1889
Complete Specification Left, 11th July, 1890—Accepted, 20th Sept., 1880
PROVISIONAL SPECIFICATION.
An Improvement in the Method of and Apparatus for Roasting
Coffee and Cocoa.
We, ANDREAS FRANS HUBERT ANDERHEGGEN of No. 107 Lauriergracht,
Amsterdam, Holland, Manufacturer, LUDWIG WILHELM SCHÖFFER of Gelnhausen,
Prussin, Merchant, ÉMILE PÉLÉRIN of rue de l'Ecuyer Brussels, Belgium, Chemist,
and HYPPOLITE AZAMBRE of No. 50, rue du Champ de Mars, Ixelles Belgium,
Engineer, do hereby declare the nature of this invention, whereof the said Ander-
heggen, Pélérin and Azambre are the inventors, to be as follows :-
:-
Our invention relates to the roasting of coffee and cocoa, and its object is to provide
new means for carrying out this process at a definite and uniform temperature.
For this purpose we roast the coffee or cocoa in a vessel which is heated by means
of a bath of oil, fat or an easily-fusible metallic alloy.
The apparatus which we preferably employ, consists in a horizontal drum adapted
to be closed tightly, a jacket surrounding the same and serving to contain the oil, fat
or alloy, and a furnace by which the jacket is heated. In the drum a stirror is
arranged, having a disk at each end and journalled in the two heads of the drum,
the front head forming a removable cover. When this cover is detached and the
stirrer is withdrawn, the disk at the rear end of the latter pushes the roasted material
out of the drum. For feeding the drum with raw material it is provided at the top
with a tubo extending through the jacket and fitted with a cover. In view of
equalizing the temperature of the whole mass of oil, &c., another stirrer may be
arranged inside of the jacket.
1000
COMPLETE SPECIFICATION.
An Improvement in the Method of and Apparatus for Roasting
Coffee and Cocoa.
We ANDREAS FRANS HUBERT ANDERHEGGEN of No. 107 Lauriergracht,
Amsterdam, Holland, Manufacturer, LUDWIG WILHELM SCHÖFFER of Gelnhausen,
Prussia, Merchant, ÉMILE PÉLÉRIN of rue de l'Ecuyer Brussels, Belgium, Chemist,
and HYPPOLITE ÁZAMBRE of No. 50, rue du Champ de Mars, Ixelles Belgium,
Engineer, do hereby declare the nature of this invention, whereof the said Ander-
heggen, Pélérin and Azambro are the inventors, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement:―
Our invention relates to the roasting of coffee & cocoa, and it consists in a new
method of, and apparatus for carrying out this process at a definite and uniform
temperature.
In the roasting of coffee it is of importance that the same be exposed to a uniform
heat, being sufficiently high, but not exceeding a certain degree of temperature. If
the coffee is roasted, as usual in drums exposed to the direct action of the fire, it is
not possible to fulfil these conditions so completely that a perfectly satisfactory
product always results. If the hent employed is too low, the coffee is roasted
insufficiently so that it then does not yield as rich an extract as otherwise, whereas if
the heat is too great, the volatile aromatic constituents are partly decomposed in such
manner that the extract assumes a disagreeable taste. Besides this, a greater portion
of these constituents is volatilized than is necessary for the complete roasting, and in
consequence a material loss in weight may result.

page_text: For the purpose of avoiding these inconveniences we roast the coffee in a vessel
which is heated through the medium of a bath of oil, fat, or an easily-fusible metallic
alloy. By these means it is possible to keep up a definite and uniform temperature
during the roasting-process. The temperature that has proved by experience to be
the most advantageous is from 20° to 225° Centigrade.
The apparatus which we preferably employ for performing the process, substantially
consists in a horizontal drum adapted to be closed tightly, a jacket surrounding the
same and serving to contain the oil, fat or alloy, a furnace by which the jacket is
heated, and a stirrer arranged in the drum.
In the annexed drawing Fig. 1 is a longitudinal and Fig. 2 a transverse sectional
view of an apparatus carried out according to our invention. A is the roasting-drum,
B the jacket, the furnace, and the stirrer. For feeding the drum with raw
material it is provided at the top with a tube G, extending through the jacket and fitted
with a well-closing cover G₁. The shaft of the stirrer is journalled in the two beads
of the drum, the front head forming a removable cover, so that the stirrer may be with-
drawn from the drum. For supporting the same when it is withdrawn, the shaft is
fitted at the rear end with a disk Fand mounted at its fore end in a carriage H
running with its wheels on over-head rails. The disk F also serves to push the coffee
forward and thus to discharge the drum when the stirrer is drawn out. Besides, the
said disk forms with the inner end of the drum a double wall whereby the coffee is
prevented from cooling at this point. For the like purpose serves the disk E, on the
fore end of the stirrer-shaft, which forms a double wall with the cover D.
From the furnace I suitable flues extend to the chimney L. K is a pipe for con-
ducting to the chimney any vapours evolved from the oil-bath, and M a tube for the
insertion of a thermometer. In view of equalizing the temperature of the liquid
contained in the jacket B, a special stirrer may be arranged therein.
The mode of operating with the apparatus is as follows. The contents of the
jacket B (fat, oil, &c.) are heated to the required temperature, and the whole
quantity of coffee to be roasted in one process, is quickly introduced into the drum
while the stirrer is kept in motion. By the action of the heat on the coffee
moisture and certain acrid and prejudicial volatile substances are first driven off.
In order that these may escape, the cover G¹ remains open for some time, say
20 minutes. The apparatus being then closed, the roasting process proper takes
place while stirring is continued, this part of the process usually requiring about
30 minutes. When the roasting is completed, the drum is quickly emptied again.
In like manner as for coffee the described method and apparatus may with
advantage be used for roasting cocoa.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :
1. The method of roasting coffee and cocoa in a vessel which is heated by means
of a bath of oil, fat or an easily-fusible alloy, substantially as described.
2. In an apparatus for roasting coffee and cocoa the combination of a drum A
having the charging-tube G, means for closing the drum, the jacket B containing
oil, fat or an easily-fusible alloy, the stirrer A, and furnace 1, substantially as
specified.
J. H. JOHNSON & Co.,
Agents.