Improvements in Torrefying or Roasting Coffee, Cocoa, Chicory, and other Organic Substances by the Application of Superheated Steam.
Year: 1888

page_text: Date of Application, 31st Mar., 1888
Complete Specification Left, 17th Aug., 1888
Complete Specification Accepted, 5th Oct., 1888
Improvements in Torrefying or Roasting Coffee, Cocoa, Chicory, and
other Organic Substances by the Application of Superheated
Steam.
I ALBERT EDGAR ALEXANDER of 19 Southampton Buildings Chancery Lane in
the County of Middlesex, Fellow of the Institute of Patent Agents do hereby declare
the nature of this invention (communicated to me from abroad by Daniel Pedro
Ferro Cardozo of Paris in the Republic of France Doctor of Sciences) to be as
follows:-
This invention relates to a novel application of superheated steam at any pressure
to the roasting of various torrefiable substances such for example as coffee, cocoa,
chicory and other organic substances.
To this end I interpose between the steam generator and the torrefier proper a
superheater of simple construction consisting of a horizontal coiled pipe in several
sections superposed one upon another and placed in a furnace constructed for the
purpose which furnace may be of any suitable or convenient shape. The supply of
superheated steam to the torrefying apparatus may be regulated by a stop cock on
the pipe leading thereto.
The torrefier proper consists of an inner cylinder surrounded by an outer cylinder
or jacket and the superheated steam passes into an annular space between these two
cylinders.
The substance to be torrefied or roasted is introduced into the inner cylinder by a
suitable manhole, and the steam is divided in a most complete manner over the
entire length of the annular space in said cylinder by longitudinal pipes communicating
at one end with a connecting pipe and having their opposite ends closed and pierced
with small holes in the direction of the length of the walls of the inner cylinder.
At the upper part of the outer cylinder or jacket is provided a dome.
A pipe
connects the inner cylinder containing the substance to be operated upon with a
condenser communicating with an air pump.

page_text: The above described arrangement allows the vapours to be continuously drawn off
from the inner cylinder by producing a vacuum; this contributes to good torrefication
of the substances under treatment, which are thus subjected to (1) the action of
steam superheated under the conditions bereinbefore referred to, (2) the action of a
vacuum, (3) the action of condensation.
The substances to be torrefied may be stirred or turned over by means of paddles
or wings fixed on a shaft revolving in the longitudinal axis of the inner cylinder and
receiving its motion from the gearing which actuates the pump, and the torrefied or
roasted substances may be drawn off through an aperture in the lower part of the
torrefier.

page_text: The accompanying drawing represents a longitudinal vertical section of the
torrefying or roasting apparatus constructed according to this invention.
Between the steam generator and the torrefier proper is interposed a superheater
of simple construction consisting of a horizontal coiled pipe S in several sections
superposed one upon another and placed in a furnaces of suitable construction.
The supply of superheated steam to the torrefyer may be regulated by a stop cock on
the pipe leading thereto as shown at r.
The torrefier proper consists of an inner cylinder B surrounded by an outer
cylinder or jacket A the superheated steam passing into the annular space between
these two cylinders.
The substance to be torrefied or roasted is introduced into the inner cylinder B
through a suitable manhole G and the steam is divided in a most complete manner
over the entire length of the annular space in said inner cylinder by means of the
longitudinal pipes a which communicate at one end with a connecting pipe and
have their opposite ends closed and pierced with small holes in the direction of the
length of the walls of the inner cylinder B. A dome D is provided at the upper part
of the outer cylinder or jacket A. The pipe H forms the connection between the
inner cylinder B containing the substance to be operated upon, and a condenser I
which is connected with an air pump K.
By the arrangement above described the vapours produced during torrefication may
be continuously drawn off from the inner cylinder by forming a vacuum therein as
will be readily understood; this contributes to good torrefication of the substances
under treatment which are subjected to (1) the action of steam superheated under the
conditions hereinbefore referred to, (2) the action of a vacuum, (3), the action of
condensation.

page_text: The substances under treatment may be stirred or turned over by means of paddles
or wings P fixed on the shaft O, revolving in the longitudinal axis of the inner
cylinder B, and receiving the motion from the gearing which actuates the pump.
One of these paddles or wings P is illustrated detached in face view on the drawings.
The substances when torrefied may be drawn off through the aperture G¹ situate at the
lower part of the torrefier. This aperture G¹ is closed in a simple manner by a plug
of any suitable construction as shewn in the drawings. It is only necessary that the
plug employed should be capable of easy and rapid manipulation.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is ;-
1. The novel application and use of superheated steam in the torrefying or roasting
of coffee, cocoa, chicory and other organic substances as specified.
2. The peculiar construction and arrangement of apparatus for torrefying or roasting
coffee cocoa chicory and other organic substances by the application of superheated
sicam substantially as hereinbefore described and illustrated.
3. In apparatus for the torrefying or roasting of coffee, cocoa, chicory, and other
organic substances by the application of superheated steam the employment of
a vacuum, in the chamber which receives the substances to be torrefied, together with
condensation, for the extraction in a continuous manner of the vapours produced
during torrefication substantially as specified.
Dated this 17th day of Awst 1888