THE

London

JOURNAL AND REPERTORY

OF

Arts, Sciences, and Manufactures.

CONJOINED SERIES.

No. LXV.

Recent Patents.

To MILES BERRY, of the Office for Patents, 66, Chancery-lane, in the county of Middlesex, civil-engineer and mechanical draftsman, for an improved apparatus for torrefying, baking, and roasting vegetable substances ; which, with certain modifications and additions, is also applicable to the evaporation and concentration of saccharine juices and other liquids.-[Sealed 13th June, 1836.]

THIS invention of improved apparatus for torrefying, baking, and roasting vegetable substances, which, with certain modifications and additions, is also applicable to the evaporation and concentration of juices and other liquids, is, in the first instance, more particularly applicable to the process of torrefying, baking, or roasting mealy or floury vegetable substances, such as wheat or 2 L

VOL. X.

potatoe starch, flour, or fecula; and is particularly applicable to the process of making or manufacturing an article of commerce commonly called "British gum," which is a mucilaginous matter used by calico printers as a substitute for foreign gums, for the purpose of thickening their colours, or as a vehicle for mixing and carrying them, and is formed of potatoe or wheat starch, or fecula, torrefied or roasted to the proper degree, according to the purpose for which it is required, and which improved apparatus is also applicable to the torrefying, roasting, or baking grain or seeds, whole or unground. And, further, this improved apparatus, by means of certain modifications and additions, is also applicable to the evaporation and concentration of syrups or juices, or saline solutions. I shall, therefore, proceed first, to describe the application of this improved apparatus to the process or operation of torrefying, baking, or roasting vegetable substances, such as starch, meal, flour, or fecula, for the purpose of making" British gum,” and then describe the modifications and additions necessary for its application to the process of evaporating syrups or saline solutions.

The several figures in Plate XIII., are representations of the apparatus for the first part of its application.

Fig. 1, is a front elevation of the apparatus; fig. 2, is a plan or horizontal view; fig. 3, is an end view; and fig. 4, is a vertical section, taken in the direction of the dotted lines A, B, and C, D, in figs. 2, and 3, the same letters of reference being marked upon similar parts in all the figures: A, A, is the brickwork of the fireplace, which has two cylindrical retorts or torrefying chambers F, F, of a similar construction placed therein; B, is the door of the furnace; c, the inside of the furnace or the fire-place; D, fire-bars or grate; E, the ash-pit;

G, G, registers or dampers, placed edgeways in the brickwork and flues, and moving horizontally to direct, at pleasure, the heat from the fire under the one or the other of the torrefying chambers: H, н, н, are the flues formed in the side and in the back of the furnace, the former conducting the heat under the ovens or torrefying vessels: i, (fig. 2,) is a damper or register, moving vertically to open or close, at pleasure, the aperture н, in the back of the furnace (see fig. 3); k, l, are other registers, also moving vertically to open or shut the passage of the smoke to the chimney; m, is the main or direct flue, constructed of iron or brickwork, and forming the chimney through which the smoke of the furnace escapes. This chimney is divided into two parts by a vertical partition n, fig. 2, in order to separate the smoke which rises on the opening of the register k, from the smoke ascending into the chimney through the register and damper 1: 0, 0, fig. 4, are apertures or doors formed in 'the brick work on each side of the furnace, and are closed air-tight, except when it is necessary to open them to inspect the interior of the furnace or the under part of the torrefying chambers.

Description of the cylindrical ovens or torrefying chambers:-The two chambers or ovens being of the same construction, it will be sufficient to describe one of them. The torrefying chamber is made of copper or other suitable metal, and is represented in detached views, figs. 5, and 6; the first of which is a vertical section taken longitudinally, and the other a transversal vertical section of the same. The chamber is about four feet long, made in two parts, placed over one another; the upper part p, is the cover, which may vary in size from one-fourth to one-eighth of the circumference of the chamber. The lower part is formed of two sheets of metal, the internal one q, and the external one r; there