IMPROVEMENTS IN THE TREATMENT OF BLOOD, NIGHT SOIL, FISH, SHODDY, LEATHER SCRAP, AND OTHER SUBSTANCES FOR THE PURPOSE OF DRYING AND POWDERING THE SAME, AND IN THE APPARATUS EMPLOYED THEREIN."
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by Campbell Forrest at the Office of the
Commissioners of Patents on the 25th January 1881.
CAMPBELL FORREST, of Upton, in the County of Essex.
"IMPROVEMENTS IN
THE TREATMENT OF BLOOD, NIGHT SOIL, FISH, SHODDY, LEATHER SCRAP, AND
OTHER SUBSTANCES FOR THE PURPOSE OF DRYING AND POWDERING THE SAME,
AND IN THE APPARATUS EMPLOYED THEREIN."
My Invention relates to the treatment of blood, night soil, fish, shoddy, leather
scrap, and other substances, in order to dry or concentrate the same, the vapours or
gases being drawn off from the substances, whilst the residuum is obtained in a
powdered condition.
In the Specification to former Letters Patent granted to me and to Alexander
Forrest, dated the 9th August 1876, No. 3151, there is described a machine
consisting of a hollow spindle containing steam revolving within a steam jacketted
drum or cylinder, into the interior of which the blood or other substance to be
dried or concentrated and powdered is reduced, the spindle being also provided with a
series of radiating hollow arms having scrapers for acting upon the substance.
According to my present Invention I employ a series of drums or cylinders with
hollow spindles and hollow arms constructed substantially in the manner herein-
before described, but by preference of smaller dimensions and arranged, say, for
example, one above the other. These drums or cylinders are placed in inter-
communication, and are supplied in the following manner, viz. :-The blood or other
substance is introduced through a self feeding hopper fitted with a revolving roller
into the upper cylinder, and having been operated upon therein and propelled
through the same is discharged into the cylinder immediately below, where it is
again operated upon and propelled and then discharged into the cylinder next
immediately below, and so on in succession throughout the series to the bottom
cylinder, whence the dried and powdered residuum is automatically discharged by
a shoot or conduit. The several hollow spindles are also in intercommunication,
steam being admitted to the upper one, and then conducted to the spindle
immediately below, and thence to the third spindle, and so on in succession to the
last spindle, whence the water of condensation is drawn off. Similarly the gases
or vapours from the whole of the cylinders are drawn off by a fan from the upper.

page_text: cylinders, the same being placed in intercommunication by means of pipes of
suitably graduated sizes for the purpose; the upper cylinder is arranged to
communicate with a worm or condenser, which may be of any suitable description.
I also combine the boiler for the supply of steam with the apparatus by arranging
the several cylinders within the steam space of the boiler, and carrying a steam
supply pipe therefrom to the upper cylinder and returning the water of condensation
to the water space of the boiler, the boiler itself in this case forming the steam
jacket for the cylinders. Or I may dispense with the steam jackets and arrange
the cylinders, say, for example, in an inclined or gradatory row in a chamber heated
by a furnace, the gases or vapours being drawn off by graduated pipes com-
municating with a main pipe common to the whole series of cylinders.
I further propose to introduce the sulphuric acid required for fixing the ammonia
into the cylinders together with the blood or other substance under treatment, the
supply of acid being regulated automatically in unison with the supply of material
from the hopper, whereby I am enabled to dispense with the vessels or apparatus for
preliminary mixing which have been previously employed.
By the use of my Invention a considerable saving is effected both in the plant and
manual labour necessary for the process, whilst at the same time the operations are
carried on under satisfactory conditions, and the efficiency of the apparatus are in
nowise impaired.