IMPROVEMENTS IN APPARATUS USED IN THE MANUFACTURE OF AMMONIACAL AND OTHER CHEMICAL SALTS
Year: 1882

page_text: LETTERS PATENT to James Forbes of the Chemical Works, Old Ford, in the
County of Middlesex for an Invention of "IMPROVEMENTS IN APPARATUS
USED IN THE MANUFACTURE OF AMMONIACAL AND OTHER CHEMICAL SALTS."
PROVISIONAL SPECIFICATION left by the said James Forbes at the Office
of the Commissioners of Patents on the 5th September 1882.
JAMES FORBES of the Chemical Works, Old Ford in the County of Middlesex
"IMPROVEMENTS IN APPARATUS USED IN THE MANUFACTURE OF AMMONIACAL AND
OTHER CHEMICAL SALTS,"
This invention has reference to the construction of apparatus for the speedy
drying of ammoniacal and other chemical salts after removal from the evaporating
pans in which crystallisation takes place, and renders unnecessary the present
practice of draining and the ordinary protracted process of drying.
The invention consists of an annular tank, the inner ring of the annulus rising
only a few inches above the bottom, and provided with an outlet for carrying off
any liquid that might otherwise accumulate there. Within this tank a vessel or
chamber having a number of perforations in its sides, open at the top and provided
with a suitable valve of large area at the bottom, is fixed to a vertical shaft that
passes upwards and through two stationary bearings. Beneath the upper bearing
there are live and dead pullies attached to the shaft, and a friction disc or bowl,
and break or other suitable contrivance for arresting motion.-The upper bearing
in which the shaft revolves is a plain one, but the lower bearing is conical to
receive a conically formed collar on the shaft.-The vessel within the tank may be
said therefore to be suspended.-Beneath the centre of this vessel there is a shoot
to receive and convey away anything that may fall thereon.
The action of the apparatus is as follows.-The suspended vessel is charged from
above with the wet salts, when motion is imparted to the shaft and the vessel
caused to rotate with great rapidity, the result being that the liquid contained in
[Price 6d1

page_text: the salt is driven out of it and through the perforations in the sides of the vessel,
and falls into the annular tank below, and is conveyed away.-In a very few
minutes the salt is completely dried, when the revolution of the vessel may be
stopped, and on opening the valve in the bottom its contents may be discharged on
to the shoot beneath, and from thence conducted to any suitable receptacle.
Instead of suspending the drying vessel in the manner described it may be
attached to a shaft that works in a bearing above and passes completely through
the vessel and shoot and terminates in a toe that revolves in a suitable step.
The drying vessel may be made of any appropriate material but where the
nature of the salts will admit of it, it is preferred to be constructed of thin steel, on
account of its strength, durability and lightness.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Forbes in the Great Seal Patent Office on the 5th March
1883.
JAMES FORBES of the Chemical Works, Old Ford, in the County of Middlesex,
"IMPROVEMENTS IN APPARATUS
AND OTHER CHEMICAL SALTS,"
USED IN THE MANUFACTURE OF
AMMONIACAL
This invention has reference to the construction of apparatus for the speedy
drying of ammoniacal and other chemical salts after removal from the evaporating
pans in which crystallisation takes place, and renders unnecessary the present
practice of draining and the ordinary protracted process of drying.
The invention consists of an annular tank, the inner ring of the annulus rising
only a few inches above the bottom, and provided with an outlet for carrying off
any liquid that might otherwise accumulate there. Within this tank a vessel or
chamber having a number of perforations in its sides, open at the top and provided
with a suitable valve of large area at the bottom, is fixed to a vertical shaft that
passes upwards and through two stationary bearings. Beneath the upper bearing
there are live and dead pulleys attached to the shaft, and a friction disc or bowl
and break or other suitable contrivance for arresting motion. The upper bearing
in which the shaft revolves is a plain one, but the lower bearing is conical to
receive a conically formed collar on the shaft, or they may both be plain bearings,
the shaft being provided with a fixed collar above the lower bearing. The vessel
within the tank may be said therefore to be suspended.-Beneath the centre of
this vessel there is a shoot to receive and convey away anything that may fall
thereon, or conduct it into a suitable receptacle.
In order that the foregoing may be more easily understood a drawing is attached
hereto of which the following is a description. The Fig. represents the annular
tank, perforated vessel and shoot in sectional elevation, the shaft, driving gear,
bearings, and supports being in elevation. A is a wooden framing upon which the
tank B is placed. C is a cylindrical chamber perforated with a very large number
of small holes in its sides and having a valve seat at D, D.-E is a disc valve
drawn in section, with a central sleeve that slides up and down the shaft F. The
valve is shown as open but when closed it rests upon D, D. The vessel C is
supported in the manner shown by the shaft F which works in bearings G, H.
fixed to a frame work I, J.-K is a strap leading from some source of motive
power, and passes over a pulley L thereby causing the shaf F and vessel C to
revolve. There may be only the one pulley L as shown, or there may be two
pulleys attached to the shaft one dead and one live. There is also a friction
wheel M and break N, together with a lever O for actuating the said break.-P is
the shoot fixed to the annular tank and Q is a sack into which the salt falls after
being dried.
The action of the apparatus is as follows. The suspended vessel is charged from
above with the wet salts, when motion is imparted to the shaft and the vessel
caused to rotate with great rapidity, the result being that the liquid contained in
the salt is driven out of it, and through the perforations in the sides of the vessel
and falls into the annular tank below and is conveyed away through the outlet R.
In a very few minutes the salt is completely dried, when the revolution of the
vessel may be stopped, and on opening the valve in the bottom its contents may
be discharged into the shoot beneath and from thence be conducted into bags or
other receptacles.
Instead of suspending the drying vessel in the manner described, it may be

page_text: attached to a shaft that works in a bearing above and passes completely through
the vessel and shoot and terminates in a toe that revolves in a suitable step.
The drying or perforated vessel may be made of any appropriate material, but
where the nature of the salts will admit of it, it is preferred to be constructed of
thin steel, on account of its strength durability and lightness.
Having now described and particularly set forth the nature of this invention
and the manner in which the same is or may be used or carried into effect, I
would observe in conclusion that I do not confine or restrict myself to the precise
details or arrangements which I have described or referred to as variations may
be made therefrom without deviating from the principles or main features of this
Invention, but what I consider to be novel and original and therefore claim as
the Invention secured to me by the herein before in part recited Letters Patent is,-
The construction of apparatus for drying ammoniacal and other chemical salts, as
herein described and shown on the drawing.
In witness whereof I the said James Forbes have hereunto set my hand and
seal this Fifth day of March in the year of our Lord One thousand eight
hundred and eighty-three.