IMPROVEMENTS IN APPARATUS FOR PREVENTING INCRUSTATION IN AND REMOVING DEPOSITS FROM PANS FOR EVAPORATING, CRYSTALLISING, AND SUCH LIKE PROCESSES
Year: 1876

page_text: LETTERS PATENT to Charles Denton Abel, of Southampton Buildings, Chancery
Lane, in the County of Middlesex, for the Invention of "IMPROVEMENTS IN
APPARATUS FOR PREVENTING INCRUSTATION IN AND REMOVING DEPOSITS FROM
PANS FOR EVAPORATING, CRYSTALLISING, AND SUCH LIKE PROCESSES." A. com-
munication from abroad by Johann Thelen, of Aix-la-Chapelle, in the German
Empire.
Sealed the 13th February 1877, and dated the 18th December 1876.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 18th December 1876.
CHARLES DENTON ABEL, of Southampton Buildings, Chancery Lane, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR PREVENTING INCRUS-
TATION IN AND REMOVING DEPOSITS FROM PANS FOR EVAPORATING, CRYSTALLISING,
AND SUCH LIKE PROCESSES." A communication from abroad by Johann Thelen, of
Aix-la-Chapelle, in the German Empire.
According to the present Invention pans in which solid deposits are separated
from solutions by evaporation, crystallisation, and such like processes, are cou-
structed of a long semi-cylindrical shape with flat ends, and are provided with a
longitudinal shaft corresponding in position to the axis of the cylinder. To this
shaft are connected by radial arms a series of bars or rods extending parallel with
the shaft nearly the entire length of the pans. Upon these rods are hung loosely a
number of flat blades or scrapers, placed somewhat obliquely to the axis of the pan,
and projecting beyond the rods to a distance somewhat greater than the distance
between the rods and the inner circumference of the
pan.
The scrapers are so arranged upon the several rods that they all lie in a helical
line described round the central shaft. A slow rotary motion being imparted by
any suitable gearing to the above described framing carrying the scrapers, the latter
while being carried round will hang down vertically until in descending they come
in contact with the surface of the pan; they will then lie in an inclined position
with their lower edge resting upon the pan, and in being carried round in this
position they will be made to scrape off any deposit on the pan that may lie in
their paths, and owing to their obliquity to the central axis each one will be made

page_text: to deliver the deposit which it removes into the path of the next one in advance,
thus causing the deposit to be gradually conveyed towards the one end of the pan,
where there is a scoop hung on the framing in a similar manner to the scrapers, but
not placed obliquely, so that on rotating it scoops up the accumulated deposit and
delivers it over the side of the pan.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 14th June
1877.
CHARLES DENTON ABEL, of Southampton Buildings, Chancery Lane, in the
County of Middlesex. "IMPROVEMENTS IN APPARATUS FOR PREVENTING INCRUS-
TATION IN AND REMOVING DEPOSITS FROM PANS FOR EVAPORATING, CRYSTALLISING,
AND SUCH LIKE PURPOSES." A communication from abroad by Johann Thelen, of
Aix-la-Chapelle, in the German Empire.
According to the present Invention pans in which solid deposits are separated from
solutions by evaporation, crystallization, and such like processes, are constructed of
a long semi-cylindrical shape with flat ends, and are provided with a longitudinal
shaft corresponding in position to the axis of the cylinder. To this shaft are con-
nected by radial arms a series of bars or rods extending parallel with the shaft
nearly the entire lengths of the pans. Upon these rods are hung loosely a number
of flat blades or scrapers, placed somewhat obliquely to the axis of the pan, and
projecting beyond the rods to a distance somewhat greater than the distance
between the rods and the inner circumference of the pan.
The scrapers are so arranged upon the several rods that they all lie in a helical
line described round the central shaft. A slow rotary motion being imparted by
any suitable gearing to the above described framing carrying the scrapers, the latter
while being carried round will hang down vertically, until in descending they come
in contact with the surface of the pan; they will then lie in an inclined position
with their lower edge resting upon the pan, and being carried round in this position
they will be made to scrape off any deposit on the pan that may lie in their paths,
and owing to their obliquity to the central axis cach one will be made to deliver
the deposit which it removes into the path of the next one in advance, thus causing
the deposit to be gradually conveyed towards the one end of the pan, where there is
a scoop hung on the framing in a similar manner to the scrapers, but not placed
obliquely, so that on rotating it scrapes up the accumulated deposit and delivers it
over the side of the pan.
The said apparatus is applicable among other purposes to the removal of precipi-
tates formed by chemical reaction upon certain solutions, such as the salts precipitated
by the action of certain gases upon alkaline solutions.
Fig. 1 represents a longitudinal section, Fig. 2 a transverse section, and Fig. 3 a
plan, and Fig. 4 an end view of an evaporating or crystallising pan with scraper
according to this Invention.
A is the pan of semi-cylindrical form; B is the scraper shaft, which is caused to
revolve slowly by worm or other gearing. From the shaft project arms C, C,
carrying rods D parallel to the shaft. On the rods D are hung loosely the scraper
blades E, each of which is set at a slight inclination to the axis, and is held in
position longitudinally between collars on the bar on which it is mounted. The
successive scrapers are arranged in a helical line round the shaft; each scraper, in
consequence of its obliquity, tends to advance longitudinally the matter which it
detaches from the surface of the pan, delivering it into the path of the next scraper
in order, which in its turn advances it to the path of the succeeding scraper, and

page_text: thus the matter scraped is gradually advanced to the one end of the pan, where the
scoop hung from one of the rods D carries it upwards and delivers it over the
edge of the pan.
Having thus described the nature of this Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent, I
claim, the use, for preventing incrustation in and removing deposits from pans for
evaporating, crystallising, and such like processes, of a revolving scraper consisting
of a number of inclined and freely hung blades arranged helically round a shaft,
constructed and operating substantially as herein described.
In witness whereof, I, the said Charles Denton Abel, have hereunto set my
hand and seal, this Fourteenth day of June, in the year of our Lord One
thousand eight hundred and seventy-seven.
CHA. D. ABEL. (L.S.)