IMPROVEMENTS IN APPARATUS FOR REBURNING ANIMAL CHARCOAL
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by James Duncan and Robert
Andrew Robertson at the Office of the Commissioners of Patents,
with their Petition, on the 25th November 1871.
We, JAMES DUNCAN, Sugar Refiner, and ROBERT ANDREW ROBERT-
SON, Manager for James Duncan, Engineer, both of Clyde Wharf,
Victoria Docks, in the County of Essex, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN APPARATUS FOR REBURNING
ANIMAL CHARCOAL," to be as follows:-
These improvements are principally applicable to the form of charcoal
kilns known as pipe kilns, and are herein described as fitted in con-
nection with such kilns, but certain of the improvements are applicable
to most if not all charcoal reburning apparatus.
In carrying out this Invention we form on the top of the kiln suitable
chambers surrounding the mouths of the pipes or retorts in which the
charcoal is reburnt in order to collect the vaporous steam or gases given
off during the reburning of the charcoal. The said chambers are
provided with moveable doors or covers so as to give access to the pipes

page_text: or retorts for charging, and are further provided with flues for carrying
off the said vapour, steam, or gases either through one or more chimneys
into the open air, thus doing away with the trouble and annoyance
caused by their rising from the charcoal while reburning, or they may
be carried off by a main flue in connection with as many kilns as may
be required, from which they are drawn or forced by means of a
chimney or chimneys or other suitable means thro' a vacuum pan or
pans, or water heater, or other apparatus by which the heat of the said
vapours, steam, or gases may be utilized.
We also propose to make the pipes or retorts of a rectangular section
at the top or mouth, and of such dimensions that when arranged in the
box or chamber in which they are set and luted they will together
occupy its whole available area, thereby avoiding the necessity of using
steadying and covering plates, and at the same time affording a very
much larger area for the escape of the vapour evolved off during the
reburning of the charcoal, and also facilitating the descent of the
charcoal in the pipes during the process. The said pipes or retorts are
made to taper down in any required form from the rectangular section
at the mouth or top to the form and dimension found most convenient
at the bottom.
We also place in or over the mouth of each pipe or retort a rod stirrer
or agitator driven by any suitable arrangement of machinery, either by
hand or other motive power, to assist the escape of the vapour evolved
during reburning, and to facilitate the descent of the charcoal in the
pipes, thereby considerably reducing the labour required to charge the
charcoal kilns of the form referred to.
In place of using the ordinary slides for withdrawing the charcoal
from the coolers at long intervals we allow the reburnt charcoal to
escape from the coolers of charcoal kilns either at long or short intervals
as required by means of an oscillating or rocking or rising and falling
plate or chamber or combination of plates and chambers below the
bottom or outlet of the coolers and driven or caused to oscillate,
rock, or rise and fall either by hand or by any suitable machinery at
any required speed. The action of these plates or chambers depends
upon the alteration of their position with regard to the angle of repose
of the charcoal contained in the cooler, thus either allowing or pre-
venting the exit of the charcoal from the cooler according to their
position at the time.

page_text: The said plates or chambers or combined plates and chambers may
be constructed of different forms (either flat or curved, for example) and
dimensions to suit different arrangements of charcoal kilns and may
also be made to act as measures of the quantity of charcoal withdrawn
at each oscillation, rock, or movement, the measure being the amount of
charcoal discharged at each movement.