IMPROVED PROCESSES AND APPARATUS FOR SAVING AND UTILIZING THE WASTE HEAT OF SUGAR REFINERIES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 9th September 1882. Communi-
cated to him from abroad by S. Morris Lillie, of Philadelphia Pennsylvania,
United States of America.
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"
WILLIAM ROBERT LAKE, of the firm of Haseltine Lake and Co, Patent Agents,
Southampton Buildings, London, 'IMPROVED PROCESSES AND APPARATUS FOR
SAVING AND UTILIZING THE WASTE HEAT OF SUGAR REFINERIES [A Communi-
cation to him from abroad by S. Morris Lillie, of Philadelphia Pennsylvania,
United States of America.]
My invention relates to processes and apparatus for saving and utilizing the heat
in the hot washings from the bone-black of sugar refineries
In sugar refineries the bone-black having served for the filtration, or decolorization,
of a batch of sugar liquor, is washed with hot water, first, to remove all of the
"sweet" from the black; the "sweet" washings are saved, and then the washing
is continued to remove as much as may be, from the black, the impurities taken up
by it from the sugar liquors; then the black is subjected to further revivifying
treatments. These second washings, that is to say those obtained after the "sweet"
has been sufficiently removed from the black, it is the object of my invention to
utilize for heating fresh water to be employed in washing bone-black; for heating
the raw or other liquors of the refinery; or as a source of heat for the evaporation
of sugar solutions or other solutions in vacuo.
In practising this invention for merely heating purposes, I conduct the hot
washings, as they leave the black, through an apparatus, such, for example, as that
hereinafter described, in which they will serve in heating fresh water or sugar
liquor, passing through the apparatus, or in one portion of which they will heat
sugar liquors, and in another portion fresh water. For the evaporation of sugar
solutions in vacuo I conduct the hot washings through the coils or tubes of a
suitable vacuum evaporating apparatus in which they will serve as a source of
heat for the evaporation of the solution contained in the apparatus. As the
washings will necessarily leave the heating tubes of the evaporator very warm,
they may afterwards be used for heating water.

page_text: One form of apparatus adapted to the carrying on of my process, as regards the
heating of sugar liquors or water, consists in a rectangular, water-tight, vertical
case divided by two horizontal partitions (one near the top, and the other near the
bottom) into three chambers; I term the middle, and largest of these three chambers
the "heating chamber" and the top and bottom chambers the eduction chamber
and the induction chamber, for reasons that will presently appear.
The induction-chamber communicates with the eduction-chamber by tubes
which extend through the heating chamber and are made air-tight through the
two partitions. The water, or liquor, to be heated enters the induction-chamber
by a suitable main, and having flowed upwards through the tube, (which extend
through the heating chamber) into the eduction chamber, leave the latter by a
conduit.
The heating chamber has an induction main which opens into it through one
side near the top, and an eduction main which leads from it near the bottom and
contains horizontal plates, or shelves, located between the two, and equidistant from
each other vertically; through these plates the tubes pass.
These plates or shelves do not extend quite across the chamber from side to side,
and touch the two sides alternately, thus forming a circuitous channel along which
any liquid passing through the chamber must flow to and fro on its way from the
induction main to the eduction main of the chamber. The eduction main of the
heating chamber extends from the said chamber upwards, and discharges at a level
with the top of the heating chamber, thus ensuring that the latter shall be con-
stantly filled with the liquid flowing through it. The heating chamber has a
suitable air-vent at the top to permit the escape of the air during the filling of the
chamber, and it has also a discharge-valve at the bottom by which it may be
entirely emptied when desired. The induction-chamber has also a similar
discharge-valve.
The operation of this apparatus in utilizing the hot washings from the black for
heating the sugar liquors, or the fresh water, is as follows, that is to say: -The
washings enter the heating chamber near the top through its eduction-main and
flow around the horizontal plates, or shelves, in the chamber and out of the eduction
main during their stay in the chamber they impart a greater or less amount of
their heat (according to circumstances) to the fresh water or the sugar liquor, which
is simultaneously flowing upwards through the tubes (which extend through the
heating chamber) from the induction-chamber to the eduction-chamber whence it
issues in a more or less heated condition.
For heating both the liquor and water I use a combination of two of these
heaters; the eduction main of the heating chamber of the first heater delivers the
washings into the induction main of the second heater, the eduction main of the first
being the induction main of the second; the washings from the black first pass
through the one heater, and afterwards through the other.
The raw liquor (which let it be supposed, is the one to be heated) flows through
the first heater on its way from the melters, in which the raw sugars are dissolved,
to the defecating or heating tanks, and is more or less heated thereby while the
water to be heated flows through the second heater and is heated, by the washings
which have left the first heater.
The heated liquid is sent from the heater into a suitable heating tank in which
it may be additionally heated if necessary.