Year: 1892

page_text: Date of Application, 19th Feb., 1892-Accepted, 19th Mar., 1892
I have observed, in the process of boiling sugars in vacuum pans, that, although
the grains of sugar boiled by this process turn out of a large size and of a brilliant.
and beautiful colour, they are very irregular in size. My invention has for its
object to overcome this defect, by using an improved feed coil in the vacuum pan.
And in order that my said invention may be properly understood, I have hereunto.
appended an explanatory sheet of drawings, whereon :-
A, is the improved feed coil, which is shown in side elevation at Fig. 1 and in
plan at Fig. 2.
B, is the flange of the coil, at the inside of the pan.
C, is the flange at the outside.
D, is a pipe, with valve D' on it, for steaming out the coil.
E, is a pipe, with valve E¹ on it, for introducing chemicals, such as "bloomer,"
sulphuric acid, etc., into the pan.
F is a pipe, with valve F on it, for feeding in the syrup or molasses.
G, Fig. 3, represents a square inch of the coil, with 49 perforations in it.
Fig. 4 is a cross section of the pipe, to an enlarged scale.
The coil A is placed in the vacuum pan, preferably, over the upper steam coil,
and is or may be secured to it. About 4" of space is, preferably, left between
the coils. When fitted in place, the flange B is secured to the inside wall of the
pan and the flange C is so fitted on the outside wall, as to correspond with the
inner flange B.
In cases where the vacuum pan is already put up, the feed coil can be made in
four or more sections and these parts be inserted through the man-hole of the pan
and then fitted in place.
The coil A is perforated at its under-side as shown at G Figs. I and 4. The
perforations extend, preferably, right round the bend or circle, as shown. In a
coil of, say, 3" diameter, the perforations would cover a breadth of 3 inches, so
that in a coil of 14 feet circumference, there would be, reckoning 49 holes to the
square inch, 24,696 holes in the pipe. By having so many holes, the pressure of
the syrup, as it issues from the coil, is reduced to a minimum.
It is advisable that, in making the feed coil, the breadth of the perforated part
should be in exact proportion to the diameter of the pipe.
The feed-coil is, preferably, made a good deal smaller in diameter than the
vacuum pan, in order that there may be plenty of space outside the coil for
ebullition purposes.
The perforated feed-coil is much better than the ordinary feed-pipe, particularly
in the graining of sugars in vacuum pans, where a small, well distributed, and
gentle charge of syrup, at intervals, is requisite. The syrup being gently sprinkled
and thoroughly distributed in the pan, there is no danger of a portion of the soft
newly-formed grains or sparks being melted shortly after they form, as is commonly
the case with the ordinary inside syrup feed pipe, which forces the syrup up into
the pan, with such pressure and violence, whether the feed cock is t, or full
open, that it destroys a large quantity of the newly formed grains, that happen to
be nearest to the feed pipe at the time of charging the vacuum pan, the consequence
is, that when these grains, that have melted and disappeared, get a chance of
forming again, they inevitably appear smaller than the others, and this is one of
the reasons for the irregularity in size of the crystals and for the percentage
[Price 83.1

page_text: of inverted sugars, which is a great loss. The "perforated feed coil" continues to
Inaintain the supplies of syrup, equally distributed, in the pan throughout the
boiling, until the striking out of the massecuite. During the operation of boiling,
every charge of syrup is so gentle and so well divided in the massecuite that each
crystal gets its equal share of syrup, and they thus continue to develope, all of the
same size, or nearly so. In this manner, the small grains, or "dust" as it is
called, by pan-boilers, do not appear amongst the crystals.
The "perforated feed coil" feeds the syrup into the pan with so much ease that
there is no fear of the large crystals breaking, as with the pressure of syrup
deposited by the ordinary feed pipe. It is a common thing to see broken up
grains in samples of the best vacuum pan sugar. The ordinary feed pipe is the
cause of this.
The "perforated feed coil" helps the pan-boiler to determine the exact quantity
of syrup he should take at each charge of syrup, as the sugar readily mixes, when
boiling.
It has also the advantage over the ordinary feed-pipe, that, should the strike
remain in the pan one or more days, through some accident or otherwise, it does
not get chocked up with sugar, and it draws immediately after starting the pan,
mixing the massecuite readily.
Having now particularly described and ascertained the nature of my said inven-
tion and in what, manner the same is to be performed, I declare that what I
claim is :-
A perforated feed coil for vacuum pans, substantially as hereinbefore set forth.
Dated this 17th day of February 1909
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.