Improvements in and Combination of Machinery for Shelling the Locust Bean Kernels.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in and Combination of Machinery for Shelling the
Locust Bean Kernels.
I, PETER CAMERON DOUGLAS CASTLE, of Fox Coverts, Bebington, in the County
of Chester, Secretary, do hereby declare the nature of this invention to be as
follows:-
-
This invention has for its object an improved process for shelling the kernels
of the locust bean and for preparing them for the extraction of pure gum tragasol.
It is impossible to use the ordinary mechanism employed for shelling or
conditioning (that is permeating with moisture or kiln drying) rice, beans, peas,
lentils and the like, because the shells or skins of these seeds are very nearly
uniform in texture whereas of two seeds taken from the same pod of a locust
bean one may be of almost adamantine hardness and not appreciably softened
whilst the others may be quite soft by conditioning and further the gummy
nature of the cotyledon causes it to become very sticky when conditioned by
moisture making it to again adhere to the husk after it has been separated from it,
and the gum is deteriorated when conditioned by kiln drying. After trying a
great number of experiments, I have discovered that by combining and strengthen-
ing several well known mechanical processes and making an entirely new cut
or dressing of mill stones. I am enabled to separate the husk and germ with
the loss of a small per centage of the cotyledon which produces the gum.
My process is as follows: -
(1) The kernels are first passed through a powerful disintegrating machine.
In this the disintegrating disc revolves at 3500 revolutions or thereby per
minute. The kernels are split up by this process and about 80 to 85% of the
germ and some portions of the husk are detached and are separated from the split
kernels by sifting.
(2) The split kernels are then graded with a machine adapted for the purpose
and divided into two, three, or more lots as the irregularity of the parcel may
indicate to be necessary.
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(3) Each lot is then taken separately and passed through a mill in all outward
respects similar to any corn grinding mill, but a novelty is introduced in the
cut"
or dress of the stones which may be of French burr stone, Derby peak or
any other suitable material. The stones have no alleys or grooves outward
from the throttle or eye. Instead of such as is usual, the upper and lower stones
are very slightly bevelled from the throttle to within from two to three inches
of their periphery. The stones are set only as far apart as prevents any grinding
of the split kernels, when passing through the flat ridge of two to three inches
above mentioned, but near enough, according to the size and thickness of the
kernels, to grind off the convex apex of the husk. The result is that the split

page_text: kernels fed from the throttle are driven by centrifugal force to the outside ridge
which they can only pass through on the Hat and the apex of the husk is there
shaven off each individual split thereby preparing it for the next operation.
(4) The partially husked kernels are then passed into a powerful pearling
machine which is made very much stronger in all its parts than any similar
machine now in use. This machine consists of a large mill-stone running on a
horizontal axis and surrounded by a steel wire gauze cylinder having an opening
for admission of feed at the top and another for discharging the material at the
bottom. This stone may be run at a speed of 120 up to 300 revolutions per
minute and the outside cylinder at .10 to 12 revolutions per minute in the same
direction as the stone and the space between the stone and cylinder is about
two-thirds full of the material. This machine if used alone would wear away a
very large portion of the cotyledon before it removed all the husk and accordingly
in order to avoid this evil the split kernels first have the apex ground off as
aforesaid and are kept in it until they are only partially husked after which
they are again graded and put into another and similar machine working as full
at the start as in the first pearling machine. This takes off a further percentage
of the husk without excising so much of the gum as would have been ground with
the husk if left till finished in the first machine. But still the husking is not
finished until they pass through a third machine of the same kind grading it
again if necessary. The above process invariably takes off the husk sooner round
the outer circle or edge of the split kernel than from its apex, hence the necessity
for first getting rid of the portion of husk on the apex. During these processes
the remainder of the germ has been knocked off the cotyledon and the entire mass
can now be sifted or winnowed to remove any fine remaining particles of husk
and germ.
בד
1
000
.
W. P. THOMPSON Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in and Combination of Machinery for Shelling the
Locust Bean Kernels.
I, PETER CAMERON DOUGLAS CASTLE, of Fox Coverts, Bebington, in the County
of Chester, Secretary, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:
This invention has for its object an improved process for shelling the kernels
of the locust bean (ceratonia siliqua), and for preparing them for the extraction
of pure gum tragasol.
Rice, beans, peas, lentils, and the like, are shelled by either permeating them
with moisture or kiln drying, and then going through a rubbing operation
whereby the shells are rubbed or broken off them. These processes however for
shelling seeds are of no use with locust beans, for this reason, that one locust bean
in the same shell will be very soft, and another very hard, so that the moisture
sufficient to condition a large percentage of the kernels in twenty four to forty
eight hours leaves a considerable moiety as hard as at first. Further, if the shells
are softened by moisture the gummy matter of the kernels exudes also and sticks
the cotyledon to the shell, thus making the bean still more difficult to shell.
On the other hand kiln drying has been found to injure the gum.

page_text: By my present invention, and after a very large number of experiments I have
discovered that by using several wellknown mechanical devices in succession,
some of them slightly altered, I have achieved a process whereby these locust
beans are shelled with a very small percentage of loss in the cotyledon.
My process is as follows;-
The kernels are first split by means of a powerful disintegrating machine of
any desired type. The material is then sifted and about eighty to eighty-five
per cent. of the germ and some portions of the husk are thus detached. They
are then graded into three or four lots as the irregularities of size in the kernels
require, so as to get all the split kernels in each batch of approximately the same
size. Each lot is then taken separately and passed through a grinding mill con-
sisting of two stones, in which the only novelty is the peculiar dress of the
stones, there being no alleys or grooves outward from the eye, but instead of
this, the upper and lower stones or one of them, are very slightly bevelled from
the throttle to within two or three inches of the periphery, thus forming a hollow
gradually increasing towards the centre. The stones are set only as far apart
as prevent any grinding of the split kernels, when passing through the flat ridge
of two or three inches above mentioned, but they are kept near enough according
to the size and thickness of the kernel to grind off the convex apex of the husk.
The result is, that the split kernels fed from the throttle or eye are driven by
centrifugal force to the outside ridge which they can only pass through on the
flat, and the apex of the husk is there shaved off each individual split kernel.
By this means they are prepared for the next operation. This consists in passing
them through a powerful pearling machine whereby the remainder of the husk
is in large part separated. If the apexes are not first cut off as already described,
a very large part of the cotyledon is wasted in the pearling, but if the apex be
cut off the husk is comparatively easily detached without much loss of cotyledon.
The material is preferably passed through the pearling machine two or three
times or through two or three different pearling machines being sifted between
cach passage so as to separate all the husk that is ground off at each operation.
Having now briefly described my process, I will describe the best machinery
known to me for carrying it out. Of the various disintegrating machines which
I have tried I find the wellknown Carter's disintegrator, in which the disinteg-
rating discs revolve at 3500 revolutions per minute is best. The grinding mill
I use is set forth in the drawings, in which, in Figure 2, a cross section of the
stone is fully set forth. For a pearling machine, almost any of the numerous
varieties in which a large mill stone or series of mill stones or grinding dises
rotate in a wire gauze cylinder or casing kept full of beans. The stone is
preferably run at a speed of 120 to 180 revolutions per minute and the outside
cylinder at 10 or 12 revolutions per minute, in the same direction as the stone,
the space between the stone and the cylinder being preferably two-thirds full
of the material, and the space between the stone and the casing being preferably
only one or two inches but any pearling machine for this material must be of
cnormously increased strength in all its parts. For sifting or grading machines,
any ordinary one now on the market will do, the sieves being arranged to the
requisite size.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. The process of decorticating locust bean kernels which consists in spliting
them, grinding off the apex of the split kernel and submitting them two or three
times in succession to the pearling action of a rice or other pearling or decorti-
cating machine, and between each of these operations sifting out the loose germ
and shell.
2. The method of and apparatus for grinding off the apex characterized by
the use of a pair of mill stones without the usual dress, but formed with a hollow

page_text: gradually decreasing towards the circumference and a flat annulus at the periphery
of a few inches, substantially as described.
3. The combination of machinery, substantialy as and for the purposes
described.
Datal the 20th day of December 1900
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.