An Improved Method of Treating Rice and other Grain for Removing the Outer Skins or Coverings thereof.
Year: 1888

page_text: Date of Application, 27th Oct., 1888
Complete Specification Left, 27th July, 1889-Accepted, 7th Sept., 1889
PROVIDIONAL
An Improved Method of Treating Rice and other Grain for Removing
the Outer Skins or Coverings thereof.
I, WILLIAM SHEDLOCK, of 61 Strathblane Road, St. Johns Hill, Wandsworth, in
the County of Surrey, Mechanical Engineer, do hereby declare the nature of this
invention to be as follows
-
My invention relates to the treatment of rice and other grain for removing the
outer skins or coverings thereof.
In the treatment of rice for this purpose as frequently heretofore practised the
grains are placed in a cylinder or other vessel in which a piston or plunger is so
arranged that it has a vertical reciprocating motion causing the said grains to be
agitated in such manner that the continual rubbing of the same together causes
the said skins or coverings to be removed. This is called the "attrition
process
and is practically the only one now employed for treating rice.
This process is attended by several inconveniences the most important of which are
first that the grains are always more or less broken thus rendering the product les
valuable as a commercial article and secondly considerable time is necessary for
carrying the operation into practice thereby causing the same to be somewhat
expensive.
According to my invention 1 combine with the attrition or rubbing the use of
suitable gases designed to have a loosening effect upon the skin of the grain and to
cause the same to be detached much more readily than is possible when the attrition
alone is dependent upon. This expedites the operation considerably and prevents or
diminishes the cracking and breakage of the grains.
As an example of a gas suitable for this purpose superheated or dry steam may
be mentioned but other gases having the requisite effect may be employed in lieu of
steam.
The gas is admitted by any suitable means to the cylinder or chamber in which
the rice or other grain is contained and provision is made for its exit when the
required effect has been produced.
It is obvious that although my invention is specially advantageous in the treatment
of rice it is also applicable to wheat barley and other grain or seed.
Dated this 26th day of October 1888.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Method of Treating Rice and other Grain for Removing
the Outer Skins or Coverings thereof.
I, WILLIAM SHEDLOCK, of 61 Strathblane Road, St. John's Hill, Wandsworth, in
the County of Surrey, 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 :-
My invention relates to the treatment of rice and other grain or seed for the purpose
of removing the skin or cuticle therefrom.
In the treatment of rice for this purpose as heretofore usually practised, the said
rice is placed in a cylindrical or other suitably shaped vessel in which a pestle or
plunger is arranged to be reciprocated vertically by means of any suitable mechanism,
thus causing the grains of rice to be agitated in such a manner that the continual
031

page_text: ruboing of the same against each other and against the said pestle or plunger and the
sides or walls of the said vessel, will remove the skin or cuticle. This process is
called the "attrition" process and is practically the only one employed at the present
time for treating rice for the purpose above mentioned.
This process is attended by several serious inconveniences, amongst which may be
mentioned the following, viz. :-the grains of rice so treated are generally more or
less broken or, crushed, thus reducing the value of the product as a commercial article.
Moreover the operation involves a considerable expenditure of time and is for this
and other reasons somewhat expensive.
An important feature of my present invention is the treatment of the rice or other
grain with hydrofluoric acid or other suitable gas in such a manner as to soften and
loosen the skin or cuticle so that it can be very readily detached.
I sometimes combine, with the attrition or rubbing process, the treatment with gas,
so that a softening or loosening effect will be produced upon the skin or cuticle of
the said grain, thereby enabling the same to be detached much more readily than is
practicable when the attrition alone is depended upon.
The operation of removing the said skin is thus considerably expedited, and the
above mentioned cracking and breakage of the grain is entirely obviated or greatly
diminished.
In carrying my said invention into practice, I find it advantageous to employ
hydrofluoric acid gas for the purpose above specified. A suitable quantity of the rice
or other grain to be treated is placed in a chamber or receptacle which can be rendered
air-tight. Hydrofluoric acid or other suitable gas generated in any well known
manner is then admitted to the air-tight chamber or receptacle. To ensure the
entrance of the gas or gases into the said receptacle, I sometimes exhaust the atmo-
spheric air from the said receptacle, or I force the gas into the said receptacle by
- means of an air-blast in any convenient manner. Suitable means are provided for
agitating or stirring the body or mass of- rice or other grain in the said receptacle
so as to expose all the grains thoroughly to the action of the said gas. The length of
time during which the said rice or other grain is allowed to remain in contact with
the said gas will vary according to the quantity of grain under treatment, and the
quality or nature of the said grain. From one to three minutes, more or less,
will however be generally found sufficient to ensure the softening or loosening of
the cuticle. The precise time required for any particular kind of grain will be best
ascertained by practical experience.
When the skin or cuticle is sufficiently loosened, the bydrofluoric acid, or other gas
is drawn off by means of an exhaust-pan, or in any other convenient manner, and
the agitation of the said grain is continued for a short time until the skin or cuticle
which has been loosened by the action of the said gas is completely detached from
the grain.
In some instances, after the supply of hydrofluoric acid or other gas has been cut
off from the said chamber or receptacle, I introduce into the latter ammonia or
other suitable gas for the purpose of neutralizing the deleterious effect that might
otherwise occasionally be produced by an excess of acid remaining in contact with
the grain.
In the event of an undue amount of moisture being present after any of the above
described treatments, I pass dry warmed air through the said chamber or receptacle
in such a manner as to dry the grain contained therein.
I. sometimes provide for carrying or conducting the charge of hydrofluoric acid or
other gas from the chamber or receptacle, when it has performed its work therein
(that is, after the rice or other grains have been sufficiently exposed to the action of
the said gas) into a suitable apparatus for fixing it by means of lime or other alkaline
substances; for this purpose I can use an exhaust-fan or other suitable means.
I am thus enabled to recover such quantity of the gas or gases as is not actually
utilized in the process, in the form of a product or products which can again be used
for the generation of the said gas.or gases.

page_text: арри
advantageous for the treatment of rice or other grains according to my said
invention.
Figure 1 is a plan of the said apparatus, partly in horizontal section.
Figure 2 is an end elevation of the same, and
Figure 3 is a vertical central section on the line a, a, Figures 1 and 2.
Figure 4 is a transverse section, drawn to an enlarged scale, showing a detail of
construction hereinafter described.
Like letters indicate corresponding parts throughout the drawings.
A is a chamber or receptacle which is preferably formed in two parts having
central flanges A¹ by means of which they are secured together in any convenient
manner so as to form a tight joint. The chamber or receptacle A is preferably
constructed of a hexagonal form tapering towards the extremities as shown in the
drawing; it may, however, be of other suitable shape. The said chamber or receptacle
is provided with hollow axles or gudgeons A2 by means of which it is supported in
suitable bearings in standards B. C is a hollow shaft or arbor which passes through
the said gudgeons A2 and through the chamber or receptacle A. In order to form
tight joints around the said hollow shaft or arbor C, I provide in the said gudgeons A'
stuffing-boxes A and glands A. is a partition extending through a part of the hollow
shaft C so as to divide the space therein into two interior portions or passages C³, C³.
The passage C is in free communication with the space in one end of the said hollow
shaft and the passage is in free communication with the space in the other end
thereof. The said hollow shaft C or that portion of it situated within the chamber
or receptacle A is preferably hexagonal, it may, however, be circular or of other
suitable shape in transverse section. D, D are hollow arms or beaters provided with
perforations as at D' and screwed into, or otherwise firmly secured in suitable holes
provided for the purpose in the said hollow shaft C, so that one half of them are in
free communication with the passage C, and the other half with the passage C³.
One extremity of the shaft C is connected to a cross-piece or branch-piece Ę by
means of a stuffing-box F and gland F1; or other suitable means are provided for
forming a tight joint between the said shaft and the said branch-piece E, whilst
permitting rotation of the said shaft. G is a bracket firmly attached to, or forming
part of one of the standards B and supporting the said branch-piece E. E', E', E³
are pipes provided with suitable stop cocks or valves H, H', H2 and communicating
respectively with suitable apparatus for the supply of hydrofluoric acid gas, ammonia
or other suitable gas, and hot air. The other extremity of the said shaft is connected
by means of a stuffing-box I and gland 1' (or other suitable means for forming a
tight joint whilst permitting rotation of the said shaft) with a pipe J. The said
pipe Jis connected with an exhaust-fan, or other convenient means for exhausting
the air from the chamber or receptacle A through the passage C³ of the shaft C and
the hollow perforated arms or beaters D connected therewith.
Suitable means are, moreover, provided for causing the chamber or receptacle A
to rotate in one direction and the shaft C and the hollow perforated arins or beaters
connected therewith to rotate in the reverse direction, thus producing a highly
effective agitation or rubbing action of the rice or other grains in the said chamber
or receptacle A. For thus rotating the said receptacle and shaft, I provide upon
one of the projecting extremities of the said shaft, a toothed wheel K which is firmly
keyed or otherwise secured thereon. The said toothed wheel K is geared with
another toothed wheel L keyed or otherwise firmly secured upon a shaft or spindle M,
carried in suitable bearings in one of the standards B and in a bracket N forming
part of, or firmly attached to the said standard. Upon one extremity of the said
shaft or spindle M is keyed or otherwise secured a pinion O, which is geared with an
internally toothed wheel P forming part of, or firmnly attached to the extremity of the
chamber or receptacle A. Upon the other extremity of the said shaft or spindle M is
keyed or otherwise secured a pulley Q.
Rotary motion is imparted to the shaft or spindle M through the said pulley Q by
means of belt-gearing from any available source of motive power. It will be seen

page_text: that upon the rotation of the said shaft or spindle, the chamber or receptacle A will
be caused to rotate in one direction through the pinion. O and internally toothed
wheel P, and the hollow shaft C and the arms D carried thereby will be caused to
rotate in the contrary direction through the toothed wheels Land K.
A is a door for permitting access to the interior of the chamber or receptacle A
and the removal of the contents thereof; the said door is preferably placed in one of
the angles of the said chamber or receptacle A as shown in the drawing so as to
facilitate the removal of the rice or other grain from the said chamber or receptacle
at the termination of the process.
To prevent injury to the interior surface of the chamber or receptacle A, or to
the surfaces of the hollow shaft C and perforated arms or beaters D by the hydro-
fluoric acid or other gas employed in the process, I coat or cover the said surfaces
with India-rubber, gutia-percha or other suitable material which is not liable to be
attacked by the said gases or to injure the rice or other grain under treatment, or I
form the said surfaces entirely of such material. I sometimes provide corrugated or
roughened removable lining plates on the interior surfaces of the said chamber or
receptacle A, so as to effect a greater attrition or rubbing action of the grains under
treatment.
The operation of the apparatus is as follows, that is to say :-The chamber or
receptacle A having been partially filled with rice or other grain, the said chamber
or receptacle is caused to rotate rapidly in one direction, whilst the shaft and arms
or beaters D are caused to rotate in the reverse direction as hereinbefore described.
The atmospheric air contained in the said chamber or receptacle A is then exhausted
in any suitable manner through the pipe J, and through the passage C³ of the hollow
shaft. C and the perforated hollow arms or heaters D connected therewith. The stop
cock or valve H is then opened and hydrofluoric acid gas is admitted to the interior
of the said chamber or receptacle A through the pipe E¹, passage (2 and arms or
beaters D connected therewith. The said gas being delivered through the
perforations D¹ in the said arms or beaters D whilst they are rapidly revolving and
passing through the body or mass of grain contained in the said chamber. or
receptacle A, the grains are subjected in a very efficient manner to the action of the
said gas, and every individual grain is equally or almost equally exposed thereto.
When the skin or cuticle of the grains has been sufficiently attacked and softened or
loosened by the action of the said hydrofluoric acid gas, the supply of the latter is
cut off by means of the said stop cock or valve H. The stop cock or valve H' is
then opened and ammonia or other suitable gas is admitted through the pipe E for
the purpose of neutralizing any excess of acid that may be contained in the said
chamber or receptacle A as herein before mentioned. The stop cock or valve H' is
. then closed and the supply of ammonia or other gas stopped, and lastly the stop
cock or valve H2 is opened and hot dry air is admitted through the pipe ³, for the
purpose hereinbefore specified.
The rotation of the chamber or receptacle A and of the hollow shaft C and arms
or beaters D is then continued for a sufficient length of time to remove from the
grains the skin or cuticle which has been attacked and loosened by the above
described treatment. The length of time during which the said rotation must be
continued will vary with the nature and quality of the grain under treatment, but a
few revolutions are usually sufficient to effect the desired result.
Although I have hereinbefore described a convenient form of apparatus for carrying
my said invention into practice, it is obvious that I can employ other suitable
apparatus. I can, moreover, employ in place of the gases hereinbefore mentioned
any other suitable gas or mixture of gases, or fumes or vapors; for example chlorine,
hydrochloric acid, chloric oxides, sulphurous acid, nitrous fumes, oxygen, dry steam
or the like.
It is obvious, moreover, that although my said invention is chiefly designed for
the treatment of rice and has been hereinbefore described more particularly in relation
thereto, the said invention is also applicable to wheat, barley, Indian-corn and other
grains or seeds.

page_text: Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed I wish it understood that, in
my present application for Letters Patent, I do not claim the improved apparatus
hereinbefore described, as no special apparatus has been referred to in my provisional
specification, and I purpose making my improved apparatus the subject of another
application for Letters Patent; but I claim':-
First. The treatment of rice or other grains or seeds with hydrofluoric acid or
other gas, for the purpose above specified.
Second. The removal of the skin or cuticle from rice or other grains or seeds by
the combined action of hydrofluoric acid or other gas or vapour and attrition.
Third. The herein described method of removing the skin or cuticle from rice or
other grains or seeds, consisting in first placing the grains or seeds in a chamber or
receptacle and then introducing hydrofluoric acid or other gas or vapour into the
said chamber or receptacle and at the same time agitating the mass of grains or seeds
therein, substantially as hereinbefore described.
E
.
1000
WILLIAM SHEDLOCK.
Haseltine Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.