IMPROVEMENTS IN THE MANUFACTURE OF STARCH, AND IN APPARATUS CONNECTED THEREWITH
Year: 1876

page_text: LETTERS PATENT to Thomas Henry Gray, of Grant Road, Clapham Junction,
in the County of Surrey, Bleacher and Starch Maker, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF STARCH, AND IN APPARATUS
CONNECTED THEREWITH."
Sealed the 7th October 1876, and dated the 30th June 1876.
PROVISIONAL SPECIFICATION left by the said Thomas Henry Gray at the
Office of the Commissioners of Patents on the 30th June 1876.
THOMAS HENRY GRAY, of Grant Road, Clapham Junction, in the County of Surrey,
Bleacher and Starch Maker. "IMPROVEMENTS IN THE MANUFACTURE OF STARCH,
AND IN APPARATUS CONNECTED THEREWITH."
My Invention of improvements in the manufacture of starch consists of an
improved process and apparatus for treating rice for the purpose of extracting the
starch contained therein without the use of alkalies or other chemical agents such
as are now employed in producing starch from rice.
My improved process is in fact mainly a mechanical one in contradistinction to
the chemical processes heretofore employed for obtaining starch from rice. I would,
however, observe that by saying my process is a mechanical one, I do not mean to
deny that chemical action may not take place during the mechanical manipulation
of the rice, and that such chemical action may not assist in separating the starchy
matters from the other substances contained in the rice.
My improved process consists in subjecting the rice to a considerable amount of
mechanical friction in the presence of water, which will hold in suspension and carry
off with it the starchy particles that have been detached from the grain by the
friction to which it has been subjected.
The apparatus whereby the object of my Invention may be effected may be
considerably varied in construction, and therefore I do not mean or intend to limit
myself to any precise form or arrangement of apparatus, as any mechanism which
will keep the rice in motion in the water and will cause the grains to rub one
against another will answer the purpose. As an example, however, of a convenient
and simple form of apparatus for the purposes of my Invention, I would remark
that I propose to use a kind of pug mill consisting of a cylindrical vessel in which
is mounted a vertical shaft provided with horizontal arms, which, when carried round
by causing the vertical shaft to rotate, will stir up the rice and keep it in constant

page_text: motion in the water. The cylindrical vessel may, if desired, be provided internally
with a series of fixed arms which will project inwardly between the movable arm
of the vertical shaft. I prefer to use broken rice, as it is much cheaper than whole
rice and answers the purpose equally well, and in carrying out my process the rice
may be simply thrown into the cylindrical vessel until it is about two thirds full,
then add as much water as will cover the rice to the depth of about three or four
inches. The rice should be allowed to soak for from 6 to 10 hours, then upon
imparting rotary motion to the pug mill shaft the rice will be stirred up and kept
in constant motion for an hour or two. The water will then become milky in
appearance, which will indicate that some of the starch has been detached from the
grains of rice. This cloudy water may then be drawn off from the top into another
vessel, where it should be allowed to remain quiescent until the grains of starch
become deposited at the bottom of the vessel and the water therein appear to be
clear. This water which will possess a slightly acid reaction may then be returned
to the pug mill, which, however, in the meantime has been supplied with more water,
and the pug mill shaft having being kept in constant motion this second supply of
water will have taken up a further quantity of starch granules and have thereby
become milky. This second charge of water is then run off into the depositing
tank or vessel in order that the starch may be deposited therefrom, and the previous
charge of water having been drawn off from the depositing tank is returned to the
pug inill, as already mentioned. In this manner (by repeating the process as often
as may be required) all the starch may be removed from the rice. The separation
of all the starch from the rice will be known when the water in the pug mill becomes
no longer turbid. The residuum may then be removed from the pug mill and a
fresh supply of rice thrown in and the operations may be repeated. If the rice to be
operated upon be dirty or damaged it may be washed before being placed in the
pug mill, and in order to economize time, the rice may, if desired, be soaked for the
requisite time in a separate vessel, and then run with the water mixed with it into
the pug mill. If desired the rice (instead of being charged into the pug mill in the
granular form) may be passed between crushing rollers so that every separate grain
may be crushed or bruised.
Another form of apparatus for separating the starch from the rice consists of a
cylinder covered with wire gauze or perforated metal, and mounted horizontally or
nearly so in a vessel or tank containing water, so that it may be slowly rotated
therein by means of suitable gearing. The rice to be operated upon is charged into
the horizontal wire covered cylinder through a suitable opening provided for the
purpose, and by imparting rotary motion to the cylinder the rice contained therein
will be rolled over and over, and by thus causing the grains by their own weight
to rub against each other the starchy particles will be detached and be carried off
by the water through the interstices of the wire gauze into the outside vessel. 'The
sides and bottom of this vessel may be inclined or curved to correspond to the form
of the rotating cylindrical vessel, and a trough-like space is formed along the bottom
of the tank to receive the deposit of starch which may be drawn off from time to
time with the water mixed with it.
The starchy matters obtained in this manner or by means of any other analogous
apparatus are separated from the water that is mixed therewith and is then dried,
stowed, finished, and prepared for the market in the ordinary manner. If required,
or it be thought desirable, the starch when removed from the depositing tanks may
be cleaned by adding thereto a small quantity of salt, enough to give to the water a
decided saline taste. The watery mixture must be well stirred so that the salt
should be enabled to act on every part of the mass, which should then be allowed to
remain at rest for a few hours. The salt water must then be drawn off and the
starch well washed with pure water to carry off the impurities and dissolve out the
salt. The starch may then be drained, dried, stoved, and finished as already
mentioned.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Henry Gray in the Great Seal Patent Office on the 29th
December 1876.
THOMAS HENRY GRAY, of Grant Road, Clapham Junction, in the County of
Surrey, Bleacher and Starch Maker. "IMPROVEMENTS IN THE MANUFACTURE OF
STARCH, AND IN APPARATUS CONNECTED THEREWITH.”
My Invention of improvements in the manufacture of starch consists of an
improved process and apparatus for treating rice for the purpose of extracting
the starch contained therein without the use of alkalis or other chemical agents
such as are now employed in producing starch from rice.
The improved process is mainly a mechanical one in contradistinction to the
chemical processes heretofore employed for obtaining starch from rice. I would,
however, observe that by saying my process is a mechanical one, I do not mean to
say that chemical action does not take place during the mechanical manipulation
of the rice, and that such chemical action may not assist in separating the starchy
matters from the other substances contained in the rice. I would here observe that
although one of the objects of my Invention is to dispense with the use of alkalis
in the manufacture of starch from rice as now practised, a part of my process may
with advantage be employed (as will be hereafter explained) for facilitating the
separation of the starch from the gluten when alkalis are employed as in. the
ordinary processes.
My improved process consists in subjecting the rice to a considerable amount of
mechanical friction in the presence of water, which will hold in suspension and
carry off with it the starchy particles that have been detached from the grain by
the friction to which it has been subjected.
I would here remark that in practice I have found it desirable to use tepid water
for the purposes of my Invention, and by preference I use the water at a tempera-
ture of about seventy degrees Fahrenheit.
The apparatus whereby the object of my Invention may be effected may be con-
siderably varied in construction, and therefore I do not mean or intend to limit myself
rigidly to any precise form or arrangement of apparatus, as any mechanism which
will keep the rice in motion in the water and will cause the grains to rub one against
another will answer the purpose. As an example, however, of a convenient and
simple form of apparatus for the purposes of my Invention, I would remark that
I sometimes use a kind of pug mill, such as that shown in the accompanying Drawing,
in which Fig. 1 is a vertical section of the apparatus. Fig. 1a is a horizontal
section of the same. It will be seen that the apparatus consists of a cylindrical
vessel a in which is mounted a vertical shaft 6 provided with horizontal arms b¹, b¹,
which, when carried round by causing the vertical shaft b to rotate, will stir up
the rice and keep it in constant motion in the water. The cylindrical vessel a may,
if desired, be provided internally with a series of fixed arms a¹, a¹, which will
project inwardly between the moveable arms 61 of the vertical shaft b. I, however,
prefer to use the apparatus shewn in sectional elevation at Fig. 2, and in sectional
plan at Fig. 3. A, A, is a strong frame of cast iron in the upper part of which is
placed the macerator A¹, and in the lower part the drying vessel B, herein-after
described. Through both these vessels A¹ and B passes the central vertical shaft
b supported at bottom in a step bearing placed on the foundation and supported
at top in a bearing formed in a cross head of the frame A*, as seen at Fig. 2. This
shaft b carries cross slotted arms a¹, a¹, (see plan view Fig. 3) in which are secured
by nuts a series of vertical pins or blades a³, a², the lower ends of which nearly
reach the bottom of the cylindrical vessel A¹. These pins or blades a³, a³, are
80 arranged that when the shaft b is rotated by means of the bevil gear 61
these pins will stir up the whole of the rice in the vessel A' as they each travel in
their own concentric circle, and the width of the blades covers the wholo
diameter of the vessel. A second pair of arms a*, a*, is shewn in plan as carried
by the shaft b. These blades a are curved and extend horizontally to the inner
periphery of the vessel A¹, and are intended principally to facilitate the removal of

page_text: the residuum after the starch has been extracted from the rice. When the shaft
bis rotated they will aid the vertical or friction arms a² in keeping the whole of
the rice in the macerator in constant motion in such a manner that the water will
carry upward the particles of starch which have been liberated by the friction,
and these particles of starch may be allowed to flow off through the cock c or may
be drawn off with the water from time to time.
In order to increase the friction between the grains of rice, and so ensure a more
perfect liberation of the particles of starch from the rice, I employ, in addition to the
means above described, the trawls A2, shown in the plan view Fig. 3, and in partial
side elevation at Fig. 2a. These trawls A2, A3, are composed of a flat plate of
iron attached to hooks or staples formed on the slotted arms a¹, a¹, by links or
chains a7.
As the shaft rotates these trawls A2, A2, will be drawn after the stirrers a²,
and will ride over the rice, thereby increasing the friction of the grains upon each
other according to the weight of the plates A² The front edges of these plates
may be turned up or inclined so as to facilitate their passage through or over
the rice.
Instead of employing the above-described means of agitating the rice in the
macerator by means of stirrers I sometimes employ a blast of air, which I force
through perforations in the bottom of the vessel so as to keep the rice in constant
motion.
For the purposes of my Invention I prefer to use broken rice, as it is much
cheaper than whole rice or ground rice and answers the purpose equally well, and
in carrying out my process the rice may simply be thrown into the cylindrical
vessel A¹ until it is about two-thirds full, then as much water as will cover the
rice to the depth of about three or four inches may be added. The rice should be
washed to cleanse it from any impurities and then allowed to soak from two to
four days before it is placed in the vessel A¹. It is desirable that the water should
be changed once or twice during the operation of soaking, then upon placing the
rice in the vessel A¹ and imparting rotary motion to the shaft b the rice will be
stirred up and kept in constant motion, say, for about three hours, or until the starch
has been liberated. The water will then have become milky in appearance, which
will indicate that some of the starch has been detached from the grains of rice.
This milky water may then be drawn off by the cocks c, c, into another vessel C,
which is an open vat provided with a perforated bottom and a straining cloth
affixed thereto. In this vessel it should be allowed to remain quiescent until the
grains of starch become deposited upon the perforated bottom of the vessel, and
when the water therein appears to be clear it may be drawn off from the tank C
and returned to the vessel A¹. In order to exhaust the grain (in the macerator
A¹) of starch a second supply of water to the vessel A¹ from the cock a³ may be
employed, which will take up a further quantity of starch granules. This second
charge of water is then run off through the cock c into the depositing tank or vessel
C in order that the starch may be deposited therefrom as before. This operation
of drawing off the starchy water is repeated every hour until a large proportion of
the starch is removed from the grain. The water from the depositing tank C may
be drawn off from below the perforated bottom of the vessel by opening the
rotary valve e¹, which is operated by the handle c³.
In this manner (by repeating the process in the vessel A¹ as often as may be
required) a large proportion of the starch may be removed from the rice in this
vessel. The residuum may then be removed from the macerator by opening the
sluice a, Fig. 3, by means of the rack and pinion a³, when it will flow down the
pipe into the vat D to be afterwards treated as herein described. A fresh
quantity of rice may then be supplied from the hopper h, and the operations may be
repeated.
In order to economize time the rice may, if desired, be washed and soaked for the
requisite time in a separate vessel, and then run with the water mixed with it into
the macerating vessel A¹.

page_text: Another form of apparatus for separating the starch from the rice is shown in
longitudinal section at Fig. 4, and in cross section at Fig. 5, Sheet II., and consists
of a cylinder d covered with wire gauze or perforated metal, and mounted
horizontally or nearly so in a vessel or tank e containing water, so that it may be
slowly rotated therein by means of suitable gearing. The rice to be operated upon
is charged into the horizontal wire covered cylinder d through an opening d¹ pro-
vided for the purpose at one end, and by imparting rotary motion to the cylinder d
the rice contained therein will be rolled over and over, and thus by causing the
grains (by their own weight) to rub against each other the starchy particles will
be detached and carried off by the water through the interstices of the wire gauze
into the outside vessel or tank e. The sides and bottom of this vessel may be
inclined, as shewn at Fig. 5, or curved to correspond to the form of the rotating
cylindrical vessel d, and a trough-like space is formed along the bottom of the tank
to receive the deposit of starch, which will fall down into it, and may be drawn off
from time to time (with the water mixed with it) into a tank where the starchy
liquor will be left to deposit its solid particles so that the clear supernatant liquor
may be drawn off therefrom. The residuum may be removed from the cylinder D
through the door d².
Another mode of obtaining this result is to employ a rotating cylinder into
which the rice is to be introduced through a suitable opening at its periphery, and
water is added thereto through its hollow axle. After rotating the cylinder or
barrel for a sufficient time (say, two hours,) the charge may be allowed to run
off and the operation may be repeated.
To the starchy matters obtained in either of the above-described manners, or by
means of any analogous apparatus, a small quantity of salt (sufficient in quantity to
give a decided saline taste) must be added to prevent fermentation. Water being
added the mixture must be well stirred so that the salt should be enabled to act on
every part of the starchy mass, which should then be allowed to remain at rest for
a few hours. The salt water must then be drawn off and the starch well washed
with pure water to carry off the impurities and dissolve out the salt.
If it be desired to flake or "reece" the starch I subject the starchy matters for
from twenty-four to thirty-six hours to the action of a weak alkaline solution, con-
sisting, of, say one pound of soda ash and two ounces of lime boiled in about a gallon
of water. This solution is added to the wet starchy matters before cleansing them
with salt as above-mentioned. After the lapse of time necessary to allow the alkali
to act on the starchy matters the salt may be added to the mass, as already men-
tioned, and the solid matters well watered to remove the salt and alkali therefrom.
The starchy mass may then be drained (while in the vessel C) through the per-
forated bottom by opening the valve c¹, or it may be run into an hydro-extractor
previous to its removal to any suitable steam dryer.
When it is desired to flake the starch by means of a weak alkaline solution, as
already explained, the starchy mixture may be run from the macerator A¹ into a
second macerator B (shewn in Figures 2 and 3, Sheet I.) which is constructed some-
what similar to the macerator A¹ before described, and consists of a cylindrical
vessel B, in which arms b² (carrying vertical blades b³) rotate. Underneath the vessel B
is a steam chamber B* extending under the greater part of the bottom and supplied
with steam by the pipe 64, an exit being provided for the condensed water by the
pipe 63. The starchy mass will thus be kept in motion over the bottom of this vessel
B for about six hours, it is then to be removed from the vessel B and run into a
depositing tank, where it will remain for about twenty-four hours, after which it
is washed in the manner already explained and dried and prepared in the ordinary
manner as starch for the market.
When as much of the starch as conveniently can be has been separated from the
rice the residuum is removed from the macerator in the manner before described
into the vessel D. In order to arrest fermentation this residuum is to be
treated with salt in the proportion of about three pounds of salt to the hundred
weight of residuum. It may be convenient that this treatment of the residuum

page_text: with salt should take place while in the macerator, which affords greater facility for
thoroughly mixing the same, but on its removal to the vessel D the residuum
should be allowed to remain in the saline liquor for about six hours. This saline
liquor may then be drawn off, and the remaining mass may be dried in any suit-
able drying apparatus or stove, when it will be in a condition to be subjected to the
ordinary process of pulverization. The residuum as above treated is applicable for
the use of bakers in the manufacture of bread, biscuits and other articles. Paper
makers, bleachers, and calenderers may use it as a size. It may also be used as an
ingredient in the manufacture of infant's food, and other farinaceous food.
Although I have described my improved process of manufacturing starch without
the use of alkalis or other chemical agents, and in this improved process of manu-
facture I have shown the advantages of employing chloride of sodium (common
salt) for the purpose of preventing fermentation and improving the quality of the
product as well as economising the time of such manufacture as herein described,
I have found that in the ordinary course of manufacture in which alkalis are em-
ployed there are great advantages in the employment of common salt at one stage
of the old process, namely, while the alkali is in combination with the slimy mass of
starch combined with other matters, and while it is being stirred for the purpose of
incorporating the same. The chloride of sodium or saline liquor may then be
added to the slimy mass and will cause the pasty granules of the starch to close and
to separate from the other matters and destroy the tendency to fermentation, which
tendency has been found so deleterious to the present mode of manufacturing starch
from rice.
Having now described my Invention of "Improvements in the Manufacture of
Starch, and in Apparatus connected therewith," and having explained the manner
of carrying the same into effect, I claim as the Invention secured to me by Letters
Patent as aforesaid―
First. Separating the starchy particles from rice by agitating the latter in water
so that by the friction of the grains or particles of rice against each other the
starchy matters may be rubbed off or detached, and when separated from the
gluten will be carried off by the water into another vessel in which they will be
deposited, and then subsequently treated, dried, and prepared for sale as a market-
able article, as herein set forth.
Second. I claim the arrangement or construction of apparatus herein shown and
described for separating the starchy particles from the other matters (contained in
the rice) by causing the grains or particles of rice to rub against each other in the
presence of water so that the starchy matters when separated may be carried off
into a depositing tank or vessel and subsequently treated, dried, and prepared for
market, as herein set forth.
In witness whereof, I, the said Thomas Henry Gray, have hereunto set my
hand and seal, the Twenty-third day of December, in the year of our
Lord One thousand eight hundred and seventy-six.
THOMAS HENRY GRAY. (L.S.)