US3566945A - Method of hulling paddy and device therefor - Google Patents

Abstract

A method of hulling paddy which comprises revolving numerous hulling vanes having outer bent ends to produce a lower atmospheric pressure zone which is virtually the same as the vacuum state, passing paddy through the said lower pressure zone to expand the gas in paddy abruptly thereby rendering paddy to the state just before the crack and immediately thereafter throwing paddy against outer bent ends of the hulling vanes to crack the hulls and then discharging the cracked paddy into the air pressure zone so that hulls and husked rice are separated perfectly.

Description

United States Patent Inventor Yutaka Aoki Tokyo, Japan App]. No. 743,565 Filed July 9, 1968 Patented Mar. 2, 1971 Assignee Sanriku Noki Co., Ltd. Priority July 13, 1967 Japan 42-45203/67 METHOD OF HULLING PADDY AND DEVICE THEREFOR 6 Claims, 7 Drawing Figs.

11.8. C1 146/223, 146/273 Int. Cl B02c 13/28, B02c 13/08 Field of Search 146/223,

[5 6] References Cited UNITED STATES PATENTS 758,664 5/1904 Kimball l46/253X 1,735,550 11/1929 Stanley 146/253 1,788,686 l/1931 Mott 146/253 2,098,521 11/1937 Seymour 146/253 3,255,793 6/1966 Clute l46/223X Primary Examiner-Andrew R. Juhasz Assistant Examiner-Z. R. Bilinsky Attorney-Oberlin, Maky, Donnelly & Renner ABSTRACT: A method of hulling paddy which comprises revolving numerous hulling vanes having outer bent ends to produce a lower atmospheric pressure zone which is virtually the same as the vacuum state, passing paddy through the said lower pressure zone to expand the gas in paddy abruptly thereby rendering paddy to the state just before the crack and immediately thereafter throwing paddy against outer bent ends of the hulling vanes to crack the hulls and then discharging the cracked paddy into the air pressure zone so that hulls and husked rice are separated perfectly.

PATENTEUHAR 2mm 13566345 SHEEI 1 BF 3 43 I L 27 3a FIG. I a

INVENTOR PATENTEU HAR 2 I97] sum 2 BF 3 METHOD OF HULLING PADDY AND DEVICE THEREFOR BACKGROUND OF THE INVENTION This invention relates to a method of removing the bulls from paddy and a device for embodying such the method.

Heretofore, hand millers, rubber-roller hullers, collisiontype hullers, etc. have been used to remove the hulls and produce brown rice from paddy, and more particularly, the automatic rubber roll type huller which comprises separator, winnower and screen coordinated by a throwing elevator is the most popular and diffused type. The separator of the rubber rolltype huller is composed of two symmetrical rubber rolls, which are placed closely together and revolve in opposite directions with different speed ratio of rotation. Therefore, paddy, when passed between the rolls, is given a twisting squeeze as done by two fingers and as a result the husks are peeled off.

According to the conventional rubber roll huller, an adjust ment of clearance between two rolls is difficult and the hulling efficiency is not sufficient. Generally, paddy is subjected to the huller twice, nevertheless, considerable amount of unhusked paddy still remains and, further, complicatedness' in the structureof the huller requires a great deal of skill for operation and, therefore, causes inconvenience to the treatment.

While, the collision-type huller is composed of a centrifugal rotor, which tosses paddy with added speed, and a separatio board, which stops and breaksthe husks. 4

According to the conventional huller of this type, the hulling yield is relatively low due to the incomplete dryness of paddy and to the high speed of rotation, and further the rice cracks and the embryo drops off thus deteriorating the suitability of long preservation of rice.

After an extensive research, the inventor has traced the fact that the bulls may be perfectlyremoved from goodand even immature paddy in such a way that paddy is rendered to the state just before the crack by utilizing the difference of the atmospheric pressure between the gas contained in paddy and the air, and the characteristic nature of paddy within the air fluid, and immediately thereafter the tip of paddy is given an instant impact and then discharged into the strong air pressure zone, so that not only good paddy but also immature paddy is completely hulled.

According to this method, the hulling yield is virtually perfeet with remarkable preservability of rice as compared with one obtained by the conventional huller and there is substantially no damage and crush of rice.

SUMMARY OF THE INVENTION It is thus a principal object of the invention to obviate all defects in the conventional roll and collision-type hulling device and to provide a new method of hulling paddy with the substantially perfect hulling efficiency and simple manner.

Another object of the invention is to provide a method of hulling paddy which comprises revolving numerous hulling vanes having an outer bent end to produce a lower atmospheric pressure zone virtually the same as the vacuum state in the vicinity of the said bent end, passing paddy through the said lower pressure zone to expand abruptly the gas in paddy thereby rendering paddy to the state just before the crack and immediately thereafter throwing paddy against the outer bent end to crack the hull and then discharging the cracked paddy into the air pressure zone so that the hulls and brown rice are separated perfectly.

Still another object of the invention is to provide a new method of hulling paddy which comprises sucking paddy with a suction hose, transferring paddy into a hulling chamber, separating the air flow by means of a cyclone separator and selecting the resulting mixture into brown rice, hulls, immature grains etc. by a winnower means to finally obtain brown Even still another object of the invention is to provide a new hulling device of simple structure with a high hulling yield, which may be operable rapidly with ease.

And yet another object of the invention is to provide a new hulling device which comprises circular hulling chamber in which numerous hulling vanes are radially arranged around a rotary shaft, a cyclone separation means for separating air now from the hulled mixture and a winnower means for selecting the hulled mixture into brown rice, immature paddy and hulls with straw dust.

And another object of the invention is to provide a paddy supplier which comprises a paddy suction means for sucking the piled paddy automatically into the hulling chamber and an air suction adjuster.

A further object of the invention is to provide a circular hulling chamber in which numerous hulling vanes having an inner bent end for guiding paddy onto the center surface of the hulling vane and an outer bent end to which a tip of paddy collides are radially arranged around a rotary shaft.

Yet a further object of the invention is to provide a hulling vane having an inner bent end for guiding paddy onto the center surface of the hulling vane and an outer bent end to which a tip of paddy collides.

And a further object of the invention is to provide a new hulling device which may be associated with a combined harvester-thresher.

BRIEF DESCRIPTION OF THE DRAWING These and other objects and advantages of this invention will become readily apparentand understood from the accompanying specifications and drawings in which the same reference numerals designate the same or similar parts throughout the drawings.

FIG. I is a perspective view of hulling device provided with a funnel;

FIG. 2 is a perspective view of hulling device provided with a suction nozzle;

FIG. 3 is a fragmentarily enlarged front elevation of hulling chamber which is one of essential features of the device according to the invention;

FIG. 4 is a plane view of hulling vane according to the invention;

FIG. Sis a side view of FIG. 4;

FIG. 6 is a pictorial view showing process for selecting paddy according to the invention; and

FIG. 7 is a pictorial view showing driving operation of hulling device according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 to 3, the reference numeral 1 denotes a funnel for storing paddy, and paddy thrown into the said funnel l is sucked into the hulling chamber 2 together with an air flow passing through a mesh portion 3 provided at the bottom end of the funnel 1 due to the gravity of paddy and the suction effect caused by the revolution of numerous hulling vanes arranged in the hulling chamber 2. Alternatively, one end of the suction hose 5 is connected to a paddy inlet 4 of the hulling chamber 2, while the other end thereof is provided with a suction nozzle 6 as shown in FIG. 2. In operation, the nozzle 6 is inserted into the deposit of paddy to suck paddy automatically into the hulling chamber 2. It will be noted that an amount of air suction through the suction nozzle 6 may be adjusted by an auxiliary air inlet means 7 which comprises several hollow pipes of different diameters and attached to the terminal por' tion of the suction nozzle 6.

In the hulling chamber 2, numerous hulling vanes 8 are arranged radially around the rotary shaft 10 and are strictly held through the welding projections 9 between two side plates 11 which rotate integrally with the hulling vanes 8 around the rotary shaft 10. The side plates 11 are contained in a circular casing 12 to which a circular covering 14 is mounted through a clamping means 13. Around an inner circumferential wall of the circular casing 12 is detachably linedwith a circular elastic plate of rubber or plastic material through a carrier 16 to absorb the shock of brown rice to the said inner circumferential wall. That is to say, when the elastic plate 15 is subjected to abrasion and damaged due to the extended period of use, it may be readily substituted for a fresh one merely by removing the carrier 16.

As shown in FIGS. 4 and 5, the hulling vane 8 comprises a straight main part 17, a inner bent end 18 for guiding paddy and an outer bent end 19 to which the tip of paddy collides. The inner bent end 18 and the outer bent end 19 are strengthened at the respective roots 20 and 21. The curvature of from 20 to of the inner bent end 18 against the main part 17 of the hulling vane facilitates a smooth slide of paddy, sucked through the inlet 4 into the hulling chamber 2, along the surface of vanes. While, it has been experimentally confirmed that the curvature of from 40 to 45 of the outer bent end 19 to the main body reduces the atmospheric pressure substantially to the same as the vacuum state upon revolution of the hulling vanes at 1,600 rpm.

Further, the outer bent portion at its inner corner 22 is somewhat projected in an acute form as shown in FIG. 5 so as to inhibit any leakage of collision of paddy to the said outer bent end.

The hulling vane 8 according to the invention is the most important feature of the present invention, so that the degrees of the curvatures of the bent ends 18 and 19 as well as the nature of material of the hulling vane affect seriously to the hulling efficiency and also quality of brown rice obtainable. More particularly, the outer bent end 19 of the hulling vane is preferably composed of the material having elasticity sufficient enough to prevent the crush of brown rice and a high resistance to abrasion since the tip of paddy collides to the outer bent end of the hulling vane just in such the state that an arrow thrusts the material.

As shown in FIG. 3, the paddy entrance 4 opened at the center of the circular covering 14 is provided with a segmental flange portion 23 .along the length of the rotary shaft of the hulling varies, which serves to inhibit an entrance of paddy into a certain direction, so that paddy led into the hulling chamber is never discharged directly toward a paddy outlet 24 provided at the right upper portion of the circular casing 12 without paddy being discharged into the air pressure zone caused between the inner circumferential wall of the casing 12 and the outer bent ends of the hulling vanes. Thus, paddy introduced into the hulling chamber through the funnel 1 or the suction hose 5, runs from the inner bent end 18 along the center surface of hulling vane in such the manner'that paddy is subjected to the most reduced air resistance, i.e. in the longitudinal form with the head of paddy. Upon revolution of the hulling vanes, the zone of the outer bent end of the hulling vane falls substantially in the vacuum state and as a result, the atmospheric pressure is remarkably reduced. When paddy sliding down along the surface of the hulling vane comes in the said lower atmospheric pressure zone, the gas contained in paddy expands abruptly and paddy is rendered to the state just before the crack. Immediately thereafter, the tip of paddy collides to the outer bent end 19 of the hulling vane and as a result, the hull is split into exact halves. The thusly split paddy is further discharged into the air pressure zone caused between the outer terminals of the hulling vanes and the inner circumferential wall of the circular casing, where the hulls and brown rice are perfectly dispersed.

The mixture after the dispersion is led as shown by an arrow from the paddy outlet 24 through a flexible conduit 25 to the cyclone separation chamber 26 as shown in FIG. 6. The cyclone separation chamber 26 comprises an air outlet 27 and a hopper 28 for storing the mixture of brown rice, hulls, immature paddy, etc. The said mixture stored in the hopper 28 is exhausted from an opening 29 provided at the bottom of the hopper 28 and falls on a bearer plate 30 and, further, drops on a sieve plate 32 through a throwing plate 31. In that case, the good grains are accumulated in the first deposit 33 as shown by the ordinary lines, while the immature and broken grains fall into an intermediate deposit 34 as shown by the chain lines, and the residual hulls flow as shown by the dotted lines in the air flow from an air inlet 36 caused by the revolution of a windmill 35 and discharged outside through a path 37 and a drain pipe 38. The path 37 at its upper portion may be provided with an air inlet 39 to save the amount of air flow from the air inlet 36.

The first deposit 33 is associated with a paddy throwing elevator 40 which elevates and discharges brown rice through an elevating pipe 41 to a reservoir (not shown). The intermediate deposit 39 in its lower portion is detachably provided with a truck-type container 42. When the immature paddy and the brown rice accumulate in the container 42, they are once again subjected to the winnower through a throwing inlet 43 to carry out the supplemental separation.

In FIG. 7, the driving force of a prime mover 44 is transmitted to the rotary shaft 10 of the hulling vanes through a pulley 45, and the revolution of the rotary shaft is further transmitted to the windmill35 and the paddy elevator 40 through the pulleys 46 and 47.

According to the laboratory tests exercised by the inventor, the method according to the invention could hull about 1 ton of paddy per hour by revolving the hulling vanes at about 1,600 rpm. and the hulling yield was 99.9 percent. Further, it has been appreciated that even the immature paddy, hulling of which has been regarded as impossible by the conventional rollerand collision-type huller, may be hulled perfectly by the method and device according to the invention.

According to the present method and device, the process from the hulling to the separation of paddy is carried out by the air flow and the air pressure, and the hulling yield is extremely high, and there can be seen no crushed rice thus promoting long preservation of rice.

Moreover, the device for embodying the present method is too simple in its structure and rich in mobility, and since the operation from the suction to the separation of paddy is all carried out automatically, the difficult and complicated operations of the screen required in the conventional huller have all become useless.

Further, the rubber roller-type huller is not suitable for the combined harvester thresher which is usually operated under the intensive oscillations. On the contrary, since the device according to the invention is not adversely affected by the oscillation and does not require any complicated adjustment as is usually done in the conventional huller, it is quite effective when combined into such the combined harvester thresher.

While certain preferred embodiments of the invention have been illustrated by way of example in the drawings and particularly described, it will be understood that various modifications may be made in the methods and constructions and that the invention is no way limited to the embodiments shown.

Iclaim:

1. A method of hulling paddy comprising the steps of placing paddy into a housing which forms a hulling chamber; providing in said hulling chamber a plurality of radially arranged vanes with outwardly bent ends rotating said vanes so as to produce a decreased pressure zone along the vanes; passing the paddy radially outwardly along the vanes and thus through the lower pressure zone to thereby enable captive gas within the paddy to expand abruptly; impacting the paddy against the bent end of the vane to split the hull; and discharging the husked paddy into an air pressure zone between the bent ends of the vanes and the housing.

2. A method of hulling paddy as in claim 1 wherein passing of the paddy along the vanes is facilitated by a bend at the radially innermost end of the vane.

3. A method of hulling paddy as in claim 1 which comprises the additional step of selecting a rate of rotation and an angle of bend for the vane whereby the pressure at the radially outermost portion of the vane is less than the pressure at the radially innermost portion of the vane.

4. A method of hulling paddy as in claim 1 which comprises additional steps of removing the huskedmixture from the hulling chamber and separatingsuch mixture into its component parts of rice and hulls.

5. A device for hulling paddy supplying means and acircular hulling chamber in which numerous hulling vanes are radially arranged arounda rotary shaft, each of said hulling vanes comprising an inner bent end for guiding the paddy, a straight I body, and an outer bent end against which the paddy impacts vane. V

Claims (6)

1. A method of hulling paddy comprising the steps of placing paddy into a housing which forms a hulling chamber; providing in said hulling chamber a plurality of radially arranged vanes with outwardly bent ends rotating said vanes so as to produce a decreased pressure zone along the vanes; passing the paddy radially outwardly along the vanes and thus through the lower pressure zone to thereby enable captive gas within the paddy to expand abruptly; impacting the paddy against the bent end of the vane to split the hull; and discharging the husked paddy into an air pressure zone between the bent ends of the vanes and the housing.

2. A method of hulling paddy as in claim 1 wherein passing of the paddy along the vanes is facilitated by a bend at the radially innermost end of the vane.

3. A method of hulling paddy as in claim 1 which comprises the additional step of selecting a rate of rotation and an angle of bend for the vane whereby the pressure at the radially outermost portion of the vane is less than the pressure at the radially innermost portion of the vane.

4. A method of hulling paddy as in claim 1 which comprises additional steps of removing the husked mixture from the hulling chamber and separating such mixture into its component parts of rice and hulls.

5. A device for hulling paddy supplying means and a circular hulling chamber in which numerous hulling vanes are radially arranged around a rotary shaft, each of said hulling vanes comprising an inner bent end for guiding the paddy, a straight body, and an outer bent end against which the paddy impacts to cause splitting of the hull of said paddy.

6. The device of claim 5 in which said inner bent has a curvature of about 20* to 28*, , and the outer bent has a curvature of about 40* to 45* relative to the main body of the hulling vane.

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