An updraft rice mill with variable cross-section whitening chamber and three-variable uniform pressure sand roller

Abstract

This invention discloses a top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller. Its features include: the rice knife (17) has a front-to-back width that is narrower at the front and wider at the back; the outer diameter of the sand roller (13) gradually decreases from front to back; the front-progress angle α of the spiral groove of the sand roller (13) is smaller than the front-progress angle α1 of the rear section; the rear-progress angle β of the spiral groove of the sand roller (13) is larger than the rear-progress angle β1 of the rear section; and the pitch S of the spiral groove of the sand roller (13) is larger than the pitch S1 of the rear section. This design enables uniform pressure within the rice milling chamber, improves conveying capacity, minimizes the occurrence of "stuck" or sieve blockage, and reduces the rate of broken rice.

Description

Technical Field

[0001] This invention is a top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller. It is specifically suitable for the hulling, whitening, and fine milling of various grains such as white rice, glutinous rice, sorghum, and Job's tears. Technical Background

[0002] Rice is the staple food for more than half of the world's population, and in my country, about 60% of the population relies on rice as their main food source, making it of paramount importance for ensuring food security. Appropriate and precise processing has become the main theme of the rice milling industry, with the primary goal of increasing rice yield and reducing energy consumption. The rice milling machine is the core equipment in the rice processing industry, playing a crucial role in improving yield and reducing energy consumption. Currently, horizontal rice milling machines use two types of suction methods: top suction and bottom suction. Bottom suction is more traditional and widely used. However, top suction, with its unique technological advantages, is gradually being adopted by the market, resulting in a market structure where both suction methods coexist. The working principle of a horizontal rice milling machine: Brown rice enters the whitening chamber through the feed hopper via a magnetic separator and flow regulating mechanism. It is then fed to the abrasive roller by a spiral head and spirals forward along the roller's surface. The sharp abrasive grains on the rotating abrasive roller at a constant linear speed grind away the bran layer of the brown rice, causing friction between rice grains and between the grains and the rice sieve, thus opening and whitening the rice. The whitening chamber is the key component of the rice milling machine, mainly composed of rollers, a rice sieve, rice knives, and a sieve support. The rice sieve is installed around the rollers, and the gap between it and the rollers is the whitening gap. When the rollers rotate, the brown rice is whitened by mechanical force within the whitening chamber, and the milled bran is discharged through the sieve's openings. Therefore, research on the core technical parameters of the whitening chamber plays a crucial role in energy saving, reducing consumption, improving rice yield, and increasing whitening efficiency in rice milling machines.

[0003] In the feeding section, the rice grains lose their axial thrust after leaving the conveyor head. Although the spiral groove of the milling roller can compensate for some of the thrust, the change in the pitch of the spiral groove between the conveyor head and the milling roller will inevitably lead to a reordering of the rice grain flow pattern, resulting in a sharp increase in rice grain density and a rapid increase in milling pressure. Therefore, it is necessary to increase the driving force.

[0004] In the whitening stage, the radial gap between the milling roller and the rice sieve needs to be reduced to increase the tumbling of rice grains and the local rice grain density, thereby increasing the whitening pressure.

[0005] In the discharge section, the rice grains should have already achieved the whitening effect. The pressure in the whitening chamber should be eased to ensure that the rice grains can be discharged smoothly.

[0006] The abrasive roller is one of the most crucial components of a rice milling machine, symbolizing its "heart." Determining the roller's dimensions and shape, among other important technical parameters, plays a vital role in energy conservation, improving rice yield, and increasing milling efficiency. Traditionally, the abrasive rollers in suction rice milling machines have the following drawbacks: Figure 1 As shown

[0007] 1. The outer diameter ΦD is usually the same size from front to back and does not change.

[0008] 2. The propulsion angle α and propulsion angle β of the spiral groove are usually the same size from front to back and do not change.

[0009] 3. The pitch S of the spiral groove is usually the same from front to back and does not change.

[0010] This can lead to uneven pressure in the rice milling chamber and inconsistent wear between the front and rear sections. At the same time, since the screw pitch does not change, the conveying capacity of the sand roller cannot be guaranteed, which can easily cause insufficient conveying force in the front section, resulting in rice accumulation and "stuck mill".

[0011] The rice cutter is also one of the core components of a rice milling machine, such as... Figure 2 As shown, traditional rice knives are distributed vertically along the length of the whitening chamber and have a consistent shape, resulting in a basically uniform cross-sectional shape of the whitening chamber. This does not actually conform to the movement pattern and pressure distribution of rice grains within the whitening chamber and can only play a role in increasing pressure, which is one of the main reasons why rice milling machines produce broken rice. Summary of the Invention

[0012] The purpose of this invention is to address the shortcomings of existing rice milling machines by providing a top-suction rice milling machine with a variable cross-section whitening chamber. This can minimize the occurrence of "stuck" and screen blockage, while reducing the broken rice rate.

[0013] The technical solution of the present invention is implemented as follows: it includes a frame (16), on which a rice milling device (2), a suction device (1), a feeding device (3), and a drive motor (4) are fixed. An upper suction hood (5) is fixed to the top of the suction device (1), a selenium collecting hopper (6) is fixed to the bottom of the suction device (1), and a selenium discharge device (15) is fixed to the bottom of the selenium collecting hopper (6). A sand roller (13) is installed inside the rice milling device (2), and a rice knife (17) is fixed to the sieve frame (18) of the rice milling device (2). The rice knife (17) is characterized in that: the rice knife (17) The width of the front and back of the 17) is narrower at the front and wider at the back. The outer diameter of the sand roller (13) of the rice milling device gradually decreases from front to back, ensuring that the cavity of the front section of the whitening chamber is reduced, thereby increasing the pressure at the front of the sand roller and making the pressure and wear of the sand roller consistent. The front angle α of the spiral groove of the sand roller (13) should be smaller than the front angle α1 of the rear section of the sand roller (13), and the rear angle β of the spiral groove of the sand roller (13) should be larger than the rear angle β1 of the sand roller (13). The pitch S of the spiral groove of the sand roller (13) should be larger than the pitch S1 of the rear section of the sand roller. This can improve the conveying capacity of the sand roller and avoid "stuck" due to insufficient conveying force at the front.

[0014] A preferred embodiment of the present invention is that the width difference of the rice knife (17) is 10-12 mm. The rice knife (17) is fixed on the top and bottom and left and right sides of the sieve frame (18). The angle α is 22.5-35 degrees, the angle β is 57-69.5 degrees, and the pitch S is 70-120 mm.

[0015] A better technical solution of the present invention is as follows: the selenium collecting hopper (6) is provided with an upper air inlet (7) and a lower air inlet (8), and an upper air inlet regulating plate (9) and a lower air inlet regulating plate (10) are respectively provided at the upper air inlet (7) and the lower air inlet (8). An upper baffle plate (11) and a lower baffle plate (12) are respectively provided on the inner side of the selenium collecting hopper (6) of the upper air inlet (7) and the lower air inlet (8). An upper air inlet guide plate (19) and a lower air inlet guide plate (14) are respectively provided on the inner side of the selenium collecting hopper (6) of the upper air inlet (7) and the lower air inlet (8).

[0016] This invention primarily utilizes the characteristics and functions of the rice cutter to determine the appropriate role for different sections within the effective length of the whitening chamber. By altering the shape of the rice cutter, the cross-sectional shape of the whitening chamber is changed, thereby achieving different rice grain densities and whitening pressures at different stages. The invention also optimizes and precisely designs the core component of the rice milling machine, the "sand roller," ensuring that its three core functions—whitening, tumbling, and conveying—are fully utilized at different stages within the whitening chamber. Through rational optimization and combination, it achieves appropriate and precise processing for different rice varieties, thereby increasing yield and reducing energy consumption. Simultaneously, improvements are made to the bran collection hopper to prevent clogging of the bran suction pipe and screen, ensuring complete separation of bran and rice residue. The separate collection and utilization of bran and rice residue increases their added value. Adding baffles and guide plates allows the incoming air to continuously agitate the bran and rice in the bran-rice separation hopper, ensuring complete separation. This also allows for uniform pressure in the rice milling chamber, further improving milling precision. Simultaneously, it can reduce the rice temperature in the milling chamber, significantly increasing the whiteness of the rice grain surface and reducing energy consumption. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an existing sanding roller.

[0018] Figure 2 This is a schematic diagram of the structure of an existing rice knife.

[0019] Figure 3 This is a schematic diagram of the structure of the present invention;

[0020] Figure 4 This is a schematic diagram of the structure of the rice milling device of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of the rice knife of the present invention;

[0022] Figure 6 for Figure 5 Side view;

[0023] Figure 7 for Figure 4 Sectional view along axis AA;

[0024] Figure 8 for Figure 4 BB-direction sectional view;

[0025] Figure 9 for Figure 4 CC-direction sectional view;

[0026] Figure 10 for Figure 4 DD section view;

[0027] Figure 11 This is a schematic diagram of the structure of the sanding roller of the present invention;

[0028] Figure 12 This is a structural diagram of the selenium collection chamber of the present invention;

[0029] Figure 13 for Figure 12 Sectional view along axis AA;

[0030] Figure 14 This is a schematic diagram illustrating the working principle of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings:

[0032] like Figure 3 , Figure 4 As shown, the present invention includes a frame (16), on which a rice milling device (2), a suction device (1), a feeding device (3), and a drive motor (4) are fixed. An upper suction hood (5) is fixed to the top of the suction device (1), a selenium collecting hopper (6) is fixed to the bottom of the suction device (1), and a selenium discharge device (15) is fixed to the bottom of the selenium collecting hopper (6). A sand roller (13) is installed inside the rice milling device (2), and a rice knife (17) is fixed to the sieve frame (18) of the rice milling device (2). The invention is characterized in that: the front of the rice knife (17)... The width is narrower at the front and wider at the back. The outer diameter of the sand roller (13) of the rice milling device gradually decreases from front to back, ensuring that the cavity at the front of the whitening chamber is reduced, thereby increasing the pressure at the front of the sand roller and making the pressure and wear of the sand roller consistent. The front angle α of the spiral groove of the sand roller (13) should be smaller than the front angle α1 of the rear section of the sand roller (13), and the rear angle β of the spiral groove of the sand roller (13) should be larger than the rear angle β1 of the sand roller (13). The pitch S of the spiral groove of the sand roller (13) should be larger than the pitch S1 of the rear section of the sand roller. This can improve the conveying capacity of the sand roller and avoid "stalling" due to insufficient conveying force at the front. Figure 5 , Figure 6 As shown, the width difference of the rice knife (17) ranges from 10 to 12 mm. The rice knife (17) is fixed on the top, bottom, left, and right sides of the sieve frame (18). The angle α is 22.5-35 degrees, the angle β is 57-69.5 degrees, and the pitch S is 70-120 mm.

[0033] like Figure 4 and Figure 7 -- Figure 10 As shown in the diagram of the core structure of the variable cross-section whitening chamber, it can be seen that after the brown rice passes through the conveyor head and enters the milling roller, it is actually divided into three different stages in the effective whitening length direction: the starting section (also known as the feeding section), the whitening section, and the ending section (also known as the discharge section). The whitening effect is different in each of the three stages.

[0034] In the feeding section, the rice grains lose their axial thrust after leaving the conveyor head. Although the spiral groove of the milling roller can compensate for some of the thrust, the change in the pitch of the spiral groove between the conveyor head and the milling roller will inevitably lead to a reordering of the rice grain flow pattern, resulting in a sharp increase in rice grain density and a rapid increase in milling pressure.

[0035] In the whitening stage, the rice knife reduces the radial gap between the milling roller and the rice sieve by changing its cross-sectional shape, thereby increasing the tumbling of rice grains and the local rice grain density, and thus increasing the whitening pressure.

[0036] In the discharge section, the rice grains should have already achieved the whitening effect. The pressure in the whitening chamber should be eased to ensure that the rice grains can be discharged smoothly.

[0037] like Figure 13 As shown, the selenium collecting hopper (6) is provided with an upper air inlet (7) and a lower air inlet (8). An upper air inlet regulating plate (9) and a lower air inlet regulating plate (10) are respectively provided at the upper air inlet (7) and the lower air inlet (8). An upper baffle plate (11) and a lower baffle plate (12) are respectively provided on the inner side of the selenium collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8). An upper air inlet guide plate (19) and a lower air inlet guide plate (14) are respectively provided on the inner side of the selenium collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8). Figure 7 As shown, rice bran and rice bran powder enter the discharge chamber (hopper) in a mixed state. Through the upper separation zone, 70% of the rice bran powder is separated from the rice bran by the blowing action of the incoming air through the air inlet. The rice bran powder is pushed to the negative pressure suction zone. The rice bran and the remaining rice bran powder mixture move downward to the lower separation zone due to their specific gravity. Through the air inlet, the remaining rice bran powder is further and thoroughly separated from the rice bran by the blowing action of the incoming air. The remaining rice bran powder is pushed to the upper separation zone and continues to be pushed to the negative pressure suction zone to the bran powder collection system.

Claims

1. A rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller, comprising a frame (16), on which a rice milling device (2), a suction device (1), a feeding device (3) and a drive motor (4) are fixed; an upper suction hood (5) is fixed to the top of the suction device (1); a collection hopper (6) is fixed to the bottom of the suction device (1); a discharge device (15) is fixed to the bottom of the collection hopper (6); a sand roller (13) is installed inside the rice milling device (2); and a rice knife (17) is fixed to the sieve frame (18) of the rice milling device (2), characterized in that: The width of the rice knife (17) is narrower at the front and wider at the back. The outer diameter of the sand roller (13) of the rice milling device gradually decreases from front to back. The front angle α of the spiral groove of the sand roller (13) is smaller than the front angle α1 of the rear section of the sand roller (13). The rear angle β of the spiral groove of the sand roller (13) is larger than the rear angle β1 of the sand roller (13). The pitch S of the spiral groove of the sand roller (13) is larger than the pitch S1 of the rear section of the sand roller.

2. The top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller as described in claim 1, characterized in that: The width difference of the rice knife (17) is 10-12 mm.

3. A top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller as described in claim 1 or 2, characterized in that: The rice knife (17) is fixed on the top, bottom and left and right sides of the sieve frame (18).

4. A top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller as described in claim 1, characterized in that: The aforementioned advance angle α is 22.5-35 degrees, the advance clearance angle β is 57-69.5 degrees, and the pitch S is 70-120 mm.

5. A top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller as described in claim 1, characterized in that: The collection hopper (6) is provided with an upper air inlet (7) and a lower air inlet (8). The upper air inlet (7) and the lower air inlet (8) are respectively provided with an upper air inlet regulating plate (9) and a lower air inlet regulating plate (10). The inner side of the collection hopper (6) of the upper air inlet (7) and the lower air inlet (8) is respectively provided with an upper baffle plate (11) and a lower baffle plate (12).

6. A top-suction rice milling machine with a variable cross-section whitening chamber and a three-variable uniform pressure sand roller according to claim 5, characterized in that: The upper air inlet (7) and the lower air inlet (8) are respectively provided with an upper air inlet guide plate (19) and a lower air inlet guide plate (14) on the inner side of the collection hopper (6).

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