Downward air suction rice husking machine with variable cross-section whitening chamber and three-variable uniform pressure emery roll

Abstract

The utility model discloses a lower air suction rice husking machine with a variable cross-section whitening chamber and a three-variable uniform pressure emery roll, which is characterized in that the front-back width of a huller blade (17) is narrow at the front and wide at the rear, the outer diameter of the emery roll (13) is gradually reduced from front to back, the front propelling angle alpha of the front section of a spiral groove of the emery roll (13) is smaller than the front propelling angle alpha 1 of the rear section of the emery roll (13), and the front propelling angle alpha 1 of the front section of the spiral groove of the emery roll (13) is smaller than the front propelling angle alpha 2 of the rear section of the emery roll (13). The propulsion relief angle beta of the front section of the spiral groove of the emery roll (13) is greater than the propulsion relief angle beta 1 of the rear section of the emery roll (13); the screw pitch S of the front section of the spiral groove of the emery roll (13) is larger than the screw pitch S1 of the rear section of the emery roll. The pressure in the rice milling chamber can be uniform, the conveying capacity is improved, the phenomena of blockage and screen blockage are avoided to the maximum extent, and meanwhile the broken rice rate is reduced.

Description

Technical Field

[0001] The utility model relates to a down-draft rice milling machine with a variable cross-section rice whitening chamber and a triple-variable equal-pressure abrasive roll, and is specifically applicable to grain processing equipment for roughing, whitening, and fine milling of various grain cereals such as white rice, glutinous rice, sorghum, and coix seed. Technical Background

[0002] The rice milling machine is the core equipment in the rice processing industry and plays a crucial role in improving the yield rate and reducing energy consumption. At present, the air suction methods of horizontal rice milling machines are divided into two forms: up-draft and down-draft. Relatively traditional and widely used air suction methods, the down-draft is more common. The working principle of a horizontal rice milling machine: Paddy rice enters the rice whitening chamber through a magnetic separation device from the feed hopper and passes through a flow regulating mechanism, and then is sent to the abrasive roll by a spiral head and advances spirally along the surface of the abrasive roll. The sharp abrasive grains on the surface of the emery abrasive roll rotating at a certain linear speed mill the cortex of the paddy rice, and make the rice grains rub against each other and against the rice sieve, so as to rough and whiten the rice. The rice whitening chamber is the key core component of the rice milling machine, which is mainly composed of parts such as a milling roll, a rice sieve, a rice knife, and a sieve support. The rice sieve is installed outside the milling roll, and the gap between the rice sieve and the milling roll is the rice whitening gap. When the milling roll rotates, the paddy rice is whitened under the action of mechanical force in the rice whitening chamber, and the milled rice bran is discharged from the rice sieve holes of the rice sieve. Therefore, the research on the core technical parameters of the rice whitening chamber plays a crucial role in the energy conservation and consumption reduction of the rice milling machine, improving the rice yield rate and the rice whitening efficiency.

[0003] In the feeding section, since the rice grains lose the axial thrust after leaving the conveying head, although the spiral groove of the milling roll can make up for a certain thrust, due to the change of the pitch of the spiral groove between the conveying head and the milling roll, the reordering of the flow pattern of the rice grains will inevitably be formed, resulting in a sharp increase in the density of the rice grains and a rapid increase in the rice whitening pressure. Therefore, it is necessary to increase the driving force.

[0004] In the rice whitening section, it is necessary to reduce the radial clearance between the milling roll and the rice sieve to increase the tumbling of the rice grains and the local density of the rice grains, thereby increasing the rice whitening pressure.

[0005] In the discharging section, the rice grains should normally have reached the rice whitening effect, and the pressure in the rice whitening chamber should be relieved to ensure that the rice grains can be discharged smoothly.

[0006] The abrasive roll is one of the most core components of the rice milling machine and symbolizes the "heart" of the rice milling machine. The determination of important technical parameters such as the outer dimension and shape of the abrasive roll plays a crucial role in the energy conservation and consumption reduction of the rice milling machine, improving the rice yield rate and the rice whitening efficiency. The abrasive roll of the traditional down-draft rice milling machine has the following defects: as Figure 1 shown

[0007] 1. The outer diameter ΦD is usually the same from front to back without change;

[0008] 2. The leading rake angle ɑ and trailing rake angle β of the spiral groove are generally the same in size from front to back without change.

[0009] 3. The pitch S of the spiral groove is also generally the same in size from front to back without change.

[0010] This will result in uneven pressure in the front and rear of the rice milling chamber and inconsistent wear in the front and rear sections. At the same time, due to the unchanged pitch, the conveying capacity of the sand roller cannot be guaranteed, and it is easy to have insufficient conveying force in the front section, causing the rice material to accumulate and resulting in "jamming".

[0011] The rice knife is also one of the core components of the rice milling machine. As Figure 2 shown, the traditional rice knife is distributed up and down in the length direction of the whitening chamber and has a consistent shape, resulting in a basically consistent cross-sectional shape of the whitening chamber, which actually does not conform to the movement law and pressure distribution of rice grains in the whitening chamber, and can only play a role in increasing pressure, which is one of the main reasons for broken rice in the rice milling machine. Summary of the Invention

[0012] The purpose of the present utility model is to address the defects of existing rice milling machines and provide a down-draft rice milling machine with a variable cross-section whitening chamber, which can maximize the avoidance of "jamming" and screen clogging phenomena, and at the same time reduce the broken rice rate.

[0013] The technical solution of the present utility model is realized as follows: It includes a frame (16), on which a rice milling device (2), an air suction device (1), a feeding device (3) and a driving motor (4) are fixed. An upper air regulating plate (5) is fixed on the top of the air suction device (1), a selenium collecting hopper (6) is fixed at the bottom of the air suction device (1), a selenium discharging device (15) is fixed at the bottom of the selenium collecting hopper (6), a sand roller (13) is installed in the rice milling device (2), and a rice knife (17) is fixed on the screen frame (18) of the rice milling device (2). Its characteristics are: the front and rear widths of the rice knife (17) are narrow in the front and wide in the rear, the outer diameter of the sand roller (13) of the rice milling device gradually decreases from front to back, ensuring that the cavity in the front section of the whitening chamber decreases, thereby increasing the pressure in the front part of the sand roller and making the pressure and wear consistent in the front and back of the sand roller; the leading rake angle ɑ of the front section of the spiral groove of the sand roller (13) is smaller than the leading rake angle ɑ1 of the rear section of the sand roller (13), and the trailing rake angle β of the front section of the spiral groove of the sand roller (13) is larger than the trailing rake angle β1 of the rear section of the sand roller (13); the pitch S of the front section of the spiral groove of the sand roller (13) is 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 "jamming" caused by insufficient conveying force in the front section.

[0014] A preferred technical solution of the present utility model is that the width difference range of the rice knife (17) is 10 - 12 mm. The rice knife (17) is fixed above, below, left and right of the sieve frame (18). The angle a 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 utility model is that the selenium - collecting hopper (6) is provided with an upper air inlet (7) and a lower air inlet (8). Upper air - inlet air - regulating plates (9) and lower air - inlet air - regulating plates (10) are respectively provided at the upper air inlet (7) and the lower air inlet (8). Upper grain - blocking plates (11) and lower grain - blocking plates (12) are respectively provided on the inner sides of the selenium - collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8). Upper air - inlet flow - guiding plates (19) and lower air - inlet flow - guiding plates (14) are respectively provided on the inner sides of the selenium - collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8).

[0016] The present utility model mainly, according to the characteristics and functions of the rice knife, within the effective length range of the whitening chamber, the functions that should be exerted in different intervals, changes the shape of the rice knife to change the shape of the cross - section of the whitening chamber, so as to achieve different rice grain densities and whitening pressures in the whitening chamber at different stages. The present utility model also optimizes and precisely designs the core component "sand roller" of the rice mill, so that the three core rice - milling functions of the sand roller, namely "whitening, tumbling, and conveying", fully play their roles at different stages in the whitening chamber. Through reasonable optimization and combination, the purpose of moderate processing and precise processing for different rice varieties is achieved, thereby improving the output rate and reducing energy consumption. At the same time, the selenium - collecting hopper is improved to prevent the bran - suction pipeline and the sieve from being blocked by bran, and to completely separate the bran and the grain. The bran and the grain are respectively collected and utilized, improving the added value of the bran and the grain. Adding grain - blocking plates and flow - guiding plates can make the incoming air continuously stir the bran and the grain in the bran - grain separation hopper, making their separation complete, making the rice - milling chamber evenly press the rice, further improving the rice - milling precision. At the same time, it can significantly reduce the rice temperature in the rice - milling chamber, improve the whiteness of the rice grain surface, and reduce energy consumption. Brief Description of the Drawings

[0017] Figure 1 ... is a schematic structural diagram of a sand roller of the prior art;

[0018] Figure 2 ... is a schematic structural diagram of a rice knife of the prior art;

[0019] Figure 3 ... is a schematic structural diagram of the present utility model;

[0020] Figure 4 ... is a schematic structural diagram of the rice - milling device of the present utility model;

[0021] Figure 5 is a schematic structural diagram of the rice knife of the present utility model;

[0022] Figure 6 is the side view of Figure 5 ;

[0023] Figure 7 is the sectional view taken along line A-A of Figure 4 ;

[0024] Figure 8 is the sectional view taken along line B-B of Figure 4 ;

[0025] Figure 9 is the sectional view taken along line C-C of Figure 4 ;

[0026] Figure 10 is the sectional view taken along line D-D of Figure 4 ;

[0027] Figure 11 . is the schematic structural diagram of the sand roller of the present utility model;

[0028] Figure 12 . is the structural diagram of the selenium collecting hopper of the present utility model;

[0029] Figure 13 is the sectional view taken along line A-A of Figure 12 ;

[0030] Figure 14 . is the working principle diagram of the present utility model; Specific embodiments

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

[0032] As shown in Figure 3 , Figure 4As shown in the figure, the utility model includes a frame (16), on which a rice milling device (2), a suction device (1), a feeding device (3) and a driving motor (4) are fixed. An upper air deflector (5) is fixed on the top of the suction device (1), and a selenium collecting hopper (6) is fixed at the bottom of the suction device (1). A selenium discharging device (15) is fixed at the bottom of the selenium collecting hopper (6). A sand roller (13) is installed in the rice milling device (2), and a rice knife (17) is fixed on the sieve frame (18) of the rice milling device (2). The front and rear width of the rice knife (17) is narrow at the front and wide at the rear. The outer diameter of the sand roller (13) of the rice milling device gradually decreases from front to back, ensuring that the cavity volume in the front section of the whitening chamber decreases, thereby increasing the pressure at the front of the sand roller and making the pressure and wear consistent before and after the sand roller. The advancing front angle ɑ of the spiral groove in the front section of the sand roller (13) is smaller than the advancing front angle ɑ1 of the rear section of the sand roller (13), and the advancing rear angle β of the spiral groove in the front section of the sand roller (13) is larger than the advancing rear angle β1 of the rear section of the sand roller (13). The pitch S of the spiral groove in the front section of the sand roller (13) is 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 "jamming" caused by insufficient conveying force in the front section. As Figure 5 , Figure 6 shown, the width difference range of the rice knife (17) is 10 - 12 mm. The rice knife (17) is fixed on the upper, lower, left and right of the sieve frame (18). The angle ɑ is 22.5 - 35 degrees, the angle β is 57 - 69.5 degrees, and the pitch S is 70 - 120 mm.

[0033] As Figure 4 and Figure 7 -- Figure 10 shown, from the core structure diagram of the variable cross-section whitening chamber, it can be seen that after the paddy rice passes through the conveying head and enters the grinding roller, in the effective whitening length direction, it is actually divided into three different stages: the starting stage (also called the feeding stage), the whitening stage, and the ending stage (also called the discharging stage). The whitening effects in the three stages are different.

[0034] In the feeding stage, since the rice grains lose the axial thrust after leaving the conveying head, although the spiral groove of the grinding roller can make up for a certain thrust, due to the change in the pitch of the conveying head and the spiral groove of the grinding roller, the reordering of the flow pattern of the rice grains will inevitably occur, resulting in a sharp increase in the density of the rice grains and a rapid increase in the whitening pressure.

[0035] In the whitening stage, the function of the rice knife is to change the cross-sectional shape, thereby reducing the radial clearance between the grinding roller and the rice sieve, increasing the tumbling of the rice grains and the local density of the rice grains, and thus increasing the whitening pressure.

[0036] In the discharging stage, the rice grains should normally have achieved the whitening effect, and the pressure in the whitening chamber should be relieved to ensure the smooth discharge of the rice grains.

[0037] As Figure 13As shown in the figure, the selenium collecting hopper (6) is provided with an upper air inlet (7) and a lower air inlet (8). An upper air inlet air regulating plate (9) and a lower air inlet air regulating plate (10) are respectively arranged at the upper air inlet (7) and the lower air inlet (8). An upper rice chaff baffle plate (11) and a lower rice chaff baffle plate (12) are respectively arranged on the inner sides of the selenium collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8). An upper air inlet flow guiding plate (19) and a lower air inlet flow guiding plate (14) are respectively arranged on the inner sides of the selenium collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8). As Figure 7 shown in the figure, rice chaff and bran powder enter the rice chaff discharging chamber (hopper) in a mixed state. 70% of the bran powder is separated from the rice chaff under the blowing action of the supplementary air through the upper separation area and the supplementary air inlet, and the bran powder is pushed towards the negative pressure bran suction area. The mixture of rice chaff and the remaining bran powder moves downward to the lower separation area due to the specific gravity relationship. Under the blowing action of the supplementary air through the supplementary air inlet, the residual bran powder is further and thoroughly separated from the rice chaff, and the residual bran powder is pushed towards the upper separation area and continues to be pushed towards the negative pressure bran suction area 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), a rice milling device (2), a suction device (1), a feeding device (3) and a driving motor (4) are fixed on the frame (16), an upper air regulating plate (5) is fixed on the top of the suction device (1), a selenium collecting hopper (6) is fixed on the bottom of the suction device (1), a selenium discharge device (15) is fixed on the bottom of the selenium collecting hopper (6), a sand roller (13) is installed in the rice milling device (2), and a rice knife (17) is fixed on the screen frame (18) of the rice milling device (2), characterized in that: The front and rear widths of the rice knife (17) are narrow at the front and wide at the rear. The outer diameter of the sand roller (13) of the rice milling device gradually decreases from front to back. The front angle ɑ of the front section of the spiral groove of the sand roller (13) is smaller than the front angle ɑ1 of the rear section of the sand roller (13). The rear angle β of the front section of the spiral groove of the sand roller (13) is larger than the rear angle β1 of the rear section of the sand roller (13). The pitch S of the front section of the spiral groove of the sand roller (13) is larger than the pitch S1 of the rear section of the sand roller.

2. A down-suction rice milling machine with a variable cross-section whitening chamber and three-variable uniform pressure sand rollers according to claim 1, characterized in that: The width difference of the rice knife (17) is in the range of 10-12 mm.

3. A down-suction rice milling machine with a variable cross-section whitening chamber and three-variable uniform pressure sand rollers according to claim 1 or 2, characterized in that: The rice cutter (17) is fixed on the upper and lower sides and the left and right sides of the screen frame (18).

4. The down-suction rice milling machine with a variable cross-section whitening chamber and three-variable uniform pressure sand rollers according to claim 1, characterized in that: The propulsion front angle a is 22.5-35 degrees, the β angle is 57-69.5 degrees, and the pitch S is 70-120 mm.

5. The down-suction rice whitening machine with a variable cross-section whitening chamber and three-variable uniform pressure sand rollers according to claim 1, characterized in that: The selenium collecting hopper (6) is provided with an upper air inlet (7) and a lower air inlet (8), and 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), and the inner sides of the selenium collecting hopper (6) at the upper air inlet (7) and the lower air inlet (8) are respectively provided with an upper baffle plate (11) and a lower baffle plate (12).

6. A down-suction rice whitening machine with a variable cross-section whitening chamber and three-variable uniform pressure sand rollers according to claim 5, characterized in that: 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).

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