High-precision grinding device for flour processing and processing method thereof

Abstract

The invention relates to the technical field of grinding devices, in particular to a high-precision grinding device for flour processing and a processing method thereof.The high-precision grinding device comprises a machine body, a grinding roller pair and a screen, a main flow channel extending in the vertical direction is formed in the machine body, the grinding roller pair is horizontally arranged in the middle of the main flow channel, and the screen is arranged below the grinding roller pair; a circulating flow guide channel is arranged in the machine body, substandard materials are guided by airflow to return to a main flow channel along the circulating flow guide channel, the screening net is in an arc shape, the material pushing roller is arranged on the inner ring of the screening net, the circulating flow guide channel comprises a flow dividing channel, and the flow dividing channel is communicated with the material pushing roller. The invention aims to solve the problems of huge equipment size, complex operation and high energy consumption due to the fact that a traditional grinding device generally adopts an up-and-down laminated grinding roller structure.

Description

Technical Field

[0001] The present invention relates to the technical field of grinding devices, and particularly to a high-precision grinding device for flour processing and its processing method. Background Art

[0002] The grinding device is an essential device for flour processing. The material enters from the feed hopper at the upper part of the machine body and is put into the gap between the two grinding rolls. After being squeezed by the rotating grinding rolls, the material falls into the accumulator hopper and then flows out. The crushed material is sieved to extract flour. The grinding device evenly transports the processed material from the feed hopper equipped with a vibrating feeder to the grinding area. The double grinding rolls forged from high-precision alloy steel work together, and the material particles are refined by the dual actions of shearing and extrusion. During the grinding process, the intelligent control system monitors the material state in real time, and dynamically adjusts the distance between the grinding rolls through the servo drive mechanism to ensure that the grinding pressure and temperature are always within the ideal range. The crushed material is separated into refined flour by the built-in vibrating screen, and the entire processing process realizes full-automatic control, and the grinding parameters are optimized through intelligent algorithms.

[0003] After the material is ground by the grinding rolls, there are usually materials that do not meet the grinding standards and need to be ground again. Traditional grinding devices usually adopt an upper and lower stacked grinding roll structure. After the material is initially ground by the upper grinding roll, it is sorted by particle size through a sieve. The fine powder that meets the requirements is directly discharged, and the unqualified coarse particles fall into the lower grinding roll for secondary grinding. Although this design realizes the grinding of materials to meet the requirements, there are significant defects: on the one hand, multiple sets of grinding rolls need to be configured, resulting in a large volume of the equipment; on the other hand, the multi-layer transmission structure makes the equipment debugging and maintenance costs relatively high, and there are problems such as complex operation and high energy consumption in actual applications. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-precision grinding device for flour processing and its processing method to solve the problems of large equipment volume, complex operation, and high energy consumption existing in traditional grinding devices that usually adopt an upper and lower stacked grinding roll structure.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A high-precision grinding device for flour processing includes a machine body, a pair of grinding rolls, and a sieve. A main flow channel extending in the vertical direction is provided inside the machine body. The pair of grinding rolls is horizontally arranged in the middle of the main flow channel. The sieve is arranged below the pair of grinding rolls. A circulating diversion channel is provided inside the machine body, and the unqualified material returns to the main flow channel along the circulating diversion channel through air flow guidance.

[0007] Preferably, it further includes a pushing roll. The sieve is arc-shaped, and the pushing roll is arranged inside the inner circle of the sieve.

[0008] Preferably, the circulating diversion channel includes a diversion channel. The pusher roller is used to push the non-compliant materials into the diversion channel, and the sieve is connected to the aggregate groove through the diversion channel.

[0009] Preferably, a blower is provided at the bottom of the aggregate groove. The blower is used to suspend and convey the materials in the aggregate groove upward.

[0010] Preferably, the circulating diversion channel further includes an ascending channel and a return slope. The ascending channel is located directly above the aggregate groove, and the return slope connects the ascending channel and the main channel.

[0011] Preferably, a diversion top wall is provided inside the machine body. The diversion top wall is located directly above the ascending channel and is used to guide the materials suspended in the ascending channel to both sides.

[0012] A method for flour processing uses the grinding device, and the specific steps are as follows:

[0013] A. Put the materials with a moisture content of 12-14% into the main channel;

[0014] B. The grinding rollers grind the materials, and the ground materials fall onto the pusher roller;

[0015] C. The pusher roller pushes the materials onto the surface of the sieve. The fine powder passing through the sieve directly enters the discharge, and the coarse grains not passing through the sieve are pushed by the pusher roller into the diversion channel and return to the main channel along the circulating diversion channel through air flow guidance.

[0016] Preferably, in step C, the coarse grains in the diversion channel slide into the aggregate groove, and the blower forms a vertically upward air flow to suspend and convey the coarse grains in the aggregate groove upward.

[0017] Preferably, it further includes D. The ascending coarse grains hit the diversion top wall and are guided to the return slope, and the coarse grains re-enter the main channel through the slope.

[0018] Preferably, the blower frequency is 30-50 Hz, and the wind speed is 5-15 m / s. When the material height in the aggregate groove reaches the set value, the wind speed is increased to accelerate the conveying.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] Through the single-stage grinding roller circulating grinding system, double breakthroughs in reducing the equipment volume and the operation complexity are achieved. Through air flow guidance and mechanical diversion, multiple cycles of grinding of materials are realized in the single-stage grinding roller area, replacing the traditional multi-layer grinding roller structure, greatly saving space. The dynamic air flow guides the non-compliant materials for circulating grinding to make the flour quality meet the standards. The overall solution optimizes the space utilization rate and economy of industrial production while ensuring the flour quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural sectional view of the present invention;

[0022] Figure 2 It is a schematic diagram of the cross-sectional structure of the body of the present invention.

[0023] In the figure: 1, body; 2, main flow channel; 3, pair of grinding rolls; 4, feeding roll; 5, screen; 6, diversion channel; 7, aggregate groove; 8, fan; 9, rising channel; 10, diversion top wall; 11, return slope; 12, diversion block; 13, feeding port; 14, discharging port. DETAILED DESCRIPTION OF THE INVENTION

[0024] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0025] Please refer to Figures 1 to 2 , the present invention provides a technical solution.

[0026] A high-precision grinding device for flour processing, comprising a body 1, a feeding port 13, a pair of grinding rolls 3, a feeding roll 4, and a screen 5, characterized in that: a main flow channel 2 extending in the vertical direction is provided inside the body 1, the pair of grinding rolls 3 is horizontally arranged in the middle of the main flow channel 2, the screen 5 is arranged below the pair of grinding rolls 3, a circulating diversion channel is provided inside the body 1, and the unqualified materials are guided by air flow to return to the main flow channel 2 along the circulating diversion channel.

[0027] The feeding port 13 is arranged at the top end of the main flow channel 2, the rotation axis of the pair of grinding rolls 3 is perpendicular to the extension direction of the main flow channel 2, the screen 5 is arc-shaped, a discharging port 14 is connected below the screen 5, the feeding roll 4 is arranged inside the screen 5, the rotation direction of the feeding roll 4 is parallel to the surface of the screen 5, and the materials are pushed along the screen surface by the blades, which can avoid the accumulation of fine powder.

[0028] The inner wall of the main flow channel 2 is polished with food-grade stainless steel, and the roughness Ra ≤ 0.8 μm.

[0029] The pair of grinding rolls 3 is independently driven by two motors, the feeding roll 4 is driven by a reduction motor through a chain, and the power source is installed at the bottom of the body 1.

[0030] A diversion channel 6 is arranged inside the machine body 1, and the pushing roller 4 is used to push the substandard materials into the diversion channel 6. The screen 5 is connected to the aggregate groove 7 through the diversion channel 6. The diversion channel 6 is located in the rotation direction of the pushing roller 4. An electromagnetic vibrator is installed on the outer wall of the diversion channel 6 with a frequency of 50-100Hz and an amplitude of 0.5-2mm. It automatically starts for 5 minutes every 30 minutes to prevent the diversion channel 6 from being blocked. An ultrasonic level meter is installed on the top of the aggregate groove 7 to monitor the material height in real time and control the upstream feeding speed in linkage.

[0031] The diversion channel 6 is located in the rotation direction of the push roller 4. The mechanical thrust generated by the rotation of the push roller 4 can be used to automatically guide the material on the surface of the screen 5 to the diversion channel 6. This design effectively avoids the accumulation of material on the surface of the screen 5, significantly reduces the risk of screen hole blockage, and ensures the continuous and stable operation of the grinding system.

[0032] The gap between the screen 5 and the push roller 4 is set to 1-3mm. The screen 5 is adjusted by an adjustable bracket to achieve precise positioning. The adjustment bracket is an adjustable mechanical structure, such as a combination of a ball screw and a guide rail system, which is installed between the inner wall of the body 1 and the screen 5. The translational fine-tuning of the screen 5 is achieved by adjusting the degree of freedom to ensure that the gap between it and the push roller 4 is accurately controlled within the range of 1-3mm. Non-contact pushing avoids mechanical friction from damaging the screen 5 and extends its service life.

[0033] An ascending channel 9 is provided inside the machine body 1, and the ascending channel 9 is located directly above the aggregate groove 7, and the upper opening size of the aggregate groove 7 is smaller than the lower opening size of the ascending channel 9. The larger lower opening of the ascending channel 9 allows more materials to pass quickly, which can prevent the materials from being blocked when rising.

[0034] A reflux slope 11 is arranged inside the body 1, and the ascending channel 9 is connected to the main channel 2 through the reflux slope 11. A guide block 12 is arranged between the guide top wall 10 and the reflux slope 11. The inclination angle of the reflux slope 11 is 15°-45°. When the material reaches the reflux slope 11 from the ascending channel 9, under the influence of the gravity component, the material will naturally slide down the slope and enter the main channel 2, thereby ensuring the smooth reflux of the material and improving the continuity and stability of the entire flour processing process. This inclination angle range can balance the sliding speed of the material. If the inclination angle is too small and the material slides down too slowly, the material will accumulate on the slope, affecting the processing efficiency. If the inclination angle is too large and the material slides down too fast, the material may impact other components in the main channel 2, causing material splashing, uneven distribution and other problems. The angle of 15°-45° can better avoid these problems.

[0035] The rising channel 9 is connected to the main channel 2 through the reflux ramp 11, enabling the materials that do not meet the grinding requirements to return to the main channel 2 for re-grinding. This cyclic grinding process can significantly improve the grinding accuracy and quality of the flour.

[0036] A blower 8 is provided at the bottom of the aggregate groove 7. The blower 8 is installed in an embedded manner and is flange-connected to the bottom of the aggregate groove 7. The air outlet is upward. The air flow velocity of the blower 8 is 5 - 15 m / s, which suspends and conveys the materials in the aggregate groove 7 to the rising channel 9. The cross-sectional area of the rising channel 9 gradually decreases along the air flow direction. The decrease in the cross-sectional area causes the air flow velocity to gradually increase, which can quickly entrain the coarse particles to the diversion top wall, shorten the cycle period, meet the high throughput requirements, and the high-speed air flow can disperse the agglomerated materials and improve the dispersion effect. The inner wall of the rising channel 9 is provided with spiral guide vanes to guide the materials to rotate and rise along the channel, reducing wall adhesion. This solution combines aerodynamics and structural innovation to solve the problems of large volume and high energy consumption of traditional equipment while ensuring the grinding quality.

[0037] The screen hole diameter of the screen 5 is 0.1 - 0.5 mm, and the inclination angle of the diversion channel 6 with the horizontal plane is 15° - 30°.

[0038] The grinding roller pair 3 includes a driving roller and a driven roller. The rotational speed of the driving roller is 1.2 - 1.5 times that of the driven roller. The different rotational speeds cause different forces on the materials between the two rollers, which can better promote the dispersion between the material particles, more effectively break and refine the material particles, and improve the grinding efficiency and quality.

[0039] A diversion top wall 10 is provided inside the machine body 1. The diversion top wall 10 is located directly above the rising channel 9. The diversion top wall 10 is of an inverted V-shaped structure, and the included angle of the diversion top wall 10 is 120° - 160°. The inverted V-shaped structure guides the materials at the top of the rising channel 9 to both sides. When gradually moving away from the rising air flow, they will fall onto the reflux ramp 11. The inverted V-shaped structure makes the residence time of the materials on the diversion top wall 10 only 0.1 - 0.3 seconds, while the traditional flat top structure is 0.8 - 1.2 seconds.

[0040] A method for flour processing is carried out using a grinding device, and the specific steps are as follows:

[0041] A. Materials with a moisture content of 12 - 14% enter the main channel 2 through the feed inlet 13. Materials with a moisture content of 12 - 14% are used, and the feeding speed is linked and controlled with the rotational speed of the grinding roller.

[0042] B. Grinding roller pair 3 grinds the material, and the ground material falls to the push roller 4. Grinding roller contact pressure: 80-120N / cm, master and slave roller speed ratio 1.3:1, gap 0.3-0.5mm, roller spacing can be adjusted by hydraulic telescopic rod (not shown), grinding temperature is controlled at 35-40℃ by circulating cooling water system;

[0043] C. Pushing roller 4 pushes the material to the surface of screen 5. Fine powder passing through screen 5 directly enters discharge port 14. Coarse particles not passing through screen 5 are pushed to the circulation guide channel by pushing roller 4 and return to main flow channel 2 along the circulation guide channel through air flow guidance. Pushing roller 4 adopts variable frequency speed regulation. Screen 5 is equipped with ultrasonic self-cleaning system with adjustable range of 300-800W and frequency of 40kHz. It automatically cleans for 30 seconds every 30 minutes. Pre-vibration is started 5 seconds before each cleaning with frequency of 20kHz.

[0044] In step C, the coarse particles that have not passed through the screen 5 are pushed to the diversion channel 6 by the push roller 4, and the coarse particles in the diversion channel 6 slide into the aggregate groove 7. The fan 8 forms a vertical upward airflow to suspend and transport the coarse particles in the aggregate groove 7 upward. The frequency of the fan 8 is 30-50Hz, and the wind speed is 5-15m / s. When the material height in the aggregate groove 7 reaches the set value, the wind speed is increased to accelerate the transportation.

[0045] It also includes D. The rising coarse particles hit the guide top wall 10 and are guided to the reflux slope 11. The coarse particles re-enter the mainstream channel 2 through the slope. A pressure sensor is provided to monitor the change of the air flow system resistance. When the resistance is greater than 2000Pa, the feeding speed is reduced by 10%. An infrared thermometer is provided to monitor the temperature of the grinding roller.

[0046] The specific solution is as follows: according to the material type, such as the moisture content of hard wheat is 14.5%-15.5%, and that of soft wheat is 13.5%-14.5%, the moisture penetration time is accurately controlled for 8-24 hours through the wheat conditioning bin, so that the endosperm is softened and the bran remains tough, reducing the grinding energy consumption; a combination of magnetic separation, specific gravity stone removal machine, color sorter and other processes are used to reduce the impurity content of the material from 1.5% to below 0.05%, avoiding hard particles from damaging the grinding rollers;

[0047] After the material is injected into the machine body 1 from the feed port 13, it falls by gravity along the main flow channel 2 to the grinding roller pair 3, and is crushed by the grinding roller pair 3 rotating in opposite directions. The crushed mixed material falls directly to the push roller 4, and the push roller 4 pushes the material to the surface of the screen 5 at a specific speed. Qualified fine powder is discharged from the discharge port 14 through the screen holes, and the unqualified coarse particles move along the screen surface to the diversion channel 6. The coarse particles slide into the aggregate groove 7 through the diversion channel 6. The rising airflow generated by the fan 8 is entrained through the rising channel 9, and turns to both sides after being blocked by the guide top wall 10, and re-enters the main flow channel 2 through the reflux slope 11. It is distributed in the front and rear end areas of the main flow channel 2 through the guide block 12;

[0048] Because the feed hopper of the traditional grinding device is usually arranged directly above the grinding roller pair 3, most of the materials fall into the area in the middle of the grinding roller pair 3. This is achieved through the specially designed diversion block 12, which guides the coarse particles to be distributed in the front and rear end areas of the grinding roller pair 3 when they fall back, forming a spatial stratification with the initial feeding, balancing the surface wear of the grinding roller pair 3, and improving the overall grinding efficiency of the equipment.

[0049] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-precision grinding device for flour processing, comprising a machine body (1), a pair of grinding rollers (3), and a screen (5), characterized in that: A main flow channel (2) extending in a vertical direction is provided inside the machine body (1), the grinding roller pair (3) is horizontally arranged in the middle of the main flow channel (2), the screen (5) is arranged below the grinding roller pair (3), and a circulation guide channel is provided inside the machine body (1), and substandard materials are guided by air flow along the circulation guide channel back to the main flow channel (2).

2. A high-precision grinding device for flour processing according to claim 1, characterized in that: It also comprises a push roller (4), the screen (5) is in an arc shape, and the push roller (4) is arranged on the inner circle of the screen (5).

3. A high-precision grinding device for flour processing according to claim 2, characterized in that: The circulation guide channel comprises a diversion channel (6), the push roller (4) is used to push substandard materials into the diversion channel (6), and the screen (5) is connected to the collection groove (7) through the diversion channel (6).

4. A high-precision grinding device for flour processing according to claim 3, characterized in that: A fan (8) is provided at the bottom of the aggregate groove (7), and the fan (8) is used to suspend and transport the material in the aggregate groove (7) upward.

5. A high-precision grinding device for flour processing according to claim 3, characterized in that: The circulation guide channel also includes an ascending channel (9) and a return flow slope (11), wherein the ascending channel (9) is located directly above the aggregate groove (7), and the return flow slope (11) connects the ascending channel (9) and the main flow channel (2).

6. A high-precision grinding device for flour processing according to claim 5, characterized in that: A flow guide top wall (10) is arranged inside the machine body (1), and the flow guide top wall (10) is located directly above the ascending channel (9). The flow guide top wall (10) is used to guide the material suspended in the ascending channel (9) to both sides.

7. A method for flour processing, characterized in that: The grinding device according to claim 6 is used, and the specific steps are as follows: A. Put the material with a moisture content of 12-14% into the main flow channel (2); B. The grinding roller pair (3) grinds the material, and the ground material falls to the push roller (4); C. The push roller (4) pushes the material onto the surface of the screen (5), and the fine powder passing through the screen (5) directly enters the discharge port, while the coarse particles that do not pass through the screen (5) are pushed by the push roller (4) to the diversion channel (6), and are guided by the air flow along the circulation guide channel to return to the main flow channel (2).

8. A flour processing method according to claim 7, characterized in that: In step C, the coarse particles in the diversion channel (6) slide down to the aggregate groove (7), and the fan (8) forms a vertical upward airflow to suspend and transport the coarse particles in the aggregate groove (7) upward.

9. A flour processing method according to claim 7, characterized in that: It also includes D. The rising coarse particles hit the guide top wall (10) and are guided to the return slope (11), and the coarse particles re-enter the main flow channel (2) through the slope.

10. A flour processing method according to claim 8, characterized in that: The frequency of the fan (8) is 30-50 Hz, and the wind speed is 5-15 m / s. When the material height in the aggregate groove (7) reaches a set value, the wind speed is increased to accelerate the conveying.

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