A kind of air intake regulating anti-backflow device suitable for grain processing mill

Abstract

The application relates to the field of grain processing equipment, in particular to an air intake amount adjusting anti-back-spraying device suitable for a grain processing mill, which comprises a material feeding pipe, a material air inlet valve assembly, a material air inlet pipe, a gas-material mixing expansion joint, a high-pressure impact main shaft, a high-pressure impact cavity, a wind speed sensor, a temperature sensor and a controller. The material feeding pipe and the material air inlet pipe are vertically installed at the top end of the gas-material mixing expansion joint, and the material air inlet valve assembly is installed at the top end of the air inlet pipe; the wind speed sensor and the temperature sensor are both installed inside the gas-material mixing expansion joint and detect the air flow speed and temperature respectively; the controller calculates the current air density based on temperature compensation, and then obtains the total resistance of the dynamic pressure and the negative pressure to obtain the actual negative pressure value, and compares the actual negative pressure value with a preset negative pressure threshold value; and the opening degree of the material air inlet valve assembly is adjusted according to the comparison result. The application realizes negative pressure closed loop calculation and air intake amount self-adaptive adjustment based on temperature compensation, and effectively solves the problems of material back-spraying and inlet bridging of the grain processing mill.

Description

Technical Field

[0001] This application relates to the field of grain processing equipment, and in particular to an air intake regulating and anti-backflow device suitable for grain processing mills. Background Technology

[0002] The feed inlet of a food cyclone mill needs to provide stable material guidance, prevent backsplashing, match the cyclone flow field, and control the feed rate. Its performance directly affects the grinding efficiency, particle size uniformity, and sample recovery rate. Currently, traditional feed inlet technologies suffer from the problem of material bridging and clogging at the inlet. At the same time, the reverse airflow generated by the high-speed cyclone can easily throw the material out, causing backflow, resulting in material loss, deterioration of the processing environment, and safety hazards. Summary of the Invention

[0003] To address the issues of material bridging at the inlet and high-speed cyclone reverse airflow causing material to be thrown out and resulting in backflow, this application provides an airflow regulation and backflow prevention device suitable for grain processing mills.

[0004] The technical solution provided in this application for an air intake regulating and anti-backflow device suitable for grain processing mills is as follows:

[0005] An air intake regulating and anti-backflow device for grain processing mills includes a material feed pipe, a material air intake pipe, a material air intake valve assembly, a gas-material mixing expansion joint, a high-pressure impact spindle, a high-pressure impact chamber, a wind speed sensor, a temperature sensor, and a controller, wherein:

[0006] The material feed pipe is vertically installed at the top of the gas-material mixing expansion joint and is used to add material into the gas-material mixing expansion joint.

[0007] The material inlet pipe is vertically installed at the top of the gas-material mixing expansion joint and is used to fill the gas-material mixing expansion joint with gas.

[0008] The material inlet valve assembly is installed at the top of the material inlet pipe and is used to regulate the gas flow rate entering the gas-material mixing expansion joint through the material inlet pipe.

[0009] The gas-material mixing expansion joint is installed on the bottom chamber of the high-pressure impact chamber to ensure that the gas and materials are fully mixed.

[0010] One end of the high-pressure impact chamber is connected to a vacuum pump via a delivery pipe, which is used to create negative pressure inside the gas-material mixing expansion joint.

[0011] The high-pressure impact spindle is installed on the bottom chamber of the high-pressure impact chamber and is used to provide power to the blades in the high-pressure impact chamber to impact and strip the incoming material.

[0012] The wind speed sensor is installed inside the gas-material mixing expansion joint to detect the airflow speed inside the gas-material mixing expansion joint in real time and output the airflow speed detection signal.

[0013] The temperature sensor is installed inside the gas-liquid mixing expansion joint to detect the temperature inside the gas-liquid mixing expansion joint in real time and output a temperature detection signal.

[0014] The controller is electrically connected to the wind speed sensor and the temperature sensor respectively, and is used to receive the airflow wind speed detection signal and the temperature detection signal, calculate the actual negative pressure value in the gas-material mixing expansion joint, and then adjust the opening of the material inlet valve assembly according to the comparison result of the actual negative pressure value and the preset negative pressure threshold, and then output the airflow wind speed detection signal, the temperature detection signal and the negative pressure signal.

[0015] By adopting the above technical solution,

[0016] Optionally, the length of the material feed pipe within the gas-material mixing expansion joint is greater than the length of the material air inlet pipe within the gas-material mixing expansion joint.

[0017] By adopting the above technical solution, the material feed pipe extends deeper into the expansion joint than the material air inlet pipe. Combined with the "high air inlet, low material inlet" external layout, the feed inlet and air inlet are staggered, ensuring uniform air and material intake and preventing material from directly clogging the air inlet channel. Simultaneously, the short insertion depth of the material air inlet pipe allows the gas to contact the material at the top of the gas-material mixing expansion joint, promoting gas-material premixing.

[0018] Optionally, the bottom end of the material feed pipe is beveled.

[0019] By adopting the above technical solution, the inclined bottom end allows the material to disperse and slide downward along the inclined surface when entering the gas-material mixing expansion joint, reducing the accumulation of material at the pipe opening, further preventing inlet bridging, and helping the material to have uniform contact with the rising airflow.

[0020] Optionally, the material inlet valve assembly includes a lower inlet circular plate and an upper inlet circular plate. The lower inlet circular plate is fixedly installed at the top of the material inlet pipe. The lower inlet circular plate has a plurality of first inlet holes along its circumference. The upper inlet circular plate is rotatably installed at the top of the lower inlet circular plate. The upper inlet circular plate has a plurality of second inlet holes equidistantly installed along its circumference.

[0021] By adopting the above technical solution, the air intake opening can be steplessly adjusted by changing the overlapping area of ​​the first air intake hole and the second air intake hole by rotating the upper air intake circular plate. The structure is simple and easy to operate, and the circular plate structure has good sealing performance, which can effectively prevent dust leakage.

[0022] Optionally, a first auxiliary plate is fixedly installed on the circumferential wall of the lower air intake plate, and a guide groove is provided at the top of the first auxiliary plate. A second auxiliary plate is fixedly installed on the circumferential wall of the upper air intake plate, and a guide block is fixedly installed at the bottom of the second auxiliary plate. The guide block is slidably installed in the guide groove.

[0023] By adopting the above technical solution, the guide block and guide groove cooperate to provide circumferential guidance and limit for the rotation of the upper air intake disc, ensuring a smooth rotation process. When the guide block is located at the left end of the guide groove, the opening is the smallest, and when it is located at the right end, the opening is the largest, which makes it easy for operators to intuitively perceive the valve's limit position.

[0024] Optionally, the controller is configured to:

[0025] It receives the airflow speed detection signal output by the wind speed sensor and the temperature detection signal output by the temperature sensor, and determines the corresponding airflow speed value and temperature value.

[0026] Determine the current air density within the gas-material mixing expansion joint based on the temperature value;

[0027] Calculate the dynamic pressure within the gas-liquid mixing expansion joint based on the wind speed and current air density;

[0028] Obtain the total negative pressure resistance, and determine the actual negative pressure value inside the gas-material mixing expansion joint based on the total negative pressure resistance and dynamic pressure;

[0029] The actual negative pressure value is compared with the preset negative pressure threshold to obtain the comparison result;

[0030] Based on the comparison results, an adjustment command is output to control the opening degree of the material inlet valve assembly.

[0031] By adopting the above technical solution, a temperature compensation mechanism is introduced to correct the air density, eliminating the deviation caused by temperature changes in wind speed measurement and negative pressure calculation, making the negative pressure calculation results more accurate, thereby providing a reliable quantitative basis for adjusting the air intake valve opening.

[0032] Optionally, the step of outputting an adjustment command based on the comparison result to control the opening degree of the material inlet valve assembly includes:

[0033] The preset negative pressure threshold includes a preset first threshold and a preset second threshold, wherein the preset first threshold is less than the preset second threshold;

[0034] When the actual negative pressure value is lower than the preset first threshold, the opening of the material inlet valve assembly is increased.

[0035] When the actual negative pressure value is higher than the preset second threshold, the opening of the material inlet valve assembly is reduced.

[0036] When the actual negative pressure value is higher than or equal to the preset first threshold and lower than or equal to the preset second threshold, it indicates that the actual negative pressure value in the gas-material mixing expansion joint is in a normal state.

[0037] By adopting the above technical solution, when the negative pressure is insufficient, the opening is increased to enhance the ejector airflow, suppress backflow and eliminate bridging; when the negative pressure is too high, the opening is reduced to avoid excessive material splashing and excessively fine crushing particles, thus achieving adaptive adjustment under different working conditions.

[0038] Optionally, the formula for calculating the current air density is:

[0039]

[0040] in, Given the current air density, Standard air density, , The temperature value collected by the temperature sensor;

[0041] The formula for calculating the dynamic pressure is:

[0042]

[0043] in, For dynamic pressure, The wind speed value collected by the wind speed sensor;

[0044] The formula for calculating the actual negative pressure value is:

[0045]

[0046]

[0047] in, The total resistance is due to negative pressure. Let L be the frictional resistance coefficient of the material inlet pipe, L be the actual length of the material inlet pipe, and D be the diameter of the material inlet pipe. It is the sum of local drag coefficients. This is the actual negative pressure value.

[0048] By adopting the above technical solution, a complete calculation model from temperature and wind speed to actual negative pressure is established based on the principles of fluid mechanics. Taking into account friction resistance and local resistance, the negative pressure calculation results accurately reflect the actual working conditions inside the gas-material mixing expansion joint.

[0049] Optionally, it may also include a display, which is electrically connected to the controller;

[0050] After calculating the actual negative pressure value, the controller outputs airflow speed detection signal, temperature detection signal and negative pressure signal;

[0051] The display is used to receive airflow speed detection signals, temperature detection signals, and negative pressure signals output by the controller, and to display the airflow speed values, temperature values, and actual negative pressure values ​​reflected by the above three signals.

[0052] By adopting the above technical solution, operators can view the airflow velocity, temperature and actual negative pressure values ​​in real time on the display, which makes it easy to intuitively grasp the operating status of the device and provide data support for manual intervention or process parameter optimization.

[0053] Optionally, it also includes a first alarm and a second alarm, both of which are electrically connected to the controller;

[0054] When the actual negative pressure value is less than the preset first threshold, the controller outputs a first alarm signal to the first alarm device, and the first alarm device sounds an alarm upon receiving the first alarm signal. When the actual negative pressure value is greater than the preset second threshold, the controller outputs a second alarm signal to the second alarm device, and the second alarm device sounds an alarm upon receiving the second alarm signal. Both the first and second alarm devices are audible and visual alarms. During the alarm process, the sounds and colors emitted by the first and second alarm devices are different.

[0055] By adopting the above technical solution, and using dual audible and visual alarms with different sounds and colors to distinguish between high and low negative pressure anomalies, operators can quickly identify the type of anomaly and handle it in a timely manner in a noisy processing environment, thereby improving the safety of equipment operation.

[0056] In summary, this application includes at least one of the following beneficial technical effects:

[0057] 1. By coordinating wind speed sensors, temperature sensors and controllers, negative pressure closed-loop calculation based on temperature compensation and dynamic adjustment of intake valve opening are achieved, effectively solving the problems of material inlet bridging and high-speed cyclone backflow.

[0058] 2. The staggered layout of "high air intake and low material intake" and the design of the inclined bottom of the material feed pipe promote uniform mixing of air and material and prevent the feed inlet from being blocked, thereby improving the crushing efficiency and particle size uniformity.

[0059] 3. Key parameters are displayed in real time on the monitor, and a differentiated audible and visual alarm mechanism is used to make the device's operating status transparent and controllable, adapting to the processing needs of different types of grain materials with different moisture contents and different particle sizes. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the structure of an air intake volume regulating and anti-backflow device for a grain processing mill, according to an embodiment of this application.

[0061] Figure 2This is a schematic diagram of the structure of a gas-material mixing expansion joint of an air intake regulating and anti-backflow device for a grain processing mill, which is missing its front end, according to an embodiment of the application.

[0062] Figure 3 This is a schematic diagram of the material inlet valve assembly of an air intake volume regulating and anti-backflow device for a grain processing mill, according to an embodiment of the application.

[0063] Figure 4 This is a system diagram of an air intake volume regulating and anti-backflow device applicable to a grain processing mill, as described in the application embodiment.

[0064] Explanation of reference numerals in the attached drawings: 1. Material feed pipe; 2. Material air inlet pipe; 3. Material air inlet valve assembly; 31. Lower air inlet circular plate; 311. First air inlet hole; 312. First auxiliary plate; 313. Guide groove; 32. Upper air inlet circular plate; 321. Second air inlet hole; 322. Second auxiliary plate; 323. Guide block; 4. Gas-material mixing expansion joint; 5. High-pressure impact spindle; 6. High-pressure impact chamber; 7. Wind speed sensor; 8. Temperature sensor; 9. Controller; 10. Display; 110. First alarm; 120. Second alarm. Detailed Implementation

[0065] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0066] This application discloses an air intake regulating and anti-backflow device suitable for grain processing mills.

[0067] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 A backflow prevention device for regulating air intake in a grain processing mill includes a material feed pipe 1, a material air intake pipe 2, a material air intake valve assembly 3, a gas-material mixing expansion joint 4, a high-pressure impact spindle 5, a high-pressure impact chamber 6, a wind speed sensor 7, a temperature sensor 8, a controller 9, a display 10, a first alarm 110, and a second alarm 120. The controller 9 is a PLC controller.

[0068] The material feed pipe 1 is vertically fixed at the top of the gas-material mixing expansion joint 4 and is used to add the grain material to be processed into the gas-material mixing expansion joint 4. The material air inlet pipe 2 is vertically fixed at the top of the gas-material mixing expansion joint 4 and is used to fill the gas-material mixing expansion joint 4 with gas. The length of the material feed pipe 1 outside the gas-material mixing expansion joint 4 is less than the length of the material air inlet pipe 2 outside the gas-material mixing expansion joint 4, forming a "high air inlet, low material feed" layout. The length of the material feed pipe 1 inside the gas-material mixing expansion joint 4 is greater than the length of the material air inlet pipe 2 inside the gas-material mixing expansion joint 4, and the bottom end of the material air inlet pipe 2 is inclined. The material air inlet valve assembly 3 is installed at the top of the material air inlet pipe 2. The operator can control the gas flow rate entering the gas-material mixing expansion joint 4 through the material air inlet pipe 2 by adjusting the opening of the material air inlet valve assembly 3.

[0069] The material inlet valve assembly 3 includes a lower inlet circular plate 31 and an upper inlet circular plate 32. The lower inlet circular plate 31 is fixedly installed at the top of the material inlet pipe 2. Multiple first inlet holes 311 are opened on the lower inlet circular plate 31 along the circumferential direction of the lower inlet circular plate 31. The upper inlet circular plate 32 is rotatably installed at the top of the lower inlet circular plate 31. Multiple second inlet holes 321 are equidistantly opened on the upper inlet circular plate 32 along the circumferential direction of the upper inlet circular plate 32.

[0070] A first auxiliary plate 312 is fixedly installed on the circumferential wall of the lower air intake plate 31. A guide groove 313 is provided at the top of the first auxiliary plate 312. A second auxiliary plate 322 is fixedly installed on the circumferential wall of the upper air intake plate 32. A guide block 323 is fixedly installed at the bottom of the second auxiliary plate 322. The guide block 323 is slidably installed in the guide groove 313.

[0071] The left end of the high-pressure impact chamber 6 is connected to a vacuum pump (not shown) via a conveying pipe (not shown). The vacuum pump is used to create a negative pressure inside the gas-material mixing expansion joint 4. The gas-material mixing expansion joint 4 is installed at the right end of the bottom chamber of the high-pressure impact chamber 6, serving as a pre-mixing chamber for gas and material. It is used to fully mix the gas and material, and after full mixing, the mixed material is sent into the high-pressure impact chamber 6 through a negative pressure airflow. The high-pressure impact main shaft 5 is horizontally fixed on the bottom chamber of the high-pressure impact chamber 6. After the device is started, the high-pressure impact main shaft 5 provides rotational power to the blades inside the high-pressure impact chamber 6, performing high-speed impact stripping on the incoming material to achieve crushing processing.

[0072] Both the wind speed sensor 7 and the temperature sensor 8 are fixedly installed inside the gas-material mixing expansion joint 4. The wind speed sensor 7 is used to detect the airflow speed inside the gas-material mixing expansion joint 4 in real time and outputs an airflow speed detection signal. The temperature sensor 8 is used to detect the temperature inside the gas-material mixing expansion joint 4 in real time and outputs a temperature detection signal. The controller 9 is electrically connected to the wind speed sensor 7 and the temperature sensor 8 respectively. After receiving the wind speed detection signal and the temperature detection signal, it calculates the actual negative pressure value inside the gas-material mixing expansion joint 4, and then adjusts the opening of the material inlet valve assembly 3 according to the comparison result between the actual negative pressure value and the preset negative pressure threshold. Then, it outputs the airflow speed detection signal, the temperature detection signal, and the negative pressure signal. It should be noted that the preset negative pressure threshold includes a preset first threshold and a preset second threshold. The preset first threshold is less than the preset second threshold, and both the preset first threshold and the preset second threshold are set according to the actual situation.

[0073] The display 10 is electrically connected to the controller 9 and is used to receive the airflow speed detection signal, temperature detection signal and negative pressure signal output by the controller 9, and display the airflow speed value, temperature value and actual negative pressure value reflected by the above three signals for the operator to view.

[0074] Both the first alarm 110 and the second alarm 120 are electrically connected to the controller 9. When the actual negative pressure value is less than a preset first threshold, the controller 9 outputs a first alarm signal to the first alarm 110, which then sounds an alarm. When the actual negative pressure value is greater than a preset second threshold, the controller 9 outputs a second alarm signal to the second alarm 120, which then sounds an alarm. It should be noted that both the first alarm 110 and the second alarm 120 are audible and visual alarms, but the sounds and colors emitted by them during the alarm process are different.

[0075] When the device starts working, the operator adds material from the material inlet pipe 2 into the gas-material mixing expansion joint 4. At the same time, the opening of the material inlet valve assembly 3 is adjusted according to the initial working condition settings so that external air enters the gas-material mixing expansion joint 4 through the material inlet pipe 2. When the device starts, the high-pressure impact spindle 5 provides power to the blades in the high-pressure impact chamber 6 to impact and strip the incoming material.

[0076] The wind speed sensor 7 and temperature sensor 8 are powered on synchronously to begin collecting initial data from inside the gas-material mixing expansion joint 4 and transmitting it to the controller 9. The flow path through which the gas sequentially passes through the material inlet valve assembly 3, the material inlet pipe 2, the gas-material mixing expansion joint 4, and the high-pressure impact chamber 6 is called the pipeline.

[0077] Controller 9 is configured as follows:

[0078] Receive the airflow speed detection signal output by the wind speed sensor 7 and the temperature detection signal output by the temperature sensor 8, and determine the corresponding airflow speed value and temperature value.

[0079] The current air density within the gas-liquid mixing expansion joint 4 is determined based on the temperature value (i.e., the air density error is corrected by temperature to eliminate the influence of temperature on air density). The formula for calculating the current air density is as follows:

[0080]

[0081] in, Given the current air density, This is the standard air density (air density at 20°C). , The temperature value collected by temperature sensor 8, 293.15, represents the absolute temperature corresponding to standard conditions, in Kelvin (K). That is, 20℃ + 273.15 = 293.15K, which corresponds to the reference temperature for standard air density. 273.15 represents the offset constant for converting Celsius temperature to Kelvin temperature. Used to convert the Celsius temperature measured by the temperature sensor Convert to thermodynamic absolute temperature.

[0082] Calculate the dynamic pressure within the gas-liquid mixture expansion joint 4 based on the wind speed and current air density. The formula for calculating the dynamic pressure is:

[0083]

[0084] in, For dynamic pressure, The wind speed value collected by wind speed sensor 7;

[0085] Obtain the total negative pressure resistance, and determine the actual negative pressure value within the gas-liquid mixing expansion joint 4 based on the total negative pressure resistance and dynamic pressure. The formula for calculating the actual negative pressure value is as follows:

[0086]

[0087]

[0088] in, It is the total resistance under negative pressure (i.e., the sum of the friction resistance and local resistance of the material inlet pipe 2). The frictional resistance coefficient of the material inlet pipe 2 is... The dimensions of the material inlet pipe 2 can be determined from the table in the engineering manual based on the roughness of the inner wall and the Reynolds number of the fluid inside the pipe. Here, L is the actual length of the material inlet pipe 2, and D is the diameter of the material inlet pipe 2. It is the sum of local drag coefficients. This is the actual negative pressure value.

[0089] It is important to know that the local resistance includes the resistance of the material inlet valve assembly 3, the resistance of the pipe bend, and the resistance of the pipe diameter change. Among them, the resistance of the pipe bend refers to the resistance when the gas flows from the gas-material mixing expansion joint 4 into the high-pressure impact chamber 6, and the flow direction changes from vertical to horizontal. The resistance of the pipe diameter change refers to the resistance when the gas flows from the material inlet pipe 2 into the gas-material mixing expansion joint 4, and the air flow area changes from small to large, and the air flow area changes from large to small when the gas flows from the gas-material mixing expansion joint 4 into the high-pressure impact chamber 6.

[0090] It can be seen that the total resistance under negative pressure can be derived from the following formula:

[0091] Gas flows in material inlet pipe 2, and a pressure drop occurs due to friction with the pipe wall. The Darcy-Weisbach friction loss formula is:

[0092]

[0093] in, This refers to the pressure loss along the material inlet pipe 2.

[0094] As gas flows through components such as the material inlet valve assembly 3, pipe bends, and pipe diameter reducers, the flow field is disturbed and eddies occur, resulting in local pressure loss. The local pressure drop of a single component is calculated using the following formula:

[0095]

[0096] in, Let be the local resistance coefficient of the i-th component.

[0097] When a pipeline has multiple local components, the formula for summing all local resistances is:

[0098]

[0099] in, The sum of the local resistance coefficients of all components; local resistance coefficient The results can be obtained by consulting tables in pneumatic conveying engineering design manuals, performing fluid simulation calculations, or calibrating through prototype pressure testing.

[0100] This leads to the total resistance under negative pressure:

[0101]

[0102] The actual negative pressure value is compared with the preset negative pressure threshold to obtain the comparison result;

[0103] Based on the comparison results, an adjustment command is output to control the opening degree of the material inlet valve assembly 3, namely:

[0104] When the actual negative pressure value is lower than the preset first threshold, the operator increases the opening of the material inlet valve assembly 3. That is, the operator rotates the second auxiliary plate 322 to drive the upper inlet circular plate 32 to rotate in the same direction, so that the second air inlet hole 321 on the upper air inlet circular plate 32 gradually aligns with the first air inlet hole 311 on the lower air inlet circular plate 31.

[0105] When the actual negative pressure value is higher than the preset second threshold, the operator reduces the opening of the material inlet valve assembly 3. That is, the operator rotates the second auxiliary plate 322 to drive the upper inlet circular plate 32 to rotate in the opposite direction, so that the solid part on the upper inlet circular plate 32 gradually blocks the first air inlet hole 311 on the lower inlet circular plate 31.

[0106] When the actual negative pressure value is higher than or equal to the preset first threshold and lower than or equal to the preset second threshold, it indicates that the actual negative pressure value inside the gas-material mixing expansion joint 4 is in a normal state.

[0107] It should be noted that during the process of the operator rotating the second auxiliary plate 322 to drive the upper air intake plate 32 to rotate, the guide block 323 will slide along the guide groove 313. When the guide block 323 is located at the left end of the guide groove 313, the solid part on the upper air intake plate 32 completely blocks the first air intake hole 311 on the lower air intake plate 31, that is, the opening is the smallest. When the guide block 323 is located at the right end of the guide groove 313, the second air intake hole 321 on the upper air intake plate 32 is completely aligned with the first air intake hole 311 on the lower air intake plate 31, that is, the opening is the largest.

[0108] The implementation principle of an air intake regulating and anti-backflow device for a grain processing mill according to an embodiment of this application is as follows: When the device is working, the air pump creates a negative pressure environment inside the gas-material mixing expansion joint 4. The material enters the gas-material mixing expansion joint 4 through the material feed pipe 1 and is fully mixed with the gas entering through the material air intake pipe 2. The wind speed sensor 7 and the temperature sensor 8 collect the airflow speed and temperature inside the gas-material mixing expansion joint 4 in real time. The controller 9 calculates the current air density based on temperature compensation, and then obtains the dynamic pressure and the total resistance of the negative pressure to get the actual negative pressure value. The controller 9 compares the actual negative pressure value with... The system compares preset negative pressure thresholds. When the actual negative pressure value is lower than the preset first threshold, the opening of the material inlet valve assembly 3 is increased to enhance the negative pressure ejection intensity, suppress reverse airflow, and prevent material bridging and back spraying. When the actual negative pressure value is higher than the preset second threshold, the opening is decreased to avoid excessive material splashing. The display 10 displays the airflow velocity, temperature, and actual negative pressure value in real time. The first alarm 110 and the second alarm 120 issue alarms in different sound and light modes when the actual negative pressure value is abnormal, prompting the operator to intervene in time, thereby forming a closed-loop control for air intake adjustment and back spray prevention.

[0109] The above are all preferred embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. An air intake regulating and anti-backflow device suitable for grain processing mills, characterized in that: The system includes a material feed pipe (1), a material air inlet pipe (2), a material air inlet valve assembly (3), a gas-material mixing expansion joint (4), a high-pressure impact spindle (5), a high-pressure impact chamber (6), a wind speed sensor (7), a temperature sensor (8), and a controller (9), wherein: The material feed pipe (1) is vertically installed at the top of the gas-material mixing expansion joint (4) and is used to add material into the gas-material mixing expansion joint (4); The material inlet pipe (2) is vertically installed at the top of the gas-material mixing expansion joint (4) and is used to fill the gas-material mixing expansion joint (4) with gas. The material inlet valve assembly (3) is installed at the top of the material inlet pipe (2) and is used to regulate the gas flow rate entering the gas-material mixing expansion joint (4) through the material inlet pipe (2); The gas-material mixing expansion joint (4) is installed on the bottom chamber of the high-pressure impact chamber (6) to ensure that the gas and materials are fully mixed. One end of the high-pressure impact chamber (6) is connected to a vacuum pump through a delivery pipe, which is used to create a negative pressure inside the gas-material mixing expansion joint (4); The high-pressure impact spindle (5) is installed on the bottom chamber of the high-pressure impact chamber (6) to provide power to the blades in the high-pressure impact chamber (6) and to impact and strip the incoming material. The wind speed sensor (7) is installed inside the gas-material mixing expansion joint (4) to detect the airflow wind speed inside the gas-material mixing expansion joint (4) in real time and output the airflow wind speed detection signal. The temperature sensor (8) is installed inside the gas-liquid mixing expansion joint (4) to detect the temperature inside the gas-liquid mixing expansion joint (4) in real time and output a temperature detection signal; The controller (9) is electrically connected to the wind speed sensor (7) and the temperature sensor (8) respectively. It is used to receive the airflow wind speed detection signal and the temperature detection signal, and calculate the actual negative pressure value in the gas-material mixing expansion joint (4). Then, it adjusts the opening of the material inlet valve assembly (3) according to the comparison result of the actual negative pressure value and the preset negative pressure threshold, and then outputs the airflow wind speed detection signal, the temperature detection signal and the negative pressure signal.

2. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 1, characterized in that: The length of the material feed pipe (1) inside the gas-material mixing expansion joint (4) is greater than the length of the material air inlet pipe (2) inside the gas-material mixing expansion joint (4).

3. The air intake regulating and anti-backflow device for grain processing mills according to claim 2, characterized in that: The bottom end of the material feed pipe (1) is sloping.

4. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 1, characterized in that: The material inlet valve assembly (3) includes a lower inlet circular plate (31) and an upper inlet circular plate (32). The lower inlet circular plate (31) is fixedly installed at the top of the material inlet pipe (2). Multiple first inlet holes (311) are opened on the lower inlet circular plate (31) along the circumferential direction of the lower inlet circular plate (31). The upper inlet circular plate (32) is rotatably installed at the top of the lower inlet circular plate (31). Multiple second inlet holes (321) are opened at equal intervals on the upper inlet circular plate (32) along the circumferential direction of the upper inlet circular plate (32).

5. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 4, characterized in that: A first auxiliary plate (312) is fixedly installed on the circumferential wall of the lower air intake plate (31). A guide groove (313) is provided at the top of the first auxiliary plate (312). A second auxiliary plate (322) is fixedly installed on the circumferential wall of the upper air intake plate (32). A guide block (323) is fixedly installed at the bottom of the second auxiliary plate (322). The guide block (323) is slidably installed in the guide groove (313).

6. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 1, characterized in that: The controller (9) is configured to: Receive the airflow speed detection signal output by the wind speed sensor (7) and the temperature detection signal output by the temperature sensor (8), and determine the corresponding airflow speed value and temperature value; The current air density inside the gas-liquid mixing expansion joint (4) is determined based on the temperature value; Calculate the dynamic pressure inside the gas-liquid mixing expansion joint (4) based on the wind speed and current air density; Obtain the total negative pressure resistance and determine the actual negative pressure value inside the gas-liquid mixing expansion joint (4) based on the total negative pressure resistance and dynamic pressure; The actual negative pressure value is compared with the preset negative pressure threshold to obtain the comparison result; Based on the comparison results, an adjustment command is output to control the opening degree of the material inlet valve assembly (3).

7. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 6, characterized in that: The step of outputting adjustment commands based on comparison results to control the opening degree of the material inlet valve assembly (3) includes: The preset negative pressure threshold includes a preset first threshold and a preset second threshold, wherein the preset first threshold is less than the preset second threshold; When the actual negative pressure value is lower than the preset first threshold, the opening of the material inlet valve assembly (3) is increased; When the actual negative pressure value is higher than the preset second threshold, the opening of the material inlet valve assembly (3) is reduced; When the actual negative pressure value is higher than or equal to the preset first threshold and lower than or equal to the preset second threshold, it indicates that the actual negative pressure value in the gas-material mixing expansion joint (4) is in a normal state.

8. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 6, characterized in that: The formula for calculating the current air density is: ， in, Given the current air density, Standard air density, , The temperature value collected by the temperature sensor (8); The formula for calculating the dynamic pressure is: ， in, For dynamic pressure, The wind speed value collected by the wind speed sensor (7); The formula for calculating the actual negative pressure value is: ， ， in, The total resistance is due to negative pressure. Let L be the frictional resistance coefficient of the material inlet pipe (2), L be the actual length of the material inlet pipe (2), and D be the diameter of the material inlet pipe (2). It is the sum of local drag coefficients. This is the actual negative pressure value.

9. The air intake volume regulating and anti-backflow device for grain processing mills according to claim 1, characterized in that: It also includes a display (10) which is electrically connected to the controller (9); After calculating the actual negative pressure value, the controller (9) outputs the airflow speed detection signal, temperature detection signal and negative pressure signal; The display (10) is used to receive the airflow speed detection signal, temperature detection signal and negative pressure signal output by the controller (9), and to display the airflow speed value, temperature value and actual negative pressure value reflected by the above three signals.

10. The air intake regulating and anti-backflow device for grain processing mills according to claim 7, characterized in that: It also includes a first alarm (110) and a second alarm (120). When the actual negative pressure value is less than the preset first threshold, the controller (9) outputs a first alarm signal to the first alarm (110). The first alarm (110) alarms after receiving the first alarm signal. When the actual negative pressure value is greater than the preset second threshold, the controller (9) outputs a second alarm signal to the second alarm (120). The second alarm (120) alarms after receiving the second alarm signal. The first alarm (110) and the second alarm (120) are both audible and visual alarms. During the alarm process, the sound and color emitted by the first alarm (110) and the second alarm (120) are different.

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