Sodium carboxymethyl cellulose feeding device and use method thereof

Abstract

The invention relates to the technical field of feeding equipment, and provides a sodium carboxymethyl cellulose feeding device and a using method thereof.The sodium carboxymethyl cellulose feeding device comprises a spiral conveyor used for conveying sodium carboxymethyl cellulose, and the spiral conveyor comprises a shell; the side wall of the shell is provided with an air cavity and an injection hole used for communicating the air cavity with an inner cavity of the shell, and the air cavity is communicated with an external air source through an air pipe and used for introducing compressed air. The side wall of the shell is provided with the air cavity and the jet hole communicating the air cavity with the inner cavity of the shell, compressed air penetrates through the jet hole to form jet flow, a material adhesion layer on the inner wall of the shell can be stripped, material blockage is avoided, the device does not depend on manpower, and the automation degree and the material conveying production efficiency are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of feeding equipment, in particular to a sodium carboxymethyl cellulose feeding device and a use method thereof. BACKGROUND

[0002] Sodium carboxymethyl cellulose (CMC-Na) is an organic matter, which is a carboxymethyl derivative of cellulose, and is the most important ionic cellulose glue. It is usually prepared by reacting natural cellulose, caustic soda and monochloroacetic acid to form an anionic polymer compound with a molecular weight of several thousand to one million. CMC-Na is a white fibrous or granular powder, odorless, tasteless, hygroscopic, and easy to disperse in water to form a transparent colloidal solution.

[0003] In the process of large-scale production or processing of sodium carboxymethyl cellulose, a screw conveyor is often used to convey the material, such as conveying sodium carboxymethyl cellulose to a grinding device for grinding and crushing, or conveying natural cellulose powder, the raw material of sodium carboxymethyl cellulose, to a batching tank to prepare sodium carboxymethyl cellulose. Because sodium carboxymethyl cellulose and its raw material natural cellulose have the characteristics of moisture absorption and caking, especially sodium carboxymethyl cellulose, the material is easy to adhere to the screw blade and the inner wall of the shell during the conveying process, causing blockage.

[0004] In the prior art, after the material blocks the screw conveyor, the screw conveyor is stopped for maintenance by the technician, and after the blocked part is dredged, the screw conveyor is powered on again to continue conveying the material. This way of relying on technicians to solve the blockage problem has low material conveying production efficiency and needs to be further optimized. SUMMARY

[0005] Therefore, in order to solve the problem of low material conveying production efficiency caused by manual solution of sodium carboxymethyl cellulose material blockage in the prior art, the present application provides a sodium carboxymethyl cellulose feeding device and a use method thereof, and the specific technical solutions are as follows: A sodium carboxymethyl cellulose feeding device, comprising a screw conveyor for conveying sodium carboxymethyl cellulose, the screw conveyor comprising a shell, a gas cavity being provided on the side wall of the shell, and a jet hole for connecting the gas cavity and the inner cavity of the shell, the gas cavity being connected with an external gas source through a gas pipe, and the gas cavity being used for introducing compressed air.

[0006] The sodium carboxymethyl cellulose feeding device has the gas cavity provided on the side wall of the shell and the jet hole for connecting the gas cavity and the inner cavity of the shell, the compressed air forms a jet through the jet hole, the material adhesion layer on the inner wall of the shell is peeled off, and the blockage of the material is avoided. It does not depend on manual operation, improves the degree of automation and the material conveying production efficiency.

[0007] Preferably, the feeding device further comprises a control center, the air cavity comprises a plurality of air cavities, the control center is configured to construct a coordinate axis along an axis of the shell, obtain historical data of blockage of an inner wall of the shell, construct a probability distribution model between a coordinate position of the inner wall of the shell and a blockage probability according to the historical data of blockage of the inner wall of the shell, construct a first mapping function between the blockage probability and an air pressure of the air cavity according to the probability distribution model, and adjust the air pressure of each air cavity according to the first mapping function.

[0008] Preferably, the feeding device further comprises a suspension bearing and a screw rod, the suspension bearing is fixedly installed on the shell, the screw rod passes through an inner ring of the suspension bearing and is fixedly connected with the inner ring, the controller is configured to obtain a Sigmoid function term for representing attenuation of a blockage risk of the feeding port according to the coordinate position of the inner wall of the shell and a blockage risk inflection point, obtain a Gaussian function term for representing a local risk peak at the suspension bearing according to the coordinate position of the inner wall of the shell and a coordinate position of the suspension bearing, obtain a blockage probability function according to the Sigmoid function term and the Gaussian function term, and finally fit the blockage probability function according to the historical data of blockage to obtain the probability distribution model.

[0009] Preferably, the controller is further configured to obtain the blockage probability according to the probability distribution model, construct a second mapping function between the blockage probability and a pulse frequency of the air pressure, so that when the blockage probability is in a preset blockage transition probability interval, the pulse frequency of the air pressure exponentially increases with the blockage probability, and when the blockage probability is in a preset blockage probability saturation interval, the pulse frequency of the air pressure is stable at a preset maximum pulse frequency.

[0010] Preferably, the shell is in a cylindrical shape, the air cavity is in an annular shape and is arranged around a side wall of the shell, and a hole axis of the injection hole is at a preset angle with a surface of an inner wall of the shell in a material conveying direction.

[0011] Preferably, the screw conveyor further comprises a spiral blade, a driving motor, a tail end bearing, a feeding port and a discharging port, the feeding port and the discharging port are respectively arranged at two ends of the shell, the screw shaft is rotatably installed in the shell, the spiral blade is fixedly installed on the screw shaft, the driving motor is fixedly installed on the shell and an output shaft is in transmission connection with one end of the screw rod, the tail end bearing is fixedly installed on one end of the shell close to the discharging port, and the other end of the screw rod is fixedly connected with an inner ring of the tail end bearing.

[0012] A method for using a sodium carboxymethyl cellulose feeding device, applied to the feeding device, comprising: feeding the sodium carboxymethyl cellulose through the screw conveyor; arranging the air cavity on a side wall of the shell of the screw conveyor; and An injection hole is provided for connecting the air cavity with the inner cavity of the shell; The air cavity is connected to an external air source through an air pipe, and compressed air is introduced into the air cavity.

[0013] Preferably, the method for using the feeding device further comprises: Construct the coordinate axis along the shell axis; Obtain historical blockage data of the shell inner wall; Constructing a probability distribution model between the coordinate position of the inner wall of the shell and the probability of blockage based on the historical blockage data of the inner wall of the shell; Constructing a first mapping function between the probability of material blocking and the air pressure of the air cavity according to the probability distribution model; adjusting the air pressure of each of the air cavities according to the first mapping function; Wherein, the air cavity includes multiple ones.

[0014] Preferably, constructing a probability distribution model specifically includes: According to the coordinate position of the inner wall of the shell And the turning point of blockage risk Get the Sigmoid function term used to represent the risk attenuation of the feed port ; According to the coordinate position of the inner wall of the shell and the coordinate position of the suspension bearing Get the Gaussian function term representing the local risk peak at the suspension bearing ; Obtaining the blocking probability function according to the Sigmoid function term and the Gaussian function term ; Fitting the material blockage probability function according to the historical material blockage data to obtain a probability distribution model; in, represents the probability of material blocking, They represent the preset maximum blocking probability of the feeding section and the maximum blocking probability of the suspension bearing, respectively. represents the natural exponential function, Indicates the preset risk diffusion range, Represents the risk attenuation rate.

[0015] Preferably, the first mapping function is expressed as ; in, Indicates the coordinate position of the inner wall of the shell The air cavity pressure at They respectively represent the maximum safe air pressure allowed by the equipment and the preset minimum air pressure for safe operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a whole structure schematic diagram of a sodium carboxymethyl cellulose feeding device in an embodiment of the present application. Figure 2 It is an axial structure section schematic diagram of a sodium carboxymethyl cellulose feeding device in an embodiment of the present application. Figure 3 It is a structure relationship schematic diagram between partial components of a sodium carboxymethyl cellulose feeding device in an embodiment of the present application. Figure 4 It is a radial structure section schematic diagram of a sodium carboxymethyl cellulose feeding device in an embodiment of the present application. Figure 5 It is a whole flow schematic diagram of a sodium carboxymethyl cellulose feeding device using method in an embodiment of the present application. Figure 6 It is a whole flow schematic diagram of a sodium carboxymethyl cellulose feeding device using method in another embodiment of the present application. Figure 7 It is a flow schematic diagram of a specific method for constructing a probability distribution model in an embodiment of the present application. Figure 8 It is a relationship schematic diagram between a plugging probability and a gas cavity air pressure adjustment in an embodiment of the present application.

[0017] Explanation of reference signs: 1, shell; 2, gas cavity; 3, injection hole; 4, spiral blade; 5, driving motor; 6, feeding port; 7, discharging port; 8, suspension bearing; 9, spiral rod; 10, high-risk area; 11, medium-risk area; 12, low-risk area. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the present application is further described in detail below in combination with its embodiments.

[0019] As shown in Figure 1 , Figure 2 and Figure 4 , an embodiment of the present application provides a sodium carboxymethyl cellulose feeding device, which comprises a spiral conveyor for conveying sodium carboxymethyl cellulose, the spiral conveyor comprising a shell 1, a gas cavity 2 and an injection hole 3 for connecting the gas cavity 2 with the inner cavity of the shell 1 being arranged on the side wall of the shell 1, the gas cavity 2 being connected with an external air source through an air pipe, and the gas cavity 2 being used for introducing compressed air.

[0020] Specifically, the air cavity 2 includes multiple. Multiple air cavities 2 can be distributed equidistantly along the axial direction of the shell 1, or can be divided into different regions according to actual needs, and each region corresponds to an air cavity 2 covering the region and different jet hole 3 densities for each region. Of course, multiple air cavities 2 can also be equidistantly arranged along the length direction of the shell 1 in each region. For example, according to historical production data of carboxymethyl cellulose sodium such as the historical number of times of CMC-Na blockage at different positions of the inner wall of the shell 1, the blockage risk level of different regions of the inner wall of the shell 1 can be determined, and then the jet hole 3 density of different regions can be determined according to the blockage risk level. Here, a risk-density mapping model between the blockage risk level and the jet hole 3 density can be constructed first, and then the jet hole 3 density of different regions can be determined according to the risk-density mapping model. In this way, by setting a matching jet hole 3 density for regions with different blockage risks, it is possible to avoid wasting energy due to too high jet hole 3 density or insufficient airflow power due to too low jet hole 3 density, and to balance energy consumption and blockage cleaning ability.

[0021] In general, referring to Figure 3 Because the CMC-Na powder is not fully fluidized and is prone to accumulate downstream or near the feed inlet 6 of the screw conveyor, the region 1-2 meters downstream of the feed inlet 6, i.e., the region of the inner wall of the shell 1 starting from the feed inlet 6 and being 1-2 meters away from the starting point along the axial direction of the shell 1, can be regarded as a high-risk region 10. For the screw conveyor with a suspension bearing 8, the presence of the protruding structure of the suspension bearing 8 also tends to cause blockage, so the region of the inner wall of the shell 1 on both sides of the suspension bearing 8 within a certain distance range can be regarded as a medium-risk region 11. The suspension bearing 8 serves to support the screw rod 9, avoid deformation and sagging of the screw rod 9 due to length and material factors, and prevent friction between the screw blade 4 and the inner wall of the shell 1, as well as prevent overloading loss caused by collapse of the screw rod 9. Since the structure and installation method of the suspension bearing 8 belong to the prior art, they will not be described here. Upstream of the discharge outlet 7, the material has been accelerated and has good fluidity, so the blockage risk is generally low, and the region near the discharge outlet 7 can be regarded as a low-risk region 12. Of course, according to the length of the shell 1 and the historical blockage of the feed inlet 6, the length and specific position of the high-risk region 10, the medium-risk region 11, and the low-risk region 12 can be adjusted appropriately.

[0022] As a preferred technical solution, the shell 1 is cylindrical, the air cavity 2 is annular and is arranged around the side wall of the shell 1, and the hole axis of the jet hole 3 is at a preset angle with the inner wall surface of the shell 1 in the direction opposite to the material conveying direction.

[0023] Exemplarily, the injection holes 3 are uniformly distributed along the annular air cavity 2 in the axial direction, the annular air cavity 2 can be formed by laser welding of 304 stainless steel, for the high-risk area 10, the injection hole 3 porosity density corresponding to the inner wall of the shell 1 can be set to 40%-60%; for the medium-risk area 11, the injection hole 3 porosity density corresponding to the inner wall of the shell 1 can be set to 20%-40%; for the low-risk area 12, the injection hole 3 porosity density corresponding to the inner wall of the shell 1 can be set to 10%-20%. The porosity density mentioned here is only for reference, which can be adjusted accordingly in different actual application scenarios. Each annular air cavity 2 is configured with a separate quick connector to connect with an external air source to realize independent air supply, so as to adjust the compressed air pressure of the annular air cavity 2 in different risk areas, thereby avoiding excessive or insufficient pressure caused by constant air pressure, and further balancing energy consumption and cleaning efficiency.

[0024] Exemplarily, when each area is provided with a plurality of equally spaced annular air cavities 2, the width of the annular air cavity 2 is typically set to 15-25 mm to ensure uniform airflow distribution, and the depth is typically set to 8-12 mm to reduce flow resistance, and the airflow pressure is between 0.1-0.6 MPa. The diameter of the injection hole 3 is between 0.1-0.3 mm, and the inclination angle is 15°±2° (i.e. the preset included angle is 15°±2°) to generate high shear jet flow, thereby avoiding material adhesion to the inner wall of the shell 1 to cause blockage and stripping of the material adhered to the inner wall. In this way, by providing the air cavity 2 and the injection hole 3, an airflow layer can be formed on the inner wall of the shell 1 to achieve dynamic stripping of the material adhered to the inner wall.

[0025] More specifically, as shown in Figure 1 and Figure 2 , the screw conveyor further comprises a spiral blade 4, a driving motor 5, a tail end bearing, a feeding port 6 and a discharging port 7, the feeding port 6 and the discharging port 7 are respectively arranged at both ends of the shell 1, the spiral shaft is rotatably installed in the shell 1, the spiral blade 4 is fixedly installed on the spiral shaft, the driving motor 5 is fixedly installed on the shell 1 and the output shaft is in transmission connection with one end of the spiral rod 9, the tail end bearing is fixedly installed on one end of the shell 1 close to the discharging port 7, and the other end of the spiral rod 9 is fixedly connected with the inner ring of the tail end bearing. Since the structure of the screw conveyor belongs to the conventional technical means in the art, it will not be described here.

[0026] In summary, the sodium carboxymethyl cellulose feeding device is provided with the air cavity 2 on the side wall of the shell 1 and the injection hole 3 connecting the air cavity 2 and the inner cavity of the shell 1, compressed air penetrates the injection hole 3 radially to form a jet flow, which can strip the material adhesion layer on the inner wall of the shell 1 and avoid material blockage, which does not depend on manual operation, thereby improving the degree of automation and material conveying production efficiency.

[0027] In one of the embodiments, the feeding device further comprises a control center, the air cavities 2 are multiple, the control center is used to construct coordinate axes along the axis of the shell 1, obtain historical blockage data of the inner wall of the shell 1, construct a probability distribution model between the coordinate position of the inner wall of the shell 1 and the blockage probability according to the historical blockage data of the inner wall of the shell 1, construct a first mapping function between the blockage probability and the air pressure of the air cavity 2 according to the probability distribution model, and adjust the air pressure of each air cavity 2 according to the first mapping function.

[0028] Specifically, the control center includes but is not limited to a controller and an upper computer, and multiple air cavities 2 can be arranged at equal intervals along the length direction of the axis of the shell 1, or one air cavity 2 is arranged in each divided area. After the coordinate axes are constructed, the coordinate positions of the air cavities 2 are calibrated based on the coordinate axes. The historical blockage data of the inner wall of the shell 1 can be stored in the control center or a cloud server for easy calling. The probability distribution model includes but is not limited to a linear model, a polynomial, an exponential function model and a segmented function model. The first mapping function includes but is not limited to a linear model, a polynomial and an exponential function model.

[0029] As a preferred technical solution, as shown in Figure 1 and Figure 2 The feeding device further comprises a suspension bearing 8 and a screw rod 9, the suspension bearing 8 is fixedly installed on the shell 1, and the screw rod 9 penetrates the inner ring of the suspension bearing 8 and is fixedly connected with the inner ring. The controller is used to obtain a Sigmoid function term for representing the risk attenuation of the feeding port 6 according to the coordinate position of the inner wall of the shell 1 and the inflection point of the blockage risk, obtain a Gaussian function term for representing the local risk peak of the suspension bearing 8 according to the coordinate position of the inner wall of the shell 1 and the coordinate position of the suspension bearing 8, obtain a blockage probability function according to the Sigmoid function term and the Gaussian function term, and finally fit the blockage probability function according to the historical blockage data to obtain the probability distribution model.

[0030] The inflection point of the risk of plugging can be understood as the position at which the material in the feeding section begins to flow stably. The Sigmoid function term represents that the risk of plugging at the feeding port 6 gradually decreases as the distance between the inner wall of the shell 1 and the feeding port 6 increases. Because the humidity is high and the impact is large near the feeding port 6, the plugging probability is the highest, and the plugging probability gradually decreases as the axial distance increases. Assuming that the feeding port 6 corresponds to a maximum plugging probability, the inflection point of the risk of plugging can be understood as the inflection point at which the risk of plugging significantly decreases, and accordingly, the plugging probability at the inflection point is generally half of the maximum plugging probability. When the coordinate position of the inner wall of the shell 1 exceeds the inflection point, the plugging probability corresponding to the coordinate position will rapidly decrease to 0. The Gaussian function term represents the local risk peak value at the suspension bearing 8, that is, the suspension bearing 8 corresponds to a maximum additional plugging probability, and the plugging probability corresponding to the coordinate positions of the inner wall of the shell 1 on both sides of the suspension bearing 8 will gradually decrease and be normally distributed. Here, the Sigmoid function term is mainly used to dominate the global plugging probability trend and capture the gradual change process of the material flow stability, and the Gaussian function term is used to describe the local effect of the mechanical structure interference, so as to superimpose the plugging probability caused by the protruding structure of the suspension bearing 8 to the Sigmoid function term, thereby obtaining the probability distribution model.

[0031] Exemplarily, the Sigmoid function term is represented as , and the Gaussian function term is represented as ; wherein, represents the coordinate position of the inner wall of the shell 1, represents the inflection point of the risk of plugging, represents the coordinate position of the suspension bearing 8, respectively represent the preset maximum plugging probability of the feeding section and the maximum plugging probability at the suspension bearing 8, represents the natural exponential function, represents the preset risk diffusion range, represents the risk attenuation rate. The coordinate axis, the coordinate position relationship of the inflection point of the risk of plugging, and the suspension bearing 8 can be referred to in Figure 3 .

[0032] The plugging probability function can be represented as , wherein, represents the plugging probability. After obtaining the plugging probability function, the parameters such as the risk diffusion range and the risk attenuation rate are fitted and calibrated, and the probability distribution model can be obtained.

[0033] Assuming that the air pressure of the air cavity 2 at the coordinate position of the inner wall of the shell 1 is represented as , the first mapping function between the plugging probability and the air pressure of the air cavity 2 can be represented as .

[0034] , wherein, respectively represent the maximum safe air pressure allowed by the device and the minimum air pressure preset for the safe operation of the system. Here, the air pressure in the air cavity 2 in the first mapping function is positively proportional to the probability of blockage, which has a linear response characteristic. It takes the probability of blockage as the air cavity 2 pressure adjustment variable, dynamically matches the probability of blockage, and can reduce the calculation amount and improve the response speed compared with the exponential function.

[0035] In this way, by constructing the probability distribution model, the probability distribution model realizes the decoupling between the two blockage sources (the feed inlet 6 and the hanging bearing 8), and for the first time creates an accurate mapping relationship between the coordinate position of the inner wall of the shell 1 and the probability of blockage, which can be used as the basis for generating different air cavity 2 air pressure and frequency control strategies. According to the probability distribution model, a first mapping function between the probability of blockage and the air pressure of the air cavity 2 is constructed, and the air pressure of each air cavity 2 is adjusted according to the first mapping function, so that the space of the air pressure can be allocated on demand, the comprehensive energy consumption is reduced, and the energy consumption and the conveying production efficiency of the material are balanced.

[0036] In one embodiment, the controller is further configured to obtain the probability of blockage according to the probability distribution model, and construct a second mapping function between the probability of blockage and the air pressure pulse frequency, so that when the probability of blockage is in a preset blockage transition probability interval, the air pressure pulse frequency increases exponentially with the increase of the probability of blockage, and when the probability of blockage is in a preset blockage probability saturation interval, the air pressure pulse frequency is stable at a preset maximum pulse frequency.

[0037] For example, assuming that the air pressure pulse frequency at the coordinate position of the inner wall of the shell 1 is represented as , the second mapping function can be represented as . Wherein, respectively represent the minimum pulse frequency and the maximum pulse frequency. The minimum pulse frequency and the maximum pulse frequency can be set according to experience. Generally, the minimum pulse frequency is between 2-3 Hz, which is mainly used to ensure the peeling effect of the material adhering to the inner wall and avoid blockage of the material adhering to the inner wall, and the maximum pulse frequency is between 10-20 Hz, which can be understood as the maximum impact frequency that can be safely applied. The parameter 10 is the slope coefficient, which can be understood as the frequency transition steepness adjustment factor, and the greater the value, the narrower the transition interval. 0.5 is the risk level dividing line, when the probability of blockage is greater than 0.5, the high frequency mode is triggered.

[0038] Assuming that the minimum pulse frequency and the maximum pulse frequency are set to 2 Hz and 18 Hz respectively, when the probability of blockage =0.3, it can be understood as low risk, and the corresponding air pressure pulse frequency is 3.9 Hz; when the probability of blockage =0.6, which can be understood as high risk, and the corresponding air pressure pulse frequency is 13.7Hz. It can be understood that when the air pressure pulse frequency is greater than 10Hz, it is a high-frequency mode, and when the air pressure pulse frequency is less than 5Hz, it is a low-frequency mode.

[0039] In this embodiment, the second mapping function has an adaptive frequency adjustment mechanism. Specifically, in high-frequency mode, it can generate a critical shear force that breaks powder agglomerates, generating micro-scale turbulence, stripping away the nascent material adhesion layer, preventing material adhesion and agglomeration, and thus preventing material blockage. In low-frequency mode, it can maintain basic airflow layer continuity, reducing airflow energy consumption while preventing excessive airflow that could cause material scattering.

[0040] For example, the preset blocking probability transition interval is set to 0.4≤ ≤0.6, the preset blocking probability saturation interval is set to Greater than 0.6. When the blockage probability is in the transition range, the air pressure pulse frequency increases exponentially with the blockage probability. When the blockage probability is in the saturation range, the air pressure pulse frequency is maintained at the highest pulse frequency, providing a powerful pulsed airflow impact on the inner wall area of ​​the shell 1 with a higher blockage probability, ensuring the effective removal of the primary biomaterial adhesion layer. Therefore, the second mapping function also has nonlinear response characteristics. Its innovative use of blockage probability as a decision variable for the pulse frequency of air cavity 2 can better balance energy consumption and efficiency compared to timed pulses, and can save energy to a certain extent.

[0041] like Figure 5 As shown, one embodiment of the present invention further provides a method for using a sodium carboxymethyl cellulose feeding device, which is applied to the feeding device and comprises the following steps: S1, transports sodium carboxymethyl cellulose through a screw conveyor.

[0042] The screw conveyor generally includes a screw rod, a suspension bearing, a housing, a feed port and a discharge port provided on the housing, etc. Since the structure of the screw conveyor belongs to conventional technical means in this field, it will not be described in detail here.

[0043] S2, an air cavity 2 is provided on the side wall of the shell of the screw conveyor.

[0044] Exemplarily, the air cavity 2 is annular, with a width typically ranging from 15 to 25 mm to ensure uniform airflow distribution, a depth typically ranging from 8 to 12 mm to reduce flow resistance, and an airflow pressure between 0.1 and 0.6 MPa.

[0045] S3, providing an injection hole for connecting the air cavity 2 with the inner cavity of the shell.

[0046] Exemplarily, the diameter of the injection hole is between 0.1-0.3mm, and the inclination angle is 15°±2°, so as to generate a high-shear jet flow, avoid material adhesion to the inner wall of the shell and cause blockage, and strip the material that has adhered to the inner wall. In this way, by arranging the air cavity 2 and the injection hole, an air flow layer can be formed on the inner wall of the shell, and dynamic stripping of the material adhered to the inner wall can be achieved.

[0047] S4, the air cavity 2 is connected with an external air source through an air pipe, and compressed air is introduced into the air cavity 2.

[0048] Specifically, the air cavity 2 can include multiple air cavities. The multiple air cavities 2 can be distributed equidistantly along the axial line direction of the shell, or can be divided into different regions according to actual needs, and each region corresponds to an air cavity 2 covering the region and different injection hole densities for each region. Of course, multiple annular air cavities 2 can also be arranged equidistantly along the length direction of the shell in each region. Exemplarily, the blockage risk level of different regions of the inner wall of the shell can be determined according to historical production data of sodium carboxymethyl cellulose, such as the historical blockage times of CMC-Na at different positions of the inner wall of the shell, and then the injection hole density of different regions is determined according to the blockage risk level. Here, a risk-density mapping model between the blockage risk level and the injection hole density can be constructed first, and then the injection hole density of different regions is determined according to the risk-density mapping model. In this way, by setting the matching injection hole density for regions with different blockage risks, the waste of energy consumption caused by too high injection hole density or the insufficient air flow caused by too low injection hole density can be avoided, and the energy consumption and blockage cleaning ability are balanced.

[0049] For sodium carboxymethyl cellulose, due to its strong hygroscopicity, it is easy to adhere to the inner wall of the shell, especially near the feed inlet and at the suspension bearing in the middle section of the screw rod, thereby causing blockage. Generally, in the feed section from the feed inlet to 1-2 meters away from the feed inlet, the CMC-Na powder does not flow well and is easy to adhere to the inner wall and cause blockage, which belongs to a high-risk area. At the suspension bearing, the bearing structure is protruding and is easy to cause blockage, which belongs to a medium-risk area. For the discharge port, since the CMC-Na powder has been accelerated and has good flowability, the blockage probability is low, which belongs to a low-risk area. According to different lengths of the shell, specific installation positions of the suspension bearing, and historical blockage conditions of the feed inlet, the length and specific position of the high-risk area, the medium-risk area, and the low-risk area can be adjusted appropriately.

[0050] For high-risk areas, the jet hole aperture density corresponding to the inner wall of the shell can be set at 40%-60%, the air pressure can be set at 0.4MPa, and the air pressure pulse frequency can be set at 10Hz; for medium-risk areas, the jet hole aperture density corresponding to the inner wall of the shell can be set at 20%-40%, the air pressure can be set at 0.25MPa, and the air pressure pulse frequency can be set at 5Hz; for low-risk areas, the jet hole aperture density corresponding to the inner wall of the shell can be set at 10%-20%, the air pressure can be set at 0.15MPa, and the air pressure pulse frequency can be set at 2Hz. The aperture density mentioned here is only for reference, and can be adjusted accordingly in different actual application scenarios. Each annular air cavity 2 is configured with an independent quick interface to connect with an external air source to realize independent air supply, so as to adjust the compressed air pressure of the annular air cavity 2 in different risk areas, thereby avoiding excessive or insufficient air pressure caused by constant air pressure, and further balancing energy consumption and cleaning efficiency.

[0051] As a preferred technical solution, as shown in Figure 6 , the feeding device uses the method further comprising: S5, constructing a coordinate axis along the axis of the shell.

[0052] As shown in Figure 3 , assuming that the distance from the feed inlet to the discharge outlet is L, in meters, and the distance along the axial direction of the screw conveyor (i.e. the axis of the shell) is represented by , the feed inlet coordinate is represented by , and the discharge outlet coordinate is represented by .

[0053] S6, obtaining historical data of the shell inner wall.

[0054] Specifically, the historical plugging data can be stored in a control center or a cloud server for retrieval. In some cases, the shell inner wall historical plugging data can also be obtained from a plurality of different plant control center databases. For example, for plant A, the basic information of a plurality of other plants for conveying CMC-Na material through the screw conveyor can be obtained within a preset radius range taking plant A as the coordinate origin, and the plurality of other plants are screened according to the basic information. The shell inner wall historical plugging data is obtained from the control center databases of the plurality of other different plants after screening. The screening method includes: first selecting other plants that convey CMC-Na material in the same way as plant A, where the material conveying purpose includes conveying CMC-Na material through the screw conveyor to the grinding equipment for grinding and crushing, and conveying raw materials to the batching tank for preparing carboxymethyl cellulose sodium, and then obtaining the screw conveyor models of plant A and the other plants, and selecting the other plants with the same screw conveyor model as the plurality of other different plants after screening. Of course, modeling can also be performed according to the basic parameters of the screw conveyor, and the shell inner wall plugging simulation data is obtained based on the finite element simulation method, and the shell inner wall plugging simulation data is integrated into the shell inner wall historical plugging data. In this way, the shell inner wall historical plugging data can be enriched to improve the accuracy of the probability distribution model construction.

[0055] S7, constructing a probability distribution model between the shell inner wall coordinate position and the plugging probability according to the historical plugging data of the shell inner wall.

[0056] Exemplarily, as shown in Figure 7 , the specific method for constructing the probability distribution model includes the following steps: S71, obtaining the shell inner wall coordinate position and the plugging risk inflection point .

[0057] The plugging risk inflection point can be understood as the position at which the material in the feeding section begins to flow stably, and the typical value range is generally 1.0-2.0 m. The Sigmoid function term represents that the plugging risk of the feeding port gradually decreases as the distance between the shell inner wall position and the feeding port increases. Because the humidity is high and the impact is large near the feeding port, the plugging probability is the highest, and as the axial distance increases, the plugging probability gradually decreases. Assuming that the feeding port corresponds to a maximum plugging probability, the plugging risk inflection point can be understood as the inflection point position at which the plugging risk significantly decreases. Accordingly, the plugging probability at the inflection point position is generally half of the maximum plugging probability, and when the shell inner wall coordinate position exceeds the inflection point position, the plugging probability corresponding thereto will rapidly decrease to 0.

[0058] S72, obtaining the shell inner wall coordinate position and the suspension bearing coordinate position ​obtaining a Gaussian function term for representing a local risk peak at the hanging bearing .

[0059] The Gaussian function term represents a local risk peak at the hanging bearing, that is, the hanging bearing corresponds to a maximum additional plugging probability, and the plugging probability corresponding to the coordinate position of the inner wall of the shell on both sides of the hanging bearing gradually decreases and is normally distributed. The coordinate position of the hanging bearing, that is, the coordinate position corresponding to the center of the hanging bearing, is generally determined according to the actual arrangement of the equipment, and the typical value range is 3.0-8.0 m.

[0060] S73, obtaining a plugging probability function according to the Sigmoid function term and the Gaussian function term .

[0061] S74, fitting the plugging probability function according to the historical plugging data to obtain a probability distribution model.

[0062] wherein, represents the plugging probability, respectively represent the preset maximum plugging probability of the feeding section and the maximum plugging probability at the hanging bearing, represents the natural exponential function, represents the preset risk diffusion range, represents the risk attenuation rate.

[0063] Exemplarily, the maximum plugging probability of the feeding section has a typical value range of 0.4-0.6. The risk attenuation rate has a typical value of , and the greater the value, the steeper the Sigmoid function attenuation. The maximum plugging probability at the hanging bearing has a typical value of 0.2-0.4. The greater the value of the risk diffusion range, the wider the influence area, and the typical value range is 0.3-0.8 m.

[0064] The Sigmoid function term is mainly used to dominate the global plugging probability trend and capture the gradual change process of the material flow stability, and the Gaussian function term is used to describe the local effect of the mechanical structure interference. The plugging probability caused by the protruding structure of the hanging bearing is superimposed on the Sigmoid function term, so as to obtain the probability distribution model.

[0065] S8, constructing a first mapping function between the plugging probability and the air pressure of the air cavity 2 according to the probability distribution model.

[0066] S9, adjusting the air pressure of each air cavity 2 according to the first mapping function.

[0067] Exemplarily, the first mapping function is represented as , and the second mapping function is represented as ; wherein, Indicates the preset minimum air pressure for safe operation of the system. Represent the pressure gain coefficient and pressure fluctuation amplitude respectively, Indicates the air pressure pulse frequency, Represent the minimum pulse frequency and the maximum pulse frequency respectively. is a real-time variable.

[0068] The pressure gain coefficient is generally set between 0.3 and 0.8. The minimum pressure for safe system operation can be set to 0.1 MPa, and the maximum safe pressure can be set to 0.5 or 0.6 MPa. The minimum and maximum pulse frequencies can be set to 2 Hz and 20 Hz, respectively. The pressure fluctuation amplitude can be set between 0.05 and 0.15.

[0069] In the first mapping function, As a static basic pressure item, it is mainly used to ensure the stability of the airflow layer penetrating the injection hole. As a dynamic pulse pressure term, it is mainly used to generate periodic shear force to ensure the peeling effect of the material adhesion layer. Assuming that the blocking probability = 0.3, the minimum air pressure is set to 0.1MPa, and the pressure gain coefficient is set to 0.6, the static basic pressure term = 0.28MPa; the blocking probability = 0.8, the minimum air pressure is set to 0.1MPa, and the pressure gain coefficient is set to 0.6, then the static basic pressure term = 0.58MPa. By analyzing the first mapping function, it can be seen that it works in coordination with the pulse frequency of cavity 2 and has the characteristics of spatiotemporal coupling. Specifically, in the spatial dimension, the first mapping function is through the blocking probability , the axial pressure gradient can be realized, that is, it decreases from the feed port to the discharge port; in the time dimension, the first mapping function generates periodic shear force through the dynamic pulse pressure term, which can realize dynamic response.

[0070] In this embodiment, the second mapping function has an adaptive frequency adjustment mechanism. Specifically, in high-frequency mode, it can generate a critical shear force that breaks powder agglomerates, generating micro-scale turbulence, stripping away the nascent material adhesion layer, preventing material adhesion and agglomeration, and thus preventing material blockage. In low-frequency mode, it can maintain basic airflow layer continuity, reducing airflow energy consumption while preventing excessive airflow that could cause material scattering.

[0071] For example, the preset blocking probability transition interval is set to 0.4≤ ≤0.6, the preset blocking probability saturation interval is set to greater than 0.6. When the plugging probability is in the transition interval, the gas pressure pulse frequency increases exponentially with the increase of the plugging probability; and when the plugging probability is in the saturation interval, the gas pressure pulse frequency is maintained at the highest pulse frequency, and the inner wall region of the shell with a higher plugging probability can be subjected to a strong pulse airflow impact to ensure effective stripping of the initial biological material adhesion layer. Therefore, the second mapping function also has a nonlinear response characteristic, which first takes the plugging probability as a decision variable of the pulse frequency of the gas cavity 2, and can better balance the energy consumption and efficiency compared with the timing pulse, and to a certain extent, save energy consumption.

[0072] By constructing a probability distribution model, the probability distribution model realizes decoupling between the two plugging sources (the feed inlet and the suspension bearing), first creates an accurate mapping relationship between the coordinate position of the inner wall of the shell and the plugging probability, and can be used as a basis for generating different gas cavity 2 pressure and frequency control strategies. According to the probability distribution model, a first mapping function between the plugging probability and the gas cavity 2 pressure is constructed, and the pressure of each gas cavity 2 is adjusted according to the first mapping function, so that the space of the gas pressure can be distributed on demand, the comprehensive energy consumption is reduced, and the energy consumption and the conveying production efficiency of the material are balanced.

[0073] As a preferred technical solution, the gas cavity 2 pressure at the coordinate position of the inner wall of the shell is represented as , and the first mapping function between the plugging probability and the gas cavity 2 pressure can be represented as . Wherein, respectively represent the maximum safe gas pressure allowed by the device and the minimum gas pressure preset for safe operation of the system. Here, the gas cavity 2 pressure in the first mapping function is in a positive proportional relationship with the plugging probability, which has a linear response characteristic, and takes the plugging probability as a pressure adjustment variable of the gas cavity 2, which can dynamically match the plugging probability, and can reduce the calculation amount and improve the response speed compared with the exponential function.

[0074] As a preferred technical solution, the first mapping function between the plugging probability and the gas cavity 2 pressure can be represented as . In this first mapping function, the plugging probability is mapped to a smooth S-shaped curve by the tanh function, and the gas cavity 2 pressure is ensured to be between the minimum pressure and the maximum safe pressure. The denominator 0.2 in the tanh function controls the sensitivity of the response as a gain coefficient, which can be adjusted according to experience, and generally, it is set as the demarcation point between the plugging probability corresponding to the low-risk area and the plugging probability corresponding to the medium-risk area. For example, when the plugging probability ∈ [0, 0.3) is taken as the low-risk area, and the plugging probability ∈ [0.3, 0.6] is taken as the medium-risk area, the denominator can be adjusted from 0.2 to 0.3.

[0075] As Figure 8As shown, assuming that the low-risk area corresponds to a plugging probability less than 0.2, the air cavity 2 air pressure is in the slow pressure-increasing stage, and the tanh function curve as a whole presents linear characteristics; the transition area corresponds to a plugging probability of , then the air cavity 2 air pressure is in the super-linear pressure-increasing stage; the high-risk area corresponds to a plugging probability greater than 0.6, at this time , then the air cavity 2 air pressure is in the saturated pressure stage, . Here, since the tanh function belongs to (-1, 1), the air pressure of the air cavity 2 can be limited between the minimum air pressure and the maximum safe air pressure, which can ensure the minimum pressure when the plugging probability is in the low-risk area, ensuring the stability of the airflow layer, and can ensure the air pressure against overloading when the plugging probability is in the high-risk area, avoiding pressure overshoot and powder scattering. The first mapping function can realize the axial pressure gradient through the plugging probability, that is, decreasing along the direction from the feed port to the discharge port.

[0076] As a preferred technical solution, taking the direction of the feed port as left and the direction of the discharge port as right, the shell inner wall area on the left side of the plugging risk inflection point, that is, the shell inner wall area between the feed port and the plugging risk inflection point, is taken as the high-risk area; the shell inner wall area of the left and right risk diffusion range of the suspension bearing coordinate position is taken as the medium-risk area; and the other shell inner wall area except the high-risk area and the medium-risk area is taken as the low-risk area.

[0077] Exemplarily, the injection holes are uniformly distributed along the axial direction of the annular air cavity 2, the annular air cavity 2 is divided into three groups and corresponds to the high-risk area, the medium-risk area and the low-risk area respectively, and the annular air cavity 2 is wrapped around and coated on the shell side wall surface of the corresponding area. For the high-risk area, the injection hole porosity density corresponding to the shell inner wall can be set to 40%-60%, the air pressure can be set to 0.4 MPa, and the air pressure pulse frequency can be set to 10 Hz; for the medium-risk area, the injection hole porosity density corresponding to the shell inner wall can be set to 20%-40%, the air pressure can be set to 0.25 MPa, and the air pressure pulse frequency can be set to 5 Hz; for the low-risk area, the injection hole porosity density corresponding to the shell inner wall can be set to 10%-20%, the air pressure can be set to 0.15 MPa, and the air pressure pulse frequency can be set to 2 Hz. The porosity density mentioned here is only for reference and can be adjusted accordingly in different actual application scenarios. Each annular air cavity 2 is configured with an independent quick connector to connect with an external air source, so as to realize independent air supply, thereby adjusting the compressed air pressure of the annular air cavity 2 in different risk areas, avoiding excessively high or low pressure caused by constant air pressure, and further balancing the energy consumption and plugging cleaning efficiency.

[0078] ​Compared with dynamically adjusting the air pressure of the air cavity 2 and the air pressure pulse frequency according to the plugging probability, the embodiment matches the constant air pressure of the air cavity 2 and the air pressure pulse frequency for high, medium and low risk areas, which can reduce the calculation amount of the control center and reduce the complexity of system control. In addition, the air pressure and pulse frequency of different areas can also be accurately controlled to avoid excessive fluctuations of the air pressure and pulse frequency.

[0079] Exemplarily, the embodiment gives a specific acquisition method of the risk decay rate and the plugging risk inflection point. First, experimental data is collected, and the probability of plugging caused by the adhesion of CMC-Na powder to the inner wall of the screw conveyor shell is collected by installing vibration sensors or pressure film sensors at different axial positions of the inner wall of the shell, or the plugging probability of different positions of the shell inner wall is obtained based on finite element simulation, or the plugging probability of different positions is obtained according to the historical plugging data of the shell inner wall obtained by the on-site technical personnel during the past maintenance period.

[0080] Exemplarily, the corresponding plugging probability of the inner wall of the shell at different positions is shown in the following table:

[0081] Then, the Sigmoid function term is fitted based on the data in the above table. Specifically, nonlinear regression (such as Levenberg-Marquardt algorithm) can be used to fit the experimental data, and the residual sum of squares is minimized as the optimization target to obtain the risk decay rate, such as the risk decay rate .

[0082] For the plugging risk inflection point, the distribution curve can be drawn based on the experimental data in the above table, and then the coordinate position corresponding to the maximum slope point of the distribution curve is taken as the plugging risk inflection point. Of course, the initial adhesion concentrated area of the material can be identified and marked as a high-risk area by infrared thermal imaging, then the adhesion material thickness is measured every 0.2m along the axial direction of the shell, the distribution curve is drawn according to the measured adhesion material thickness data, and finally the coordinate position corresponding to the maximum slope point of the distribution curve is taken as the plugging risk inflection point, such as the plugging risk inflection point m.

[0083] Because the probability of blockage is different at different positions of the inner wall of the screw conveyor housing, variable pitch helical blades are used to match the probability of blockage. For example, in the feeding section, the pitch of the helical blades is increased to accelerate the material conveying, which can prevent the material from accumulating and blocking, and in the discharging section, the pitch of the helical blades is reduced to achieve stable conveying. Generally speaking, in the screw conveyor, the larger the pitch, the faster the material advancing speed, but the more intense the stirring, which may increase the risk of adhesion; the smaller the pitch, the slower the advancing speed, but the stirring is gentle. Therefore, the pitch and the material advancing speed need to be balanced. Considering the continuity of space and the limitation of mechanical structure, the pitch should not be suddenly changed, and therefore the change of the pitch of the helical blades needs to be smoothed.

[0084] In order to optimize the pitch of the helical blades, in one of the embodiments, the method for using the feeding device further includes a pitch parameter acquisition and determination process, which includes the following steps: In the first step, historical blockage data of a plurality of screw conveyors with the same model and the same conveying purpose of CMC-Na material are acquired, and a third mapping function between the blockage probability and the pitch is constructed.

[0085] Preferably, the housing angles of the plurality of screw conveyors are the same so that the corresponding historical blockage data has reference significance. The third mapping function can be set by the technician according to experience, and the model type thereof includes but is not limited to a linear function, a polynomial function and an exponential function.

[0086] In the second step, the maximum blockage probability of the feeding section and the maximum blockage probability at the hanging bearing in the historical blockage data of the plurality of screw conveyors are acquired, the first average of the plurality of maximum blockage probabilities of the feeding section and the second average of the plurality of maximum blockage probabilities at the hanging bearing are calculated, and the first average and the second average are respectively taken as the blockage probability of the feeding port and the blockage probability at the hanging bearing of the target screw conveyor.

[0087] In the third step, the minimum safe pitch (for example, 0.5-0.8 times of the diameter of the screw rod) is determined or the reference pitch is set according to experience.

[0088] In the fourth step, the pitch size of the feeding port and the pitch size at the hanging bearing are determined according to the first average, the second average and the third mapping function, and the pitches of the helical blades in the high-risk area, the medium-risk area and the low-risk area are determined according to the pitch size of the feeding port, the pitch size at the hanging bearing, the minimum safe pitch or the pitch size of the feeding port, the pitch size at the hanging bearing, the reference pitch.

[0089] For example, it is assumed that the pitch size of the feeding port is equal to 1.8 times of the diameter of the screw rod, the pitch size at the hanging bearing is equal to 1.5 times of the diameter of the screw rod, the reference pitch and the minimum safe pitch are both 0.8 times of the diameter of the screw rod, and if If the distance between the blocking risk inflection point and the medium risk area is less than the preset distance threshold, the pitch of the spiral blade at the feed inlet is set to 1.8 times the screw diameter, and the pitch of the spiral blade at the suspension bearing is set to 1.5 times the screw diameter. Then, the pitch of the spiral blade between the feed inlet and the suspension bearing is smoothly reduced from 1.8 times to 1.5 times the screw diameter. If the distance is less than the preset distance threshold, it can be understood that the distance between the high-risk area and the medium-risk area is limited. If the spiral blade pitch in the high-risk area is uniformly set to 1.8 times the screw rod diameter and the spiral blade pitch in the medium-risk area is uniformly set to 1.5 times the screw rod diameter, the distance from the blocking risk inflection point to the medium-risk area is too small, and it may not be possible to effectively smoothly decrease the spiral blade pitch in the low-risk area. The purpose of setting the preset distance threshold here is to ensure a smooth transition of the spiral blade pitch in the low-risk area between the high-risk area and the medium-risk area.

[0090] like If the distance between the high-risk and medium-risk areas is not less than the preset distance threshold, it means that the distance between the high-risk and medium-risk areas is sufficient to ensure a smooth transition of the spiral blade pitch. In this case, the spiral blade pitch in the high-risk area can be uniformly set to 1.8 times the screw rod diameter, and the spiral blade pitch in the medium-risk area can be uniformly set to 1.5 times the screw rod diameter. The spiral blade pitch in the low-risk area between the high-risk and medium-risk areas can be smoothly reduced from 1.8 times to 1.5 times.

[0091] Of course, assuming the coordinates at the discharge port are ,exist When the distance is less than the preset threshold, it can be understood that the distance between the discharge port and the medium-risk area is limited. At this time, the pitch of the spiral blade at the suspension bearing can be set to 1.5 times the diameter of the screw rod, and the pitch of the spiral blade between the suspension bearing and the discharge port can be smoothly reduced from 1.5 times to 0.8 times the diameter of the screw rod. Not less than the preset distance threshold, it can be understood that the distance between the discharge port and the low-risk area is sufficient for a smooth transition of the decreasing pitch. At this time, the pitch of the spiral blades in the medium-risk area can be uniformly set to 1.5 times the diameter of the screw rod, and the coordinates To the discharge port The pitch of the spiral blades between them decreases smoothly from 1.5 times to 0.8 times.

[0092] That is, assuming the preset distance threshold is ,like , set the spiral blade pitch at the feed inlet to 1.8 times the screw rod diameter, set the spiral blade pitch at the suspension bearing to 1.5 times the screw rod diameter, and then the spiral blade pitch between the feed inlet and the suspension bearing will decrease smoothly from 1.8 times to 1.5 times the screw rod diameter. Otherwise, set the spiral blade pitch in the high-risk area to 1.8 times the screw rod diameter, and set the spiral blade pitch in the medium-risk area to 1.5 times the screw rod diameter. The spiral blade pitch in the low-risk area between the high-risk area and the medium-risk area will decrease smoothly from 1.8 times to 1.5 times. If , set the spiral blade pitch at the suspension bearing to 1.5 times the screw rod diameter, and make the spiral blade pitch between the suspension bearing and the discharge port decrease smoothly from 1.5 times to 0.8 times the screw rod diameter. Otherwise, set the spiral blade pitch in the medium risk area to 1.5 times the screw rod diameter. To the discharge port The spiral blade pitch between them decreases smoothly from 1.5 times to 0.8 times. In this way, not only can the spiral blade pitch be optimized according to the probability of material blockage, but also the spiral blade pitch of the screw conveyor can be smoothly transitioned, balancing the pitch and material advancement speed.

[0093] In this embodiment, the time span of the historical blockage data can be one quarter, six months, or one year. The preset distance threshold is set by the technician based on experience. After determining the pitch parameters of each region of the target screw conveyor's spiral blade, the spiral blade can be welded and installed according to the determined pitch parameters. For example, multiple spring-type spiral blades with corresponding pitch parameters can be spliced ​​together to obtain a complete spiral blade.

[0094] As a preferred technical solution, the third mapping function is expressed as .in, They represent the maximum safe pitch (such as 1.5-1.8 times the diameter of the screw rod) and the minimum safe pitch (such as 0.5-0.8 times the diameter of the screw rod). They represent the attenuation intensity coefficient (generally between 1.5-2.5) and the nonlinear adjustment factor (generally between 0.8-1.2). It represents the maximum value among the maximum blocking probabilities of multiple feeding sections. Indicates location The probability of material blocking at the feed inlet Equal to the first mean, the suspension bearing Equal to the second mean.

[0095] For the feed port, , pitch Therefore, the large pitch can reduce the material filling rate and avoid the accumulation of feed materials and the resulting blockage; approximately equal to zero, provided that equal to 0.8, the attenuation intensity coefficient and the non-linear adjustment factor are 2 and 1 respectively, and the corresponding pitch Therefore, by slowing down the material advancing speed through small pitch, the material compression force is increased, backflow is inhibited, and stable conveying is achieved.

[0096] The attenuation intensity coefficient is used to control the pitch attenuation speed, and the default value is set to 2.0. The non-linear adjustment factor is used to adjust the response non-linearity, and the default value is 1.0. In the third mapping function model, the negative exponential can ensure that the pitch monotonically decreases with the increase of the blockage probability, and the power exponential can enhance the sensitivity of the medium and high risk areas. Therefore, the third mapping function model has a double exponential cooperative control mechanism.

[0097] The constant 0.2 in the third mapping function model can be understood as a probability demarcation point, which can be linked with the constant 0.2 in the first mapping function , so that they remain consistent and change synchronously. That is to say, 0.2 is essentially the demarcation point between the blockage probability corresponding to the low risk area and the blockage probability corresponding to the medium risk area. When the blockage probability ∈ [0, 0.3) is taken as the low risk area, and the blockage probability ∈ [0.3, 0.6] is taken as the medium risk area, the denominator can be adjusted from 0.2 to 0.3. Here, the constant 0.2 in the third mapping function model mainly functions to enhance the sensitivity of the model to the medium and high risk areas through the power exponential.

[0098] Through the third mapping function, a precise mapping relationship between the blockage probability and the pitch can be constructed to prevent the accumulation of the CMC-Na material during the conveying process, thereby achieving stable transmission. The linkage with the first mapping function and the determination of the probability demarcation point 0.2 can be coupled with the air chamber 2 air pressure control to construct a cooperative anti-blocking mechanism.

[0099] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the protection scope of the present application patent should be subject to the appended claims.

Claims

1. A sodium carboxymethyl cellulose feeding device comprising a screw conveyor for conveying sodium carboxymethyl cellulose, the screw conveyor comprising a housing, characterized in that, The side wall of the shell is provided with an air cavity and a jet hole for connecting the air cavity with the inner cavity of the shell, the air cavity is connected with an external air source through an air pipe, and the air cavity is used for introducing compressed air.

2. The charging device of claim 1, wherein Further comprising a control center, the air cavity comprises a plurality of air cavities, the control center is used for constructing coordinate axes along the axial line of the shell, obtaining historical blocking data of the inner wall of the shell, constructing a probability distribution model between the coordinate position of the inner wall of the shell and the blocking probability according to the historical blocking data of the inner wall of the shell, constructing a first mapping function between the blocking probability and the air pressure of the air cavity according to the probability distribution model, and adjusting the air pressure of each air cavity according to the first mapping function.

3. The charging device of claim 2, wherein The feeding device further comprises a suspension bearing and a screw rod, the suspension bearing is fixedly installed on the shell, the screw rod passes through the inner ring of the suspension bearing and is fixedly connected with the inner ring, the controller is used for obtaining a Sigmoid function item for representing the risk attenuation of the feeding port according to the coordinate position of the inner wall of the shell and the inflection point of the blocking risk, obtaining a Gaussian function item for representing the local risk peak at the suspension bearing according to the coordinate position of the inner wall of the shell and the coordinate position of the suspension bearing, obtaining a blocking probability function according to the Sigmoid function item and the Gaussian function item, and finally fitting the blocking probability function according to the historical blocking data to obtain the probability distribution model.

4. The charging device of claim 3, wherein The controller is further used for obtaining the blocking probability according to the probability distribution model, constructing a second mapping function between the blocking probability and the air pressure pulse frequency, so that when the blocking probability is in a preset blocking transition probability interval, the air pressure pulse frequency increases exponentially with the increase of the blocking probability, and when the blocking probability is in a preset blocking probability saturation interval, the air pressure pulse frequency is stable at a preset maximum pulse frequency.

5. A charging device according to claim 4, wherein The shell is in a cylindrical shape, the air cavity is in an annular shape and is arranged around the side wall of the shell, and the hole axis of the jet hole is at a preset angle with the surface of the inner wall of the shell in the direction opposite to the material conveying direction.

6. The sodium carboxymethyl cellulose charging device of claim 5, wherein The screw conveyor further comprises a spiral blade, a driving motor, a tail end bearing, a feeding port and a discharging port, the feeding port and the discharging port are respectively arranged at two ends of the shell, the screw shaft is rotatably installed in the shell, the spiral blade is fixedly installed on the screw shaft, the driving motor is fixedly installed on the shell and an output shaft is in transmission connection with one end of the screw rod, the tail end bearing is fixedly installed on one end of the shell close to the discharging port, and the other end of the screw rod is fixedly connected with the inner ring of the tail end bearing.

7. A method of using a sodium carboxymethylcellulose charging device in a charging device according to any one of claims 1 to 6, characterized in that, Comprise: Conveying sodium carboxymethyl cellulose through the screw conveyor; Providing an air cavity on the side wall of the shell of the screw conveyor; Providing a jet hole for connecting the air cavity with the inner cavity of the shell; Connecting the air cavity with an external air source through an air pipe and introducing compressed air into the air cavity.

8. The method of using a charging device of claim 7, wherein, Further comprise: Constructing coordinate axes along the axial line of the shell; Obtaining historical blocking data of the inner wall of the shell; Constructing a probability distribution model between the coordinate position of the inner wall of the shell and the blocking probability according to the historical blocking data of the inner wall of the shell; Constructing a first mapping function between the blocking probability and the air pressure of the air cavity according to the probability distribution model; Adjusting the air pressure of each air cavity according to the first mapping function; The air cavity comprises a plurality of air chambers.

9. The method of using a charging device of claim 8, wherein, The constructing the probability distribution model specifically comprises: According to the coordinate position of the inner wall of the shell And the risk inflection point of plugging Obtain the Sigmoid function term for representing the risk attenuation of the feed inlet ; According to the housing inner wall coordinate position and the suspension bearing coordinate position Obtaining a Gaussian function term representing a local risk peak at the suspension bearing ; According to the Sigmoid function term and the Gaussian function term, a blockage probability function is obtained ; Fitting the blockage probability function according to the historical blockage data to obtain a probability distribution model; and wherein, represents a probability of plugging, respectively represent a preset maximum plugging probability of the feeding section and a maximum plugging probability at the suspension bearing, represents a natural exponential function, represents a preset risk diffusion range, represents a risk decay rate.

10. The method of using a charging device of claim 9, wherein, The first mapping function is represented as ; wherein, represents the air cavity air pressure at the coordinate position of the inner wall of the shell, respectively represent the maximum safe air pressure allowed by the device and the minimum air pressure for the preset safe operation of the system.​

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