System for preventing raw material conveying mechanism from being stuck and judgment method

Abstract

The invention relates to a system for preventing a raw material conveying mechanism from being stuck and a judgment method, the system for preventing the raw material conveying mechanism from being stuck comprises a main control unit, and the main control unit is electrically connected with a pre-filtration pressure sensor, a post-filtration pressure sensor and a box body pressure sensor; the pre-filtration pressure sensor is arranged on the pipeline between the extruder and the filter and used for detecting the pressure in the pipeline between the extruder and the filter, and the post-filtration pressure sensor is arranged on the pipeline between the filter and the metering pump and used for detecting the pressure in the pipeline between the filter and the metering pump; the box body pressure sensor is arranged on the pipeline between the metering pump and the spinning box and used for detecting the pressure in the pipeline between the metering pump and the spinning box, or the box body pressure sensor is arranged on the spinning box and used for measuring the pressure of a flow channel in the spinning box. Whether the pressure in the pipeline is too large or not is judged through the pressure sensor, and therefore whether the raw material conveying mechanism is stuck or not is judged.

Description

Technical Field

[0001] The present invention relates to the technical field of nonwoven fabrics, and more particularly to a system and a judgment method for preventing a raw material conveying mechanism from getting stuck. Background Art

[0002] In order to provide the spinning box with stable pressure and a continuous supply of polymer melt, thereby ensuring the stability of spinning, power units such as screw extruders and metering pumps and filter units such as melt filters are often required. The pressure of the spinning box is positively correlated with the pipeline pressure between the metering pump and the screen changer (referred to as the post-filter pressure), that is, in order to ensure the stability of the spinning box pressure, the post-filter pressure must be stable. However, as the interception volume of the filter unit gradually accumulates, the pressure difference before and after the filter will gradually increase. Therefore, in order to maintain the stability of the post-filter pressure, the pressure before the filter must be adjusted at any time. In addition, there are filter screens in the filter and the spinning box, and both require manual screen replacement, which will cause pressure fluctuations during the period, and the change in output requires the adjustment of the metering pump speed, which are all sources of instability in the spinning system.

[0003] Therefore, how to better ensure the pressure stability of the raw material conveying mechanism is exactly the technical problem to be solved by this application. Summary of the invention

[0004] In view of the shortcomings of the prior art, on the one hand, the present invention proposes a system for preventing the raw material conveying mechanism from getting stuck. The system determines whether the pressure in the pipeline is too high by using a pre-filter pressure sensor, a post-filter pressure sensor and a box pressure sensor, thereby determining whether there is a material jamming problem in the raw material conveying mechanism.

[0005] The present invention provides a system for preventing a material conveying mechanism from getting stuck, and the technical solution is as follows:

[0006] A system for preventing a raw material conveying mechanism from getting stuck comprises a main control unit, wherein the main control unit is electrically connected to a pre-filter pressure sensor, a post-filter pressure sensor and a box pressure sensor;

[0007] The extruder is connected to the filter through a pipeline, the filter is connected to the metering pump through a pipeline, and the metering pump is connected to the spinning box through a pipeline;

[0008] The pre-filter pressure sensor is arranged on the pipeline between the extruder and the filter, and is used to detect the pressure in the pipeline between the extruder and the filter. The post-filter pressure sensor is arranged on the pipeline between the filter and the metering pump, and is used to detect the pressure in the pipeline between the filter and the metering pump.

[0009] The box pressure sensor is arranged on the pipeline between the metering pump and the spinning box to detect the pressure in the pipeline between the metering pump and the spinning box, or the box pressure sensor is arranged on the spinning box to measure the flow channel pressure in the spinning box.

[0010] On the other hand, a judgment method for preventing the material conveying mechanism from getting stuck is proposed, which includes the following process:

[0011] The main control unit is provided with a preset pressure difference value. When the main control unit determines that the pressure difference value detected by the pre-filter pressure sensor and the post-filter pressure sensor is greater than the preset pressure difference value, an alarm signal is generated;

[0012] The main control unit is provided with a box pressure alarm value. When the main control unit determines that the pressure value detected by the box pressure sensor is greater than the box pressure alarm value, an alarm signal is generated.

[0013] In summary, the above technical scheme has the following beneficial effects: the raw material conveying mechanism of spunbond woven fabric is generally connected to the extruder through a feeding weighing system through a pipeline, the extruder is connected to the filter through a pipeline, the filter is connected to the metering pump through a pipeline, and the metering pump is connected to the spinning box through a pipeline, so that the material is melted into a solution and then spun. Specifically, the feeding weighing system is responsible for sucking the granular polymer material from a distant or low position and accurately weighing and mixing it for use by the extruder. The extruder is responsible for heating and plasticizing the mixed granular material and finally extruding it into a continuous and uniform high-temperature polymer melt. The filter, also known as the screen changer, is responsible for the initial filtration of the melt at the outlet of the extruder. The metering pump, also known as the spinning pump, mainly performs further pressure boosting, voltage stabilization and volume measurement on the filtered melt. The metering pump motor is a power source that delivers power to the metering pump. The spinning box can evenly distribute and filter the melt at the outlet of the metering pump along the width direction, and finally generate thousands of melt streams.

[0014] When the filter screen is put into use, impurities and ash in the melt begin to accumulate on the working surface of the filter screen, which gradually reduces the effective filtering area of ​​the filter screen, increases the filtering resistance, reduces the flow rate, and then causes the pressure after filtering to drop; in order to keep the pressure after filtering stable, the main control unit sets the extruder to accelerate, thereby increasing the pressure before filtering, increasing the pressure difference of the melt on both sides of the filter to increase the flow rate, and restore the pressure after filtering to the normal setting value. When the melt pressure difference on both sides of the filter reaches the preset pressure difference a, the control system alarms and prompts the operator to replace the filter screen, 3MPa≤a≤5MPa.

[0015] When the melt pressure in the spinning box reaches the box pressure alarm value b, the control system alarms and prompts the operator to replace the filter of the spinning box, 4MPa≤b≤8MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the module structure of a system for preventing a material conveying mechanism from getting stuck;

[0017] Figure 2 A schematic diagram of a material conveying mechanism of a system for preventing the material conveying mechanism from getting stuck;

[0018] Figure 3 A schematic diagram of a sensor for a system for preventing a material conveying mechanism from getting stuck;

[0019] Figure 4 A schematic diagram of a safety component of a system for preventing a material conveying mechanism from getting stuck;

[0020] Figure 5 The present invention is a schematic flow chart of a method for preventing a material conveying mechanism from getting stuck.

[0021] Figure numerals: 10, main control unit; 11, pre-filter pressure sensor; 12, post-filter pressure sensor; 13, box pressure sensor; 14, pre-filter pressure relief valve; 15, box pressure relief valve; 20, feeding weighing system; 30, extruder; 40, filter; 50, metering pump; 60, spinning box; 70, motor; 80, insurance part; 81, connecting part; 82, fixing part. DETAILED DESCRIPTION

[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, a system for preventing a raw material conveying mechanism from getting stuck includes a main control unit 10, the main control unit 10 is electrically connected with a pre-filter pressure sensor 11, a post-filter pressure sensor 12 and a box pressure sensor 13; the extruder 30 is connected to the filter 40 through a pipeline, the filter 40 is connected to the metering pump 50 through a pipeline, and the metering pump 50 is connected to the spinning box 60 through a pipeline; the pre-filter pressure sensor 11 is arranged on the pipeline between the extruder 30 and the filter 40, and is used to detect the pressure in the pipeline between the extruder 30 and the filter 40, the post-filter pressure sensor 12 is arranged on the pipeline between the filter 40 and the metering pump 50, and is used to detect the pressure in the pipeline between the filter 40 and the metering pump 50; the box pressure sensor 13 is arranged on the pipeline between the metering pump 50 and the spinning box 60, and is used to detect the pressure in the pipeline between the metering pump 50 and the spinning box 60, or the box pressure sensor 13 is arranged on the spinning box 60, and is used to measure the flow channel pressure in the spinning box 60.

[0024] The raw material conveying mechanism of spunbond fabric is generally connected to the extruder 30 through a pipe through a feeding weighing system 20, the extruder 30 is connected to the filter 40 through a pipe, the filter 40 is connected to the metering pump 50 through a pipe, and the metering pump 50 is connected to the spinning box 60 through a pipe, so that the material is melted into a solution and then spun. Specifically, the feeding weighing system 20 is responsible for sucking the granular polymer material from a distant or low position and accurately weighing and mixing it for use by the extruder 30. The extruder 30 is responsible for heating and plasticizing the mixed granular material and finally extruding it into a continuous and uniform high-temperature polymer melt. The filter 40, also known as the screen changer, is responsible for the initial filtration of the melt at the outlet of the extruder 30. The metering pump 50, also known as the spinning pump, mainly performs further pressure boosting, voltage stabilization and volume measurement on the filtered melt. The motor 70 of the metering pump 50 is a power source for delivering power to the metering pump 50. The spinning box 60 can evenly distribute and secondary filter the melt at the outlet of the metering pump 50 along the width direction, and finally generate thousands of melt thin streams.

[0025] When the filter screen of the filter 40 is put into use, impurities, ash, etc. in the melt begin to accumulate on the working surface of the filter screen, which gradually reduces the effective filtering area of ​​the filter screen, increases the filtering resistance, reduces the flow rate, and then causes the pressure after filtering to drop; in order to keep the pressure after filtering stable, the main control unit 10 sets the extruder 30 to accelerate, thereby increasing the pressure before filtering, increasing the pressure difference of the melt on both sides of the filter 40 to increase the flow rate, and restore the pressure after filtering to the normal setting value. It is also possible that the metering pump 50 is blocked, causing the pressure sensor 12 after filtering to be greater than the pressure sensor 11 before filtering. Each pressure sensor is monitored in real time. When the pressure difference of the melt on both sides of the filter 40 reaches the preset pressure difference a, the control system alarms and prompts the operator to replace the filter screen, 3MPa≤a≤5MPa.

[0026] When the melt pressure in the spinning box 60 reaches the box pressure alarm value b, the control system alarms and prompts the operator to replace the filter screen of the spinning box 60, 4MPa≤b≤8MPa. The pressure in the pipeline between the metering pump 50 and the spinning box 60 is the same as the flow channel pressure in the spinning box 60.

[0027] The filter further includes a pre-filter pressure relief valve 14 , which is disposed on a pipeline between the extruder 30 and the filter 40 and is used to release the pressure in the pipeline between the extruder 30 and the filter 40 .

[0028] In order to protect the extruder 30 system, a pre-filter limit pressure value c is set for the pre-filter pressure. When the pressure detected by the pre-filter pressure sensor 11 reaches the pre-filter limit pressure value c, an alarm signal is generated to remind the worker to replace the filter screen, 15MPa≤c≤20MPa. The pre-filter pressure relief valve 14 can be an independent device. When the post-filter pressure sensor 12 fails or the operator cannot change the screen on time, the pressure value continues to increase. When the pressure reaches its own limit value, it automatically opens to relieve the pressure of the melt pipeline between the extruder 30 outlet and the filter 40 inlet. The independent pre-filter pressure relief valve 14 can withstand a pressure range of 15MPa to 20MPa. The pre-filter pressure relief valve 14 can also be electrically controlled when it is started, and is electrically connected to the main control unit 10 and controlled to open by the main control unit 10.

[0029] When the pre-filter pressure sensor 11 fails, the main control unit 10 generates an alarm signal. When the pre-filter pressure sensor 11 fails, it is impossible to determine the pressure value at the front end of the filter 40, and the main control unit 10 generates an alarm signal for prompting.

[0030] It also includes a box pressure relief valve 15, which is arranged on the pipeline between the metering pump 50 and the spinning box 60 to release the pressure of the pipeline between the metering pump 50 and the spinning box 60, or the box pressure relief valve 15 is arranged on the spinning box 60 to release the flow channel pressure in the spinning box 60.

[0031] In order to protect the metering pump 50 and the spinning box 60 system, the box pressure of the spinning box 60 is set to a box pressure value d, 10MPa≤d≤15MPa. When the box pressure value in the pipe in front of the spinning box 60 is d, the main control unit 10 generates an alarm signal to remind the worker to replace the filter. The box pressure relief valve 15 can be an independent device. When the operator cannot replace the filter inside the spinning box 60 in time, the pressure exceeds the capacity of the box pressure relief valve 15, and it will start and release the pressure of the melt pipe between the outlet of the metering pump 50 and the inlet of the spinning box 60, or release the pressure of the flow channel in the spinning box 60. The independent box pressure relief valve 15 can also withstand a pressure range of 10MPa to 5MPa. The box pressure relief valve 15 can also be started by electrical control, electrically connected to the main control unit 10 and controlled to open by the main control unit 10.

[0032] When the box pressure sensor 13 fails, an alarm signal is generated. After the box pressure sensor 13 fails, it is impossible to determine the pressure of the front end pipeline of the spinning box 60, so an alarm signal is generated for prompting.

[0033] The motor 70 is also included. A safety member 80 is provided at the output end of the motor 70. The safety member 80 is connected to the rotating part of the metering pump 50 through a universal shaft. The motor 70 drives the metering pump 50 to operate through the safety member 80 and the universal shaft.

[0034] When the equipment is started after being preheated from a cold state, there are residual polymers that are not completely melted inside, which can easily cause the metering pump 50 to get stuck. Therefore, the metering pump 50 and the metering pump 50 reduction motor 70 are connected by a universal shaft, and the universal shaft and the metering pump 50 reduction motor 70 are connected by a safety piece 80. When the metering pump 50 gets stuck, the safety piece 80 between the metering pump 50 reduction motor 70 shaft and the universal shaft is relatively rotated and dislocated, and the safety piece 80 is finally sheared and broken, thereby protecting the metering pump 50 and the metering pump 50 reduction motor 70 from damage.

[0035] The safety member 80 includes a connecting member 81 and a fixing member 82 . The connecting member 81 is fixedly connected to the output end of the motor 70 , and one end of the universal joint shaft away from the metering pump 50 is fixed to the connecting member 81 through the fixing member 82 .

[0036] The fixing member 82 is made of a material with poor hardness, which can fix the universal shaft and the connecting member 81 and can withstand the torque when the motor 70 rotates. However, when the metering pump 50 is stuck and the torque on the universal shaft is too large, the fixing member 82 can be disconnected.

[0037] The connecting member 81 is a flange. The fixing member 82 is an aluminum latch. The universal shaft is connected by the aluminum latch and the flange. When the metering pump 50 is stuck, the flange between the metering pump 50 reduction motor 70 shaft and the universal shaft is relatively rotated and dislocated and eventually the aluminum latch is sheared and broken, thereby protecting the metering pump 50 and the metering pump 50 reduction motor 70 from damage.

[0038] like Figure 5 According to another aspect of the present invention, a method for preventing a material conveying mechanism from getting stuck is provided, comprising the following process:

[0039] St10, the main control unit 10 is provided with a preset pressure difference. When the main control unit 10 determines that the pressure difference detected by the pre-filter pressure sensor 11 and the post-filter pressure sensor 12 is greater than the preset pressure difference, an alarm signal is generated.

[0040] St20, the main control unit 10 is provided with a box pressure alarm value. When the main control unit 10 determines that the pressure value detected by the box pressure sensor 13 is greater than the box pressure alarm value, an alarm signal is generated. The preset pressure difference is greater than or equal to 3MPa and less than or equal to 5MPa; the box pressure alarm value is greater than or equal to 4MPa and less than or equal to 8MPa.

[0041] St30, when the main control unit 10 detects that the pre-filter pressure sensor 11, the post-filter pressure sensor 12 or the box pressure sensor 13 fails, an alarm signal is generated.

[0042] St40, the main control unit 10 is preset with a fuse replacement pressure value. When the main control unit 10 determines that the pressure value detected by the post-filter pressure sensor 12 is greater than the fuse replacement pressure value, the main control unit 10 generates an alarm signal. When the metering pump 5 is stuck, the pressure value of the post-filter pressure sensor 12 will increase, and there is a positive correlation. If the safety part 80 breaks during the operation of the raw material conveying mechanism, the production will be interrupted, and the impact will be relatively large. The present application sets the fuse replacement pressure value, so that when the pressure value detected by the post-filter pressure sensor 12 is greater than the fuse replacement pressure value, an alarm signal is generated, so that the staff can check the safety part 80 after the end of this round of production, so that the safety part 80 can be replaced in advance before it breaks. Of course, whether to replace the aluminum latch of the safety part 80 can be determined based on the workers' experience.

[0043] St50, the main control unit 10 determines whether the fuse 80 is broken by the current of the motor 70. When it is determined that the fuse 80 is broken, the pressure value of the post-filter pressure sensor 12 is recorded as the breaking pressure value. The replacement fuse pressure value is less than the breaking pressure value.

[0044] The working current of the motor is usually between 70% and 100% of the rated value. If the motor is connected to a load, the current of the motor is relatively large. Therefore, by monitoring the change in the current of the motor, the load condition of the motor can be determined. Specific monitoring methods include using devices such as an ammeter or a current sensor. The breaking pressure value depends on the quality of the insurance part 80, and it changes within a certain range. The insurance replacement pressure value can be set manually, as long as it is less than the interval of the breaking pressure value.

[0045] The beneficial effects that this technology can achieve are as follows:

[0046] 1. Solve the problem that the filter becomes dirty and clogged gradually during filter replacement or operation, causing unstable pressure after filtration and even in the box, and ultimately leading to unstable spinning.

[0047] 2. Prevent the metering pump 50 from getting stuck or the metering pump 50 motor 70 from being damaged due to insufficient melting of possible residual polymers inside under cold start conditions.

[0048] 3. Double protection to prevent the failure of the pressure sensor or improper operation of personnel from causing excessive pressure in the melt pipe, which in turn causes damage to the extruder 30.

[0049] 4. Control logic to maintain spinning stability and the pressure sensor distribution designed accordingly;

[0050] 5. In order to implement the safety of the above control logic, the pressure relief valve layout is introduced;

[0051] 6. The specially designed connection between the metering pump 50 and the motor 70 to prevent the metering pump 50 from getting stuck adopts an aluminum safety pin structure. The above are only preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A system for preventing a material conveying mechanism from getting stuck, characterized in that: It comprises a main control unit (10), wherein the main control unit (10) is electrically connected to a pre-filter pressure sensor (11), a post-filter pressure sensor (12) and a box pressure sensor (13); The extruder (30) is connected to the filter (40) through a pipeline, the filter (40) is connected to the metering pump (50) through a pipeline, and the metering pump (50) is connected to the spinning box (60) through a pipeline; The pre-filter pressure sensor (11) is arranged on the pipeline between the extruder (30) and the filter (40) to detect the pressure in the pipeline between the extruder (30) and the filter (40); the post-filter pressure sensor (12) is arranged on the pipeline between the filter (40) and the metering pump (50) to detect the pressure in the pipeline between the filter (40) and the metering pump (50); The box pressure sensor (13) is arranged on the pipeline between the metering pump (50) and the spinning box (60) to detect the pressure in the pipeline between the metering pump (50) and the spinning box (60), or the box pressure sensor (13) is arranged on the spinning box (60) to measure the flow channel pressure in the spinning box (60).

2. A system for preventing a material conveying mechanism from getting stuck according to claim 1, characterized in that: The invention also comprises a pre-filter pressure relief valve (14), which is arranged on the pipeline between the extruder (30) and the filter (40) and is used to release the pressure of the pipeline between the extruder (30) and the filter (40).

3. A system for preventing a material conveying mechanism from getting stuck according to claim 2, characterized in that: The invention also includes a box pressure relief valve (15), which is arranged on the pipeline between the metering pump (50) and the spinning box (60) to release the pressure of the pipeline between the metering pump (50) and the spinning box (60), or the box pressure relief valve (15) is arranged on the spinning box (60) to release the flow channel pressure in the spinning box (60).

4. A system for preventing a material conveying mechanism from getting stuck according to claim 3, characterized in that: The invention also comprises a motor (70), wherein the output end of the motor (70) is provided with a safety element (80), the safety element (80) is connected to the rotating part of the metering pump (50) via a universal shaft, and the motor (70) drives the metering pump (50) to operate via the safety element (80) and the universal shaft.

5. A system for preventing a material conveying mechanism from getting stuck according to claim 4, characterized in that: The safety member (80) comprises a connecting member (81) and a fixing member (82); the connecting member (81) is fixedly connected to the output end of the motor (70); and one end of the universal shaft away from the metering pump (50) is fixed to the connecting member (81) via the fixing member (82).

6. A system for preventing a material conveying mechanism from getting stuck according to claim 5, characterized in that: The connecting piece (81) is a flange.

7. A system for preventing a material conveying mechanism from getting stuck according to claim 5, characterized in that: The fixing member (82) is an aluminum latch.

8. A method for preventing a material conveying mechanism from getting stuck, based on the system for preventing a material conveying mechanism from getting stuck as claimed in claim 4, characterized in that: The process includes: The main control unit (10) is provided with a preset pressure difference value, and when the main control unit (10) determines that the pressure difference value detected by the pre-filter pressure sensor (11) and the post-filter pressure sensor (12) is greater than the preset pressure difference value, an alarm signal is generated; The main control unit (10) is provided with a box pressure alarm value, and when the main control unit (10) determines that the pressure value detected by the box pressure sensor (13) is greater than the box pressure alarm value, an alarm signal is generated.

9. A system for preventing a material conveying mechanism from getting stuck according to claim 8, characterized in that: When the main control unit (10) detects that the pre-filter pressure sensor (11), the post-filter pressure sensor (12) or the box pressure sensor (13) fails, an alarm signal is generated.

10. A system for preventing a material conveying mechanism from getting stuck according to claim 8, characterized in that: The main control unit (10) is preset with a fuse replacement pressure value, and when the main control unit (10) determines that the pressure value detected by the post-filter pressure sensor (12) is greater than the fuse replacement pressure value, the main control unit (10) generates an alarm signal.

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