A method for controlling the feeding of a non-steady process

Abstract

The application relates to a feeding control method of a non-steady process, which is mainly aimed at the head and tail of material and the flow interruption stage, combines material monitoring technology in the conveying process, adopts double feeding devices and variable flow control modes in different production stages, changes the setting value of the material flow and the material liquid application mode, reduces the influence of the material flow change in different production stages on the feeding precision, stabilizes the instantaneous feeding precision in the head and tail of material and the flow interruption process, further guarantees the overall feeding precision and the uniformity of batch feeding, and improves the feeding quality.

Description

Technical Field

[0001] This invention belongs to the field of tobacco processing technology, specifically relating to a feeding control method for a non-steady-state process. Background Technology

[0002] In the processing of tobacco materials, feeding is a key step in improving the sensory quality of cigarettes and reducing irritation and off-flavors. Currently, tobacco materials are mostly fed using a drum feeding method. The feeding nozzle is installed at the front end of the drum equipment, and the batch material flow rate is set to a fixed value. The feeding program tracks the actual material flow rate according to the set feeding ratio. Therefore, changes in the material flow rate will cause fluctuations in the instantaneous accuracy of feeding, thus affecting the uniformity of feeding.

[0003] In actual production, the material flow rate is relatively small at the beginning and end of the batch, or there may be a material interruption, resulting in significant fluctuations in the material flow rate. This leads to a large deviation between the actual feeding ratio and the set feeding ratio. To ensure feeding accuracy for the entire batch, the feeding program uses an over-set ratio method to replenish the material when the actual feeding is lower than the set ratio, and a under-set ratio method to reduce the material when the actual feeding is higher than the set ratio. This results in poor instantaneous feeding accuracy within the batch, leading to uneven material application within the batch. Furthermore, because the material volume at the beginning and end of the batch is relatively small, using a single front-end feeding method results in high steam (or compressed air) pressure for the material injection. Applying the material too early causes it to penetrate the inner wall of the material spraying drum, causing material adhesion; applying it too late results in some material not receiving any material, further affecting the uniformity of batch feeding. Summary of the Invention

[0004] The purpose of this invention is to provide a feeding control method for unsteady-state processes, which, combined with material monitoring technology during the conveying process, solves the problem of uneven material application within a batch due to unstable material flow.

[0005] To achieve the above objectives, this application employs the following technical solution:

[0006] A feeding control method for an unsteady-state process includes the following steps:

[0007] S1. When the equipment is started, no material signal is detected by any material monitor. The material to be fed enters the back end of the feeding hopper of the flow control system.

[0008] S2. Determine the material head production stage: The time period from when the second and third material monitors at the bottom of the feeding hopper detect material to when the eighth material monitor at the feeder outlet detects material is the material head production stage. At this time, the material flow rate is set to M1. The front-end feeding device does not feed material. After the sixth material monitor at the front-end feeding device detects material, the back-end feeding device tracks and feeds material according to the actual material flow rate m1 collected by the electronic scale and the feeding ratio set for this batch.

[0009] S3. Determine the normal production stage of feeding: In this stage, the material flow rate is set to M2. The front-end feeding device feeds materials according to the material flow rate M1 set in step S2 and the feeding ratio set for this batch. The back-end feeding device tracks the feeding according to the actual material flow rate m2 collected by the electronic scale, according to the material flow rate m2-M1 and the feeding ratio set for this batch.

[0010] S4. Determine the tail-end production stage: The time period from when the first, second, and third material monitors at the bottom of the feeding hopper fail to detect any material until the seventh material monitor at the rear feeding device detects no material is the tail-end production stage. At this time, the material flow rate is set to M3. The front-end feeding device stops feeding, and the rear feeding device tracks and feeds according to the actual material flow rate m3 collected by the electronic scale and the feeding ratio set for this batch.

[0011] Furthermore, all material monitors in step S1 include a first material monitor, a second material monitor, and a third material monitor located at the bottom of the feeding hopper of the lifting feeder; a fourth material monitor located at the rear end of the electronic scale; a fifth material monitor located at the inlet of the feeder; a sixth material monitor located at the front-end feeding device; a seventh material monitor located at the rear-end feeding device; and an eighth material monitor located at the outlet of the feeder.

[0012] Furthermore, step S2 also includes the automatic raising of the vibrating trough baffle at the feeder inlet, and the lowering of the vibrating trough baffle after the fifth material monitor at the feeder inlet detects the material, allowing the material to enter the feeder.

[0013] Furthermore, it also includes flow interruption stage control: when the cumulative weight of the material in this batch collected by the flow control system does not reach the total weight of the material in this batch, and the fourth material monitor at the back end of the electronic scale and the fifth material monitor at the inlet of the feeder do not detect the material, it is determined to be a flow interruption stage, and the flow and feeding are controlled according to the above steps S2 to S4.

[0014] Furthermore, in step S3, the material flow rate is set to M2, which is consistent with the material flow rate of the process technology standard for this batch of materials.

[0015] Furthermore, M1 = M2 x 70%, M3 = M2 x 30%.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention provides a feeding control method for non-steady-state processes. Combining material monitoring technology during the conveying process, it employs a dual feeding device and variable flow control for different production stages. Focusing on the material head, tail, and flow interruption stages, it reduces the impact of material flow rate variations on feeding accuracy by changing the setpoint of the material flow rate and the method of material application. This stabilizes the instantaneous feeding accuracy at the material head, tail, and flow interruption stages, thereby ensuring overall feeding accuracy and batch feeding uniformity. Through the implementation of this invention, the instantaneous feeding accuracy is reduced from over 3% to less than 1%, the overall batch feeding accuracy is reduced from approximately 0.5% to less than 0.2%, and the amount of material adhering to the drum is reduced from 10-20 kg / batch to less than 3 kg / batch, significantly improving feeding quality. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the flow control system of the present invention.

[0019] Figure 2 This is a schematic diagram of the feeding control for the unsteady-state process of the present invention.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1. Feeding bin; 2. Elevator belt; 3. Metering tube; 4. Electronic scale; 5. Inlet vibrating trough; 6. Feeding roller; 7. Outlet vibrating trough conveyor belt; 8. Front-end feeding device; 9. Rear-end feeding device; 10. Baffle plate; T1, First material monitor; T2, Second material monitor; T3, Third material monitor; T4, Fourth material monitor; T5, Fifth material monitor; T6, Sixth material monitor; T7, Seventh material monitor; T8, Eighth material monitor. Detailed Implementation

[0022] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, and should not be construed as limiting the technical solution of the present invention.

[0023] like Figure 1 and Figure 2 As shown, this application provides a feeding control method for a non-steady-state process, comprising the following steps:

[0024] (1) Material head stage control: The material to be fed first enters the rear end of the feeding bin of the flow control system. After the high material level of the first material monitor T1 detects the material, the bottom conveyor belt of the feeding bin starts to rotate and drives the material forward until the high material level of the third material monitor T3 detects the material and stops feeding. After the low material level of the second material monitor T2 detects no material, feeding continues. When there is material at the high material levels of both the second material monitor T2 and the third material monitor T3, the lifting conveyor belt starts to transport the material and the material baffle of the feeder inlet vibrating trough is raised. The material enters the electronic scale through the metering tube. The electronic scale measures and controls the weight of the material according to the material flow rate M1 set by the feed head, and then the material falls into the vibrating trough. When the fifth material monitor T5 detects the material, the material baffle automatically falls, and the material enters the feeding drum. Under the action of the drum rotation, it continues to move forward. When the sixth material monitor T6 detects the material, the rear feeding nozzle begins to apply liquid material. The material after the liquid material is applied continues to move forward and finally falls into the vibrating trough below the feeding drum. When the eighth material monitor T8 detects the material, the feed head control stage is completed.

[0025] During this process:

[0026] 1a: Since there is a lot of material in the feed hopper at this stage, it is easy to reach the material flow rate M2 required in the normal production stage. In order to reduce the impact of material flow rate fluctuations on feeding accuracy at this stage, and to facilitate a smooth transition with the material flow rate in the normal production stage, it is advisable to set the flow rate setting value M1 to 70% of the normal production material flow rate setting value.

[0027] 1b: After the seventh material monitor T7 of the back-end feeding device detects the material, it tracks and feeds the material according to the set batch feeding ratio S, based on the material flow rate m1 actually collected by the electronic scale and the time t1 seconds before the material passes through the fourth material monitor T4 to the seventh material monitor T7.

[0028] (2) Normal Production Stage Control: Material that has been fed with slurry falls from the feeder into the vibrating trough (or conveyor belt). After the eighth material monitor T8 detects the material, it feeds back to the flow control system. The flow control system automatically adjusts the material flow rate setpoint to M2. The flow control system divides the collected real-time material flow rate m2 into two parts: one part, with a flow rate of M1, instructs the front-end feeding device to apply slurry, and the other part, with a flow rate of (m2-M1), instructs the rear-end feeding device to apply slurry. When none of the material monitors (T1, T2, T3) detects any material, the normal production control stage is completed.

[0029] This process:

[0030] 2a: After the material flow rate is adjusted to M2, the front-end feeding device delays for t2 seconds (the time it takes for the material to pass through the fourth material monitor T4 to the sixth material monitor T6), and then feeds the material according to the fixed material flow rate M1 and the set batch feeding ratio S.

[0031] 2b: After a delay of t1 seconds, the back-end feeding device tracks and feeds materials according to the material flow rate (m2-M1) and the set batch feeding ratio S.

[0032] (3) Material tail stage control: When the material monitors (T1, T2 and T3 high material level) have not detected any material, the flow control system will automatically adjust the material flow rate to M3. When the eighth material monitor T8 detects no material, the material tail control stage is completed.

[0033] This process:

[0034] 3a: Since there is less material in the silo at the tail end of the material stage, it is difficult to lift the remaining material and the duration is long. In order to reduce the impact of material flow fluctuation and poor material application accuracy caused by excessively small flow rate, the material flow rate should be reduced to 30% of M2.

[0035] 3b: The front-end feeding device stops feeding after a delay of t2 seconds; the rear-end feeding device, after a delay of t2 seconds, tracks and feeds materials according to the set batch feeding ratio S based on the actual material flow rate m3 collected by the electronic scale.

[0036] (4) Interruption control: During normal production, if the cumulative weight of batch materials collected by the flow control system does not reach the total weight of the batch, and neither the fourth material monitor T4 at the back end of the electronic scale nor the fifth material monitor T5 at the feeder inlet detects any material, it is judged as an interruption.

[0037] 4a: The front-end feeding device stops feeding after a delay of t2 seconds; the rear-end feeding device, after a delay of t2 seconds, tracks and feeds materials according to the set batch feeding ratio S based on the actual material flow rate m3 collected by the electronic scale.

[0038] 4b: When the fourth material monitor T4 detects material again, continue to control the material flow rate and feeding method according to the requirements of steps A1, A2, and A3.

[0039] Table 1 shows the comparison results of the overall batch feeding accuracy, instantaneous feeding ratio accuracy, amount of material adhering to the inner wall of the drum, and sensory quality score of the product after adopting the feeding control method of the present invention:

[0040]

[0041] As can be seen from the test results in Table 1, the feeding method described in this invention effectively solves the problems of large flow fluctuations and poor overall and instantaneous feeding accuracy in traditional feeding methods at the beginning, end and end of the material flow, thus improving product quality and significantly reducing material adhesion.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features therein, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of charge control of a non-steady process, characterized by, The method comprises the following steps: S1, the device starts, all material monitors do not detect material signals, and after the material to be fed enters the back end of the feeding bin of the flow control system; S2, the material head production stage is determined: the second material monitor and the third material monitor at the bottom of the feeding bin of the feeding bin for lifting feeding both detect material, and the time period from when the eighth material monitor at the outlet of the feeding device detects material to when the sixth material monitor at the front end of the feeding device detects material is the material head production stage, at this time, the material flow is set to M1, the front end of the feeding device does not feed, after the sixth material monitor at the front end of the feeding device detects material, the rear end of the feeding device tracks feeding according to the actual material flow m1 collected by the electronic scale, and the feeding ratio of the current batch is tracked for t1 seconds; S3, the normal feeding production stage is determined: at this stage, the material flow is set to M2, the front end of the feeding device delays for t2 seconds, and the material flow M1 set in step S2 is fed according to the feeding ratio of the current batch; after the rear end of the feeding device delays for t1 seconds, the actual material flow m2 collected by the electronic scale is tracked according to the material flow m2-M1 and the feeding ratio of the current batch; S4, the material tail production stage is determined: the time period from when the first material monitor, the second material monitor and the third material monitor at the bottom of the feeding bin of the feeding bin for lifting feeding all do not detect material to when the seventh material monitor at the rear end of the feeding device detects no material is the material tail production stage, at this time, the material flow is set to M3, the front end of the feeding device stops feeding after delaying for t2 seconds, and the rear end of the feeding device tracks feeding according to the actual material flow m3 collected by the electronic scale after delaying for t2 seconds, and the feeding ratio of the current batch is tracked; The method also comprises the control of the flow interruption stage: when the cumulative weight of the material of the current batch collected by the flow control system does not reach the total weight of the material of the current batch, and the fourth material monitor at the rear end of the electronic scale and the fifth material monitor at the inlet of the feeding device both do not detect material, it is determined that the flow interruption stage is reached, the front end of the feeding device stops feeding after delaying for t2 seconds, and the rear end of the feeding device tracks feeding according to the actual material flow m3 collected by the electronic scale after delaying for t2 seconds, and the batch feeding ratio S is tracked according to the set batch feeding ratio; When the fourth material monitor T4 detects material again, the flow and feeding control are performed according to the above steps S2 to S4; The material flow in step S3 is set to M2, which is consistent with the material flow of the material process technical standard of the current batch; M1=M2 x 70%, M3=M2 x 30%.

2. The non-steady process feed control method of claim 1, wherein, The first material monitor, the second material monitor and the third material monitor at the bottom of the feeding bin of the feeding bin for lifting feeding, the fourth material monitor at the rear end of the electronic scale, the fifth material monitor at the inlet of the feeding device, the sixth material monitor at the front end of the feeding device, the seventh material monitor at the rear end of the feeding device and the eighth material monitor at the outlet of the feeding device are all included in step S1.

3. The method of charge control of a non-steady process according to claim 1, wherein In step S2, the vibrating chute blocking plate at the inlet of the feeding device is automatically raised, and the vibrating chute blocking plate falls after the fifth material monitor at the inlet of the feeding device detects material, and the material enters the feeding device.

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