A method for improving batch charging uniformity

Abstract

The present application relates to a method for improving batch feeding uniformity, comprising head stage control, normal production stage control and tail stage control. The technical scheme combines the monitoring technology of material in the conveying process, adopts double feeding device and different production stage variable flow control mode, changes the setting value of material flow and the application mode of material liquid, reduces the influence of material flow change in different production stages on feeding accuracy, stabilizes the instantaneous feeding accuracy of head, tail, normal production and flow interruption process, and further ensures the overall feeding accuracy and batch feeding uniformity. Through the implementation of the present application, the instantaneous feeding accuracy is reduced from more than 3% to within 1%, the overall batch feeding accuracy is reduced from about 0.5% to within 0.2%, the material adhesion in the roller is reduced from 10-20 kg / batch to within 3 kg / batch, and the feeding quality is significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of tobacco processing technology, specifically relating to a method for improving batch feeding uniformity. 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 method for improving the uniformity of batch feeding, so as to solve the problem of uneven batch feeding caused by the inability of the current feeding method to adapt to changes in material flow rate in a timely manner.

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

[0006] A method for improving batch feeding uniformity includes control at the beginning stage, control during normal production, and control at the end stage, specifically comprising the following steps:

[0007] Material head stage control:

[0008] The material to be fed first enters the front end of the feeding hopper of the flow control system. After the high material level of the first material monitor detects the material, the conveyor belt at the bottom of the feeding hopper starts to rotate, driving the material to move backward.

[0009] When the high material level of the second material monitor and the high material level of the third material monitor both detect the presence of material, the lifting conveyor starts to convey the material, which enters the electronic scale through the metering pipe, and the electronic scale measures and controls the weight of the material according to the material flow M1 set by the material head. The material after the electronic scale falls onto the inlet vibrating chute, and then enters the feeding roller. When the sixth material monitor detects the material, the rear-end feeding device starts to apply the material liquid, and the material after the application of the material liquid continues to move forward and finally falls into the outlet vibrating chute below the feeding roller. When the eighth material monitor detects the material, the material head control phase is completed.

[0010] Normal production phase control:

[0011] The material that has been applied with the material liquid in the material head control phase falls from the feeding roller into the outlet vibrating chute. After the eighth material monitor detects the material, feedback is given to the controller, which adjusts the material flow to M2 and divides the collected real-time material flow m2 into two parts. One part of the real-time material flow is M1, and the controller instructs the front-end feeding device to apply the material liquid. The other part of the real-time material flow is m2-M1, and the controller instructs the rear-end feeding device to apply the material liquid. When the first material monitor, the second material monitor, and the third material monitor all do not detect the material, the normal production phase control is completed.

[0012] Tail phase control:

[0013] Under the condition of normal production phase control, when the first material monitor, the second material monitor, and the third material monitor all do not detect the material, the controller adjusts the material flow to M3. The front-end feeding device stops feeding after a second set time, and the rear-end feeding device stops feeding after a second set time, and according to the actual material flow m3 collected by the electronic scale, the tracking feeding is performed according to the set batch feeding ratio.

[0014] Further, M1 = M2 x 70%, and M3 = M2 x 30%.

[0015] Further, under the condition of material head phase control, when the high material level of the third material monitor detects the material, the bottom conveying belt of the feeding bin stops. When the low material level of the second material monitor detects the absence of material, the feeding continues.

[0016] Further, under the condition of material head phase control, when the seventh material monitor detects the material, the first set time is traced according to the actual material flow m1 collected by the electronic scale, and the tracking feeding is performed according to the set feeding ratio of the batch.

[0017] Further, the first set time is the time for the material to pass through the fourth material monitor to the seventh material monitor.

[0018] Further, under the condition of normal production stage control, after the material flow is adjusted to M2, the front end feeding device is delayed for a second set time, and constant feeding is performed according to the constant material flow M1 and the feeding ratio set for the batch, and the rear end feeding device is extended for a first set time, and tracking feeding is performed according to the material flow m2-M1 and the feeding ratio set for the batch.

[0019] Further, the second set time is the time for the material to pass through the fourth material monitor to the sixth material monitor.

[0020] Further, the method further comprises flow interruption stage control.

[0021] In the normal production stage, when the cumulative weight of the batch material collected by the controller does not reach the total weight value of the 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 drum do not detect the material, the flow interruption condition is judged, the front end feeding device is stopped after being delayed for a second set time, the rear end feeding device is tracked according to the actual material flow m3 collected by the electronic scale after being delayed for a second set time, and the set feeding ratio of the batch is tracked; when the fourth material monitor detects the material again, the material flow and the feeding mode are controlled in sequence according to the head material stage control, the normal production stage control, and the tail material stage control.

[0022] Compared with the prior art, the method has the following beneficial effects:

[0023] The technical solution combines the monitoring technology of the material in the conveying process, adopts double feeding devices and variable flow control mode in different production stages, changes the set 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 accuracy, stabilizes the instantaneous feeding accuracy of the head material, the tail material, the normal production, and the flow interruption process, and further guarantees the overall feeding accuracy and the uniformity of batch feeding. Through the implementation of the method, the instantaneous feeding accuracy is reduced from more than 3% to within 1%, the overall accuracy of batch feeding is reduced from about 0.5% to within 0.2%, the material adhesion amount in the drum is reduced from 10-20 kg / batch to within 3 kg / batch, and the feeding quality is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the flow control system of the application.

[0025] Figure 2 The figure is a schematic diagram of the flow control system of the application.

[0026] The figure is a schematic diagram of the flow control system of the application.

[0027] 1, feed bin; 2, lifting belt; 3, metering pipe; 4, electronic scale; 5, inlet vibrating trough; 6, feeding roller; 7, outlet vibrating trough; 8, front end feeding device; 9, rear end feeding device; 10, material blocking 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 DESCRIPTION

[0028] The technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only exemplary and can only be used to explain and illustrate the technical solutions of the present application, but cannot be interpreted as a limitation of the technical solutions of the present application.

[0029] As shown in Figure 1 and Figure 2 , the present application comprises the following steps:

[0030] (1) Head phase control:

[0031] The material to be fed first enters the rear end of the feed bin 1 of the flow control system. After the first material monitor T1 detects the material at a high level, the bottom conveyor belt of the feed bin starts to rotate to move the material forward. When the third material monitor T3 detects the material at a high level, the feeding stops. When the second material monitor T2 detects no material at a low level, the feeding continues. When the high levels of the second material monitor T2 and the third material monitor T3 both detect material, the lifting belt 2 starts to convey the material, which enters the electronic scale 4 through the metering pipe 3. The electronic scale controls the weight of the material according to the material flow M1 set for the head. After that, the material falls into the inlet vibrating trough 5, which is loosened by vibration, and then the feeding roller 6 continues to move forward under the action of the rotating feeding roller. When the sixth material monitor T6 detects the material, the nozzle of the rear end feeding device 9 starts to apply the material liquid. The material continues to move forward after the application of the material liquid, and finally falls into the outlet vibrating trough 7 below the feeding roller. When the eighth material monitor T8 detects the material, the head control phase is completed.

[0032] During the head phase control process:

[0033] 1a: Since there is a lot of material in the feed bin at this stage, it is easy to meet the requirement of the normal production material flow M2. In order to reduce the influence of material flow fluctuation at this stage on the feeding accuracy, and facilitate the smooth transition of the material flow with the material flow in the middle stage, it is appropriate to set the flow value M1 to 70% of the setting value of the material flow in the middle stage. In this technical solution, the material flow M2 is the set flow of the batch of material in the normal production stage.

[0034] 1b: After the seventh material detector T7 of the rear end feeding device 9 detects the material, the actual material flow ml collected by the electronic scale is used to track the feeding according to the preset batch feeding ratio S for the first preset time tl (the first preset time refers to the passing time of the material through the fourth material detector T4 to the seventh material detector T7).

[0035] (2) Normal production stage control:

[0036] After the material to which the liquid has been applied falls from the feeding roller to the outlet vibration chute (or conveying belt), the eighth material detector T8 detects the material and feeds back to the controller of the flow control system. The controller automatically adjusts the material flow set value to M2. The controller divides the real-time material flow m2 into two parts. One part is M1, which is used to instruct the front end feeding device 8 to apply the liquid. The other part is (m2-M1), which is used to instruct the front end feeding device to apply the liquid. When the material detectors (T1, T2, and T3) do not detect the material, the normal production control stage is completed.

[0037] Normal production stage control process:

[0038] 2a: After the material flow is adjusted to M2, the front end feeding device is delayed for a second preset time t2 (the second preset time refers to the passing time of the material through the fourth material detector T4 to the sixth material detector T6), and the constant value material flow M1 and the preset batch feeding ratio S are used for constant value feeding.

[0039] 2b: After the rear end feeding device is delayed for the first preset time tl, the material flow (m2-M1) and the preset batch feeding ratio S are used for tracking feeding.

[0040] (3) Tail stage control:

[0041] When the material detectors (T1, T2, and T3 high material level) do not detect the material, the controller automatically adjusts the material flow to M3. When the eighth material detector T8 does not detect the material, the tail control stage is completed.

[0042] Tail stage control process:

[0043] 3a: Because the material in the tail stage silo is less, the remaining material is difficult to lift for a long time. To reduce the impact of material flow fluctuation and poor liquid application precision caused by being too small, it is appropriate to reduce the material flow to 30% of M2.

[0044] 3b: The front end feeding device is stopped after being delayed for the second preset time t2; the rear end feeding device is tracked according to the preset batch feeding ratio S based on the actual material flow m3 collected by the electronic scale after being delayed for the second preset time t2.

[0045] (4) the flow interruption stage control:

[0046] In the normal production stage, when the cumulative weight of the batch material collected by the flow control system does not reach the total weight value of the batch, and the fourth material monitor T4 behind the electronic scale and the fifth material monitor T5 at the inlet of the feeding drum do not detect material, it is judged as a flow interruption condition.

[0047] 4a: the front-end feeding device stops feeding after a second delay of the second set time t2; the rear-end feeding device delays for the second set time t2, and then tracks the feeding according to the set batch feeding ratio S based on the actual material flow m3 collected by the electronic scale.

[0048] 4b: when the fourth material monitor T4 detects material again, the material flow and the feeding mode are controlled according to the requirements of the head stage control, the normal production control, and the tail stage control.

[0049] After the feeding control method of the present application is adopted, the overall accuracy of batch feeding, the instantaneous feeding ratio accuracy, the amount of material adhering to the inner wall of the drum, and the product sensory quality score comparison results are shown in Table 1:

[0050] Table 1: Feeding quality test comparison

[0051]

[0052] As can be seen from the test results in Table 1, the feeding method of the present application effectively solves the problems of large flow fluctuation, poor overall and instantaneous accuracy of feeding, and reduces the amount of material adhering to the inner wall of the drum.

[0053] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing examples, or make equivalent substitutions for some or all of the technical features, and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the present application.

Claims

1. A method for improving batch feeding uniformity, a first material monitor, a second material monitor and a third material monitor are arranged in sequence from the front end to the rear end of the feeding bin, a fourth material monitor is located at the rear end of the electronic scale, a fifth material monitor is located at the inlet of the feeding roller, a sixth material monitor is located at the front end of the feeding roller, a seventh material monitor is located at the rear end of the feeding roller, and an eighth material monitor is located at the outlet of the vibrating trough, characterized in that, The method comprises head stage control, normal production stage control and tail stage control, and specifically comprises the following steps. The head stage control comprises the following steps. The material to be fed first enters the front end of the feeding bin of the flow control system, and when the high material level of the first material monitor detects the material, the bottom conveying belt of the feeding bin starts to rotate and moves the material backward. When the high material level of the second material monitor and the high material level of the third material monitor both detect the material, the lifting conveying belt starts to convey the material, the material is weighed by the electronic scale according to the material flow M1 set in the head stage, and then the material after the electronic scale falls onto the inlet vibrating chute and then enters the feeding roller. When the sixth material monitor detects the material, the rear end feeding device starts to apply the liquid, and the material after the liquid application continues to move forward and finally falls into the outlet vibrating chute. When the eighth material monitor detects the material, the head stage control is completed. The normal production stage control comprises the following steps. When the first material monitor, the second material monitor and the third material monitor all do not detect the material, the normal production stage control is completed. The tail stage control comprises the following steps. Under the condition of the normal production stage control, when the first material monitor, the second material monitor and the third material monitor all do not detect the material, the material flow is adjusted to M3 by the controller, the front end feeding device stops feeding after a second set time, and the rear end feeding device stops feeding after a second set time and then tracks the feeding according to the material flow m3 actually collected by the electronic scale and the batch feeding ratio set. Under the condition of the head stage control, when the seventh material monitor detects the material, the first set time is tracked according to the material flow m1 actually collected by the electronic scale, and the feeding is tracked according to the batch feeding ratio set. The first set time is the time for the material to pass through the fourth material monitor to the seventh material monitor. Under the condition of the normal production stage control, after the material flow is adjusted to M2, the front end feeding device performs constant feeding according to the constant material flow M1 and the batch feeding ratio set after a second set time, and the rear end feeding device performs tracking feeding according to the material flow m2-M1 and the batch feeding ratio set after a first set time. The method further comprises flow interruption stage control. In the normal production stage, when the cumulative weight of the batch material collected by the controller does not reach the total weight value of the batch, and the fourth material monitor behind the electronic scale and the fifth material monitor at the inlet of the feeding drum do not detect material, it is judged as a flow interruption. The front-end feeding device stops feeding after a second set time, and the back-end feeding device performs tracking feeding according to the actual material flow m3 collected by the electronic scale and the set proportion of this batch after a second set time; when the fourth material monitor detects material again, the material flow and feeding mode are controlled in turn according to the head stage control, normal production stage control, and tail stage control. M1 = M2 x 70%, M3 = M2 x 30%; The second set time is the time for the material to pass through the fourth material monitor to the sixth material monitor.

2. The method of improving batch charging uniformity according to claim 1, wherein, In the head stage control, the bottom conveyor of the feeding bin stops when the high material level of the third material monitor detects material, and continues to feed when the low material level of the second material monitor detects no material.

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