Scraper conveying system
By introducing a frequency converter and control unit into the scraper conveyor system, the speed of the scraper conveyor is adjusted according to the current signal, which solves the problems of easy chain damage and frequent failures, and achieves efficient operation and cost savings of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-24
- Publication Date
- 2026-04-07
AI Technical Summary
In waste-to-energy plants, scraper conveyors suffer from problems such as chain jamming due to ash leakage from the furnace bottom, short chain life, frequent malfunctions, and high maintenance costs.
A scraper conveying system is adopted, including a scraper conveyor, a frequency converter and a control unit. By detecting the current signal output by the frequency converter, the control unit performs logic calculations to adjust the speed of the scraper conveyor, so as to achieve a high speed when there are many foreign objects and maintain a minimum speed when there are few foreign objects.
It extends the chain life of the scraper conveyor, reduces the frequency of failures and maintenance costs, improves equipment utilization, and reduces energy consumption.
Smart Images
Figure CN224091026U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a scraper conveyor technical field especially is related to a scraper conveying system. BACKGROUND
[0002] At present, the scraper conveyor is applied more in the garbage incineration power plant, such as horizontal flue, cloth bag, grate leakage residue, and the scraper conveyor is needed to convey the ash residue. Figure 1 Taking the furnace bottom ash leakage conveyor as an example, the scraper conveyor is mainly composed of a box body 1, a scraper 2, a chain 3, a front shaft 4, a rear shaft 5, a speed reducer 6 and a motor 7. The running process is that the motor 7 drives the speed reducer 6, the speed reducer 6 drives the front shaft 4, the front shaft 4 rotates to drive the chain 3 and the rear shaft 5 to rotate, and the scraper 2 fixed on the chain 3 drives the ash in the box body 1 to move. In this process, the following problems occur:
[0003] Firstly, the furnace bottom ash leakage conveyor is caused by the size of the gap of the grate, and the grate will randomly fall the ash residue of different sizes, and the ash residue will be stuck on the chain, which will cause the chain to be pulled off or the furnace bottom ash leakage conveyor to be overloaded and tripped;
[0004] Secondly, the furnace bottom ash leakage conveyor is directly rubbed with the chain and the scraper when running, and the service life of the chain and the scraper is only one year, and the annual cost of the scraper chain of a single furnace bottom ash leakage conveyor is 18440 yuan, accounting for 47% of the total cost;
[0005] Thirdly, the furnace bottom ash leakage conveyor has frequent faults, as high as 8.6 times per month, and the processing time after the fault is long, and the boiler load is greatly affected. INVENTION CONTENTS
[0006] The utility model aims at solving the problem that the chain of the scraper conveyor is frequently damaged, and provides a scraper conveying system.
[0007] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:
[0008] A scraper conveying system, comprising a scraper conveyor, a frequency converter and a control unit;
[0009] The scraper conveyor is connected with the frequency converter, and the frequency converter is connected with the control unit;
[0010] The frequency converter is used to provide power supply for the scraper conveyor, transmit the output current signal to the control unit, receive the frequency conversion given instruction of the control unit, change or keep the frequency of the scraper conveyor according to the frequency conversion given instruction, so as to change or keep the rotating speed of the scraper conveyor;
[0011] The control unit is configured to receive the current signal and increase, decrease or keep the frequency according to the current signal, and send a variable frequency setting instruction to the variable frequency controller.
[0012] In some embodiments, the control unit comprises an analog input module, a comparison module, a two-way module, and an analog output module, the analog input module is connected to the input of the comparison module, the output of the comparison module is connected to the input of the two-way module, and the output of the two-way module is connected to the analog output module.
[0013] The analog input module is configured to collect the analog signal of the current signal or the frequency output by the variable frequency controller, so as to convert the analog signal of the current signal or the frequency into a specific value and display the specific value.
[0014] The comparison module is configured to compare the value of the current signal with a predetermined value, and output a first signal when the current signal is greater than the predetermined value, and output a second signal when the current signal is less than the predetermined value.
[0015] The two-way module is configured to select an output value according to the first signal and the second signal, so as to determine the frequency value of the scraper conveyor.
[0016] The analog output module is configured to convert the specific value into an analog signal and transmit the analog signal to the variable frequency controller, so as to control the frequency output by the variable frequency controller.
[0017] In some embodiments, the comparison module comprises first to fourth comparison units, and the two-way module comprises first to fourth two-way units, the first comparison unit is connected to the first pin of the first two-way unit, the second comparison unit is connected to the first pin of the second two-way unit, the third comparison unit is connected to the first pin of the third two-way unit, the fourth comparison unit is connected to the first pin of the fourth two-way unit, the output of the first two-way unit is connected to the second pin of the second two-way unit, the output of the second two-way unit is connected to the second pin of the third two-way unit, the output of the third two-way unit is connected to the second pin of the fourth two-way unit, and the input values of the third pins of the first to fourth two-way units are fixed values and the values increase in turn.
[0018] In some embodiments, the control unit further comprises a switching register module, and the comparison module is further connected to the switching register module, the switching register module is configured to receive the first signal and output the first signal to the scraper conveyor protection stop.
[0019] In some embodiments, the comparison module further comprises a fifth comparison unit, which is connected with the switch quantity register module, and the switch quantity register module is used for receiving the first signal output of the fifth comparison unit to the scraper conveyor protection stop.
[0020] In some embodiments, the control unit is a DCS.
[0021] The utility model has the advantages of the following:
[0022] The scraper conveying system of the utility model comprises a scraper conveyor, a frequency converter controller and a control unit, the current output by the frequency converter controller is detected, the current signal is transmitted to the control unit, the control unit increases, reduces or keeps the frequency through logical operation, so that the speed is high when there are many foreign matters, and the lowest speed is kept when there are few foreign matters, and the utilization rate of the scraper conveyor is improved. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 It is a structural schematic view of a furnace bottom ash leakage conveyor in the prior art;
[0024] Figure 2 It is a structural schematic view of a scraper conveying system in the embodiment of the utility model;
[0025] Figure 3 It is a structural schematic view of a scraper conveying system in one embodiment of the utility model;
[0026] Figure 4 It is a frequency converter control principle diagram of a furnace bottom ash leakage conveyor in the embodiment of the utility model;
[0027] Figure 5 It is a DCS multi-section frequency setting logical schematic view in the embodiment of the utility model;
[0028] Explanation of reference signs:
[0029] 1-box, 2-scraper, 3-chain, 4-front axle, 5-rear axle, 6-reducer, 7-motor, AIN-analog input module; AOUT-analog output module; CMP-comparison module, SWCH-two-choice module. DETAILED DESCRIPTION
[0030] The embodiment of the utility model is described in detail below. It should be emphasized that the following description is only exemplary, and is not intended to limit the scope of the utility model and its application.
[0031] It is to be understood that when an element such as a layer, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. It will also be understood that, when a device or element is referred to as being "coupled" to another device or element, mechanical or electrical connection between the devices or elements is not required.
[0032] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like, specify relative positions and orientations based on the orientations or positions shown in the drawings, and are used only for the purpose of facilitating the description of the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.
[0033] In addition, the terms "first", "second", "third", etc. are used only for descriptive purposes and should not be construed as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second", etc. can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.
[0034] The utility model discloses a kind of scraper conveyer systems, the scraper conveyer system can monitor the current of furnace bottom ash leakage conveyor, according to the size of current judges the output of furnace bottom ash leakage conveyor judges the amount of ash residue gives corresponding rotating speed, when ash residue is more, rotating speed is high, when ash residue is less, keep minimum rotating speed, to play the role of energy saving and prolonging the life of scraper conveyer.
[0035] Reference Figure 2 The utility model embodiment provides a kind of scraper conveyer system, including scraper conveyer, frequency conversion controller and control unit;
[0036] The scraper conveyer is connected with the frequency conversion controller, and the frequency conversion controller is connected with the control unit;
[0037] The frequency conversion controller is used to provide power supply for the scraper conveyer, and the output current signal (the numerical value of the operating current of the scraper conveyer) is transmitted to the control unit, and the frequency given instruction of the control unit is received, the frequency of the scraper conveyer is changed or kept according to the frequency given instruction, to change or keep the rotating speed of the scraper conveyer;
[0038] The control unit is used to receive current signal, and according to current signal increases, reduces or keeps frequency, sends frequency given instruction to frequency conversion controller.
[0039] ReferenceFigure 3 In the furnace bottom ash conveyor, the control unit is a DCS, the DCS comprises an analog input module, a comparison module, a two-way selection module and an analog output module, the analog input module is connected to the input end of the comparison module, the output end of the comparison module is connected to the input end of the two-way selection module, and the output end of the two-way selection module is connected to the analog output module.
[0040] The analog input module AIN is used to collect the analog signal of the current signal or frequency (4-20 mA) output by the frequency converter controller, so as to convert the analog signal of the current signal or frequency into a specific numerical value and display the specific numerical value.
[0041] The comparison module is used to compare the value of the current signal with a predetermined value, and output a first signal when the current signal is greater than the predetermined value, and output a second signal when the current signal is less than the predetermined value.
[0042] The two-way selection module is used to select an output value according to the first signal and the second signal, so as to determine the frequency value of the furnace bottom ash conveyor.
[0043] The analog output module AOUT is used to convert the specific numerical value into an analog signal and transmit the analog signal to the frequency converter controller, so as to control the frequency output by the frequency converter controller.
[0044] The comparison module CMP comprises first to fourth comparison units, and the two-way selection module SWCH comprises first to fourth two-way selection units. The first comparison unit CMP1 is connected to the first pin of the first two-way selection unit SWCH1, the second comparison unit CMP2 is connected to the first pin of the second two-way selection unit SWCH2, the third comparison unit CMP3 is connected to the first pin of the third two-way selection unit SWCH3, the fourth comparison unit CMP4 is connected to the first pin of the fourth two-way selection unit SWCH4, the output end of the first two-way selection unit SWCH1 is connected to the second pin of the second two-way selection unit SWCH2, the output end of the second two-way selection unit SWCH2 is connected to the second pin of the third two-way selection unit SWCH3, the output end of the third two-way selection unit SWCH3 is connected to the second pin of the fourth two-way selection unit SWCH4, and the input values of the third pins of the first to fourth two-way selection units are fixed values and the values increase in turn.
[0045] The DCS further comprises a switching register module, and the comparison module is further connected to the switching register module. Specifically, the comparison module further comprises a fifth comparison unit, and the fifth comparison unit is connected to the switching register module. The switching register module is used to receive the first signal and output the first signal to the furnace bottom ash conveyor protection stop.
[0046] Reference Figure 4 , Figure 4The frequency control mode of the original furnace bottom ash conveying machine is changed to the frequency conversion control mode, the original control box is changed to the frequency conversion control cabinet, and the frequency conversion cabinet transmits remote, fault, operation, operation frequency and operation current signals to the DCS (the remote, fault, operation, operation frequency and operation current signals can be distinguished by accessing the address of the DCS hardware module). The DCS transmits the frequency given, start command and stop command to the frequency conversion cabinet. Different from the original control mode, the DCS can receive the operation current signal, and the DCS can change the frequency given instruction to change the rotating speed of the furnace bottom ash conveying machine. In the embodiment, when the DCS receives the current signal less than or equal to 50% In (the rated current is 4.5 A), the DCS gives the frequency instruction of 5 HZ; when the DCS receives the current signal greater than 50% In and less than or equal to 62% In, the DCS gives the frequency instruction of 10 HZ; when the DCS receives the current signal greater than 62% In and less than or equal to 71% In, the DCS gives the frequency instruction of 15 HZ; when the DCS receives the current signal greater than 71% In and less than or equal to 80% In, the DCS gives the frequency instruction of 25 HZ; when the DCS receives the current signal greater than 80% In and less than or equal to 88% In, the DCS gives the frequency instruction of 30 HZ; and when the DCS receives the current signal greater than 88% In, the DCS gives the stop instruction, judges the furnace bottom ash conveying jamming and sends the alarm signal.
[0047] Reference Figure 5 In the embodiment, the comparison module includes first to fourth comparison units, namely, the first comparison unit CMP1, the second comparison unit CMP2, the third comparison unit CMP3 and the fourth comparison unit CMP4, and the two-select module includes first to fourth two-select units, namely, the first two-select unit SWCH1, the second two-select unit SWCH2, the third two-select unit SWCH3 and the fourth two-select unit SWCH4. When the value of the pin 1 is greater than the value of the pin 2, the pin Q outputs 1, otherwise, the pin Q outputs 0. When the pin S is 1, the two-select unit outputs the value of the pin Pv2, and when the pin S is 0, the two-select unit outputs the value of the pin Pv1.
[0048] When the DCS receives the AIN2 current signal less than or equal to 2.3A (rated current 4.5A), the first comparison unit CMP1 pin 1 value is less than pin 2 value 2.3 pin Q output 0, the second comparison unit CMP2 pin 1 value is less than pin 2 value 2.8 pin Q output 0, the third comparison unit CMP3 pin 1 value is less than pin 2 value 3.2 pin Q output 0, the fourth comparison unit CMP4 pin 1 value is less than pin 2 value 3.6 pin Q output 0, the fifth comparison unit CMP5 pin 1 value is less than pin 2 value 4 pin Q output 0, the first two selection unit SWCH1 pin S receives the first comparison unit CMP1 pin Q for 0 signal selection pin Pv2 value 5 output, the second two selection unit SWCH2 pin S receives the second comparison unit CMP2 pin Q for 0 signal selection pin Pv2 value 5 output, the third two selection unit SWCH3 pin S receives the third comparison unit CMP3 pin Q for 0 signal selection pin Pv2 value 5 output, the fourth two selection unit SWCH4 pin S receives the fourth comparison unit CMP4 pin Q for 0 signal selection pin Pv2 value 5 output, the bottom ash conveyor manual operation module MSA1 pin PV receives the fourth two selection unit SWCH4 output 5 signal pin OP output 5 to the analog output module AOUT1, so that the DCS given frequency command is 5HZ.
[0049] When the DCS receives the current signal greater than 2.3A less than or equal to 2.8A, the first comparison unit CMP1 pin 1 value is greater than pin 2 value 2.3 pin Q output 1, the second comparison unit CMP2 pin 1 value is less than pin 2 value 2.8 pin Q output 0, the third comparison unit CMP3 pin 1 value is less than pin 2 value 3.2 pin Q output 0, the fourth comparison unit CMP4 pin 1 value is less than pin 2 value 3.6 pin Q output 0, the fifth comparison unit CMP5 pin 1 value is less than pin 2 value 4 pin Q output 0, the first two selection unit SWCH1 pin S receives the first comparison unit CMP1 pin Q for 1 signal selection pin Pv1 value 10 output, the second two selection unit SWCH2 pin S receives the second comparison unit CMP2 pin Q for 0 signal selection pin Pv2 value 10 output, the third two selection unit SWCH3 pin S receives the third comparison unit CMP3 pin Q for 0 signal selection pin Pv2 value 10 output, the fourth two selection unit SWCH4 pin S receives the fourth comparison unit CMP4 pin Q for 0 signal selection pin Pv2 value 10 output, the bottom ash conveyor manual operation module MSA1 pin PV receives the fourth two selection unit SWCH4 output 10 signal pin OP output 10 to the analog output module AOUT1, so that the DCS given frequency command is 10HZ.
[0050] When the DCS receives the current signal greater than 2.8A and less than or equal to 3.2A, the first comparison unit CMP1 pin 1 value is greater than pin 2 value 2.3 pin Q output 1, the second comparison unit CMP2 pin 1 value is greater than pin 2 value 2.8 pin Q output 1, the third comparison unit CMP3 pin 1 value is less than pin 2 value 3.2 pin Q output 0, the fourth comparison unit CMP4 pin 1 value is less than pin 2 value 3.6 pin Q output 0, the fifth comparison unit CMP5 pin 1 value is less than pin 2 value 4 pin Q output 0, the first two selection unit SWCH1 pin S receives the first comparison unit CMP1 pin Q for 1 signal selection pin Pv1 value 10 output, the second two selection unit SWCH2 pin S receives the second comparison unit CMP2 pin Q for 1 signal selection pin Pv1 value 15 output, the third two selection unit SWCH3 pin S receives the third comparison unit CMP3 pin Q for 0 signal selection pin Pv2 value 15 output, the fourth two selection unit SWCH4 pin S receives the fourth comparison unit CMP4 pin Q for 0 signal selection pin Pv2 value 15 output, the furnace bottom ash conveyor manual operation module MSA1 pin PV receives the fourth two selection unit SWCH4 output 15 signal pin OP output 15 to the analog output module AOUT1, so that the DCS given frequency command is 15HZ.
[0051] When the DCS receives the current signal greater than 3.2A and less than or equal to 3.6A, the first comparison unit CMP1 pin 1 value is greater than pin 2 value 2.3 pin Q output 1, the second comparison unit CMP2 pin 1 value is greater than pin 2 value 2.8 pin Q output 1, the third comparison unit CMP3 pin 1 value is greater than pin 2 value 3.2 pin Q output 1, the fourth comparison unit CMP4 pin 1 value is less than pin 2 value 3.6 pin Q output 0, the fifth comparison unit CMP5 pin 1 value is less than pin 2 value 4 pin Q output 0, the first two selection unit SWCH1 pin S receives the first comparison unit CMP1 pin Q for 1 signal selection pin Pv1 value 10 output, the second two selection unit SWCH2 pin S receives the second comparison unit CMP2 pin Q for 1 signal selection pin Pv1 value 15 output, the third two selection unit SWCH3 pin S receives the third comparison unit CMP3 pin Q for 1 signal selection pin Pv1 value 25 output, the fourth two selection unit SWCH4 pin S receives the fourth comparison unit CMP4 pin Q for 0 signal selection pin Pv2 value 25 output, the furnace bottom ash conveyor manual operation module MSA1 pin PV receives the fourth two selection unit SWCH4 output 25 signal pin OP output 25 to the analog output module AOUT1, so that the DCS given frequency command is 25HZ;
[0052] When the DCS receives the current signal greater than 3.6A and less than or equal to 4A, the first comparison unit CMP1 pin 1 value is greater than pin 2 value 2.3 pin Q output 1, the second comparison unit CMP2 pin 1 value is greater than pin 2 value 2.8 pin Q output 1, the third comparison unit CMP3 pin 1 value is greater than pin 2 value 3.2 pin Q output 1, the fourth comparison unit CMP4 pin 1 value is greater than pin 2 value 3.6 pin Q output 1, the fifth comparison unit CMP5 pin 1 value is less than pin 2 value 4 pin Q output 0, the first two selection unit SWCH1 pin S receives the first comparison unit CMP1 pin Q for 1 signal selection pin Pv1 value 10 output, the second two selection unit SWCH2 pin S receives the second comparison unit CMP2 pin Q for 1 signal selection pin Pv1 value 15 output, the third two selection unit SWCH3 pin S receives the third comparison unit CMP3 pin Q for 1 signal selection pin Pv1 value 25 output, the fourth two selection unit SWCH4 pin S receives the fourth comparison unit CMP4 pin Q for 1 signal selection pin Pv1 value 30 output, the furnace bottom ash conveyor manual operation module MSA1 pin PV receives the fourth two selection unit SWCH4 output 30 signal pin OP output 30 to the analog output module AOUT1, so that the DCS given frequency instruction is 30HZ.
[0053] When the DCS receives the current signal greater than 4A, the first comparison unit CMP1 pin 1 value is greater than pin 2 value 2.3 pin Q output 1, the second comparison unit CMP2 pin 1 value is greater than pin 2 value 2.8 pin Q output 1, the third comparison unit CMP3 pin 1 value is greater than pin 2 value 3.2 pin Q output 1, the fourth comparison unit CMP4 pin 1 value is greater than pin 2 value 3.6 pin Q output 1, the fifth comparison unit CMP5 pin 1 value is greater than pin 2 value 4 pin Q output 1, the first two selection unit SWCH1 pin S receives the first comparison unit CMP1 pin Q for 1 signal selection pin Pv1 value 10 output, the second two selection unit SWCH2 pin S receives the second comparison unit CMP2 pin Q for 1 signal selection pin Pv1 value 15 output, the third two selection unit SWCH3 pin S receives the third comparison unit CMP3 pin Q for 1 signal selection pin Pv1 value 25 output, the fourth two selection unit SWCH4 pin S receives the fourth comparison unit CMP4 pin Q for 1 signal selection pin Pv1 value 30 output, the furnace bottom ash conveyor manual operation module MSA1 pin PV receives the fourth two selection unit SWCH4 output 30 signal pin OP output 30 to the analog output module AOUT1, the on-off register module PBO1 receives the fifth comparison unit CMP5 pin Q for 1 signal output to the furnace bottom ash conveyor protection stop.
[0054] The embodiment of the utility model has the following beneficial effects:
[0055] 1. The stress condition of the fault times of the furnace bottom ash leakage conveyor can be analyzed through the historical data of the DCS, and strong data support is provided for the maintenance and replacement cycle of the furnace bottom ash leakage conveyor;
[0056] 2. The alarm signal and stop command can be sent before the chain of the furnace bottom ash leakage conveyor receives abnormal tension, reminding the on-duty personnel that the furnace bottom ash leakage conveyor is stuck by foreign matter or other mechanical faults, and informing the maintenance personnel to check and handle, which can effectively prevent the chain of the furnace bottom ash leakage conveyor from being pulled out or causing damage to other components, greatly reducing the maintenance cost and reducing the fault handling time.
[0057] 3. Compared with the original power frequency control mode, the annual running mileage of the chain of the furnace bottom ash leakage conveyor is shortened by 1 / 3, and the friction loss is also reduced to 1 / 3 of the original, the service life of the chain scraper of the furnace bottom ash leakage conveyor is extended from one year to two years, and the spare parts of 9220 yuan per year per furnace are saved. Moreover, the control mode also plays a role in saving electric energy due to the reduction of frequency and power output.
[0058] The above content is a further detailed description of the utility model made in combination with specific / preferred embodiments, and cannot be regarded as the specific implementation of the utility model being limited to these descriptions. For ordinary skilled persons in the technical field to which the utility model belongs, some substitutions or modifications can be made to the described embodiments without departing from the concept of the utility model, and these substitutions or modifications should be regarded as belonging to the protection scope of the utility model. In the description of the specification, the description of the reference terms "an embodiment", "some embodiments", "a preferred embodiment", "an example", "a specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In the case of not contradicting each other, the skilled person in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples. Although the embodiments of the utility model and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made in this paper without departing from the protection scope of the patent application.
Claims
1. A scraper conveying system, characterized in that, Includes scraper conveyor, frequency converter and control unit; The scraper conveyor is connected to the frequency converter, and the frequency converter is connected to the control unit; The frequency converter is used to provide power to the scraper conveyor, transmit the output current signal to the control unit, and receive the frequency conversion command from the control unit. According to the frequency conversion command, the frequency of the scraper conveyor is changed or maintained, thereby changing or maintaining the rotational speed of the scraper conveyor. The control unit is used to receive the current signal and, based on the current signal, increase, decrease, or maintain the frequency, send a frequency conversion command to the frequency converter.
2. The scraper conveying system as described in claim 1, characterized in that, The control unit includes an analog input module, a comparison module, a 2-to-1 multiplexer module, and an analog output module. The analog input module is connected to the input terminal of the comparison module, the output terminal of the comparison module is connected to the input terminal of the 2-to-1 multiplexer module, and the output terminal of the 2-to-1 multiplexer module is connected to the analog output module. The analog input module is used to acquire the analog current signal or frequency signal output by the frequency converter, thereby converting the analog current signal or frequency signal into a specific value and displaying it. The comparison module is used to compare the value of the current signal with a predetermined value, and output a first signal when the current signal is greater than the predetermined value, and output a second signal when the current signal is less than the predetermined value; The two-to-one module is used to select an output value based on the first signal and the second signal to determine the frequency value of the scraper conveyor. The analog output module is used to convert the specific value into an analog signal and transmit it to the frequency converter, thereby controlling the frequency output by the frequency converter.
3. The scraper conveying system as described in claim 2, characterized in that, The control unit further includes a digital quantity register module, and the comparison module is connected to the digital quantity register module. The digital quantity register module is used to receive the first signal and output it to the scraper conveyor for protection stop.
4. The scraper conveying system as described in claim 2, characterized in that, The comparison module includes first to fourth comparison units, and the two-to-one module includes first to fourth two-to-one units. The first comparison unit is connected to the first pin of the first two-to-one unit, the second comparison unit is connected to the first pin of the second two-to-one unit, the third comparison unit is connected to the first pin of the third two-to-one unit, and the fourth comparison unit is connected to the first pin of the fourth two-to-one unit. The output terminal of the first two-to-one unit is connected to the second pin of the second two-to-one unit, the output terminal of the second two-to-one unit is connected to the second pin of the third two-to-one unit, and the output terminal of the third two-to-one unit is connected to the second pin of the fourth two-to-one unit. The input values of the third pins of the first to fourth two-to-one units are fixed values that increase sequentially.
5. The scraper conveying system as described in claim 4, characterized in that, The comparison module further includes a fifth comparison unit, which is connected to the switch register module. The switch register module is used to receive the first signal output from the fifth comparison unit and send it to the scraper conveyor for protection stop.
6. The scraper conveying system as described in claim 1, characterized in that, The control unit is a DCS.