Control method for a grain dryer and a grain dryer

Abstract

The application relates to the technical field of grain drying machines, and discloses a control method for a grain drying machine and the grain drying machine, which is used for circulating drying of grain and comprises a drying system, a circulating system and a lifting system. The circulating system is arranged below the drying system and downwardly conveys the grain in the drying system to be transferred to the lifting system. The lifting system is used for upwardly lifting the grain to be re-transferred to the drying system. The control method comprises the following steps: acquiring a real-time current of a lifting motor of the lifting system; determining that the real-time current of the lifting motor is greater than a preset current, and that a real-time current difference between the real-time current of the lifting motor and the preset current is greater than a preset current difference; and reducing a grain conveying speed of the circulating system. The control method for the grain drying machine and the grain drying machine can early judge that the lifting system has an overload risk to avoid a blocking situation, and effectively improve the drying operation efficiency of a user.

Description

Technical Field

[0001] This application belongs to the technical field of grain dryers, specifically relating to a control method for a grain dryer and a grain dryer. Background Technology

[0002] Grain dryers are the core equipment of drying centers, but grain dryers often experience material blockage. Once blocked, the blockage must be cleared before normal operation can be restored, which is time-consuming and labor-intensive, seriously affecting the drying efficiency of users. Summary of the Invention

[0003] The purpose of this application is to provide a control method and a grain dryer for a grain dryer, which can effectively improve the user's drying operation efficiency.

[0004] To achieve the above objectives, this application provides a control method for a grain dryer. The grain dryer is used for circulating grain drying and includes a drying system, a circulation system, and a lifting system. The circulation system is located below the drying system and conveys the grain in the drying system downwards to the lifting system. The lifting system is used to lift the grain upwards to re-transfer it to the drying system. The control method includes:

[0005] Obtain the real-time current I1 of the lifting motor of the lifting system;

[0006] It is determined that the real-time current I1 of the lifting motor is greater than the preset current I0, and the real-time current difference ΔI1 between the real-time current I1 of the lifting motor and the preset current I0 is greater than the preset current difference ΔI0.

[0007] Reduce the grain transport speed of the circulation system.

[0008] In some specific embodiments, the circulation system includes a grain-dispensing wheel disposed in the grain channel between the drying system and the circulation system, and a frequency converter for controlling the rotational speed of the grain-dispensing wheel. Reducing the grain conveying speed of the circulation system includes:

[0009] Adjust the frequency of the inverter to reduce the rotational speed of the grain feeding wheel.

[0010] In some specific embodiments, the control method further includes:

[0011] When adjusting the frequency of the inverter to reduce the speed of the grain feeding wheel, the adjustment time T1 of the speed of the grain feeding wheel is recorded.

[0012] If the speed adjustment duration T1 is determined to be less than the preset duration T0 and the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the frequency of the inverter is continuously adjusted until the real-time current difference ΔI1 is less than the preset current difference ΔI0.

[0013] In some specific embodiments, after the real-time current difference ΔI1 is less than the preset current difference ΔI0, the control method further includes:

[0014] The frequency of the inverter is kept constant to maintain the rotational speed of the grain feeding wheel until the drying process is complete.

[0015] In some specific embodiments, the control method further includes:

[0016] If the speed adjustment duration T1 is greater than the preset duration T0 and the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the grain dryer is controlled to stop.

[0017] In some specific embodiments, the control method further includes:

[0018] When the grain dryer is shut down, a shutdown alarm signal is issued.

[0019] In some specific embodiments, after determining that the real-time current I1 of the hoisting motor is greater than the preset current I0, and the real-time current difference ΔI1 between the real-time current I1 of the hoisting motor and the preset current I0 is greater than the preset current difference ΔI0, the control method further includes:

[0020] The system is controlled to emit a frequency signal.

[0021] The control system adjusts the frequency of the inverter according to the frequency signal to reduce the rotational speed of the grain feeding wheel.

[0022] In some specific embodiments, the grain dryer further includes a lower conveying system disposed between the circulation system and the lifting system, wherein the circulation system transfers grain to the lifting system via the lower conveying system, and the control method further includes:

[0023] If the lower conveyor system is found to be overloaded, the grain dryer is controlled to stop.

[0024] In some specific embodiments, the control method further includes:

[0025] The types of food obtained;

[0026] The values ​​of the preset current I0 and the preset current difference ΔI0 are determined based on the type of grain.

[0027] A second aspect of this application provides a grain dryer, including a control system that performs the control method described above for a grain dryer.

[0028] Through the above technical solution, the control system of the grain dryer can judge in advance the risk of overload of the lifting system based on the real-time current difference between the real-time current of the lifting motor and the preset current. This allows for timely reduction of the grain conveying speed of the circulation system, thereby avoiding severe material blockage in the dryer due to insufficient manual adjustment of the circulation system, which helps improve the user's drying operation efficiency.

[0029] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without any inventive effort. In the drawings:

[0031] Figure 1 A structural schematic diagram of a grain dryer according to a specific embodiment of this application is shown;

[0032] Figure 2 A schematic diagram of the grain passage and grain conveyor of the circulation system is shown;

[0033] Figure 3 A control flowchart of one specific embodiment of this application is shown.

[0034] Explanation of reference numerals in the attached figures

[0035] 1. Drying system 2. Circulation system

[0036] 21 Grain Transport Route 22 Grain Dispatch Wheel

[0037] 3. Lifting System 4. Lower Conveying System

[0038] 5. Upper conveyor system 6. Tempering system Detailed Implementation

[0039] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this application.

[0040] Existing grain dryers frequently experience material blockages. Once a blockage occurs, it requires clearing the blockage before normal operation can resume, which is time-consuming and labor-intensive, severely impacting the drying efficiency of users. Therefore, the inventors of this application, after careful consideration, discovered that to reduce users' purchase costs, improve equipment efficiency, and gain market competitiveness, existing grain dryers are mostly multi-purpose dryers, capable of drying rice, wheat, corn, and small grains such as rapeseed. However, different grains have different resistance coefficients, and even the same type of grain has different resistance coefficients depending on its moisture content. The grain flows down the dryer at varying speeds during circulation, especially in the circulation system that controls the grain circulation speed. This leads to insufficient conveying capacity of subsequent equipment, frequently causing blockages.

[0041] In addition, in order to solve the problem of material blockage, existing grain dryers improve the conveying capacity of the downstream equipment of the circulation system to meet the conveying needs of different types of grains and grains with different moisture content. However, this design not only increases manufacturing costs but also increases user operating costs, which is not conducive to market competition.

[0042] In view of this, such as Figure 1 and Figure 3 As shown, this application provides a novel control method for a grain dryer and a grain dryer. The grain dryer is used for circulating grain drying and includes a control system, a drying system 1, a circulation system 2, and a lifting system 3. The control system is communicatively connected to the drying system 1, the circulation system 2, and the lifting system 3. The circulation system 2 is located below the drying system 1 and conveys the grain in the drying system 1 downwards so that the grain can be transferred to the lifting system 3. The lifting system 3 is used to lift the grain upwards so that the grain can be transferred back to the drying system 1.

[0043] The control method for a grain dryer in this application includes:

[0044] Obtain the real-time current I1 of the lifting motor of lifting system 3;

[0045] It is determined that the real-time current I1 of the lifting motor is greater than the preset current I0, and the real-time current difference ΔI1 between the real-time current I1 of the lifting motor and the preset current I0 is greater than the preset current difference ΔI0.

[0046] Reduce the grain transport speed of circulation system 2.

[0047] Thus, by collecting the real-time current I1 of the lifting motor in real time through the control system, and comparing the real-time current I1 of the lifting motor of the lifting system 3 with the preset current I0, and determining that the real-time current difference ΔI1 between the lifting motor's real-time current I1 and the preset current I0 is greater than the preset current difference ΔI0, the control system can predict in advance that the lifting system 3 has an overload risk. This allows for timely reduction of the grain conveying speed in the circulation system 2, ensuring that subsequent conveying equipment remains within its rated load range. This prevents severe material blockage in the dryer due to insufficient manual adjustment of the circulation system 2, thereby improving the user's drying efficiency. This grain dryer has low manufacturing costs, fast response, and does not experience blockage or overload. It also features intelligent control, effectively solving equipment blockage problems caused by different grains and different grain conditions at a low cost.

[0048] The conveying structure of the circulation system 2 can vary, and may include a grain-dispensing wheel structure or a pivot valve structure. When the conveying structure of the circulation system 2 includes a grain-dispensing wheel structure, the grain conveying speed of the circulation system 2 can be adjusted by controlling the rotational speed of the grain-dispensing wheel; when the conveying structure of the circulation system 2 includes a pivot valve structure, the grain conveying speed of the circulation system 2 can be adjusted by controlling the opening degree of the pivot valve.

[0049] Optionally, such as Figure 1 As shown, the grain dryer of this application also includes a lower conveying system 4, an upper conveying system 5, and a tempering system 6. The control system is also communicatively connected to the lower conveying system 4 and the upper conveying system 5, respectively. The tempering system 6, the drying system 1, and the circulation system 2 are arranged sequentially from top to bottom. The lower conveying system 4 is located between the circulation system 2 and the lifting system 3. The circulation system 2 transfers grain to the lifting system 3 through the lower conveying system 4. The upper conveying system 5 is located between the tempering system 6 and the lifting system 3. The lifting system 3 transfers grain to the tempering system 6 through the upper conveying system 5. Thus, the grain circulation drying process of the grain dryer of this application is: circulation system 2 → lower conveying system 4 → lifting system 3 → upper conveying system 5 → tempering system 6 → drying system 1 → circulation system 2. The grain circulates in this process until it is dried.

[0050] In some specific embodiments, the circulation system 2 may include a grain-distributing wheel 22 disposed in the grain passage 21 between the drying system 1 and the circulation system 2, and a frequency converter for controlling the rotational speed of the grain-distributing wheel 22. For example... Figure 2As shown, the grain feeding wheel 22 is an important component of the circulation system 2, and it is used to control the circulation speed of the grain. To prevent the grain feeding wheel 22 from becoming clogged due to impurities, a certain gap is left between the grain feeding wheel 22 and the grain channel 21. Some grain will slide down through this gap. Therefore, the grain falling from the circulation system 2 consists of two parts: the grain fed down by the grain feeding wheel 22 and the grain that flows down by gravity from the grain channel 21. The amount of grain that flows down by gravity varies depending on the type and moisture content of the grain, which will cause fluctuations in the load on subsequent equipment.

[0051] Optionally, the step of reducing the grain conveying speed of the circulation system 2 may specifically include:

[0052] Adjust the frequency of the inverter to reduce the speed of the grain feeding wheel 22.

[0053] In this way, by controlling the rotational speed of the grain-distributing wheel 22 in the circulation system 2, the amount of grain circulating can be controlled, preventing subsequent equipment in the circulation system 2, especially the elevator, from becoming clogged due to excessive load. The rotational speed of the grain-distributing wheel 22 is automatically controlled by a frequency converter. The input signal is the comparison result between the real-time current I1 of the elevator motor and the preset current I0, as well as the comparison result between the real-time current difference ΔI1 and the preset current difference ΔI0. When the load of the elevator increases, the real-time current I1 increases, the rotational speed of the elevator motor decreases, and the lifting amount decreases. If the load of the elevator motor is not reduced at this time, the elevator system 3 will not be able to receive the grain delivered by the conveying system 4 in time, causing the elevator system 3 to become clogged, and further causing the machine to stop due to protection. The control system of the grain dryer of this application can detect the risk of overload in the elevator system 3 in advance, and reduce the rotational speed of the grain-distributing wheel 22 by adjusting the frequency of the frequency converter in time, so that the subsequent conveying equipment is within the rated load range, thereby avoiding the situation of severe material blockage in the dryer due to insufficient manual adjustment of the circulation system 2.

[0054] Furthermore, such as Figure 3 As shown, the control method may also include:

[0055] When adjusting the frequency of the inverter to reduce the speed of the grain feeding wheel 22, the speed adjustment time T1 of the grain feeding wheel 22 is recorded.

[0056] If the speed adjustment time T1 is less than the preset time T0 and the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the frequency of the inverter is continuously adjusted until the real-time current difference ΔI1 is less than the preset current difference ΔI0.

[0057] That is, within the allowed preset time period T0, when the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the frequency of the inverter can be continuously adjusted until the real-time current difference ΔI1 is less than the preset current difference ΔI0. When the real-time current difference ΔI1 is less than the preset current difference ΔI0, the control system considers the real-time current I1 of the hoisting motor of the hoisting system 3 to be within the normal range, and thus stops adjusting the frequency of the inverter.

[0058] Furthermore, after the real-time current difference ΔI1 is less than the preset current difference ΔI0, the control method also includes:

[0059] The frequency of the frequency converter is kept constant to maintain the rotational speed of the grain feeding wheel 22 until the drying is finished.

[0060] After the drying operation is completed, the frequency of the inverter of the grain feeding wheel 22 returns to normal.

[0061] In some specific implementations, the control method may further include:

[0062] If the speed adjustment time T1 is greater than the preset time T0 and the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the grain dryer will be stopped.

[0063] If the real-time current difference ΔI1 is still greater than the preset current difference ΔI0 within the allowed preset time T0, it indicates that the lifting system 3 is abnormal and the control system will stop. At this time, the cause of the fault can be checked manually.

[0064] Optionally, in order to promptly alert operators to check for faults, the control method also includes:

[0065] When the grain dryer is shut down, a shutdown alarm signal is issued.

[0066] In some specific embodiments, after determining that the real-time current I1 of the hoisting motor is greater than the preset current I0, and that the real-time current difference ΔI1 between the real-time current I1 of the hoisting motor and the preset current I0 is greater than the preset current difference ΔI0, the control method may further include:

[0067] The control and lifting system 3 sends out a frequency signal;

[0068] The control circulation system 2 adjusts the frequency of the inverter according to the frequency signal to reduce the speed of the grain feeding wheel 22.

[0069] In some specific implementations, the control method may further include:

[0070] If the conveyor system 4 is found to be overloaded, the grain dryer will be shut down.

[0071] In some abnormal situations, such as a loose belt in the lifting system 3, belt misalignment in the lifting system 3, or a coupling failure in the lifting system 3, the lower conveyor system 4 may become overloaded. Even if the lifting motor of the lifting system 3 is functioning normally, the control system will shut down due to the overload of the lower conveyor system 4. The control step of adjusting the grain conveying speed of the circulation system 2 based on the real-time current I1 of the lifting motor is applicable when other systems such as the lower conveyor system 4 and the upper conveyor system 5 of the grain dryer are operating normally, and is considered the lowest priority. There are various ways to determine if the lower conveyor system 4 is overloaded. For example, it can be determined by acquiring the real-time current of the conveyor motor of the lower conveyor system 4 and confirming that the real-time current is not within the preset allowable current range; or, a pressure sensor can be installed in the lower conveyor system 4, and the real-time pressure value of the pressure sensor can be acquired and confirmed to be outside the preset allowable pressure range to determine if the lower conveyor system 4 is overloaded.

[0072] With the increasing variety of grains across different regions, multi-purpose dryers are being used more and more frequently. Different grains, and even the same grain with varying moisture content, exhibit different resistance to gravity flow, resulting in varying circulation volumes. To broaden the applicability of grain dryers, the control system can be set with preset current I0, preset current difference ΔI0, and preset duration T0 for different grains. Therefore, the control method may also include:

[0073] The types of food obtained;

[0074] The preset current I0, preset current difference ΔI0, and preset duration T0 are determined based on the type of grain.

[0075] Before the drying process, the type of grain is selected, and the control system can automatically identify and switch the preset current I0, preset current difference ΔI0, and preset time T0.

[0076] In some specific embodiments, in order to make the operation of the grain dryer more reliable and further improve the grain drying quality, after the step of reducing the grain conveying speed of the circulation system 2, the control method may further include:

[0077] Adjust the air intake or drying temperature of the drying system 1 according to the grain conveying speed of the circulation system 2.

[0078] The change in the grain conveying speed of the circulation system 2 affects the storage time of the grain in the drying system 1, thus affecting the drying quality of the grain. In order to reduce the grain breakage rate and ensure the drying quality of the grain, after reducing the grain conveying speed of the circulation system 2, the air intake or drying temperature of the drying system 1 can be reduced.

[0079] Since the grain dryer of this application includes a control system that executes the control method for the grain dryer described above, the grain dryer of this application possesses all the technical effects of the control method for the grain dryer described above, and therefore will not be repeated here.

[0080] It should be noted that the composition and structure of the drying system, tempering system, grain feeding wheel, lifting system, lower conveying system and upper conveying system in this application are well known to those skilled in the art and are not part of the core improvement of this application, so they will not be described in detail here.

[0081] In summary, the control method and grain dryer of this application mainly solve the problem of grain blockage in multi-purpose dryers. Regardless of the type of grain being dried or the moisture content of the grain, the dryer's conveying equipment will not be blocked due to excessive conveying volume, thus effectively improving the user's drying operation efficiency.

[0082] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0083] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0084] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0085] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A control method for a grain dryer, characterized in that, The grain dryer is used for circulating grain drying and includes a drying system (1), a circulation system (2), and a lifting system (3). The circulation system (2) is located below the drying system (1) and conveys the grain in the drying system (1) downwards to the lifting system (3). The lifting system (3) is used to lift the grain upwards to re-transfer it to the drying system (1). The control method includes: Obtain the real-time current I1 of the lifting motor of the lifting system (3); It is determined that the real-time current I1 of the lifting motor is greater than the preset current I0, and the real-time current difference ΔI1 between the real-time current I1 of the lifting motor and the preset current I0 is greater than the preset current difference ΔI0. Reduce the grain transport speed of the circulation system (2); Adjust the air intake or drying temperature of the drying system (1) according to the grain conveying speed of the circulation system (2); The circulation system (2) includes a grain conveying wheel (22) disposed in the grain channel (21) between the drying system (1) and the circulation system (2) and a frequency converter for controlling the rotational speed of the grain conveying wheel (22). The reduction of the grain conveying speed of the circulation system (2) includes: Adjust the frequency of the inverter to reduce the rotational speed of the grain feeding wheel (22); When adjusting the frequency of the inverter to reduce the speed of the grain feeder (22), the speed adjustment time T1 of the grain feeder (22) is recorded. If the speed adjustment duration T1 is determined to be less than the preset duration T0 and the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the frequency of the inverter is continuously adjusted until the real-time current difference ΔI1 is less than the preset current difference ΔI0.

2. The control method for a grain dryer according to claim 1, characterized in that, After the real-time current difference ΔI1 is less than the preset current difference ΔI0, the control method further includes: The frequency of the inverter is kept constant to maintain the rotational speed of the grain feeding wheel (22) until the drying is finished.

3. The control method for a grain dryer according to claim 1, characterized in that, The control method further includes: If the speed adjustment duration T1 is greater than the preset duration T0 and the real-time current difference ΔI1 is greater than the preset current difference ΔI0, the grain dryer is controlled to stop.

4. The control method for a grain dryer according to claim 3, characterized in that, The control method further includes: When the grain dryer is shut down, a shutdown alarm signal is issued.

5. The control method for a grain dryer according to claim 1, characterized in that, After determining that the real-time current I1 of the hoisting motor is greater than the preset current I0, and the real-time current difference ΔI1 between the real-time current I1 of the hoisting motor and the preset current I0 is greater than the preset current difference ΔI0, the control method further includes: The lifting system (3) is controlled to emit a frequency signal; The control system (2) adjusts the frequency of the inverter according to the frequency signal to reduce the rotational speed of the grain feeding wheel (22).

6. The control method for a grain dryer according to claim 1, characterized in that, The grain dryer further includes a lower conveying system (4) disposed between the circulation system (2) and the lifting system (3), wherein the circulation system (2) transfers grain to the lifting system (3) through the lower conveying system (4), and the control method further includes: If the lower conveying system (4) is found to be overloaded, the grain dryer is controlled to stop.

7. The control method for a grain dryer according to claim 1, characterized in that, The control method further includes: The types of food obtained; The values ​​of the preset current I0 and the preset current difference ΔI0 are determined based on the type of grain.

8. A grain dryer, characterized in that, It includes a control system that performs the control method for a grain dryer according to any one of claims 1 to 7.

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