Microelement uniform adding device for compound fertilizer

Abstract

The utility model discloses a kind of trace element uniform adding device for compound fertilizer production, device includes trace element storage bin, feeding mechanism, primary mixing mechanism and secondary mixing mechanism connected in sequence.The storage bin bottom is equipped with arch breaking mechanism driven by motor, prevent material caking;The feeding mechanism is screw conveyor, and with storage bin is installed on the scale body supported by weighing sensor, constitutes weightlessness scale system;The primary mixing mechanism is venturi mixer, utilizes negative pressure to inhale trace element;The secondary mixing mechanism is dynamic mixer with stirring blade.The utility model is combined by weightlessness scale closed-loop control and two-stage mixing, realizes the high-precision measurement of trace element and high-efficiency uniform mixing, effectively solve the existing technology in the discharging blockage, measurement inaccuracy and mixing uneven problem, significantly improve compound fertilizer product quality.

Description

Technical Field

[0001] This utility model relates to the technical field of compound fertilizer production equipment, specifically a device for uniformly adding trace elements to compound fertilizer. Background Technology

[0002] Compound fertilizers are an important production material in modern agriculture, typically containing macronutrients such as nitrogen, phosphorus, and potassium. To meet the specific growth needs of different crops, micronutrients such as zinc, boron, manganese, and iron are often added to compound fertilizers to produce targeted, high-efficiency specialty fertilizers.

[0003] In the production of compound fertilizers, the addition of trace elements is a crucial step in ensuring product functionality and quality. However, due to the small amounts of trace elements required, their predominantly powdery form, and their tendency to absorb moisture and clump, they face significant challenges in continuous industrial production. Currently, the common method of addition is manual or simple mechanical feeding at the inlet of the mixer or granulator. This method has several major problems: 1. Poor feeding stability: Powdered trace elements are prone to "bridging" and "rat holes" in the storage silo, resulting in interrupted feeding or inconsistent supply, which makes it impossible to achieve continuous and stable supply and seriously affects the continuity of production.

[0004] 2. Low metering accuracy: Traditional volumetric feeding (such as screw conveyors) is greatly affected by the material's density and moisture content, while manual feeding has even greater errors. This leads to an uncontrolled ratio between trace elements and main fertilizers, making it impossible to guarantee the accuracy and consistency of the product's nutrient content, which affects fertilizer efficiency and causes raw material waste.

[0005] 3. Poor mixing uniformity: Directly adding trace powders to a large amount of main fertilizer lacks an effective premixing and dispersion mechanism. Relying solely on the brief mixing during the subsequent granulation process makes it difficult to achieve uniform distribution at the microscale. This easily leads to localized enrichment or deficiency of trace elements in the finished fertilizer, preventing some crops from absorbing the necessary nutrients, while other areas may suffer fertilizer damage due to excessively high concentrations.

[0006] These problems directly restrict the development and production of high-quality, functional compound fertilizer products. Therefore, there is an urgent need in this field for a trace element addition device that can achieve stable feeding, precise metering, and efficient mixing to improve the overall quality and production efficiency of compound fertilizers. Summary of the Invention

[0007] The technical problem to be solved by this utility model is to provide a micronutrient uniform addition device for compound fertilizer. Through the integrated design of arch breaking, precise feeding and two-stage mixing, it effectively solves the problems of blockage, inaccurate metering and uneven mixing in the micronutrient addition process.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a micronutrient uniform addition device for compound fertilizer, comprising a micronutrient storage silo, a storage silo discharge pipe at the bottom of the micronutrient storage silo, the storage silo discharge pipe being connected to the feeding mechanism inlet pipe of the feeding mechanism, the feeding mechanism inlet pipe being provided with a feeding mechanism discharge pipe, the feeding mechanism discharge pipe being connected to the primary mixing mechanism inlet pipe of the primary mixing mechanism, the primary mixing mechanism output end being connected to the secondary mixing mechanism inlet pipe of the secondary mixing mechanism, and the secondary mixing mechanism also being provided with a secondary mixing mechanism discharge pipe connected to the granulator.

[0009] In a preferred embodiment, the output end of the secondary mixing mechanism is connected to a buffer tank, the bottom of the buffer tank is provided with a buffer tank discharge pipe, and the bottom of the buffer tank discharge pipe is connected to the feed pipe of the secondary mixing mechanism.

[0010] In a preferred embodiment, the trace element storage silo is equipped with a rotating shaft, the lower end of which extends into the discharge pipe of the storage silo, and an arch-breaking plate is provided on the rotating shaft located in the discharge pipe of the storage silo.

[0011] In a preferred embodiment, the top of the trace element storage silo is equipped with a motor for driving the rotating shaft.

[0012] In a preferred embodiment, the rotating shaft is a sleeve structure, the outer shaft can move axially relative to the inner shaft, and the inner and outer shafts are radially fixed by a keyway fit.

[0013] In a preferred embodiment, a wave groove is provided on the outer wall of the outer shaft, and a fixing rod is fixedly provided on the inner wall of the trace element storage bin. The fixing rod is horizontally set, with one end fixed to the inner wall of the trace element storage bin and the other end located in the wave groove.

[0014] In a preferred embodiment, the trace element storage bin is supported on a support plate by a bracket, and weighing sensors are provided at the bottom of the four corner points of the support plate.

[0015] In a preferred embodiment, the feeding mechanism is a screw conveyor; The primary mixing mechanism is a Venturi mixer, and the feed pipe of the feeding mechanism is connected to the feed pipe of the primary mixing mechanism on the throat of the Venturi mixer. The input end of the Venturi mixer is connected to a pneumatic conveying pipe for material transport, and the buffer tank is located at the end of the diffuser section of the Venturi mixer.

[0016] In a preferred embodiment, the secondary mixing mechanism is inclined, and a stirring shaft driven by a motor is provided inside the secondary mixing mechanism, with stirring blades on the stirring shaft.

[0017] The micronutrient uniform addition device for compound fertilizer provided by this utility model has the following beneficial effects by adopting the above structure: (1) By integrating the storage, feeding and weighing systems into an integrated scale body and using the loss-in-weight method for measurement, the discharge rate of trace elements can be monitored and controlled in real time, thereby achieving precise proportional linkage with the main fertilizer. This fundamentally solves the problems of inaccurate measurement and uncontrolled ratio in traditional addition methods, and significantly improves the uniformity and stability of product nutrients. (2) By using the mechanical arch-breaking mechanism installed in the discharge pipe of the storage silo, the material can be broken by radial rotation while simultaneously performing small-amplitude axial reciprocating motion, effectively destroying the "bridging" agglomeration of the material and ensuring the continuity of subsequent feeding. (3) The Venturi mixer is used for initial pneumatic dispersion, and then combined with the mechanical forced stirring of the dynamic mixer to form a highly efficient two-stage mixing system, which ensures that the trace components are evenly distributed at the microscale in a large amount of main fertilizer, greatly improving the quality and efficiency of fertilizer products. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0019] In the diagram: 1. Trace element storage bin, 101 discharge pipe of storage bin, 2. Feeding mechanism, 201 feed pipe of feeding mechanism, 202 discharge pipe of feeding mechanism, 3. Primary mixing mechanism, 301 feed pipe of primary mixing mechanism, 4. Secondary mixing mechanism, 401 feed pipe of secondary mixing mechanism, 402 discharge pipe of secondary mixing mechanism, 5. Buffer tank, 501 discharge pipe of buffer tank, 6. Rotary shaft, 7. Arch breaking plate, 8. Motor, 9. Wave groove, 10. Fixed rod, 11. Support plate, 12. Weighing sensor. Detailed Implementation

[0020] like Figure 1 The present invention discloses a micronutrient uniform addition device for compound fertilizer production, the core components of which include a micronutrient storage bin 1, a feeding mechanism 2, a primary mixing mechanism 3 and a secondary mixing mechanism 4, and a corresponding control system can be added.

[0021] in: The trace element storage silo 1 is used to store powdered trace elements. Its bottom conical opening is connected to a storage silo discharge pipe 101. To solve the problem of material caking and blockage, a rotating shaft 6 is installed inside the silo, driven by a motor 8 fixed to the top of the silo. The lower end of the rotating shaft 6 extends into the storage silo discharge pipe 101 and is equipped with an anti-caking plate 7. When the motor 8 drives the rotating shaft 6 to rotate, the anti-caking plate 7 can effectively break up the caking material at the discharge port, ensuring smooth material flow.

[0022] As a preferred embodiment, the rotating shaft 6 can adopt a sleeve shaft structure, meaning the outer shaft can move axially relative to the inner shaft while maintaining radial fixation through a keyway. A wave groove 9 is formed on the outer wall of the outer shaft, and one end of a horizontal fixing rod 10 fixed to the inner wall of the chamber is embedded in this wave groove 9. When the outer shaft rotates, guided by the wave groove 9 and the fixing rod 10, the outer shaft will generate a regular axial up-and-down movement while rotating, thereby driving the arch-breaking plate 7 to perform an additional up-and-down lifting action on top of the rotational arch-breaking action, forming a more effective "kneading" arch-breaking effect, far exceeding that of simple rotation.

[0023] The feeding mechanism 2 is preferably a screw conveyor, whose feed pipe 201 is sealed to the discharge pipe 101 of the storage bin through a flexible connecting sleeve (such as a canvas sleeve), and whose discharge pipe 202 is connected to the primary mixing mechanism 3.

[0024] To achieve accurate measurement, the entire storage and feeding system is supported on an independent rigid support plate 11, with a high-precision weighing sensor 12 installed at each of the four corners of the support plate 11. This means that the total weight of the trace element storage bin 1, the feeding mechanism 2, and the materials inside them is entirely supported by these four weighing sensors 12, forming a loss-in-weight scale system.

[0025] The added control system is centered around a programmable logic controller (PLC). The PLC's analog input module is connected to a signal aggregator of the four weighing sensors 12 to collect the total weight of the system in real time. Simultaneously, the PLC is electrically connected to the drive motor of the feeding mechanism 2 via a frequency converter 14 to precisely control its speed. The PLC is also connected to a human-machine interface (HMI) touchscreen for parameter setting, status display, and alarm functions.

[0026] The control logic of the control system is as follows: The PLC receives the main fertilizer flow signal from the main production line and calculates the target flow rate of the feeding mechanism 2 based on the preset trace element addition ratio. Simultaneously, the PLC collects the weight value from the weighing sensor 12 at high frequency and calculates the instantaneous actual flow rate by measuring the weight loss per unit time. Subsequently, the PLC compares the actual flow rate with the target flow rate, performs calculations using its built-in PID control algorithm, and outputs a control signal to the frequency converter to dynamically adjust the speed of the screw conveyor motor, forming a high-precision closed-loop control to ensure that the actual feeding flow rate remains stable near the target value.

[0027] In addition, the PLC is interlocked with the arch-breaking motor 8. When the flow rate detected by the weighing sensor 12 is continuously lower than the set lower limit, the PLC can determine that the material feeding is not smooth and automatically start the arch-breaking motor 8 to work for one cycle, thereby realizing intelligent arch breaking.

[0028] The primary mixing mechanism 3 is a Venturi mixer. Its throat section is equipped with a primary mixing mechanism inlet pipe 301, which connects to the feeding mechanism outlet pipe 202. The air inlet of the Venturi mixer is connected to the pneumatic conveying pipeline of the main fertilizer via a flange.

[0029] The secondary mixing mechanism 4 is preferably an inclined dynamic mixer, with a stirring shaft and stirring blades driven by a motor inside its cylinder. The feed pipe 401 of the secondary mixing mechanism is directly connected to the output end of the primary mixing mechanism 3 (i.e., the outlet of the diffuser section of the Venturi mixer) to ensure a smooth transition of the inner wall and no material retention. The mixed material is finally discharged from the discharge pipe 402 of the secondary mixing mechanism and enters the downstream granulator.

[0030] A buffer tank 5 can be added between the end of the diffusion section of the Venturi mixer and the secondary mixing mechanism 4. The bottom of the buffer tank 5 is connected to the feed pipe 401 of the secondary mixing mechanism via the buffer tank discharge pipe 501. The function of the buffer tank 5 is to reduce the speed of the gas-solid two-phase flow after the initial mixing in the Venturi mixer, achieving initial gas-solid separation. The solid material falls to the bottom and is stably conveyed to the secondary mixing mechanism by the feeding mechanism, while the gas is discharged from the top or connected to the dust removal system. This makes the subsequent mechanical mixing more stable and efficient.

[0031] Taking potato-specific fertilizer as an example, the principle of this invention is as follows: 1. System Initialization: After the equipment is powered on, the PLC reads the status of each sensor. The operator sets the addition ratio of trace elements such as zinc and manganese to the main fertilizer (industrial monoammonium phosphate, potassium sulfate, ammonium nitrate phosphate, etc.) via the touch screen 15. The main production line begins to add the main fertilizer to the designated feeding points according to the ratio.

[0032] 2. Intelligent Arch Breaking and Continuous Feeding: The main production line start signal is transmitted to the control system of this utility model. The PLC then starts the screw conveyor of the feeding mechanism 2 and runs it at the initial speed. At the same time, the arch breaking mechanism in the storage silo 1 is started to ensure that the zinc, manganese and other trace element powders can be stably and continuously discharged from the storage silo outlet pipe 101 and enter the feeding mechanism 2.

[0033] 3. Closed-loop metering and control (core): This is a continuously operating closed-loop process.

[0034] 3.1 Data Acquisition: Weighing sensor 12 measures the total weight of the system in real time at high frequency and transmits the signal to PLC.

[0035] 3.2 Flow Calculation: The PLC accurately calculates the instantaneous actual flow rate of trace elements such as zinc and manganese based on the amount of weight reduction per unit time.

[0036] 3.3 Deviation Comparison and Adjustment: The PLC compares the instantaneous actual flow rate with the target flow rate calculated based on the potato-specific fertilizer formula in real time to obtain the flow rate deviation.

[0037] 3.4 Output Execution: The PLC's internal PID control algorithm calculates based on the magnitude and trend of the deviation, outputting an adjustment signal to the frequency converter. The frequency converter then adjusts the speed of the screw feeder motor. If the actual flow rate is low, the speed is increased; conversely, the speed is decreased. This process repeats continuously, achieving automatic, precise, and stable flow rate control.

[0038] 4. Two-stage high-efficiency mixing: Precisely metered zinc and manganese powders are discharged through the feed mechanism's outlet pipe 202 and first enter the primary mixing mechanism 3, where they are drawn in by the high-speed flow of the main fertilizer airflow and achieve initial dispersion and mixing. Subsequently, this premixed material enters the secondary mixing mechanism 4 for forced mechanical stirring to achieve high uniformity. Finally, this uniformly mixed material is discharged from the secondary mixing mechanism's outlet pipe 402 and directly and accurately conveyed to the granulator for granulation, perfectly replacing the original extensive method of directly adding trace elements into the granulator.

[0039] 5. Interlocking and Protection: Throughout the process, the PLC monitors all critical parameters. If abnormalities such as excessive flow or equipment malfunction occur, the PLC will trigger an audible and visual alarm and display it on the HMI. If necessary, it will automatically shut down to ensure system and product safety.

[0040] The potato fertilizer granules, which come out of the granulator and are uniformly containing zinc and manganese, are then dried in a dryer, cooled in a cooler, screened out as qualified granules by a screening machine, coated by a coating machine, and finally packaged by a packaging scale to obtain the finished product.

Claims

1. A device for uniformly adding trace elements to compound fertilizer, characterized in that: The system includes a trace element storage silo (1), the bottom of which is provided with a storage silo discharge pipe (101), the storage silo discharge pipe (101) is connected to the feeding mechanism inlet pipe (201) of the feeding mechanism (2), the feeding mechanism inlet pipe (201) is provided with a feeding mechanism discharge pipe (202), the feeding mechanism discharge pipe (202) is connected to the primary mixing mechanism inlet pipe (301) of the primary mixing mechanism (3), the output end of the primary mixing mechanism (3) is connected to the secondary mixing mechanism inlet pipe (401) of the secondary mixing mechanism (4), and the secondary mixing mechanism (4) is also provided with a secondary mixing mechanism discharge pipe (402) connected to the granulator.

2. The micronutrient uniform addition device for compound fertilizer according to claim 1, characterized in that: The output end of the secondary mixing mechanism (4) is connected to the buffer tank (5). The bottom of the buffer tank (5) is provided with a buffer tank discharge pipe (501). The buffer tank discharge pipe (501) at the bottom of the buffer tank discharge pipe (501) is connected to the feed pipe (401) of the secondary mixing mechanism.

3. The micronutrient uniform addition device for compound fertilizer according to claim 1, characterized in that: The trace element storage bin (1) is equipped with a rotating shaft (6), the lower end of which extends into the storage bin discharge pipe (101). The rotating shaft (6) located in the storage bin discharge pipe (101) is equipped with an arch-breaking plate (7).

4. The micronutrient uniform addition device for compound fertilizer according to claim 3, characterized in that: The top of the trace element storage bin (1) is equipped with a motor (8) for driving the rotating shaft (6).

5. A micronutrient uniform addition device for compound fertilizer according to claim 4, characterized in that: The rotating shaft (6) is a sleeve shaft structure. The outer shaft can move axially relative to the inner shaft, and the inner and outer shafts are radially fixed by keyway cooperation.

6. The micronutrient uniform addition device for compound fertilizer according to claim 5, characterized in that: The outer wall of the outer shaft is provided with a wave groove (9), and a fixing rod (10) is fixedly provided on the inner wall of the trace element storage bin (1). The fixing rod (10) is horizontally set and one end is fixed on the inner wall of the trace element storage bin (1), and the other end is located in the wave groove (9).

7. A micronutrient uniform addition device for compound fertilizer according to claim 5, characterized in that: The trace element storage bin (1) is supported on a support plate (11) by a bracket, and a weighing sensor (12) is provided at the bottom of the four corners of the support plate (11).

8. The micronutrient uniform addition device for compound fertilizer according to claim 1, characterized in that: The feeding mechanism (2) is a screw conveyor; The primary mixing mechanism (3) is a Venturi mixer, and the feeding mechanism feed pipe (201) is connected to the primary mixing mechanism feed pipe (301) on the throat of the Venturi mixer; The input end of the Venturi mixer is connected to a pneumatic conveying pipe for material conveying, and the buffer tank (5) is located at the end of the diffusion section of the Venturi mixer.

9. A micronutrient uniform addition device for compound fertilizer according to claim 1, characterized in that: The secondary mixing mechanism (4) is inclined and has a stirring shaft driven by a motor inside, with stirring blades on the stirring shaft.

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