An automatic weighing and preparation system

Abstract

This utility model provides an automatic weighing and material preparation system. The technical solution includes a material storage tank and a transfer tank. The outlet of the material storage tank is connected to the inlet of the transfer tank via a pipeline. A conveying pump and a shut-off valve are sequentially installed along the conveying direction on this pipeline. The outlet of the transfer tank is connected to the user via a pipeline, on which a transfer pump is installed. The beneficial effects of this utility model are: (1) Dual monitoring redundancy design to prevent production accidents caused by sensor failure; (2) Dual data verification to reduce material preparation errors; (3) Automatic pressure relief protection to avoid the risk of damage to pipelines and pumps; (4) Full-process DCS automatic control to reduce labor costs and improve production efficiency.

Description

Technical Field

[0001] This utility model belongs to the technical field of chemical material conveying devices, and in particular relates to an automatic weighing and material preparation system. Background Technology

[0002] The automatic weighing and material preparation system is a core link connecting raw material storage and final production. Its main function is to accurately transport the raw materials in the material storage tank to the transfer tank for temporary storage, and to quantitatively deliver materials according to the needs of the user end (such as the reactor or the feed port of the production line) to ensure the stability and efficiency of subsequent production.

[0003] Currently, most existing automatic weighing and material preparation systems employ a single sensor monitoring and simple pump-valve control. This involves installing a weight sensor on the transfer tank to monitor the weight of the material inside and control the start and stop of the conveying pump and the transfer pump. When the weight reaches a set high level, the conveying pump is shut off to prevent overflow; when the weight drops to a set low level, the transfer pump is shut off to avoid empty pump operation. However, this single monitoring mode has significant reliability flaws. If the weight sensor wears out due to long-term use, signal interference, or malfunction, the system will lose its basis for judging the amount of material in the transfer tank. This can easily lead to production accidents such as material overflow due to excessive weight failing to stop the conveying pump, or pump damage due to insufficient weight failing to stop the transfer pump. In severe cases, shutdown for repair is required, resulting in economic losses.

[0004] Meanwhile, existing systems generally lack pressure protection mechanisms for user-end material interruption needs. When the user end does not need to feed material (such as when subsequent processes are suspended), the transfer pump may still continue to operate due to control delays, or the residual pressure in the pipeline may not be released after the shut-off valve is closed, causing a sudden increase in pressure in the inlet and outlet pipelines of the transfer pump. If no effective pressure relief structure is set up, excessive pressure will not only damage the pump body seals and pipeline joints, but may even cause the pipeline to burst, posing a great safety hazard.

[0005] In addition, some traditional systems still rely on manual monitoring and intervention. For example, manual checks of material quantity in transfer tanks are required periodically, or pump valves must be manually shut off when pressure is abnormal. This not only increases the labor intensity of manual workers, but also causes fluctuations in material preparation accuracy due to delays in manual response, making it difficult to meet the requirements of unmanned, high-precision, and high-stability modern production lines.

[0006] In summary, existing automatic weighing and material preparation systems suffer from core pain points such as low monitoring reliability, high safety risks, and insufficient automation. There is an urgent need for a technical solution with dual monitoring redundancy, automatic pressure protection, and high automation to improve the stability, safety, and batching accuracy of the system. Summary of the Invention

[0007] To address the problems in the prior art, this utility model provides an automatic weighing and material preparation system. The technical solution includes a material storage tank and a transfer tank. The outlet of the material storage tank is connected to the inlet of the transfer tank via a pipeline. A conveying pump and a shut-off valve are sequentially installed on the pipeline along the conveying direction. The outlet of the transfer tank is connected to the user via a pipeline, and a transfer pump is installed on the pipeline.

[0008] In a preferred embodiment, a weighing module is installed on the side wall lug of the transfer tank.

[0009] In a more preferred embodiment, the weight data collected by the weighing module is transmitted to a weight sensor, which then transmits the data to a DCS control system. The DCS control system controls the start and stop of the delivery pump, the opening and closing of the shut-off valve, and the start and stop of the transfer pump.

[0010] In a more preferred embodiment, the top of the transfer tank is equipped with a remote level gauge, which transmits the material level data of the transfer tank to the DCS control system.

[0011] In a preferred embodiment, the top of the material storage tank is provided with a first exhaust pipe.

[0012] In a preferred embodiment, the top of the transfer tank is also provided with a second exhaust pipe.

[0013] In a preferred embodiment, a safety valve is connected in parallel between the inlet and outlet pipes of the transfer pump.

[0014] The beneficial effects of this utility model are: (1) The weighing module of the side wall lug of the transfer tank collects the material weight in real time. The data is transmitted to the DCS control system through the weight sensor to form the main logic of weight monitoring and pump valve control. When the weight reaches too high, the DCS automatically shuts down the conveying pump to prevent overflow. When the weight drops to too low, the transfer pump is automatically shut down to avoid dry grinding of the pump, and accurately matches the regular material preparation requirements. Meanwhile, the remote level gauge on the top of the transfer tank serves as a redundant monitoring method. Its set limits are: the weight at the highest level is higher than the weight sensor's limit, and the weight at the lowest level is lower than the weight sensor's limit. If the weight sensor fails due to a malfunction, the DCS can immediately switch to the level monitoring logic. When the level is too high, the transfer pump will be forcibly shut down; when the level is too low, the transfer pump will be forcibly shut down. This completely solves the problem of production interruptions or safety accidents caused by the failure of a single sensor in the traditional system, and improves the system's continuous operation reliability by more than 95%. (2) The weight and liquid level data are synchronized to the DCS in real time. The system can automatically compare the consistency of the two sets of data (such as whether the theoretical liquid level corresponding to the weight matches the actual liquid level). If the deviation is too large, an alarm will be triggered to indicate the abnormality, which will help the operation and maintenance personnel to troubleshoot in time and avoid fluctuations in the material preparation accuracy due to the distortion of a single data. (3) The safety valves connected in parallel to the inlet and outlet pipelines of the transfer pump form a pressure protection closed loop for material interruption at the user end: When the user does not need to feed material (such as when the subsequent process is suspended), the flow of material in the pipeline is blocked, which causes the pressure to rise. Once the pressure reaches the preset threshold of the safety valve, the safety valve will automatically open, so that the material in the pipeline can form a circulation pipeline from the outlet of the transfer pump to the safety valve and then to the inlet of the transfer pump, and quickly release the overpressure. (4) The DCS control system realizes full-process automation of material conveying, weighing, start-stop control and abnormal alarm: there is no need for manual periodic verification of the material quantity in the transfer tank, nor is there a need to manually operate the pump valve when the pressure is abnormal or the sensor alarms. Only the maintenance personnel need to monitor the system status through the DCS interface, which greatly reduces the intensity of manual labor and avoids problems such as overflow and empty pump caused by manual response delay. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0016] In the diagram: 1. Material storage tank; 2. Transfer pump; 3. Shut-off valve; 4. Transfer tank; 5. Transfer pump; 6. Safety valve; 7. Weighing module; 8. Weight sensor; 9. Remote level gauge; 10. First exhaust pipe; 11. Second exhaust pipe; 12. DCS control system. Detailed Implementation

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Example like Figure 1 An automatic weighing and material preparation system is shown, including a material storage tank 1 and a transfer tank 4. The outlet of the material storage tank 1 is connected to the inlet of the transfer tank 4 through a pipeline. A conveying pump 2 and a shut-off valve 3 are sequentially installed on the pipeline along the conveying direction. The outlet of the transfer tank 4 is connected to the user through a pipeline, and a transfer pump 5 is installed on the pipeline.

[0019] Furthermore, a weighing module 7 is installed on the side wall lug of the transfer tank 4.

[0020] Furthermore, the weight data collected by the weighing module 7 is transmitted to the weight sensor 8, which in turn transmits the data to the DCS control system 12. The DCS control system 12 controls the start and stop of the delivery pump 2, the opening and closing of the shut-off valve 3, and the start and stop of the transfer pump 5.

[0021] Furthermore, the top of the transfer tank 4 is equipped with a remote level gauge 9, which transmits the material level data of the transfer tank 4 to the DCS control system 12.

[0022] Furthermore, the top of the material storage tank 1 is provided with a first exhaust pipe 10.

[0023] Furthermore, the top of the transfer tank 4 is also provided with a second exhaust pipe 11.

[0024] Furthermore, a safety valve 6 is connected in parallel between the inlet and outlet pipes of the transfer pump 5.

[0025] The transfer pump 5 is a vertical process hydraulic diaphragm pump from Ailipu, the weighing module 7 is a Siemens SIWAREX WP521 / 522 ST, and the safety valve 6 is a HengHua A41W-25P spring-loaded safety valve.

[0026] Both the weight sensor 8 and the remote level gauge 9 use conventional sensors.

[0027] The operation of the above system is as follows: The DCS control system 12 monitors the initial weight of the transfer tank 4 in real time. If the weight is lower than the low weight level (or the tank is empty), the system automatically triggers a material preparation command. First, the shut-off valve 3 on the pipeline between the material storage tank 1 and the transfer tank 4 is opened, and then the conveying pump 2 is started. The material flows out from the outlet of the material storage tank 1 and is continuously injected into the transfer tank 4 by the conveying pump. During the process of material injection into the transfer tank 4, the original air in the tank is discharged through the second tail gas vent pipe 11 at the top. At the same time, the negative pressure formed in the material storage tank due to the reduction of material is drawn in outside air through the first tail gas vent pipe at the top (or inert gas is provided by the gas source, depending on the material characteristics), so as to avoid interruption of material conveying due to pressure imbalance between the two tanks. Weighing module 7 continuously collects the weight data of the material in transfer tank 4 and transmits it to the DCS via a weight sensor. When the weight approaches the excessive weight level, the DCS automatically reduces the operating power of the conveying pump to slow down the material conveying speed and prevent the weight from exceeding the limit due to inertia. When the weight reaches the excessive weight level, the DCS immediately issues a command to shut down the conveying pump first. After the remaining material in the pipeline has basically flowed into transfer tank 4, the shut-off valve 3 is closed, and the material preparation stage of transfer tank 4 ends. During the material preparation process, the remote level gauge 9 synchronously collects the liquid level data of the material in transfer tank 4 and transmits it to the DCS. The system automatically compares the theoretical liquid level corresponding to the weight with the actual liquid level. If the deviation is within the allowable range, weight monitoring continues as the primary method; if the deviation exceeds the threshold, the DCS triggers an alarm to remind staff to investigate.

[0028] When a user requests material feeding, the DCS immediately monitors the current weight of transfer tank 4. If the weight is higher than the minimum weight threshold, the transfer pump 5 is automatically activated. Simultaneously, the valves on the inlet and outlet pipes of transfer pump 5 remain open, allowing material to flow from the outlet of transfer tank 4 and be transported to the user via the transfer pump and pipeline. During the feeding process, if the user suddenly stops feeding (e.g., subsequent processes are paused, or user valves are closed), the material flow in the pipeline is obstructed, and the pressure gradually increases. When the pressure reaches the preset threshold of safety valve 6, safety valve 6 automatically activates, allowing the material in the pipeline to form a circulation loop through the safety valve, the outlet of transfer pump 5, safety valve 6, and the inlet of transfer pump 5. This quickly releases the overpressure, preventing pipeline rupture or damage to transfer pump 5 due to pressure buildup (the pressure of the material in transfer tank 4 is lower than the pressure of the returning material, so the returning material is prioritized for pumping). Once the user resumes feeding and the pipeline pressure returns to normal, safety valve 6 automatically resets, and material is resumed being transported to the user. The weighing module 7 continuously transmits the weight data of the transfer tank 4 to the DCS. When the weight drops to an excessively low level, the DCS immediately shuts down the transfer pump 5 to prevent the transfer pump 5 from running dry. If the user still needs to feed material, the DCS automatically returns to the material preparation stage of the transfer tank 4, restarts the conveying pump 2 and the shut-off valve 3, replenishes the transfer tank 4, and then continues to supply material, forming a cycle of material preparation and then material supply.

[0029] When gravity sensor 8 fails, if the material preparation stage of transfer tank 4 is underway, the remote level gauge 9 will detect that the liquid level has reached the high level (above the weight limit). The DCS will then forcibly shut down the transfer pump 2 and the shut-off valve 3 to prevent material overflow. If the material is being supplied to the user at this time, the remote level gauge 9 detects that the liquid level has dropped to an extremely low level (below the weight limit). The DCS will then forcibly shut down the transfer pump 5 to prevent the pump from running dry. At the same time, the DCS will trigger an alarm to remind maintenance personnel to carry out timely repairs.

Claims

1. An automatic weighing material preparation system comprising a material storage tank (1) and a transfer tank (4), characterized in that, The discharge port of the material storage tank (1) is connected to the inlet of the transfer tank (4) through a pipeline. A conveying pump (2) and a shut-off valve (3) are sequentially installed on the pipeline along the conveying direction. The discharge port of the transfer tank (4) is connected to the user through a pipeline. A transfer pump (5) is installed on the pipeline.

2. The automatic weighing material preparation system according to claim 1, wherein, A weighing module (7) is installed on the side wall lug of the transfer tank (4).

3. The automatic weighing material preparation system according to claim 2, wherein, The weight data collected by the weighing module (7) is transmitted to the weight sensor (8), and the weight sensor (8) transmits the data to the DCS control system (12). The DCS control system (12) controls the start and stop of the delivery pump (2), the opening and closing of the shut-off valve (3), and the start and stop of the transfer pump (5).

4. The automatic weighing material preparation system according to claim 3, wherein, The top of the transfer tank (4) is equipped with a remote level gauge (9), which transmits the material level data of the transfer tank (4) to the DCS control system (12).

5. The automatic weighing material preparation system according to claim 1, wherein, The material storage tank (1) is provided with a first exhaust pipe (10) at the top.

6. The automatic weighing system of claim 1, wherein, The top of the transfer tank (4) is also provided with a second exhaust pipe (11).

7. The automatic weighing system according to claim 1, wherein, A safety valve (6) is connected in parallel between the inlet pipe and the outlet pipe of the transfer pump (5).

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