In the production processes of industries such as chemical, pharmaceutical, food, and new energy, precise measurement and stable transportation of powder materials are key links to ensure product quality and production efficiency. The powder automatic metering and conveying system integrates advanced metering technology, automation control technology, and pneumatic conveying technology to achieve the full process automation management of powder materials from storage, metering to conveying, effectively solving the problems of low accuracy, low efficiency, and dust pollution in traditional manual operations, and becoming an indispensable core equipment in modern industrial production.

1、 System working principle

The powder automatic measuring and conveying system is based on the principle of vacuum negative pressure or positive pressure pneumatic conveying, combined with high-precision measuring technology to achieve the transportation and measurement of powder materials. In vacuum conveying mode, after the vacuum pump is started, a negative pressure environment is formed inside the pipeline. The external atmospheric pressure presses the powder material from the storage bin into the pipeline, and the material mixes with the airflow to form a gas-solid two-phase flow, which is transported along the pipeline to the target position; Positive pressure conveying uses the pressure of compressed air to push materials forward.

The measurement process is mainly achieved through weighing or volumetric measurement. Weighing measurement adopts high-precision weighing sensors to monitor real-time changes in material weight and accurately calculate material flow rate through the control system; Volumetric metering utilizes devices such as rotary valves and screw pumps to transport materials at a fixed volume and control flow rate through rotational speed. The system automatically adjusts the conveying speed and measurement accuracy based on preset process parameters, ensuring that materials are accurately conveyed according to established requirements.

2、 Core system composition

（1） Material storage unit

Powder materials are stored in dedicated silos, which are usually made of stainless steel with smooth inner walls to prevent material adhesion. The silo is equipped with a level sensor to monitor the material inventory in real time. When the material falls below the set value, an automatic alarm is triggered to remind the operator to replenish the material. Some silos are also equipped with vibrators and arch breaking devices to prevent material clumping and bridging, ensuring smooth material discharge.

（2） Measurement unit

Weighing measuring device: composed of a weighing platform, weighing sensors, and control system. The accuracy of the weighing sensor can reach 0.05% FS, and it can achieve dynamic or static weighing. In dynamic weighing mode, materials continuously pass through the weighing platform, and sensors collect real-time weight data. The control system adjusts the speed of the conveying equipment according to the preset flow rate to ensure accurate measurement.

Volumetric metering devices: Common ones include rotary valve meters, screw metering pumps, etc. The rotary valve gauge sends out the powder material in a fixed volume through the rotation of the rotor; The screw metering pump uses the spiral motion of the screw to push materials, and controls the material flow rate by adjusting the screw speed. The volumetric measuring device has a simple structure and is suitable for powder materials with good fluidity.

（3） Conveyor unit

Vacuum conveying system: mainly composed of vacuum pump, suction nozzle, conveying pipeline, filter, and discharge valve. The vacuum pump provides negative pressure power, the suction nozzle sucks the material into the pipeline, the filter separates the gas-solid mixture, and the clean air is discharged. The material then enters the next process through the discharge valve. Vacuum conveying has the advantages of long conveying distance and no dust leakage, making it suitable for industries with high hygiene requirements such as food and pharmaceuticals.

Positive pressure conveying system: Using compressed air as a power source, materials are conveyed to the target location through sending tanks, conveying pipelines, and valves. Positive pressure conveying is suitable for long-distance and high flow powder conveying, commonly used in industries such as chemical and building materials.

（4） Control system

The control system is the core of the powder automatic metering and conveying system, usually using a programmable logic controller (PLC) combined with a human-machine interface (HMI). PLC is responsible for collecting sensor data, executing control algorithms, and driving actuator actions; HMI provides operators with an intuitive interface for parameter settings, recipe management, and monitoring of operational status. The system can also be connected to the factory production management system (MES) through network interfaces to achieve data sharing and remote monitoring.

3、 Typical application scenarios

（1） Pharmaceutical industry

In pharmaceutical production, the powder automatic metering and conveying system is used for precise metering and dust-free conveying of raw materials and excipients, ensuring accurate drug composition and preventing cross contamination. For example, in the tablet production process, the system accurately measures the ratio of various raw materials and transports the materials to the mixing equipment in a closed manner through vacuum conveying, in compliance with GMP specifications.

（2） Food industry

In the field of food processing, this system is used for measuring and transporting powdered materials such as milk powder, seasonings, starch, etc. The system is made of food grade stainless steel material and is fully enclosed to prevent dust from flying and foreign objects from entering, ensuring food safety. On the milk powder production line, the system precisely controls the ratio of various nutrients to ensure stable product quality.

（3） Chemical industry

In chemical production, powder automatic metering and conveying systems are used for the processing of materials such as catalysts, pigments, and plastic particles. The system has explosion-proof design and can safely transport flammable and explosive powder materials. For example, in the production of positive electrode materials for lithium batteries, the system accurately measures powder raw materials such as lithium iron phosphate and delivers them to the mixing equipment through positive pressure to ensure consistent battery performance.

（4） Building materials industry

In the building materials industry, this system is used for the measurement and transportation of materials such as cement, fly ash, and gypsum powder. By high-precision measurement and continuous conveying, production efficiency is improved and labor intensity is reduced. On the dry powder mortar production line, the system automatically measures various raw materials and delivers them to the mixer according to the formula ratio to ensure stable mortar quality.

4、 Technological advantages and development trends

（1） Technical advantages

High precision measurement: Advanced measurement technology ensures that material ratio errors are controlled within a very small range, improving product quality stability.

High degree of automation: The entire process is automated, reducing manual intervention, lowering labor intensity, and improving production efficiency.

Good environmental performance: The fully enclosed conveying method effectively prevents dust leakage, improves the working environment, and meets environmental protection requirements.

Strong flexibility: The conveying route and measurement parameters can be adjusted according to production needs, supporting simultaneous conveying and measurement of multiple materials.

（2） Development Trends

Intelligent upgrade: Introducing artificial intelligence and IoT technology to achieve equipment failure prediction, automatic calibration, and adaptive control.

Energy saving and environmental protection: Develop energy-saving vacuum pumps and conveying equipment, optimize system design, and reduce energy consumption.

Multi functional integration: Integrating functions such as metering, conveying, and mixing to reduce equipment footprint and improve overall system performance.

Safe and reliable: Strengthen explosion-proof and anti-static design to improve the safety of the system in hazardous environments.

The automatic powder metering and conveying system plays an important role in modern industrial production due to its excellent performance and wide applicability. With the continuous advancement of technology, this system will develop towards a more intelligent, efficient, and environmentally friendly direction, providing strong support for the high-quality development of various industries.