The core of flour pneumatic conveying is to form a gas-solid two-phase flow of flour in a closed pipeline, powered by air, to complete the conveying process. The entire process is sealed without dust leakage and meets the requirements of food grade production. The system is mainly composed of gas source, feeding, conveying pipeline, gas-solid separation/dust removal, control and other units. According to the pressure state of the pipeline, it is divided into two mainstream methods: negative pressure and positive pressure. The flour industry also optimizes the effect by combining the conveying form of dilute phase/dense phase.

Power generation: The vacuum pump draws air at the end of the pipeline, creating a negative pressure environment inside the pipeline that is lower than the outside.

Material inhalation: The external atmosphere pushes the air to carry the flour and enter the pipeline through the suction port, forming a gas-solid two-phase flow.

Gas solid separation: After the mixture reaches the destination, it passes through a separator/filter, and the flour falls into the silo by gravity. The air is purified by dust removal and then discharged.

Flour adaptability: No dust leakage, suitable for conveying from multiple feeding points to one silo, such as feeding and batching processes.

Power generation: The fan/compressor injects air at the beginning of the pipeline, creating a positive pressure higher than the outside inside of the pipeline.

Material push: The feeding device evenly sends the flour into the pipeline, mixes it with the airflow, and transports it along the pipeline under the pressure difference.

Gas solid separation: After reaching the endpoint, the flour is collected by the separation/dust removal device at the top of the silo, and the remaining gas is purified before being discharged.

Flour adaptability: With a longer conveying distance, it is possible to unload from one material point to multiple silos, such as conveying finished flour to different storage tanks.

Dilute phase transportation: With high airflow velocity, flour particles are suspended in the airflow for transportation, suitable for short distance, medium and small flow rates. It is widely used in daily transportation in flour mills.

Dense phase transportation: The airflow velocity is low, and the flour moves forward in the form of group flow/plunger flow, suitable for long distances and large flow rates, which can reduce pipeline wear and flour damage.

Air source purification: Use oil-free dry air to prevent flour from being contaminated by oil and meet food grade standards.

Dust removal and recovery: The separation/dust removal device can recover fine powder carried in the airflow, avoiding waste and preventing excessive emissions.

Explosion proof protection: Flour is a combustible dust, and the system needs to take protective measures such as anti-static grounding and explosion-proof valves to eliminate safety hazards.

Scenario: A medium-sized food enterprise specializing in pasta production in southern China. The factory planning strictly follows food grade cleanliness standards. In the production process, the ingredient areas of the raw material warehouse and the production workshop are divided into different functional areas. The core requirement is to stably transport raw materials such as wheat flour packaged in ton bags from the ton bag unpacking station in the warehouse storage area to multiple parallel fully automatic ingredient scales in the production workshop, providing raw materials for subsequent kneading and rolling processes.

Pain point: Previously, companies used manual handling and feeding methods, where workers had to pour the unpacked flour into the ingredient scale hopper. During the process, dust was easily leaked from the feeding port, which not only led to substandard cleanliness in the workshop and difficulty in passing the annual food production permit review, but also posed a risk of cross contamination of raw materials - different batches and varieties of flour dust mixed together, directly affecting the gluten and taste of pasta. At the same time, the efficiency of manual feeding is greatly affected by personnel status, requiring additional manpower during peak hours, resulting in high labor intensity and high raw material loss rates.

Solution: The technical team will design a negative pressure dilute phase pneumatic conveying system based on the functional zoning layout of the factory area. The system starts from the storage area and builds a closed food grade pipeline network. After the pipeline extends to the production workshop, multiple sets of pneumatic automatic reversing devices are used to achieve flexible allocation from a single conveyor main line to multiple ingredient scales. After completing dust-free unpacking at the ton bag unpacking station, the raw materials are driven by the airflow generated by the negative pressure fan and transported at a constant speed along the pipeline. At the end, they are combined with a cyclone separator and a bag filter to achieve gas separation. The flour falls smoothly into the batching scale, and the separated clean air is treated and discharged to meet the standard. The entire system is made of food grade stainless steel material, and the inner walls of the pipes are polished to ensure no hygiene blind spots.

Effect: There is no dust leakage during the entire transportation process, and the cleanliness of the workshop directly meets the A-level standard for food production, completely solving the problems of dust pollution and cross contamination. The feeding process realizes one click automation operation without manual intervention, and the batching rhythm fully matches the continuous operation requirements of the production line, reducing manual input by more than 60%. At the same time, closed conveying avoids the loss of raw materials due to spillage, and the utilization rate of raw materials is increased to 99.8%. With only two aspects of raw material saving and labor cost reduction, significant economic benefits have been achieved in the short term.

Scenario: A large noodle group in Henan Province has multiple production lines for fresh wet noodles, with extremely high daily production capacity. During the production process, multiple powder raw materials such as wheat flour, cassava starch, gluten flour, konjac flour, etc. need to be transported simultaneously. These raw materials are stored in independent raw material silos in the factory area and ultimately need to be transported to mixing and stirring equipment on different production lines, which is a typical scenario of multi material, multi station, and high-capacity transportation.

Pain point: The original conveying system built a simple conveying line for each material separately, which not only had a messy pipeline layout and occupied a large amount of workshop space, but also had the problem of low conveying efficiency. Manual assisted feeding cannot keep up with the high production capacity demand of the production line, and there are often situations where ingredient supply is cut off, resulting in production line downtime. In addition, the feeding process of different raw materials is scattered, and the accuracy of manual ingredients is difficult to control. The proportion of raw materials fluctuates greatly between batches, resulting in poor consistency in the taste and elasticity of wet noodle products, and a high customer complaint rate. At the same time, the ventilation conditions in some raw material storage areas are generally poor, and the process of open-air stacking of raw materials is prone to absorbing moisture from the air, getting damp, and clumping. Once the clumped raw materials enter the production line, they can damage the mixing equipment and affect production continuity.

Solution: The enterprise will comprehensively upgrade the raw material conveying system and establish a positive pressure dilute phase pneumatic conveying network. The system is powered by a high-pressure Roots blower and leads out conveying branch pipes from the bottom of each raw material silo. These pipes are then connected to the main conveying pipeline through a high-precision pneumatic directional valve, achieving orderly switching and conveying of multiple materials on a single line without the need to separately lay complete pipelines for each type of raw material. In response to the characteristics of easily adhesive materials such as starch and gluten powder, the conveying pipeline adopts food grade wear-resistant and anti stick lining to reduce material wall residue. The system is linked with the level gauge of the raw material silo and the mixing equipment of the production line. According to the raw material requirements of the mixing equipment, the corresponding material conveying process is automatically started and stopped to achieve on-demand feeding.

Effect: The brand new transportation network has completely simplified the pipeline layout in the factory area, and the utilization rate of workshop space has been increased by 30%. The conveying process is fully continuous, and multiple materials are compatible for conveying. The conveying efficiency has been more than doubled compared to before, fully matching the high production capacity requirements of the production line and eliminating downtime caused by ingredient supply interruptions. The automation control of the ingredient process greatly improves the accuracy of raw material ratio, significantly improves the consistency of taste and elasticity of wet noodle products, and reduces customer complaint rates by 80%. At the same time, the raw materials are transported in a sealed manner from the silo to the mixing equipment, completely solving the problem of moisture and agglomeration, and significantly reducing the equipment failure rate.

Scenario: A food processing factory in East China that specializes in the production of Chinese pastries. It belongs to the small and medium batch production mode and produces more than ten types of pastries. Each type of pastry has different raw material formulas and flour usage. The production workshop area of the enterprise is limited and the layout is compact. Flour is mainly packaged in small bags of 25 kilograms. It needs to be transported from the raw material storage area in the corner of the workshop to multiple dough mixers and mixers in the central production area. The conveying distance is short, but it requires frequent switching of conveying target equipment.

Pain point: Due to the limited space in the workshop, it is impossible to build a large conveying pipeline system. Previously, manual unpacking, handling, and feeding methods have been used. During the unpacking process, flour dust flies everywhere, not only polluting the workshop environment, but also adhering to the surface of the workshop equipment, increasing the difficulty of equipment cleaning. At the same time, manual handling of small bags of flour is labor-intensive, and the feeding requirements of different pastry production lines are different. Workers need to shuttle back and forth between various equipment, resulting in low feeding efficiency and difficulty adapting to the production rhythm of multiple categories and small batches. In addition, when unpacking the small bag, it is easy to mix in threads, impurities, etc., which affects the food safety of pastry products.

Solution: Design a combination of dust-free feeding station and small bin pump for dense phase conveying, taking into account the production characteristics of compact workshop space and small batches with multiple varieties. Two small dust-free feeding stations are set up in the raw material storage area. Workers put small bags of flour into the feeding stations and complete unpacking and dumping under negative pressure. The screening device built into the feeding stations can synchronously remove impurities from the raw materials. A small dense phase bin pump is connected below the feeding station as the core equipment for conveying. The bin pump is controlled by a PLC system and linked with the level sensors of each dough mixer and mixer. When the target equipment level is insufficient, the bin pump automatically starts and uses high-pressure airflow to deliver the flour in a dense phase state to the designated equipment hopper through a short closed pipeline. The entire equipment layout is compact, with pipelines laid along the workshop walls and ceilings, without occupying production operation space.

Effect: The unpacking process is completed in the negative pressure feeding station, with no dust leakage throughout the entire process. The cleanliness of the workshop environment is greatly improved, and the workload of equipment cleaning is reduced by more than 50%. The screening device effectively removes impurities from the raw materials, further ensuring the food safety of pastries. The automated operation of the warehouse pump enables on-demand feeding, with workers only responsible for handling small bags of flour and placing them into the feeding station, significantly reducing labor intensity and reducing manual input by 40%. The compact equipment layout perfectly adapts to the space limitations of small and medium-sized workshops, and can flexibly switch conveying targets, fully meeting the production needs of multiple categories and small batches. The material loss rate has also been reduced from the original 3% to below 0.5%.

Scenario: A large baking leisure food enterprise in North China, mainly producing products such as biscuits, bread, cakes, etc., which consume a large amount of flour every day. In order to ensure the flexibility of raw material supply, the enterprise adopts a differential pressure truck as the internal raw material turnover tool. After the flour is transported from the supplier to the factory area, it is first loaded into the differential pressure truck and then transferred to the raw material receiving area of each production workshop by the differential pressure truck. The flour in the differential pressure truck needs to be quickly unloaded into the workshop storage bin to prepare for subsequent production.

Solution: A dedicated differential pressure truck unloading+positive pressure pneumatic conveying system has been designed to meet the demand for differential pressure truck unloading. Fixed discharge interfaces are set up in the raw material receiving areas of each production workshop, and the differential pressure truck is quickly connected to the discharge interface through food grade flexible hoses. The system is powered by a high-pressure blower. After the differential pressure vehicle is connected to the interface, the positive pressure conveying system is started. Using the positive pressure airflow generated by the blower, the flour in the differential pressure vehicle is directly sent to the workshop storage bin along the conveying pipeline. In order to ensure food safety, multi-level straight row magnet devices are installed at key positions on the conveyor line, which can effectively absorb metal impurities that may be mixed in flour. At the same time, a high-level material level sensor is installed at the top of the storage bin, which is linked with the conveying system. When the storage bin reaches the set material level, the system automatically stops unloading to avoid material overflow. After unloading is completed, the system will automatically start the cleaning program to blow the remaining flour in the pipeline to the storage bin, reducing material residue.

Pain point: Previously, the unloading of differential pressure trucks in enterprises was carried out using manual assistance, which resulted in low unloading efficiency. The unloading time of one differential pressure truck was as long as one hour, making it difficult to meet the raw material needs of multiple production lines. During the unloading process, flour is prone to leakage from the interface, resulting in dust pollution. More importantly, there is a risk of metal impurities being mixed in during the turnover and unloading process of raw materials, and the control of metal impurities in baked goods is extremely strict. Once metal impurities are mixed in the product, it will cause serious food safety accidents.

Effect: The unloading process is fully automated, reducing the unloading time of a differential pressure truck to less than 20 minutes and increasing the unloading efficiency by three times. It can quickly respond to the raw material needs of various production lines. The sealed connection between flexible hose and fixed interface, combined with the closed pipeline of positive pressure conveying, completely eliminates the problems of flour leakage and dust pollution. The multi-stage straight row magnet device effectively removes metal impurities from raw materials, with a metal foreign object detection rate of 100%, greatly improving the food safety assurance level of the product. The linkage control of the level sensor enables the unloading process to be orderly and controllable, avoiding waste caused by raw material overflow, and significantly improving the automation and safety of the entire raw material receiving process.