The core principle of pneumatic conveying of soybean meal powder is to use a gas source to form a pressure difference and airflow in a closed pipeline, so that the soybean meal powder particles are suspended or grouped and move with the airflow, achieving material conveying; The material is separated from the air by a gas-solid separation device at the end, and the exhaust gas is purified before being discharged. The following are three mainstream process forms suitable for soybean meal powder, all of which are qualitative descriptions without parameters:

The power end is located at the end of the system, and a negative pressure environment below atmospheric pressure is created inside the pipeline through a vacuum pump or negative pressure fan.

The pressure difference draws external air and soybean meal powder into the pipeline together from the feed inlet, and the material is entrained by the airflow to form a gas-solid two-phase flow.

After the mixture is transported to the end, it is first subjected to coarse separation by a cyclone separator, and then fine powder is filtered by a bag filter. The separated soybean meal powder falls into the silo.

The purified exhaust gas is discharged after being silenced by a fan, and the entire process is sealed without dust escaping, suitable for the working condition of multi-point feeding to single point conveying.

The power end is located at the beginning of the system, and compressed air is introduced into the pipeline through a compressor or Roots blower, creating a positive pressure environment above atmospheric pressure.

Soybean meal powder is quantitatively fed into the pipeline through a feeder, and is transported forward along the pipeline in the form of suspension or group flow under the push of airflow.

After reaching the destination, the material is discharged into the silo through the separator, and the remaining air is purified by the top dust collector before being discharged.

Suitable for single point feeding to multi-point unloading, or long-distance, high-volume soybean meal powder transportation scenarios.

Adopting intermittent conveying mode, soybean meal powder first enters the bin pump tank, and after completing the feeding, the feeding valve is closed.

Inject compressed air into the warehouse pump to create a high-pressure environment inside the tank, while using the bottom gasification device to make the material fluidized and avoid accumulation.

Open the discharge valve, and high-pressure airflow pushes the material into the pipeline in the form of a group flow, transporting it to the final material bin.

After the transportation is completed, release the pressure inside the tank and enter the next feeding cycle, suitable for transporting high concentration and short distance soybean meal powder, which can effectively reduce pipeline wear.

Blockage prevention and fluidization: Soybean meal powder has a certain degree of adhesion, and its flowability needs to be improved through gasification and arch breaking devices. At the same time, a suitable airflow pattern should be selected to avoid pipeline blockage.

Sealing and dust removal: The entire process adopts sealed pipeline transportation, and the end is equipped with dust removal equipment, which not only prevents material loss but also meets environmental protection requirements.

Explosion proof and protection: Soybean meal powder belongs to combustible dust, and the system needs to use explosion-proof equipment and set up anti-static grounding to avoid safety hazards.

As a leading feed production enterprise in the region, a large feed factory in East China needs to receive a large amount of soybean meal powder raw materials every day. The traditional unloading method is not only inefficient, but also due to the fine and easy to fly characteristics of soybean meal powder particles, the dust pollution in the raw material receiving area of the factory is serious, and manual unloading is prone to material residue, increasing raw material loss. In response to this pain point, the factory adopts a mobile negative pressure suction unit in the raw material receiving process, which is specifically used for unloading and storing soybean meal powder in bulk tankers.

During operation, the operator only needs to flexibly insert the suction nozzle into the discharge port of the tanker truck. After the vacuum pump at the end of the system is started, a stable negative pressure environment is quickly formed in the closed pipeline. Under the pressure difference, the external air enters the conveying pipeline with the soybean meal powder in the tanker, forming a uniform gas-solid two-phase flow. After the mixture is transported through pipelines to the separation system next to the raw material silo in the factory area, most of the soybean meal powder is roughly separated by a cyclone separator. The unseparated fine powder is efficiently captured by a bag filter. Finally, all soybean meal powder falls into the raw material silo, and the purified exhaust gas is reduced in noise by a muffler before meeting the emission standards.

This process completely changes the drawbacks of traditional unloading, with no dust escaping throughout the entire process, solving the problem of dust pollution in the factory area from the root. At the same time, negative pressure airflow can effectively overcome the problem of poor unloading caused by the slight adhesion of soybean meal powder, and the unloading process is continuous and smooth. The design of the mobile unit also allows the equipment to move flexibly, perfectly adapting to the multi-point feeding requirements of multiple tank wheels for material exchange and unloading, greatly improving the automation level and operational efficiency of raw material reception.

A small oil and fat factory in North China mainly engages in the processing of edible oils and fats, with soybean meal powder as a by-product that needs to be crushed and processed as feed raw material for export. In the crushing section, the factory originally used mechanical conveying to collect crushed soybean meal powder. However, the conveying corridor of the mechanical conveying equipment is prone to residual materials, and dust leakage is prone to occur in the gaps of the equipment, which not only leads to excessive dust concentration in the workshop, but also causes cross contamination of different batches of soybean meal powder due to material residue, affecting product quality.

To solve this problem, the factory has carried out a linkage transformation between the crusher and the negative pressure suction system, creating an integrated operation process of crushing and conveying. When the crusher is working, the crushed soybean meal powder is directly sucked into the closed conveying pipeline by the airflow generated by the negative pressure suction system at the moment it is discharged from the discharge port. Under negative pressure, soybean meal powder is transported steadily with the airflow to the separation equipment next to the batching bin. After gas-solid separation, the soybean meal powder falls into the batching bin for temporary storage, while the tail gas carrying fine powder is filtered and purified by a bag filter, partially recycled in the system, and the remaining part is discharged in compliance with standards.

The inner wall of the pipeline of the negative pressure suction system is smooth, and the soybean meal powder is not retained by the airflow, completely avoiding the problem of material residue and effectively preventing cross contamination of different batches of products. At the same time, the fully enclosed conveying method ensures no dust leakage in the crushing section, significantly improves the workshop working environment, and meets safety standards for dust concentration. In addition, the system has a simple structure, compact equipment layout, and does not require a large amount of workshop space. Daily cleaning and maintenance are also very convenient, which is very suitable for the production scale and process requirements of small oil factories.

The core production workshop under a certain feed group in South China mainly produces various formulas of livestock and poultry feed. Soybean meal powder, as the core protein raw material, needs to be transported from the raw material silo to three different ingredient section silos according to different formula requirements. Due to the compact layout of equipment in the workshop and the need for continuous and uninterrupted production processes, traditional mechanical conveying methods are not only difficult to lay pipelines, but also unable to achieve flexible switching between single point feeding and multi-point unloading, making it difficult to meet the production needs of multiple formulas and sections.

Therefore, the factory adopts a dilute phase positive pressure pneumatic conveying system and constructs a soybean meal powder batching and conveying network in the workshop. The power end of the system is located next to the raw material silo, and compressed air is introduced into the conveying pipeline through a Roots blower to create a stable positive pressure environment. The rotating feeder at the bottom of the raw material silo accurately controls the conveying volume of soybean meal powder, and evenly and quantitatively sends it into the positive pressure pipeline. Under the propulsion of compressed air, soybean meal powder is smoothly transported forward along the pipeline in the form of a suspended flow. When the material reaches the batching section area, the discharge port can be flexibly switched through the pneumatic branching valve on the pipeline, and the soybean meal powder is sent to three different batching silos. The exhaust gas at the end of the conveyor is purified by the bag filter at the top of each silo and discharged.

The biggest advantage of this process is its flexible layout. The conveying pipeline can be flexibly laid along the workshop beams, columns, and walls, without the need for large-scale renovation of the factory building, perfectly adapting to the equipment layout of the existing workshop. At the same time, the system has achieved full automation control, and the switching of branch valves can be remotely operated through the central control system without manual intervention, meeting the needs of continuous production in the workshop. In addition, the airflow velocity of positive pressure conveying is moderate, which can effectively reduce the crushing and adhesion of soybean meal powder, ensure the integrity of materials, and provide guarantee for the quality of feed products.

The soybean meal powder finished product section of a large grain and oil processing plant in Northeast China needs to transport the soybean meal powder in the finished product warehouse to the hopper of the automatic packaging machine to prepare for subsequent quantitative packaging, sealing, and palletizing operations. The core requirements for the conveying process in this section are low material damage rate and stable conveying flow rate. If soybean meal powder is excessively crushed during the conveying process, producing too much fine powder, it will affect the quantitative accuracy of the automatic packaging machine, resulting in packaging weight deviation exceeding the standard. At the same time, the flying of fine powder will also cause material loss and environmental problems.

In response to this demand, the factory has adopted dilute phase positive pressure pneumatic conveying technology in the finished product conveying process. The star shaped feeder at the bottom of the finished product warehouse uniformly feeds soybean meal powder into the conveying pipeline according to the feeding speed of the automatic packaging machine, avoiding pipeline blockage caused by too fast feeding or affecting packaging efficiency due to too slow feeding. The low-pressure compressed air provided by the Roots blower serves as the conveying power, pushing the soybean meal powder to be transported along the pipeline at a lower speed to the top of the packaging machine. In order to further ensure the integrity of the materials, a small cyclone separator is installed at the end of the conveyor. After gas-solid separation, the soybean meal powder smoothly falls into the packaging machine hopper, while the tail gas carrying a small amount of fine powder is filtered by a small dust removal device at the top of the separator and recycled into the system for reuse, achieving zero emission of tail gas.

This process adopts a low-speed conveying mode, with a gentle conveying process that minimizes collisions and friction between soybean meal powder particles and between particles and the inner wall of the pipeline. The material damage rate is controlled at an extremely low level. At the same time, the quantitative feeding characteristics of the feeder ensure that the conveying flow rate remains stable, ensuring that the automatic packaging machine can continuously and accurately complete packaging operations. The fully enclosed transportation method also avoids moisture absorption, agglomeration, and dust flying of finished soybean meal powder, reducing material loss and maintaining a clean environment in the finished product section, fully meeting the process requirements of finished product transportation.