At present, in the food industry, some raw materials of powder and granules are transported by pneumatic conveying in the production and transportation, which can greatly improve the production efficiency. However, in the food industry, there are some special materials that need special attention in the process of pneumatic conveying.

1. Materials that are easily worn and broken; materials that require high integrity

Pneumatic conveying realizes the conveying of materials through the energy of air flow. Therefore, during the conveying process in the pipeline, the material particles will inevitably collide with each other. Due to the collision and friction between the material and the pipe wall and between the material and the material, it is easy to wear The material will inevitably be broken. In addition, the material will also be subjected to friction, shearing, compression or tension and other forces, and the external environment will also cause thermal stress, electrical force, etc. These influencing factors will cause the material to be broken.

However, many products have certain requirements for the integrity of the shape of the material. For example, some granular and flake food raw materials, especially in the food industry, grain materials such as black beans and mung beans have high requirements for the integrity of the shape, so it is necessary to control the raw materials. The crushing rate during the conveying process.

In the pneumatic conveying system, how to ensure the conveying integrity of such materials? This requires experienced scheme designers to conduct certain tests on the characteristics of the material and conveying parameters, and select the appropriate material-to-air ratio and airflow speed, which can effectively reduce the impact of the conveying process on the material.

2. Materials that are easy to stick and adhere; materials with high hygroscopicity

In the food industry, it is not uncommon for materials that are easy to adhere, such as starch, flour and other baking materials. In addition, some materials with strong hygroscopicity, such as fine sugar, will also bond and form in a high humidity environment. group.

Materials that are easy to stick to in the process of feeding, transportation, storage, packaging and other process links in the pneumatic conveying system, due to the characteristics of the materials themselves, are easy to stick in the pipeline, which will not only reduce production efficiency, but also lead to pipeline blockage. , affecting the normal operation of the system. In some environments, due to the adhesion of materials, the materials that are bonded into agglomerates may also be mildewed and scaled at the adhesion, which directly affects the quality of the product.

Therefore, in the design of pneumatic conveying of food raw materials, we should fully consider the characteristics of materials that are easy to adhere Consider the characteristics. Under normal circumstances, we can consider reducing the moisture content, reducing the gas temperature and increasing the air volume, taking preventive measures at the elbows that are easy to adhere, etc., through effective preventive measures to prevent material adhesion and ensure the normal operation of the system.