Comparison of Characteristics between Positive Pressure Conveying and Negative Pressure Conveying
In pneumatic conveying, there are two conveying methods based on air pressure: positive pressure and negative pressure,Positive pressure conveyingIt is conveyed by rotating feeders or bin pumps, material sealing pumps, and conveying pumps; Negative pressure is the method of inhalation, and when conveying powdered materials, one can choose the appropriate conveying method according to their own material or site.
? ? ?1、 From the principle of conveying: Positive pressure pneumatic conveying uses a Roots blower to inject compressed air into the pipeline, and uses the pressure difference between the starting point and midpoint of the pipeline to transport materials and air inside the pipeline. In a positive pressure conveying system, materials are transported from the feeding device to the conveying system. At the end of transportation, the material is separated from the air. The negative pressure conveying system is driven by the difference between the negative pressure formed by the exhaust device at the end of the conveying system and the external pressure. Due to the pressure difference, external air is drawn into the pipeline, and materials enter the pipeline with the movement of the air. After the material reaches the destination, it is separated and collected from the air. The air is purified and discharged into the atmosphere or recycled. Compared with negative pressure pneumatic conveying systems, positive pressure conveying systems have a longer conveying distance.
? ? ?2、 Scope of application: Positive pressure conveying system is suitable for decentralized conveying, that is, conveying from one point to multiple points. In the conveying pipeline, materials can be separated from the conveying medium at any discharge point by the gravity of the materials
? ? ?Negative pressure conveying system is mainly used for centralized conveying, that is, multi-point to point-to-point conveying, such as workshop dust removal, grain storage, etc. The advantage of negative pressure conveying is that it can effectively collect materials without them entering the atmosphere, which is particularly important for pneumatic conveying of toxic materials. However, due to the influence of vacuum, the conveying distance is limited to a certain extent.
Advantages of negative pressure conveying:
? ? 1. No dust during material transportation
? ? 2. Suitable for transportation occasions such as bulk, low-lying, and broken bags
? ? 3. The gas source is at the end, and lubricating oil and water will not mix
? ? 4. The pipeline is in a negative pressure and vacuum state, and the material will not leak
? ? 5. Convenient air treatment, suitable for occasions that require clean air transportation
? ? 6. Suitable for centralized transportation in multiple locations
Advantages of positive pressure conveying:
? ? 1. During transportation, the temperature of the gas can dry the material.
? ? 2. The internal pressure of the system is positive, making it easy to unload materials.
? ? 3. The pipeline is under positive pressure, and even if there is a gap at the system connection, the external atmosphere will not affect the materials in the pipeline
? ? 4. Compared with negative pressure conveying, it has lower energy consumption, longer conveying distance
Application of Negative Pressure Conveying
? ? 1. Manual feeding
? ? 2. Recycling of loose materials and floor fabrics 3. Material transportation at the bagging and feeding station
? ? 3. Recycling when the height of the recycling point is limited. 5. Toxic material transportation
? ? 4. Multiple outlets for one location transportation
Application of positive pressure conveying
? ? 1. Large particle transportation
? ? 2. Special gas transportation
? ?3. General material pneumatic conveying
The specific conveying method depends on the materials to be conveyed and the site requirements. If you have any further questions about conveying, please feel free to contact us,Shandong Juheng Environmental Protection Equipment Co., LtdExperts will provide you with answers one by one.