Pneumatic Conveying Methods

Pneumatic conveying systems are divided into two types: lean phase and dense phase. Although these methods are fundamentally different, the primary distinction lies in the type of pressurized gas supply equipment used for conveying. If the pressurized gas is supplied by a blower, it is a lean phase pneumatic conveying system. If the pressurized gas is supplied by a compressor, it is a dense phase pneumatic conveying system.

The top transfer line in the image below represents a process using a lean phase pneumatic conveying system. Upon examining the image, it is evident that the pipeline pressure is low while the flow velocity is high. In this method, raw material is conveyed through the pipeline with high air velocity and flow rate, using a blower as the compressed air source.

The bottom transfer line in the image represents a process using a dense phase pneumatic conveying system. Unlike lean phase systems, it operates at a higher pipeline pressure, lower flow velocity, and a much higher material concentration within the pipeline. Compressors are used as the air supply source in these processes.

As explained above, the main difference between the two methods is the conveying pressure and flow velocity within the pipeline. These differences result in various advantages and disadvantages for each system. Dense phase systems operate at high pressure and low velocity, making them suitable for long-distance material transfer. The conditioning of compressed air is easier and more cost-effective in these systems. If the material and process require air to meet specific quality standards, dense phase pneumatic conveying is the more suitable option. Additionally, the air consumption required for conveying is lower. However, the main drawback of this system is its higher initial investment cost.

Lean phase pneumatic conveying systems offer greater flexibility for different processes. In facilities with space limitations, they allow for more adaptable solutions. Their lower initial investment cost makes them an attractive choice for many industries.