Dense Phase Advantages
A well designed dense phase pneumatic conveying system provides the following benefits:
- Low energy consumption
- Low maintenance and down time
- Low pipe wear
- Low material degradation
- Minimal segregation of blended materials
- Small ancillary equipment
1. Low Energy Consumption
By conveying material below the saltation velocity in slugs of material the energy used per lbs/kg of material to lbs/kg of air is very low compared to dilute or vacuum systems.
2. Low MAINTENANCE
Due to very low velocity, pipeline life is extended, requiring little to no maintenance. In addition, most dense phase pneumatic conveying systems have few wearing parts, reducing the need for spare parts and maintenance. The combination of these factors contribute to minimal maintenance and down time.
3. Low Pipe Wear
As material is conveyed in a solid form, only a small percentage of particles conveyed are in contact with the pipe reducing pipe wear. This is important in conveying materials such as sand which is highly abrasive.
The relationship between velocity and pipe wear is as follows:
System B operates at 2.5 M/S
4. Low Material Degradation
The best regimes for preventing product degradation are discontinuous dense phase and solid dense phase in which two conditions exist:
(a) Low velocity
(b) Stability, i.e., there is no inter-particle activity, meaning particles do not collide with each other.
These two conditions combined produce very low rates of material degradation – often important when conveying very fragile materials.
5. Minimal Segregation of Blended Materials
Many processes mix and blend two or more materials such as glass, food, and chemical processes. Once the blending process is complete, the material must be conveyed without separation of the ingredients. Often, there is considerable difference in the characteristics of the ingredients, e.g., particle size and particle density. If the conveying velocity is high, as is the case in a dilute phase system, the individual particles tend to convey at different velocities and separate as they are airborne.
The best regime for these applications is discontinuous dense phase.
6. Smaller ancillary equipment
Low air consumption, typical for a dense phase system, enables utilization of:
(a) Smaller filters, which will reduce the initial cost of the system and subsequent maintenance costs.
(b) Smaller compressors and dryers, which will reduce the cost of the installation and reduce energy consumption.