In industries that employ Flue Gas and Water treatment plants, the safe, efficient, and equipment-minimal transportation of bulk materials is paramount. This task is accomplished through the utilization of material handling equipment, with pneumatic conveyors emerging as a prime solution, particularly for long-distance transfers. Let us delve into a comprehensive analysis of the types and applications of pneumatic conveyor systems.
DEFINITION OF PNEUMATIC CONVEYOR
A Pneumatic Conveyor constitutes a meticulously engineered assembly of components that collectively facilitate the secure, efficient, and economical movement of substances and materials. It employs a series of flexible pipes connected to a fan or blower, utilizing airflow to transport dry, fine materials.
Owing to their minimalist componentry compared to other conveying systems, pneumatic conveyors are ideally suited for long-distance transportation of aggregates such as sand, lime, cement powder, sugar, wheat, and other low-bulk density products in fine powder form, as well as dry materials like activated carbon, slaked lime, soda ash, clay, polymers, etc.
MECHANISM OF PNEUMATIC CONVEYING SYSTEM
The airflow is tailored according to the distance and feed rate, with the powder being directly injected into the pneumatic conveyor pipe. Pressure and velocity are meticulously controlled via sensors, ensuring all components remain fully sealed to prevent any leakage. For the transportation of fine powders, a blower or fan is incorporated into the system to enhance its operational efficacy.
ADVANTAGES OF PNEUMATIC CONVEYORS
Pneumatic conveyors offer several advantages over other systems:
- Flexibility and Customization: They can be tailored to fit around existing powder processing equipment, showcasing their versatility and space-saving installation.
- Efficient Material Handling: They convey material rapidly and without losses, making them ideal for aggregates that are challenging to transport safely and with minimal waste.
- Low Maintenance: With fewer moving parts susceptible to wear and tear, they require less maintenance than other systems.
- Enhanced Safety: They are safer for both maintenance workers and operators, presenting a lower risk of plant contamination due to the material being moved through fully enclosed tubes or pipes.
- Extended Reach: They enable Dry sorbent Injection at distances unattainable by classic screw conveyors.
TYPES OF PNEUMATIC CONVEYORS
Pneumatic conveyors are classified into three types based on the material they convey and their airflow source:
-
DILUTE PHASE PNEUMATIC CONVEYORS (Commonly Used in Dry Sorbent Injection)
- This type is suited for non-fragile materials. It employs high-velocity, low-pressure air streams to fluidize fine particles. A screw feeder pushes the material into the conveying line and then propelled through an air mover at high speeds. These conveyors excel with low-bulk density powders and can effectively transport materials that tend to pack under pressure.
-
DENSE-PHASE PNEUMATIC CONVEYORS
- Unlike dilute phase conveyors, this type uses low velocity and high pressure, making it ideal for fragile products. The material is loaded into a pressure vessel and forced into the conveying line by high pressure, sometimes assisted by air injectors. These conveyors gently move abrasives, heavy bulk-density products, and other fragile materials.
-
SEMI-DENSE PHASE PNEUMATIC CONVEYORS
- This type offers a midpoint between the other two systems, combining their qualities. With an air mover and pressurization, they can transport bulk material at a slightly higher speed while still protecting it. They are well-suited for aeratable, abrasive materials such as fly ash and cement.