Positive-Negative Pressure Dense Phase Conveying System – Advanced Powder Transport Technology

Positive-negative pressure dense phase conveying is an advanced powder material transport technology that combines the advantages of both positive and negative pressure conveying methods, transporting materials at high solids concentration within enclosed pipelines.

Conveying Principle

• Negative Pressure (Vacuum/Suction) Section: Uses a fan to create negative pressure inside the pipeline, drawing materials from hoppers or bins into the system. Suitable for conveying from multiple pick-up points to a single collection point, effectively preventing dust leakage.

• Positive Pressure (Pressure) Section: Pushes materials to target points using positive pressure. Suitable for long-distance, high-capacity conveying with multi-point discharge capability.

• Dense Phase Conveying: Materials flow in the pipeline as plugs or dunes. Low gas-to-solid ratio (typically <15:1), low material velocity, minimal wear, and low breakage rate.

Core Advantages

• Low Loss & High Quality: Low material velocity results in minimal wear on both equipment and materials. Particularly suitable for fragile, easily segregated, or high-quality powders (e.g., milk powder, pharmaceutical powders).

• Dust-Free & Environmentally Friendly: Fully enclosed transport eliminates dust leakage at the source, improving workshop environment and complying with environmental protection and safety production requirements.

• Flexible & Adaptable: Capable of long-distance (hundreds of meters) and high-capacity transport. Piping can be flexibly arranged to adapt to complex plant layouts, supporting multi-point pick-up and multi-point discharge.

• Intelligent & Stable: Integrated with PLC control systems for automated continuous operation. Adjustable parameters and stable performance reduce manual intervention.

Main Components

• Air Source System: Roots blowers, screw compressors, etc., providing positive and negative pressure power.

• Feed Device: Rotary feeders, Venturi suction nozzles, etc., ensuring stable material feeding.

• Conveying Pipeline: Wear-resistant stainless steel or carbon steel pipes, with linings or special materials selected based on operating conditions.

• Separation & Discharge Device: Cyclone separators, bag filters, etc., achieving gas-solid separation and material discharge.

• Control System: PLC + touchscreen for precise control and monitoring of parameters such as flow rate, pressure, and velocity.

Typical Application Scenarios

• Food Industry: Milk powder, protein powder, starch, coffee powder, seasonings, etc. – meeting hygiene and low-breakage requirements.

• Pharmaceutical Industry: Active pharmaceutical ingredient powders, traditional Chinese medicine extracts, health supplement powders, etc. – compliant with GMP standards.

• Chemical Industry: Pigments, carbon black, plastic pellets, catalysts, etc. – suitable for corrosive and flammable/explosive materials.

• Building Materials Industry: Cement, lime powder, fly ash, etc. – achieving efficient and environmentally friendly bulk material transport.