Dense Phase Conveying vs Lean Phase Conveying

Dense Phase Conveying vs Lean Phase Conveying

Usually when we think of dense phase pneumatic conveying, two basic measurement parameters appear in our mind: Pressure and Velocity.

The combination of these two variables generates the movement of the material, both powders or granules.

In dilute lean phase conveying, the combination of low pressure and high speed makes the particles move while suspended in the air inside the pipeline. Whilst, in dense phase conveying the particles form plugs which are then pushed through the pipeline by compressed air.  Precisely for this reason dense phase conveying method is the best choice in the case of fragile, mixed or abrasive products.

The Dense Phase Pressure Vessels are the main proponents of dense phase technology. They make it possible to move bulk materials from one point to another within a closed pipe, whether horizontal or vertical, by means of a gas (usually compressed air or nitrogen).

Let’s take into account the transport pressure.

Inside a dense phase pneumatic conveyor, the high pressure gently pushes the material inside the pipeline, sometimes with the help of special systems for the introduction of air. Pneumatic conveying always requires a pressure difference between the beginning and the end of the line. This difference depends not only on the length and layout of the line, but also on the concentration of the material within the pipeline. Likewise, the pressure is influenced by the physical characteristics of the product and the flow rate.

The low speed is what most distinguishes dense phase technology from the dilute lean phase one.

Compressed air at the beginning of the line expands as it approaches the end of the line, so that the speed also increases. Within a dense phase transport system, the speed can vary at the point of arrival, but rarely exceeds 10 m/s.

The right combination of high pressure and low speed creates the homogeneous flow of product plugs within the conveyor line.

Dense Phase Conveying














Dense Phase pneumatic conveying is extremely flexible in terms of the routing and the length of the pipeline.

The main application fields of pneumatic conveyors are feeding operations of mixers, reactors, packaging machines, and every similar application that requires to handle powders, granules, flakes, and dry bulk.

Pneumatic conveyors are used primarily for granules and powders. Some commonly conveyed products include sugar, flour, coffee, plastic granules, chemicals products, cement, silica sand, feldspar, fly ash, glass cullet, alumina, glass batch mix, and carbon black.

The correct design of a dense phase conveying system has the right balance between pressure and speed in order to prevent the breakage of the material, the wear of the pipeline or the formation of clogging in the case of delicate, abrasive and cohesive materials of those that react to temperature changes.

Mobile Dense Phase Conveying Skid

Filquip has developed a mobile dense phase conveying skid solution for  pneumatic conveying of cement, silica fume, salt and other building material plant additives. The mobile skid contains all of the equipment required for conveying the products, all that is required is a compressed air connection by Nitto hose and 240V power.

The mobile dense phase conveying skid can fill Silos, Hoppers and Bins up to 30m tall at rates up to 1T/hour.

Mobile Dense Phase Conveyor Skid

New Dense Phase Conveying Brochure

Filquip has a new Dense Phase Conveying Brochure detailing the Sand Conveyingadvantages of a Dense Phase Conveying system for materials handling.

Detailing the different models that can be provided to convey almost any product at flow rates up to 100T/h and distances up to 500m. Dense phase systems are perfect for conveying hard to handle products and can be filled from Bulk Bag Unloaders, Silo’s, Hoppers, Chutes, Screw Conveyors and most other filling equipment types.

Some of the advantages include:

  • High product conveyed to Air used ratio = Energy saving and cost saving
  • Less moving parts = Reduced maintenance and costs
  • Lower velocity conveying = Lower pipeline wear = Reduced maintenance and costs
  • High Internal cleaning = Increased efficiency
  • Completely closed system = Increased safety
  • Reduced product stratification and impacts = Perfect for fragile and mixed materials

Open the Filquip Dense Phase Conveying Brochure