Six pie-shaped sectors (each subdivided into six aeration zones) and continuous blending in a timed discharge pattern provide the lowest energy gravity blending silo available. Power consumption on cement raw meal as low as 0.07 kWh / metric ton! New and retrofit installations with minimum downtime.

When an aeration zone is activated, layers are mixed through a funnel effect as material in the zone flows to its designated collection point on the gathering Airslide® conveyor. The inverted cone prevents material exiting without flowing through a collection point.

At FLSmidth we engineer all our blending silos to maximize the benefits of fluidization and gravity technologies over mechanical.

Technologies that give you operating efficiency, flexibility and increased productivity. Our product range can also combine storage and blending for space-saving plant layouts.
Unit of Measure

Blending Applications


  • Mixing two or more products
  • Homogenation of individual products
  • Size uniformity
  • Color uniformity
  • Chemical uniformity
  • Temperature uniformity
  • Reduce process variations
  • Recycle out spec material
  • Add trace elements
  • Chemical modification



  • No moving parts
  • Low pressure air
  • Compact PD blowers
  • Gravity withdrawal
  • Center or side discharge
  • Maximum bottom aeration coverage
  • Small inverted central cone



  • Reduced maintenance
  • Clean, dry, oil free
  • Low power usage
  • Space on ground floor
  • No segregation
  • Flexible plant layout
  • Maximum cleanout
  • Low installation cost
  • Maximum storage capacity

Subtraction = Addition

N/A The advanced engineering of the Fuller® Random Flow™ (FRF) gravity blending system delivers increased capacity, productivity and savings by decreasing:

  • Power consumption
  • Maintenance
  • Dust
  • Capital costs
  • Kiln fuel consumption
  • Air flow
The innovative process and simple design of the FRF system achieves accepted blending efficiencies for dry, pulverized, free-flowing particles saving you both time and money.

Competitive Advantage

N/A The FRF gravity blending system is FLSmidth’s response to the cement industry’s demand for a more energy-efficient, cost-effective system. Designed for higher production at lower costs, the FRF system has already proven its capabilities in new installations and retrofits worldwide. In retrofits, it can increase your capacity up to 40% over fluidized systems while decreasing kiln fuel costs through a more uniform blend.

Free Power

N/A The FRF system minimizes costly mechanical power requirements and maximizes the "Free" power of gravity for a variety of blending applications. In fact, the FRF system can reduce power consumption from 2.0 kWh/metric ton of raw mix to as low as 0.07 kWh/ metric ton! In addition, the FRF system utilizes oil-free dry air from equal-size, positive-displacement blowers, offering uniformity of parts, less component wear and minimal lubrication requirements.

62 = 1 Powerful Solution

N/A The FRF system is a cost-effective gravity blending system that requires low power consumption but provides high blending efficiency. The system is well suited to converting existing fluid bed blenders and storage silos to gravity blenders. The silo floor consists of six sectors. Each sector has six collection points. Blending is achieved by systematically withdrawing layered material from a total of thirty-six collection points. The material is withdrawn by low-pressure air in closed-type Airslide® conveyors from the collection points to the silo discharge. A relatively small inverted cone, centrally positioned over the silo discharge, prevents material from exiting without first flowing through a collection point.


Power Consumption On Cement Raw Meal (Min.)

N/A 0.07 kWh/metric ton