Saxlund International Limited

Innovative solutions for Bulk Materials handling and Biomass Combustion
Biomass Combustion

Biomass Combustion

Combustion Grate


Saxlund Sliding Frame

Optimum Discharge for Sludge Storage Silos


Sliding Frame technology was developed and patented by Saxlund back in the 1960’s as a method of discharging non-free flowing materials from a round flat bottom silo. Since then the Saxlund Sliding Frame has been successfully used extensively around the world in thousands of installations.


The original Saxlund Sliding Frame utilised a Single Frame reciprocating across the bottom of the silo, recently we have patented a new Twin Element Sliding Frame. This design has some advantages for special cases and for larger silo designs.



Saxlund Single Element Sliding Frame


Saxlund Twin Element Sliding Frame

Operating principle

Non-free flowing materials will generally form a bridge across any hole or chute used to discharge the material and require some form of device to “dig” the material out and break any bridges that form.

The Saxlund Sliding frame is driven by powerful hydraulic cylinders that reciprocate the sliding frame(s) across the silo floor. The Saxlund Sliding Frame is designed with a cross-section that when travelling in one direction, slides under the stored material, in the other direction will push the material. Therefore the Saxlund Sliding Frame is designed to break any bridges when moving in one direction, and slide under the material when moving the opposite direction, thereby promoting bulk material flow. Because of this bulk material flow the Saxlund Sliding Frame is a “First in, First out” technology, which is an added benefit for materials that can degrade over time such a Sewage Sludge Cake.

Material removed by the Saxlund Sliding Frame is then discharged into one or more screw conveyors, the control scheme of the Saxlund Sliding Frame is to ensure that these screws are always kept full of product, to ensure accurate metering.

Controlled feed of non-free flowing materials


Typical Discharge Rate

  • Up to 130m³/hr
    (dependent on material and application)


Typical Sizes

  • Diameters  2.5 to 11m
  • Silo capacities  5 to 2,500m³



  • Effective and simple operation
  • Uniform drawdown of material on “first in, first out” principle
  • Largest size discharge openings possible
  • Accurate discharge and metering of stored material on demand
  • Enclosed lidded design – no odour
  • External maintenance possible - even with the silo full.
  • Sliding frame moves only required loose materials resulting in
    o Low power usage -
    o Low maintenance costs -
  • Flat bottom silos - more economical to manufacture /maximized storage


Typical Materials

  • Sewage sludge cake
  • Paper sludge
  • Sugarbeet pulp
  • Woodchip


Typical Applications

  • Tipper truck reception
  • Buffer storage for metered process feed ie (dryer).
  • Truck loading - prior to onward transport