In Tank Contaminant Removal

Floor Scraper & Grit Discharge System

In Tank Floor ScraperSinking contaminants and grit that get fed into the digesters along with the feedstock will sink to the floor of the digester throughout the digestion cycle. If left there, this accumulated grit will create significant operation problems including reduced digester capacity & therefore biogas production and interference with agitators. The floor scraper solves this problem by rotating at regularly operator defined intervals, pushing sinking materials and grit to a bottom outlet in the floor slab. The material is then pumped to an external gravity separator that eliminates the grit and allows the liquid organics fraction to re-enter the digester.

Scraper Specifications

  • Fits digesters with internal dimensions of Ø 18m/59ft x 10m/33ft height
  • Weight-reducing arm geometry
  • Mechanical and electrical overload protection
  • Running of discharge pump coordinated by scraper control
  • Drive unit with slowly rotating palnetary gear on digester ceiling
  • Gas-tight shaft duct
  • Low maintenance
  • Scraper control in into plant control
  • Discharge by centrifugal pump (115mm/4.5inches ball passage)

In Tank Floor Scraper


  • Skims/removes indigestible floating material (plastic, Styrofoam, fibers) for the substrate surface in the digester
  • Prevents scum layer from forming
  • Easy access from the top
  • Gas-tight design under every operating condition
  • Flow-optimized inlet geometry
  • Mounting either on roof of digester or exterior wall

Gravity Separator

  • Grit discharge by screw conveyor
  • Free flowing drainage and overflow into digester
  • Low maintenance operation
  • Thermally insulated