Incinerator design

Our incineration process consists of the following main components:-

  • X-ray package surveying process
  • Auger Shredder and Ram feed system
    Three liquid lances and sludge delivery pumping systems
  • Primary Combustion Chamber (PCC)
  • Secondary Combustion Chamber (SCC)
  • Waste Heat Boiler (WHB) with economiser, capable of generating 3 tonnes/hr low pressure steam
  • Ash Handling Systems
  • Flue Gas Treatment Plant (FGT)
  • Induced Draught (ID) Fan and Stack

Process overview
Solid wastes are introduced into the shredding system via a waste bin elevator. Together with sludge, this material is then fed into the Primary Combustion Chamber (PCC - rotary kiln) and the gases generated by the combustion process are transported to the Secondary Combustion Chamber (SCC) to assure complete combustion of residual organics. Small packages of waste can be directly injected into the kiln via a ram feed/lift system. Liquid wastes are fed into the PCC faceplate via three lances; one of high calorific value waste; one of low calorific value waste; one water lance for process control. Sludge’s are fed from the hopper via a cavity pump directly into the PCC.

From the incinerator, exhaust flue gases are passed to a waste heat boiler and economiser where the combustion energy is captured to produce low pressure steam while combustion gases are cooled to a temperature where they are suitable to pass through the flue gas treatment system. Three tonnes of steam per hour is fed from the waste heat boiler into the site low pressure steam system.  Bottom ash drops from the PCC into a quench bath containing water with a phosphoric acid buffer to control pH. This is conveyed into skips for off-site disposal. Fly ash from the waste heat boiler (furnace, boiler, and economiser sections) is screw fed into this waste.  Conditioned gases are cleaned in a two-stage fabric filter. In order to achieve good neutralisation of acid gases and filtration of organic particles and to protect the filter bags, reagents consisting of sodium bicarbonate and activated carbon are injected into the flue gas upstream of the fabric filter.

Design capacity

 Parameter  Unit  
 Thermal Capacity  MW 6
 Waste Feed Rate (max)  Kg/hr 1500 at CV 14.4 MJ/kg
 Kiln Temperature (PCC)  °C 800-1200
 SCC Temperature  °C  900-1100
 Flue Gas Flow Rate  Nm3/hr  8000-11000
 Oxygen in Flue Gas  %  > 6

Compliance and monitoring
Continuous emissions monitoring is conducted through:
  • Infra red analyser
  • Ultra violet analyser
  • Zirconium cell analyser
  • Flame ionisation detector
  • Light scattering dust monitor.