The term, ‘incinerate’ means, to burn something until nothing is left but sterile ash.
In an incinerator, the high levels of heat are kept inside the furnace or unit so that the waste is burnt quickly and efficiently.
‘Flue gases’ are generated from this waste burning process.
In a double chamber incinerator, these flue gases are also incinerated in the second chamber before being sent to the air pollution control device
The flue gases are cleaned of pollutants before they are dispersed in the atmosphere.
Ash after incineration is deep buried
Thus, ‘Dual chamber’ systems operate by incinerating materials in a primary chamber and then incinerating the gases for a second time in a secondary combustion chamber.
Resulting emissions from this system are cleaner and safer for the environment.
Primary Chamber
The primary chamber is where all waste will be loaded and incinerated for the first time.
Volatilisation of waste is achieved in primary chamber.
In this starved-air chamber, the low air-to-fuel ratio dries and facilitates volatilization of the waste, and most of the carbon burns.
Secondary Chamber
Volatile/gasified matters from waste are taken up to the secondary chamber.
In the second stage, excess air is added to the volatile gases formed in the primary chamber to complete combustion.
Secondary chamber temperatures are higher than primary chamber temperatures
The gaseous products (volatile mater) are completely oxidised in the secondary chamber due to sufficient residence time, high temperature and 100% excess air
After the gases leave the secondary chamber, they are treated
The gases finally enter the droplet separator wherein the moisture is removed from the gases. This reduces the flue gas temperatures making it safe to be let out in the atmosphere
Reference:
GOI 2009. TECHNICAL INSTRUCTIONS ON INCINERATOR; DTE OF WORKS ENGINEER-IN-CHIEF’S BRANCH INTEGRATED HQ OF MOD (ARMY)
Rotary Kiln: http://www.ihatepsm.com/blog/rotary-kiln-incinerator
Double Chamber Incinerator: http://www.ihatepsm.com/blog/double-chambered-incinerator