Single chamber incinerator - incinerators mostly started as small refractory brick constructions used mainly by hospitals, restaurants and shops. After-burning was not well known and if present, would be part of the stack itself. Loading was mostly manual and the chamber operated under positive pressure, causing fire and flames to come out if the door was opened during operation. Today's incinerator works at a pressure below atmospheric pressure and considers operator safety as a prime factor in its design.

 

Addition of a secondary combustion chamber to the incinerator- Full fledged chambers replaced stack after burning, allowing for complete combustion of generated flue gases and thereby cleaner emissions. Chambers were operated under a slight negative pressure and loading was done automatically, making it safer. As an alternative, many manufacturers provide a very large single chamber incinerator in which flue gases have sufficient residence time, usually in the upper part and this itself acts as a secondary combustion zone.

 

Air pollution control devices - Air emission regulations which are critical aspects of an incinerator's performance were promulgated. The first scrubbers consisted of simple water spray towers or dry cyclonic

dust collectors which were effective in only collecting large dust particles. Today, air quality from an incinerator can be extremely clean, with possibilities of using even HEPA filters.

 

Energy recovery - has always been a part of incineration from the beginning. The first few incinerators in New York City were able to generate power from incineration of trash. Modern incinerators recover hot air, hot water, generate steam and power in sophisticated waste heat recovery boilers.

 

Fully automatic systems and emission monitoring equipment - Today's incinerators are at the other end of the evolutionary process. They can be made to operate with the push of a single button. The entire process is controlled by a computer, valves automatically control flow of utilities, instruments monitor critical parameters and emissions are strictly monitored and counter measures are clearly in place for non-compliance to any requirement or for any emergency.

 

You can look up more details on Haat's instrumentation and automatic incinerators here - Instrumentation / Automation