Almost all systems are designed with functional and safety specification as top priorities and complementary robust engineering methods, as after thought activities. The end result is that the installed incineration systems work according to design but do not work at its optimum efficiency. Robust engineering methods, if applied at the early stage of design cycle, may bridge the gap and provide a more reliable and efficiency system on implementation.

What are the considerations of system development methods (eg spiral, waterfall) and the appropriate techniques in achieving robust engineering design in a waste incineration system?

I am a practicing instrument engineer and I am also pursuing a Bachelor of Science in Technology (BSTE) degree course. This subject is my final year project.

 

In my experience, the single most important (robust?) step is the sorting/selection of waste. If your front-end loader operator has that
ability, then, double his/her salary!

Regards,
Phil Corso, PE
(Boca Raton, FL) [[email protected]] {[email protected]}

 

Thanks for your comments. In an industrial plant, such as pharmaceuticals, multiple solvent wastes streams are generated in a typical primary batch process. The streams are collected in aqueous and solvent storage tanks before being pumped away into a waste incinerator. Due to its varied solvent composition, it is difficult to use them as sole burning fuel, to support combustion at required temperature. It has to be supplemented with another known fuel, such as diesel in an liquid injected incineration plant. Question is how can we optimize the four main parameters that influence completeness of the combustion process, the temperature, the residence time in the combustion chamber, the turbulence (air/waste) and the size of the waste particles and yet meet the statutory requirements? Or are there other ways to achieve robustness in incinerator control?

 

I have seen a reductive thermal oxidizer (RTO) used with hydrocarbon vapours. Essentially, the RTO is a voluminous gas oven filled with specially designed ceramic shapes where the gas burners keep them at high temperature. The vapour takes a sufficient amount of time to pass through the chamber to be completely burned. In addition, a certain amount of the exhaust of the RTO is passed back to the inlet. Perhaps your liquid solvents could be vapourized.

Haden Drysys is one such company I know that does RTO's. http://www.hadenenvironmental.com/tech-thm-a.asp

 

Best control of the incinerator should insure compliance to regulatory demands. There are several ways to build a control system to operate switching the controlled variable, dynamic tuning, model-based control and others that could be used to allow an incinerator to operate efficiently but get over-ridden to always ensure compliance.

The latest (to me), very interesting, control system model that should handle your requirements is a Fuzzy Logic Tunnel Controller. Dr. Fred Thomasson of Savannah, Georgia did a presentation on this for our ISA in January.

Hope this helps.

Kevin Totherow
Sylution Consulting
[email protected]

 

Reuben, I apologize for misinterpreting your query! Unless, of course, you are able to fit a front-end loader amongst the piping and vats in a
pharmaceutical operation.

Regards,
Phil Corso, PE
(Boca Raton, FL) [[email protected]] {[email protected]}

 

Thanks for your comments. The trend today is moving towards greater adaptation of Commercial-Off-The Shelf Components and Internet-Related Technology in Process Control. Are those mentioned, control system specific technology or portable technology that can be adapted for use in any DCS or conventional control system? I understand that ExperTune has a product that can do PID Analysis, Tuning and Simulation Software that makes it easy to optimize PID loops in any industrial controller. It also has powerful simulation, modeling, robustness and frequency analysis capabilities. Any comments on that or other similar technology that can be used for the said application? Thanks.