Q1: for some fuels your solution will work fine, might even better then my first design.
However, the solution must be industrial proof and suited for multiple types of fuel. Fluffy fuel is more of the problem as pellets.
Q2: the green lines indicate the position of the swirl baffles to guide the fluegas in a swirl motion around the coil, forcing the fluegas to release its energy more effective towards the coil surface.
Q3: the ash pit as per my design, allows for automated cleaning even during runtime, even possible to use water lock waterflow system or just augers. ( reducing overall downtime )
Q4: the ash should not fall thru the coil, only to be conveyed with the fluegas speed, hence the flow control shield to reduce speed in the ash pit zone, and the baffles to increase the speed again.
The ash pit zones are designed for lower airspeeds, the ash will settle, just below the stack there is also a water spray system to take out the residu from the fluegas stream.
Working on a new type economizer to use the waste heat from the stack to preheat the feedstock/fuel before it go’s to the gasifier/burner. ( extracting vinegar and water , some portion can be injected in the reduction zone to temper the heat and reduce the klinker )
Hi Koen, thank you for your answers to my questions. I hope I’m not bothering you, I’m just curious of such an industrial project, I truly want you & yours to succeed wonderfully.
I noticed your ignition unit in your latest round of snapshots, and it reminds me somewhat of a propane furnace type ignition/manifold. Does your unit have a safety device that turns the ignition & auger off, based on operating conditions inside the furnace and stack? I worry that IF an amount of unburned flammable gas, exists inside the huge vessel, [due to faulty ignition, or operator error, improper fuel feed rate, overheating, or underheating, vessel leakage, boiler problems, or whatever] if ignition is suddenly restored…the thing will go boom? I guess it might take 10 minutes or more to completely clear the industrial furnace & stack of any flammable residue with blower air only, or even an auxiliary blower so that ignition might resume operation in a safe way at the fuel/air/mixture/ignition nozzle only?
The reason I mention this is because my home propane furnace might be similar in a very small way, occasionally it misfires for whatever reason, and it will not operate, nor resume operating until it has ‘completely cleared the furnace area of the furnace with a wash of auxiliary blower air & zero fuel’ safely clearing any residual gases that may or may not have built up inside the furnace & chimney vent caused from the misfire… The thing never goes boom, due to the working safety devices.
Any design is compliant with the according industrial standard.
at the base the air is always dominant in the control, also before shutting down, the boiler is “flushed” with fresh air according regulation or better.
If you know what volume and airspeed is involved, then its easy to calculate the "flush time " required.
The air flow volume for this large boiler is about 6000 cbm per hour or 1.8 Cbm per second.
The total volumetric size of this boiler is about 12 cbm or 6 seconds for 1 flush…
all safety is basic knowledge and such systems are already in use for more then 30 years even for the O2 sensors and AFR controls.
Hi Koen, thanks again for your answers. I guess it is the ‘A mystery build’ this thread, your progress, or goal seems more clear to me now, I am glad you have shared your project details with us here at DOW.