The smoke generator for the mine office is now working.
Dave Bodnar posted an interesting implementation of a smoke generator that created smoke by burning glycerine using heating coils from electronic cigarettes. Like Dave, my implementation uses KangerTech 1.8 ohm heating element coils to make the smoke. However, my original implementation of his solution, although functional, was not reliable. My solution used copper fittings to hold a replaceable coil and this leaked glycerine. I believe this caused the heating coil to dry out and fail.
I redesigned my solution to use the Kanger GeniTank Mega atomizer. My new implementation now used the manufacturer designed vaping tool for the coil and glycerine tank.
At the bottom of the atomizer is a screw type threaded connection with a centre pin for the electrical connection. This is intended to screw into a vape battery, but I modified an aluminum holder for the atomizer to be used as my support. Now, when the atomizer is screwed into the holder it completes the electrical connection.
The complete assembly is contained in a 1 inch diameter copper pipe coupling fitting. A small 6V air pump feeds into the bottom of the fitting to push air through the coil. I power the system with a 5Ah 6V SLA battery that uses a solar panel charge controller. I can charge the battery with a 9V solar panel or a CC-CV power supply set to 7.5V and a maximum current of 350ma.
The atomizer coil is powered by another CC-CV power supply that operates in constant current mode and limits the coil current to 1.3 A. This generate sufficient smoke for the fireplace.
I am still not completely convinced of the reliability of this solution. I now operate the smoke on a timer for 60 seconds and then let it rest for 9 minutes. I ran a test using a cycle of one minute on and 4 minutes off for 40 trials successfully, but at that time when I examined the atomizer it appeared to be out of glycerine. When I added glycerine and restarted the smoker no smoke came out and it appeared that the coil had failed.
I am not sure how long the coils last?
The glycerine smoke is also not completely satisfactory. It floats in the air and does not seem to dissipate.
More testing is required.