I have just managed to get more heat from it, than I need....
I have just managed red heat on the gas bottle casing at last.
It seems an inadequate oil flow was probably the cause of it not producing enough output before.
Latest changes are a mica window fitted in the door, so I can see what's happening inside at the burner, rather than peering down the air pipe. Then I fitted an 8mm compression T in the feed pipe to enable the thing to be fed from two separate header tanks. The single pipe down from the T was close to the flue, so warm anyway and making the oil flow easily. One tank had MVO and the other WVO - I previously found that these would not mix in the same tank, but no reason why both cannot be fed into the last section of warm pipe to mix.
The burner was just an old small cast iron frying pan about 5" diameter, sat on top of a bit of 3x3 steel box section, both placed on the inside bottom of the gas bottle.
Prior to today's test, the oil had been dripping into the pan and immediately vaporising. Today, with both oil sources turned on and more flow, a pool of oil actually built up in the pan and this seems to be the secret to getting heat from it.
My IR temperature unit measured temperatures beyond its range (>650 deg C) around the mid-point of the gas bottle, 350 on the flue and a definite red glow from the gas bottles steel casing. With outdoor temperature at 3.5, the temperature in my workshop quickly got up 30 deg C - at which point doors had to be opened to cool it down.
I previously found it ran best, with the end of the air pipe about 1/2" above the bottom of the pan. With more oil going in, this height had to be changed to 1.5" above the pan to enable increased air to for the extra burning taking place.
This all suggests that 1/4" is not big enough for a gravity oil feed, I used 8mm (3/8"), but even 8mm is not big enough if the oil is cold enough that there is a need for heating - unless some means can be found to preheat the oil in the tank or increase the head. I am working with a 5' head using small test tanks.
The next thing to do will be to swap the cast iron flat bottomed pan for something which slopes down to the centre, to concentrate the oil in the middle.
Lighting this thing is real easy and clean...
Turn the oil supply on, pour a cap full of parafin (kerosin) down the air pipe into the pan, open the door, close the air-in damper and iginite the parafin - the rubbish in the pan from the last use, acts as a wick until the flame can self sustain itself. Quickly shut the door and open the damper. Five minutes later you have heat flowing.
Turn the oil off and a minute or so later the flame goes out. A slight fall and then rise in the oil feed pipe not far from the burner, means the flow will stop and start even quicker - rather than continueing to flow by syphonic action.
