Here's something a little different and I'm hoping that some of the Tilley experts will be able to shed some light. This appears to be a normal preheater off a Br49, but it is lacking a feed tube from the cock to supply the paraffin. I've looked over this with a careful eye and as far as I can tell it hasn't been altered in any way, therefore never had one. The shroud I haven't photographed, but is basically the same as the normal ones but unlike my others which have the patent number on, this one has "Patent app for" so I wonder if this must date it to before Tilley was granted the patent for this preheater. According to @JEFF JOHNSON post here the patent is around 1930/31 if this is covered under that same patent application. There are some differences to those drawings though and this one does have more similarities to the later ones so it has me puzzled somewhat. Has anyone seen one like this before?
If there's no fuel feed tube then how would fuel (i.e. paraffin / kerosene) get to the curly-wurly wick? If it had to be added manually then that would defeat half the point of the paraffin preheater i.e. to save carrying a different fuel in a separate container. With that as it is, you'd have to carry the same fuel in a separate container. My guess would be that the paraffin preheater came about in two stages - the first stage as you have it and the second stage was to add the extra cock to the pricker control feeding fuel from the tank through a feed tube to the wick. That satisfies my sense of logic anyway. Good stuff, Matt...
Hi David, that was also on my mind about how the paraffin gets in there. One thing I wondered was the earlier version, which is fitted to a table lamp of Pete's and also a Tl10 Ian posted in the gallery was filled by letting paraffin spill from the vapouriser jet which ran down and soaked into the wick. Perhaps this is the next stage from that and was intended to rely on the same principal, I can't think it would work well though as the paraffin would run down the middle of the preheater as well. Could perhaps even be a special order, some one wanted to do away with the clip on preheater and use this type with meths?
With the paraffin running down the vapouriser jet to the to the wick, I would have thought once the wick was lit, it would lead to a very black/carbon coated glass?
I think the best case scenario would be a lot of paraffin liquid running down the sides of the tank onto the kitchen table! But to answer your question, Digout, yes and no. Yes, if you don't know the correct way to use these preheaters or are impatient; otherwise, no. Paraffin (kerosene) is a much larger molecule than methylated spirit and requires much more oxygen for complete combustion to carbon dioxide and water. The oxygen gets to the burning kero vapour and resulting flame by two routes - firstly, through a series of holes at the bottom of the preheater which communicate with more holes above exiting next to the inside of the curly-wurly wick and above it; secondly, through the holes on the shroud. The idea is that the burning kero creates an upward convection current of air by the 'chimney effect'. However, this process won't work straight away with a cold preheater so if you're impatient and rush things you'll get the yellow, non-aerated smoky flame and a dirty globe resulting from that. I've found out by experience the correct way to use these preheaters is as follows:- 1. Lift the shroud and let kero flow into the preheater and right round it until it's full. Turn off the kero flow. 2. Keep the shroud lifted and light the kero and wait until the flame is lit right around the preheater. On no account should you lower the shroud. The flame should be aerated i.e. mostly blue 3. Keep the shroud lifted for at least a minute while the preheater gets hot. 4. Keep the shroud lifted for a bit more time. 5. Slowly lower the shroud onto the preheater body. If the flame goes yellow at any point, simply lift the shroud and wait some more time before you try again. Doing it like that ensures the preheater flame has sufficient oxygen at all times and is blue i.e. aerated and never smoky yellow. Works for me, every time...
Some teachers are better than others, luckily your not the clip round the ear hole kind or do you just hide it well An excellent explanation and one i will be using when i eventually get my BR49 ready for the first light up
