Gas Vapourizer

[JWF]

My concern is that without a fan as the oxalic rapidly sublimates it'll push through the gaps in the cover. What it needs is a set of bellows!

If you create a system that could get overpressurised if the outlet tube gets blocked, you need an effective pressure relief arrangement to make sure you don't create a small explosive device.

 

[Eyeman]

If you create a system that could get overpressurised if the outlet tube gets blocked, you need an effective pressure relief arrangement to make sure you don't create a small explosive device.

I'll see how it performs for the rest of the season. It survived 40+ sublimations and the fans cost just over £1 each so if I need to replace a fan a season it wont be a problem.
Main worry is the fan breaking down mid way through treatment. I may have to put together a small repair kit, including a 9V battery and spare camping gaz!

 

[Eyeman]

You need 160 oC for OA to sublimate and only if any is left and temp gets to 190 do you get formic and co2.

Hi Dano41 I have the Sublimox APF-PLUS and just tested it after 8 minutes it runs at a constant 300c hope this helps.

Just found this on an easlier thread.
That removes an worries I might have had about the blow torch overheating the cannister.

 

[maddydog]

If you create a system that could get overpressurised if the outlet tube gets blocked, you need an effective pressure relief arrangement to make sure you don't create a small explosive device.

There's so many potential escapes I'd be amazed if you could get it to explode. The oxalic that condenses is still pretty friable so I don't think pressure could build up sufficiently to cause any damage. A pipe bomb it is not

 

[Beefriendly]

Just found this on an easlier thread.
That removes an worries I might have had about the blow torch overheating the cannister.

Interesting, I didn't know the operating temp of a sublimox, but it does the job. Although I love the idea of the portability of a hand held job.
I think the ideal might be a gas heated sublimox equivalent, with a chamber heated by gas and a PTFE cap with O ring which can be filled (upside down) and then inverted so the OA drops into the already heated chamber and force of the sublimation and the only exit being the short nozzle gives you a nice powerful blast of sublimated OA.

 

[wightbees]

I have read that it's only after 300c that it goes to formic .
That's why I thought fogger would be ok.

 

[Beefriendly]

Nope, you just need to see the spec for it here.
Look for sublimation temp 157oC and then below is melting temp (decomposes) 189.5oC.
If I've interpreted the chemistry correctly the small amounts we use will all have sublimated before it reaches 189.5. Unless you have a massive amount of the stuff that you are trying to sublimate.

 

[maddydog]

Made a fume board similar to eyeman's. Swap with the crownboard and vape from the side with the vaporisor self supported by a bracket. Plenty of vapour escaping through the entrance and omf so looks far more effective.
I bought some motorcycle heat shield that I'm hoping will help shelter and concentrate the flame.

 

[Gilberdyke John]

There's so many potential escapes I'd be amazed if you could get it to explode. The oxalic that condenses is still pretty friable so I don't think pressure could build up sufficiently to cause any damage. A pipe bomb it is not

Plus even if it's not rotating your fan will give passage of the air and vapours.

 

[Gilberdyke John]

Made a fume board similar to eyeman's. Swap with the crownboard and vape from the side with the vaporisor self supported by a bracket. Plenty of vapour escaping through the entrance and omf so looks far more effective.
I bought some motorcycle heat shield that I'm hoping will help shelter and concentrate the flame.

I'm presently trialling a modified 50mm eke with a slot in the side for the shaft of a tray sublimation unit plus a 3mm polycarbonate top sheet for observations of the sublimation. The material vapourises and drifts across the frames and downwards onto the frames and bees.. Normal bee activity will spread the condensed particles through the brood box
If the trial results on mites are satisfactory I'll use it on all my hives. it's a simple matter to lift the crownboard or super off, lay the prefilled sublimator on top of the frames, fit the eke and poly sheet. Couple the leads to the battery and observe. With decent joints on the brood box, eke and poly sheet no vapours escape but usual precautions apply.
Working smoothly the bees didn't even notice I was there. I made another eke to use with a poly nuc too. As the heated tray is on the centre of the wooden frames there is no potential to damage the polystyrene.

 

[Eyeman]

Just had a look at the fan- basic chinese 40mm computer cooling fan- retails at less than £1. It's rated at 12V and the device has a 9V power supply. I have sourced some 9V rated fan units which I'll try as they may be more efficient.

 

[rook66]

Just had a look at the fan- basic chinese 40mm computer cooling fan- retails at less than £1. It's rated at 12V and the device has a 9V power supply. I have sourced some 9V rated fan units which I'll try as they may be more efficient.

Is it advisable to have a spare at the ready? For the iliterate in electrics, can you list the requirment.
Thanks for all the help and advise.

 

[maddydog]

Just had a look at the fan- basic chinese 40mm computer cooling fan- retails at less than £1. It's rated at 12V and the device has a 9V power supply. I have sourced some 9V rated fan units which I'll try as they may be more efficient.

A more powerful fan would definitely be useful but not crucial when vaping from above. It looks as though the vapour rapidly becomes heavier than air once it leaves the nozzle.

I'll try and post a photo.

 

[maddydog]

I'm presently trialling a modified 50mm eke with a slot in the side for the shaft of a tray sublimation unit plus a 3mm polycarbonate top sheet for observations of the sublimation. The material vapourises and drifts across the frames and downwards onto the frames and bees.. Normal bee activity will spread the condensed particles through the brood box
If the trial results on mites are satisfactory I'll use it on all my hives. it's a simple matter to lift the crownboard or super off, lay the prefilled sublimator on top of the frames, fit the eke and poly sheet. Couple the leads to the battery and observe. With decent joints on the brood box, eke and poly sheet no vapours escape but usual precautions apply.
Working smoothly the bees didn't even notice I was there. I made another eke to use with a poly nuc too. As the heated tray is on the centre of the wooden frames there is no potential to damage the polystyrene.

Yes, vaping from above definitely appears to be the way forwards. I've seen it mentioned in the forum before (HM?) but having copied Eyeman's eke it's the best way I've found of administering oxalic

There's a video on YouTube of a German guy who's constructed a unit using a plastic cloche. Looks good but too much engineering for me

 

[BeeJuice]

I've been following this thread with interest. I like the idea of vaping from above. I've followed what others have described - a clear cover, hole in the side, a shortened pipe and a heat shield. (this isnt really necessary with my set up as I use a blow torch aimed at 90 degrees.

I have gone one little step further with very good results... once the OA is fully vapourised and fills the eke, I then use a blast of compressed air to blow the vapour down and through the hive. The force of air (turbulence) ensures that the vapour is distributed throughout the hive and the eke quickly clears of vapour.

With the inspection tray in place and the entrance blocked the bees get the full dose.

If you're thinking where do I get compressed air - there are a few places..

Compressed air is sold by the can for cleaning printers and computers -
http://bit.ly/2wACMX4

Or something a bit bigger like this - http://bit.ly/2wAERCj

Or a diving cylinder - http://ebay.eu/2wyf53z (You get get it refilled from any place that sells airguns or a dive shop)

 

[Eyeman]

Is it advisable to have a spare at the ready? For the iliterate in electrics, can you list the requirment.
Thanks for all the help and advise.

Hi
The fan in the device measures 40mmx40mmx20mm so if you get the same size it will fit. It's a DV 12V 0.76W model.
This is the cheapest one one ebay at £1.81
1Pcs DC Brushless Cooling PC Computer Fan 12V 4020s 40x40x20mm 0.13A 2 Pin Wire

I've ordered a 9V one to try but it is only 10mm deep so may need shorter bolts- I let you know if it's any better than the 12V model.

 

[rook66]

Hi
The fan in the device measures 40mmx40mmx20mm so if you get the same size it will fit. It's a DV 12V 0.76W model.
This is the cheapest one one ebay at £1.81
1Pcs DC Brushless Cooling PC Computer Fan 12V 4020s 40x40x20mm 0.13A 2 Pin Wire

I've ordered a 9V one to try but it is only 10mm deep so may need shorter bolts- I let you know if it's any better than the 12V model.

That's good to know. Thanks

 

[Eyeman]

Just done my second round of treatment- Treated 44 nucs before the gaz ran out!. Got some replacements coming tomorrow- interesting the gaz is Butane only not the usual butane/propane mix.
Much more successful today. Didn't accidentally switch the fan off once.
I did have a single significant blowback of OA through the fan which I discovered was due to a side wind defecting the flame causing the temp of the cannister and tube to drop (you usually hear the OA start to boil within 5 seconds of starting the treatment, on this occasion boiling was delayed for 15-20 seconds)- OA then condensed in the tube and the fan stopped. I had a hex key so easy to clear the OA powder and restarted. After that I used a piece of wood to clean the tube out after each vape- didn't happen again.
It definitely pays to get the cannister very hot.
I may modify mine again by further shortening the main tube. Firstly all the tube will be closer to the flame so less condensation. Also it should reduce the outflow resistance which should result in less blowback through the fan.

 

[maddydog]

I did have a single significant blowback of OA through the fan which I discovered was due to a side wind defecting the flame causing the temp of the cannister and tube to dropQUOTE]

This is why I'm going to try and add a bit of heat shield to act as baffle (?) and stop the flame dissipating

 

[Eyeman]

I did have a single significant blowback of OA through the fan which I discovered was due to a side wind defecting the flame causing the temp of the cannister and tube to dropQUOTE]

This is why I'm going to try and add a bit of heat shield to act as baffle (?) and stop the flame dissipating

Let us know what sort of design works?
Thanks