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Anyone got a hydrogen generator?

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Ian Parkin13/03/2019 11:37:50
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617 forum posts
168 photos

Has anyone got one of these hydrogen generators i bought it for acrylic edge smoothing but seems it can be used for small repairs on jewellery etc

it came with some naoh 500grms.the instructions say make up a 15% solution..so that’s 150gr of naoh to 1 litre of water?

anyhow does anyone use one and have any operating tips?

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Bill Davies 213/03/2019 13:25:51
80 forum posts
10 photos

Hi, Ian. You've probably found these too:

Oxygen-hydrogen generator

Hydrogen generator polisher

A couple of manuals for potassium hydroxide electrolyte (different makes, using similar technologies):

Manual 1

Manual 2

I hope this is relevant and useful,

Bill

John Paton 113/03/2019 13:34:35
164 forum posts
6 photos

I think this unit is similar to the Microflame and Pioneer Hobbyflame units. The one caution I would make is to ensure that the hypodermic needle used for the flame is kept pouting away from people at all times. If there is a blowback the needle becomes a potentially injurious dart as it flies off the handpiece.

Also beware that the flame from these units is so clean that I think is effectively invisible so can easily be directed where it should not.

That said these are invaluable tops for certain jobs.

John

not done it yet13/03/2019 14:25:41
3029 forum posts
11 photos
Posted by Ian Parkin on 13/03/2019 11:37:50:

it came with some naoh 500grms.the instructions say make up a 15% solution..so that’s 150gr of naoh to 1 litre of water?

Nope! That would be 150g in one litre of solution. Assuming it is % wt/vol, which is the usual way of making % solutions of solids in solvent. I don't expect your dilution would make that much difference to the operation.

Gary Wooding13/03/2019 14:44:40
545 forum posts
127 photos

I have an Aqua-Flame unit, which is very similar to a Microflame.

John is correct in stating that the flame is virtually invisible. Fortuitously, the ratio of oxygen and hydrogen produced is just right for burning, and doesn't have to be changed, but, although the flame is very hot - approaching that of oxy-acetylene - it is relatively low in energy. To counteract this, it has something called a booster tank.

Output from the generator is fed through the booster and then to the torch. A liquid is placed in the booster to achieve two things, a) to counter the effects of a blowback, and b) to change the flame temperature. If the booster contains water, then pure oxy-hydrogen is burnt, but if it contains a suitable chemical, the flame temperature and calorific value, is changed. I use methylethylketone (which, I believe, is used in dry-cleaning) to reduce the temperate to about 2000C and increase its calorific value.

Flame size is determined by the size of the torch tip, which is rather like a hypodermic needle, and not by a regulator valve. The flame produced ranges from about 3-4mm wide and 80mm long for the biggest tip I have, to about 0.5mm wide and 2mm long for the smallest one. I am able to hard-solder the tiniest chains with the small tip.

Ian Parkin13/03/2019 15:55:16
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617 forum posts
168 photos

Well i filled it with my mix of 150g naoh and 1 litre of water and filled the booster with methanol as directions and it certainly works well.

as said teh flame is very hot and virtually invisible though it polished some 15mm Perspex edges very well..

How long should i leave the electrolyte in? And if it should be removed can i save it and reuse?

 

It was only £110 delivered from Belgium by ups 

Edited By Ian Parkin on 13/03/2019 15:57:26

not done it yet13/03/2019 16:24:36
3029 forum posts
11 photos
Posted by Ian Parkin on 13/03/2019 15:55:16:

Well i filled it with my mix of 150g naoh and 1 litre of water and filled the booster with methanol as directions and it certainly works well.

as said teh flame is very hot and virtually invisible though it polished some 15mm Perspex edges very well..

How long should i leave the electrolyte in? And if it should be removed can i save it and reuse?

I would expect it will not change - need CO2 to change it to washing soda. You will get 44 litres of hydrogen from each 18ml of water in the electrolyte and only need to replenish the electrolysed water as the level drops.

You could work out the hydrogen generation rate from the number of coulombs passed, but measuring the water level might tll you the same thing.

Looks like a useful piece of kit for the right jobs.

not done it yet13/03/2019 16:24:37
3029 forum posts
11 photos
Posted by Ian Parkin on 13/03/2019 15:55:16:

Well i filled it with my mix of 150g naoh and 1 litre of water and filled the booster with methanol as directions and it certainly works well.

as said teh flame is very hot and virtually invisible though it polished some 15mm Perspex edges very well..

How long should i leave the electrolyte in? And if it should be removed can i save it and reuse?

I would expect it will not change - need CO2 to change it to washing soda. You will get 44 litres of hydrogen from each 18ml of water in the electrolyte and only need to replenish the electrolysed water as the level drops.

You could work out the hydrogen generation rate from the number of coulombs passed, but measuring the water level might tll you the same thing.

Looks like a useful piece of kit for the right jobs.

Gary Wooding14/03/2019 07:33:00
545 forum posts
127 photos

I've never bothered to change it in my Aqua-Flame.

John Rutzen14/03/2019 09:14:34
88 forum posts
1 photos

Hi, this looks interesting. Please could you tell me if it looks well made? Also what are the dimensions? Have you any experience yet as to it's usefulness? The price seems to vary very much on Amazon but they all look exactly the same.

Ian Parkin14/03/2019 10:07:00
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617 forum posts
168 photos

John R

it certainly looks well made

its like a small welder 30cm x 20 x 20cm and weighs 5 kg empty

i’ve only done edge polishing but the flame looks good enough for precision heating of small parts/jewellery etc

it runs for about 20 seconds and then switches off on a pressure switch then cycles on/off as you use the produced gas

Edited By Ian Parkin on 14/03/2019 10:08:39

John Rutzen14/03/2019 12:30:47
88 forum posts
1 photos

Thank you, I am wondering whether to get one. Have you tried silver soldering any tiny parts?

not done it yet14/03/2019 13:05:46
3029 forum posts
11 photos

Oops, another silly mistake in my post above. The volume of one mole of gas at STP is 22.4 litres. 18 g of water will produce only one mole of hydrogen gas and 1/2 mole of oxygen.

Robin Graham14/03/2019 23:08:47
549 forum posts
126 photos

I noticed that NDIY, an easy enough mistake to make.

I didn't realise how cheaply these things could be had, so have pushed possible purchase from 'yeah, never' territory into 'perhaps'.

Armchair engineering (cellar is at 11.2C, that's my excuse):

Based on a gas output of 150 litres /hour of mixed gas, heat of combustion of hydrogen 286 kJ per mole, I get 345W at the nozzle. That's hot for such a small flame - maybe I've miscalculated?

Robin.

 

 

Edited By Robin Graham on 14/03/2019 23:13:27

John Paton 115/03/2019 07:46:41
164 forum posts
6 photos

Yes the flame certainl is exceedingly hot. I bubble mine through ordinary methylated spirits and it does small soleering and brazing very well. There is inadequate energy there for anything over about 1.5mm diameter or 0.5mm thick sheet the size of postage stamp however that may be because my Hobby Flame unit is the smaller one in that range.

John Paton 115/03/2019 07:46:42
164 forum posts
6 photos

Yes the flame certainl is exceedingly hot. I bubble mine through ordinary methylated spirits and it does small soleering and brazing very well. There is inadequate energy there for anything over about 1.5mm diameter or 0.5mm thick sheet the size of postage stamp however that may be because my Hobby Flame unit is the smaller one in that range.

John Paton 115/03/2019 07:46:43
164 forum posts
6 photos

Yes the flame certainl is exceedingly hot. I bubble mine through ordinary methylated spirits and it does small soleering and brazing very well. There is inadequate energy there for anything over about 1.5mm diameter or 0.5mm thick sheet the size of postage stamp however that may be because my Hobby Flame unit is the smaller one in that range.

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