Fire (combustion) requires three things to \u2018burn\u2019.
\n1. a fuel source (in this case, hydrogen)
\n2. oxygen
\n3. heat (including ignition energy)<\/p>\n
In this case we are dealing with a gas (Brown\u2019s Gas, HHO, BG, HydrOxy, etc.) that IS a perfect (stoichiometric) combustible fuel mixture (of hydrogen and oxygen) so fuel is no problem.<\/p>\n
The BG can be ignited with static electrical spark or by compressing or by raising it\u2019s temperature or with a shock wave or with something as simple as inserting a sharp point into the gas (or a combination of the above).
\nOnce ignited, the combustion provides it\u2019s own heat to self propagate.<\/p>\n
Note: When igniting a torch that is using BG as a fuel, the gas coming out of the torch orifice MUST exceed the open air burning velocity of the BG flame (about 22 fps) or the flame will burn back into the torch itself. \u00a0As long as the gas velocity is coming out of the torch faster than the BG can burn back, you are fine.
\nOnce a BG flame is burning in an enclosed area it accelerates to detonation velocities (> 5000 fps) and the resulting \u2018bang\u2019 sounds like a rife shot.<\/p>\n
NOTE: The BG really isn\u2019t a \u2018thermal\u2019 flame as much as an \u2018electrical\u2019 flame. \u00a0Releasing it\u2019s electrons into whatever it contacts\u2026 Which is why a tiny flame that measures less than 300\u00b0F with an infrared thermometer can melt tungsten at > 5000\u00b0F.<\/p>\n
The point is, if you have inadvertently allowed your torch flame to enter your torch, you are now trying stop the combustion of a high velocity (shock wave) high energy (electrons) gas.<\/p>\n
To stop the combustion of any flame you must remove one (or more) of it\u2019s ignition requirements.
\nIn our case, removing the fuel or oxygen is out of the question, because both are inextricably mixed together.
\nSo our only option is to remove the heat and shockwave.<\/p>\n
I\u2019ve experimented (since 1986) on various ways to reliably stop this combustion.
\nThe traditional torch check valves are useless. \u00a0They are meant to stop combustible gasses from mixing. \u00a0BG is already mixed\u2026 And the BG is burning far too fast for a mechanical device to respond before the combustion is already past.
\nThe traditional torch \u2018backfire\u2019 screen (designed to suck the \u2018heat from the flame and thus \u2018quench it\u2019 is useless because the high energy combustion simply vaporizes the fine screen and the shock wave goes right through it in any case.
\nEven a tightly closed solenoid valve will not stop a BG backfire once the detonation reaches it\u2019s full velocity (in about 2 feet of hose) because the shockwave goes right through the solid metal and \u2018ignites\u2019 the BG on the other side.
\nImagine my surprise when I learned that fact as I was designing systems for automatic shutoff of shapers (CNC controlled torch tables). \u00a0I did solve that issue BTW, using an \u2018air purge\u2019 apparatus.<\/p>\n
Metal wool is a common solution to stopping BG backfires because it does absorb both heat and shockwave\u2026 But it is NOT reliable and is inconvenient. \u00a0You can increase reliability by making sure the wool is wet, so it absorbs more heat and shockwave. \u00a0But for it to work, it needs to be compressed tightly and very wet, so often restricts the flow of the BG. \u00a0Also, fine metal wool is FULL of sharp points and edges which can ignite the BG and finally, BG often has some electrolyte come out with it, which eventually plugs up metal wool filled backfire arresters.<\/p>\n
And FYI, while the BG flame is MADE from water, it does not \u2018burn under water\u2019 any better than any other torch fuel gas\u2026 In fact, if you try it you will almost certainly cause your torch to backfire because the water mass and pressure will slow the gas velocity coming out of the torch orifice enough that the flame will \u2018burn back\u2019 into the torch.<\/p>\n
So\u2026 The ONLY reliable and easily maintained backfire arrestor I\u2019ve discovered (some of which are still operational since 1986) are liquid bath (usually water) bubblers that separate the gas into fine bubbles and bubble up through at least 4 inches of water. \u00a0Such bubblers reliably absorb both the heat and shockwave of the backfire.<\/p>\n
NOTE: even a poorly designed bubbler will not work because the BG shockwave can \u2018jump\u2019 from bubble to bubble, thus traveling down through the liquid and past the bubbler. \u00a0This is why you must have fine bubbles, and enough water depth so that both the heat and shockwave are reliably dissipated.<\/p>","protected":false},"featured_media":0,"template":"","meta":{"_acf_changed":false},"product-resource-group":[97,98,99,100,101],"restricted-resource-tag":[],"class_list":["post-741","product-resource","type-product-resource","status-publish","hentry","product-resource-group-ac50-resources","product-resource-group-ea-h160-resources","product-resource-group-er50-resources","product-resource-group-browns-gas-book-1-resources","product-resource-group-browns-gas-book-2-resources"],"acf":[],"_links":{"self":[{"href":"https:\/\/aquacure-jeffro-dev.linksdev.com\/es\/wp-json\/wp\/v2\/product-resource\/741","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aquacure-jeffro-dev.linksdev.com\/es\/wp-json\/wp\/v2\/product-resource"}],"about":[{"href":"https:\/\/aquacure-jeffro-dev.linksdev.com\/es\/wp-json\/wp\/v2\/types\/product-resource"}],"wp:attachment":[{"href":"https:\/\/aquacure-jeffro-dev.linksdev.com\/es\/wp-json\/wp\/v2\/media?parent=741"}],"wp:term":[{"taxonomy":"product-resource-group","embeddable":true,"href":"https:\/\/aquacure-jeffro-dev.linksdev.com\/es\/wp-json\/wp\/v2\/product-resource-group?post=741"},{"taxonomy":"restricted-resource-tag","embeddable":true,"href":"https:\/\/aquacure-jeffro-dev.linksdev.com\/es\/wp-json\/wp\/v2\/restricted-resource-tag?post=741"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}