4 ms·
This is blowing my mind, probably envisioning the wrong size of the candle for this kind of output: > The candle supplied by MineARC Systems burns for approxim
by ck2 4y ago
This is blowing my mind, probably envisioning the wrong size of the candle for this kind of output:
> The candle supplied by MineARC Systems burns for approximately 60-90 minutes, producing 2600L of oxygen. This amount can provide approximately 20 hours of breathable air for four people. An oxygen candle cannot have its oxygen production regulated or halted and once ignited; it produces oxygen at a rate of approximately 28 Litres per minute until it is exhausted.
Oh I see now, it's that big metal cylinder on the floor, they are going to pour the powder into it and ignite?
https://minearc.com/wp-content/uploads/2021/01/cristel-training-underground-11.2018-1.jpeg https://minearc.com/wp-content/uploads/2021/01/cristel-train...
- joosters 4y agoI'm also struggling to get an idea of the size of the candle; the article gives no information and it's unclear if the photos of the demo are using the same product as described in the text. Surely something that can produce 2600L of oxygen must be pretty big? It's a shame that the page gives no clue as to the size and weight. Another page details a 'rugged oxygen generator' - https://minearc.com/products/emergency-response-products/rugged-oxygen-generator-rog/ https://minearc.com/products/emergency-response-products/rug... that produces 90L of oxygen over 15 minutes, and that is 115mm x 284mm, weighing 2.3kg. Confusingly, the PDF of the product specs shows that it comes with a mask - so 90L of oxygen is for one person, for just 15 minutes here? And if used with a mask, is it actually pure oxygen being produced, or breathable air (where does the nitrogen come from?) I'd love to know more, but the website doesn't tell us.
- aspectmin 4y agoAverage human: breathes approximately 7 liters per minute of air, give or take @ 21% oxygen. Maybe 22L of oxygen under normal respiratory demand. More if under stress of course. At 100% oxygen that’s 105L of O2? So guesstimating almost 100% O2? Source: am paramedic, not doctor or respiratory therapist.
- kzrdude 4y agoBreathed air is diluted right, to some lower % of oxygen content, but it needs to be in the calculation.
- urban_winter 4y agoExhaled air is about 17% oxygen, 4% carbon dioxide. So, as previous poster noted, scrubbing the CO2 is your first priority. You can't breathe air with greater than about 4% CO2 indefinitely. Oxygen levels lower than 15% are also bad. Diving rebreathers are an interesting implementation of these rules in that they are lethal if you get it wrong.
- arrosenberg 4y agoIt's not ignited, this is how airplane oxygen systems work. A phosphorus match provides the activation energy (as heat), which causes the decomposition of Sodium Chlorate (NaClO3) to Sodium Chloride (NaCl, table salt) and free oxygens. The oxygens combine to form atmospheric oxygen (O2).
- nickelpro 4y agoAt standard conditions, a single mole of oxygen occupies 22.4L. The conversion rate from NaClO3 to O2 is 2-to-3, so for every two moles of sodium chlorate you burn, you get three moles of Oxygen, or 67.2L. The molar mass of NaClO3 is 106.44g. So some quick math, to fill 2600L we need 116 moles of oxygen, which we can produce with 77 moles of sodium chlorate. Multiply by the molar mass and we get ~8kg. Sodium chlorate has a density of 2.49 g/cm^3, so an 8kg slug will fit in a 3.2L bucket. 3L of powder gets you 2600L of oxygen, not bad!
- VaxWithSex 4y agoThanks, I attempted to do the calc in my head... and it's been to long, that I learned Chemistry in school apparently.
- nickelpro 4y agoWhat this boils down to is "salt is a couple orders of magnitude more dense than air, so we can fit a lot of air in very little salt". Which is a sentiment I think most people can feel is correct even if they don't know their ideal gas law or whatever.
- manholio 4y agoHe did the math, what a legend.