Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [compressed-gases]

53 questions
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Why was Freon used in spray cans before it was declared a threat to ozone?

I've heard that in the past, spray cans (aerosol cans) contained Freon. I found that the Montreal Protocol made the usage of Freon illegal due to its effect on the ozone layer, but I can't find the reason for why Freon was used in the first place. I…
Physther
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Air compressor that doubles as a pneumatic motor?

I am working on a compressed air energy storage system. The size and weight of the system are heavily constrained; nothing should (ideally) exceed a few pounds. For this reason, I would like to store the energy (compress the gas) and extract the…
MikeJava
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What are the advantages of chemical oxygen generation over compressed tank storage?

Chemical oxygen generation (COG) is used in commercial airliners to supply emergency oxygen to passengers and crew if the plane is depressurized. Weight for weight it produces far more oxygen than compressed oxygen tanks. I read the original paper…
Leavenotrace
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Velocity of flue gases through a pipe

I was wondering if there is any equation that helps to calculate flue gas velocity through a pipe? Can I use the Poiseuille Equation to solve this problem by assuming the flue gas is acting as a newtonian fluid? The pipe diameter is 3.66m, change in…
user510
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Time-rate of change of P and T in a pressurized rigid volume with a hole in it

I am trying to model the time-rate of change of pressure and temperature of a gas being held within a pressurized rigid volume as it escapes: an unsteady, open system with no heat transfer. Most examples of an open system provided in-class and…
J. Day
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Is it possible to increase the heat output of a gas stove by connecting two gas supply canisters to it at the same time, and is it safe to do so?

Here's a typical outdoor gas stove: It is fed by a low-pressure gas supply in the form of a camping cartridge or via an LPG cylinder connected to a low-pressure regulator (around 30mbar) like this one: My question is: is it possible to increase…
WackGet
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gas regulator exhaust gas during diaphragm adjustment?

On my air tool compressor or scuba gear you can see or hear a diaphragm regulator sloughing off a tiny amount of gas to the atmosphere when you adjust the regulator down. Does a natural gas regulator do the same if there is variation in the supply…
Andyz Smith
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Advice on Literature pertaining to transient pipe flow with heat transfer and friction

For a project I am working on I need to model the flow of argon in a long pipe. The flow is transient in nature since the tanks and regulator from which it enters cause the mass flow to change. Moreover, it reaches low temperatures due to the…
Filip Gajowniczek
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What is the maximum possible compression with fuel injection in a gasoline combustion engine?

Maximum possible compression in a gasoline engine was originally determined by knocking in engines with carburetor. With fuel injection the fuel could be injected after compression and thus eliminate knocking. How high compression does fuel…
David Jonsson
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Why no hydraulic piston gas compressors?

I've been looking at solutions to compress gases and getting stunned by the cost and maintenance requirements of existing systems to fill cylinders (whether for SCBA or chemical storage) to 2000-4000psi: The cost of entry is over 4 figures, with…
feetwet
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Valve for mini CO2 gas canister?

I am in the process of helping my son design a sort of model of the Bloodhound SSC car for his school project, using balsa wood, model aircraft wheels, etc... It doesn't have to a like of like, but vaguely resemblant so that you can tell what it is…
am304
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Do pressurised cans still pose a risk to bursting in normal conditions, but after being exposed to heat?

We're planning on shipping some items from the US to Australia as you cannot get them here, that being: https://www.chewy.com/sentry-stop-that-noise-pheromone-dog/dp/56486 I have been in contact with a freight forwarder who can ship them to…
Brett
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Injecting CO$_2$ into water: how does injection work?

I've been wanting to design my own water carbonation device for a while. For reference, I've been looking at devices like the Sodastream, which injects pure CO$_2$ into water to dissolve it with up to seven injections per bottle. The more…
asoftbird
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Parts needed for controlling vacuum line pressure with pressurized nitrogen

I'm trying to assemble a simple setup where a line which is typically under vacuum can be pressurized by an external nitrogen supply, with this pressure regulated to less than 1 bar absolute (let's say 700 mbar). This nitrogen supply comes from the…
Gino
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How to balance flow and pressure in nitrogen purged chambers?

I have an instrument that is technically a humidity controlled chamber. It measures how much moisture is picked up by the sample through a microbalance(Zone 1). Nitrogen gas flows from zone 3 and split into 2 chambers (by a union Tee ) in Zone 2.…
Zaid assaf
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