Questions tagged [gas]
The gas tag has no usage guidance.
68
questions
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2answers
44 views
Ideal gas law, theory vs reality
I am trying to get an idea of the amount of hydrogen that I can store in some pressurized steel tanks underground.
Based on the ideal gas law PV=nRT
I did a simple calculation
pressure = 200bar
...
2
votes
0answers
16 views
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 ...
0
votes
1answer
16 views
How to contain air ions inside a chamber without loosing their charge?
I would like to create an experiment where I would hold ionized air molecules. Most likely negative O2-1 ions. I am looking for the most appropriate enclosure so that the ions do lose as little of ...
0
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2answers
46 views
Calculating mass of gas in container
Given pressure is directly proportional to density, my understanding is that you can use the pressure of gas in a container to calculate the mass of the gas in the container. My reasoning being;
$p=k\...
1
vote
2answers
51 views
Cheapest way to measure gas flow (mass)?
I understand that there are quite a few fairly simple and cheap methods to measure the flow of gas in terms of volume, allowing you to get a flow rate in terms of litres per minute for example.
...
0
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0answers
19 views
Modeling Friction-reduced Pressure Drop in Natural Gas Flowing along a Horizontal Cylindrical Trunkline (Pipe)
I am seeking some help related to part of a project I am currently working on, where I require to (data-driven) model the pressure drop due to friction for natural gas flowing along a horizontal ...
0
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1answer
47 views
Classic Thermodynamics: Ideal gas question
The question is in the attached picture. I know how to solve the first part of the problem, but the second part confused me a lot.
Now when the oven (system) is unsealed, doesn’t make that an open ...
2
votes
0answers
28 views
Liquid phase gas flow through valve
I have been trying to figure out how to calculate the required dimensions for liquid phase gas through a solenoid valve. Many companies (Swagelok, Bürkert, Asco) provide "Flow coefficient calculators" ...
0
votes
1answer
26 views
Safe, cheap method to dissolve nitrogen in small batches of water (10l)
I am interested in creating a nitrogen infused drink. I want to be able to make small batches of my drink (its not coffee) and testing the market before having to buy expensive equipment.
I think a ...
3
votes
1answer
54 views
Would pumping down (below 0 psi) on a gas cylinder regulator cause it to break?
Would pumping down on a gas cylinder regulator cause the needle of the valve to break since it’s trying to go below zero? Would this also cause a problem with the regulator itself?
I’ve included the ...
5
votes
1answer
64 views
Easily compute a good approximation of heat conductivity of cooled semi-vacuum (water vapor + air)
I am preparing a classroom demonstration about heat, including a demo of how a satellite loses heat only radiatively, since it's flying through a vacuum. I'd like to make the vacuum-production ...
0
votes
1answer
162 views
Programming a gas mass flow controller rig
I'm trying to upgrade a multiple gas flow controller, which must be capable of controlling the mass flowrates of three gases independently through one outlet line to our system, and am in need of a ...
1
vote
2answers
49 views
Is there an optical technology able to measure the temperature of dry air?
Optical IR sensors are able to measure the surface temperature of solids. But is there a range of the EM spectrum that can accomplish the same for measuring the temperature of nitrox (dry nitrogen, ...
0
votes
1answer
35 views
Relationship heat rate with capacity
I am an economist, so please keep replies simple ;)
I am searching for the relationship between heat rate and capacity for gas-fired power plants. Here is what I refer to as heat rate, i.e. the ...
1
vote
0answers
20 views
Equation for temperature of gas at Joule-Thompson Inversion State
Assume that a gas obeys the following equation of state:
$\nu = {\frac{RT}{P}}-{\frac{a}{T}} + b$
Where $a , b $ are constant.
Derive an equation for the temperature at the Joule-Thompson ...
1
vote
1answer
78 views
Which type of sensors to analyze polluting gas from vehicle emissions
I am thinking to develop a remote-sensing applications for vehicle pollutions. In such cases generally expensive optical IR and UV devices are used because more precise. These devices are generally ...
2
votes
0answers
39 views
Oxygen sensors in trace gas environments
Do Oxygen lambda sensors (used in automotive applications) work in trace gas environments?
My requirements for a trace Oxygen gas sensor:
The sensor must be capable of working in an inert gas ...
2
votes
1answer
273 views
What are the differences between compressor stations, pump stations, and booster stations?
I am doing some research on impacts related to natural gas compressor stations. In some states, I've received data for compressor stations alongside other facilities in the oil and gas world. These ...
0
votes
1answer
55 views
maximum capacity factors of combined cycle gas power plants
What is the maximum annual capacity factor that can be expected of a CCGT plant? I see in US in 2015 the average was about 0.56, but can it be higher? I guess it needs some time for maintenance but I ...
2
votes
2answers
244 views
What is a reference that i can use to find the interpretation of a symbol in a gas line schematic?
I have a schematic for some gas lines in a wafer processing unit. One of the symbols which occurs is a circle with an x in it that has the left and right quarters filled in to form two black ...
0
votes
1answer
49 views
Will natural gas or propane generators also run off of methane?
I'm looking at building a sustainable energy project that will convert biogas (methane) into electricity. I haven't found any biogas or methane electric generators for sale. It seems that there are ...
0
votes
2answers
23 views
Measuring gas flow from a low-output device
My lab uses a home-built biomedical instrument that acts as a ventilator for test-subjects. In other words: our device combines nitrogen and oxygen gases and pumps them down the line at a specified ...
1
vote
1answer
67 views
Why is gas pressure specified instead of mass flow?
Clarification: This question is all about the gas supply to the water heater. It has nothing to do with the water supply.
My hot water heater specifies 5.5-10.5 W.C. (water column inches) of pressure....
2
votes
2answers
433 views
Lpg cylinder to compressed air tank
I am building a small robot having pneumatic system. I am using 12v car tyre inflator as my compressor.But i didn't find any 3ltr to 6ltr standardrd air tank. Can i convert my old 3ltr lpg tank into ...
-1
votes
2answers
83 views
why doesn't soda go flat immediately after opening? [closed]
so, soda is under pressure and has gas dissolved in it. But, when you open it, the gas is still dissolved in it. But, if we wait a few hours, the gas has escaped into the atmosphere.
What factors ...
1
vote
1answer
51 views
Is there any option other than a gas welder
I want to repair a dent in a piece of cast iron with brass. I want to fill the site with brass.
For some reason, I want to do it by myself. I can buy an instrument for this work in a limited budget(...
2
votes
2answers
44 views
Can I improve this exhaust gas probe to be immune to pressure changes?
I'm designing a probe to provide a stable and continuous stream of exhaust gas sample to an analyser. The probe has to be inserted into the exhaust for about 20–30 cm to keep outside air from entering ...
0
votes
1answer
49 views
Natural gas boiler Vs. Electric Heater efficiency
If a facility buys natural gas at 8 dollars/Mcf to provide heating from an 85% efficient natural gas boiler, what is the equivalent cost of electricity ($/kWh) for a 95% efficient electric heater?
I'...
1
vote
0answers
53 views
Is there a 5% range CO sensor with a response rate higher than 1Hz?
I'm building a portable emission analyser which measures emissions from a tailpipe, to aid in troubleshooting and tuning an engine. For this, I need a $\text{CO}_{2}$ , a $\text{CO}$, and an $\text{O}...
0
votes
1answer
266 views
Determining gas properties in a steam and air gas mixture
I have a gas mixture (steam and air) contained in a tank.
I know the tank pressure ($P$), temperature ($T$) and the massic air fraction ($x_a$).
I would like to determine the density of both gases ...
0
votes
2answers
62 views
Thermodynamic, ideal gas problem
I already know solution, I just want to understand something in part b.
A vertical cylinder fitted with a piston contains air initially at 120kPa and 100 celcius. The piston is restrained by a set of ...
1
vote
1answer
230 views
What ramping constraints for gas plant - CCGT, combustion and steam turbine?
I am using the publication Current and Prospective Costs of Electricity Generation until 2050 to source ramping constraints for an economic model of three different gas power plants - CCGT, combustion ...
1
vote
1answer
480 views
Difference between gas combustion engine and gas turbine?
I am a non-engineer and I am using a gas power plant data base. Some plants listed are of the type "combustion engine", some of the type "gas turbine", some "steam turbine" and some "combined cycle". ...
1
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0answers
88 views
Creating a “pinhole” small enough to allow only one molecule to pass through
Consider a "cartridge" of sorts. Is it possible to construct a "pinhole" in the cartridge such that only one molecule will pass through at a time? If so, what sort of equipment would I need to ...
2
votes
0answers
43 views
Ambient helium level monitoring
I am looking for a solution to monitor and log ambient He levels down to 50-100ppm.
The detector is meant to be installed in an experimental hall where a large number of Photo Multiplier Tubes are ...
1
vote
0answers
20 views
Spades used in pressure testing PE Pipe lines [closed]
As we all know the industry is heading into PE pipelines in the gathering fields fast. Some applications use DN560-DN1000, and the spades is very heavy and in awkward positions. Is there PE spades/...
4
votes
2answers
91 views
Can cyclonic separators be used to separate heavier and lighter gases?
I'm trying to increase the Helium detection capabilities of a sniffer unit. Could a cyclonic separator, like that used in the oil/gas industry, with enough fluid velocity move the heavier gas ...
3
votes
1answer
107 views
Can mercury escape undectectably from a CFL bulb? or does it have to shatter for the mercury to be liberated?
I read that the mercury vapour inside a fluorescent lamp is pressurized at 0.2% of atmospheric pressure.
Can mercury escape undectably through a small crack in the glass yet still light up? Or will ...
1
vote
1answer
75 views
Helium is leaking through manometer
I have connected a 200 bar helium tank and a manometer to a pressure regulator. The end of the manometer's tube connected to the regulator is leaking. It's attached with anaerobic thread sealant, so I ...
1
vote
2answers
2k views
Diesel or Gasoline? Which one is more dangerous to our health?
I have an overall question that's been bothering me for years. Which is more dangerous for our health, a diesel car or a gasoline car?
This is quite a cliche question and I can find a lot of ...
0
votes
0answers
51 views
Roskam Book equation of dry air density is not clear. I need explanation
Preface:
Roskam in book "Airplane Aerodynamics and Performance" explains (in paragraph "1.1 ATMOSPHERIC FUNDAMENTALS"):
To determne how water vapor affects air density, consider a given volume ...
1
vote
2answers
1k views
How do you prevent ignition of the gas-air mixture before it reaches the burner nozzle?
I believed that the flame propagates over the place where fuel contacts the oxygen. If it contacts a fule+O2 mixture, the mixture inflames as well, and so on and on and on until there is no more ...
0
votes
1answer
541 views
Natural gas mass flow conversion
I have a question about gas valve selection and working out the CV. The equation I have needs the mass flow in kg/hr, but I have been given the volumetric flow rate in litres/minute. How do I go about ...
1
vote
1answer
80 views
Pressure Differential Analysis
In these units: cm³.20μ/m².24hr.atm - (definition) cubic centimeters for a 20 micron film thickness per square meter per 24 hours under a pressure difference of 1 atm.
My question is what does the "...
1
vote
0answers
42 views
How to convert permeation units to molecules/second?
How do I convert $\dfrac{\text{cm}^3\cdot\text{mm}}{\text{m}^2 \cdot \text{day} \cdot \text{atm}}$ for permeation of gas through EVOH to molecules of gas permeating per second as a function of ...
0
votes
1answer
66 views
Understanding Permeation Units
I have encountered a type of unit that I cannot understand. The unit describes the rate of permeation through a substance:(cm^3 . mm)/m^2 . d . atm
Could someone please explain how to interpret ...
-1
votes
1answer
373 views
Highest pressure helium(lifting gas)can be stored at? [closed]
What is the highest pressure possible today?
I have a sketchy idea of using a weather balloon with the lightest possible pressure vessel that can pack as much helium as possible and would like some ...
4
votes
2answers
152 views
Is steel air (argon) tight?
I need to build an air tight system that can hold gas (Argon Gas). I see that most pipes use steel. Is steel tight enough to hold that gas? Argon is very dense, so I think it should have no problem.
2
votes
2answers
7k views
What material is used to make gas pipes?
What is the most common material gas pipes made of?
I read in a unreliable website it's steel, is it true?
Also how good is steel at stopping or slowing down the leaking of gas?
The gas I am ...
5
votes
1answer
647 views
How do gas flow regulators avoid choking?
According to compressible flow theory, a downstream pressure of 0.528 times upstream pressure is sufficient to choke a flow device.
So, how do industrial grade pressure regulators throttle a wide ...
