Engineering Stack Exchange
Engineering Stack Exchange

Questions tagged [vacuum]

73 questions
12
votes
1 answer

Replace mercury with silicone oil in diffusion pump

We have obtained an old mercury-vapor diffusion pump for high vacuum. However, we do not want to operate it with mercury in our lab due to health concerns (which is presumably the reason it was scrapped by the original owner). Instead, we plan to…
dominecf
  • 273
  • 1
  • 5
6
votes
1 answer

How to protect a pressure gauge from condensation in a vacuum steam boiler?

Pressure gauges are protected from steam condensation in a regular boiler by using a siphon where steam condenses and prevents steam from going further up to the gauge. However in a vacuum steam boiler when the boiler is re pressurized after use the…
Manu de Hanoi
  • 285
  • 1
  • 9
6
votes
2 answers

Could a vacuum tank ever be light enough to be boyant in air?

Given futuristic materials, could a structure ever be strong enough to contain a vacuum, yet light enough to provide buoyancy under standard atmospheric pressure? Obviously "futuristic materials" is highly ambiguous because we don't know what exists…
Lorry Laurence mcLarry
  • 238
  • 1
  • 6
5
votes
1 answer

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 apparatus very simple and cheap. The kind of pump used…
Michael Turner
  • 53
  • 3
4
votes
1 answer

Are ABS/PLA too volatile to be used in cryo vacuum?

I need to use a custom part inside high vacuum (cryo vacuum), for example as a shadow mask. If PLA/ABS are not volatile, I could just print the part I need. The question is, are ABS or PLA too volatile to be used in cryo vacuum chambers?
Sparkler
  • 223
  • 2
  • 5
4
votes
0 answers

What is the reason for the instant loss of a vaccum through the sealed glass tube after shuting off a pump?

A pump is connected to a glass tube to evacuate it. The reading shows 0.4 mbar when the pump is on because of a vacuum. As soon as the pump is turned off, the pressure in the tube becomes equal to atmospheric pressure.
Rahul
  • 41
  • 1
4
votes
1 answer

Need help identifying this vacuum chamber flange

I know this might not be the most ideal place to ask this question, but I couldn't think of any place better. I recently purchased a high vacuum chamber setup and have been disassembling it for transport. I removed the hot cathode ion gauge, and…
mes
  • 43
  • 4
4
votes
2 answers

Arduino CNC - which vacuum pump?

I have an arduino powered CNC machine with the Protoneer v3.00 shield. I have a probe setup for auto levelling which works correctly, I get a depth map for the board. But the issue is that this depth map is created to the point at which the bit…
James Elder
  • 141
  • 1
3
votes
1 answer

How thick does an aluminium vacuum cylinder have to be?

Take a hollow aluminium cylinder with outer radius $r$ and length $h$, capped with two circular endcaps. How thick does the aluminium have to be, that is what is the inner diameter of the cylinder, to withstand 1 atm on the outside and 0 mbar on…
user1717828
  • 133
  • 5
3
votes
2 answers

Reverse Suspension Spring

So, in a car either a liquid or a gas gets compressed when force is applied to the suspension, and when the force is removed the gas/liquid tries to expand again which makes an effect like a spring, But could you make the opposite, or does it…
Marius Wanscher
  • 31
  • 2
3
votes
1 answer

Vacuum Pump Power Calculation

This may be a silly question, but I'm not a mechanical engineering. What's the best way to calculate the energy required to reduce the pressure of a gas stream below atmospheric pressure? Obviously you could work out the energy for isentropic…
tom
  • 151
  • 1
  • 1
  • 4
3
votes
2 answers

What is the equivalent of a capacitor in pneumatics?

I am building a desoldering gun. While the pump I am using provides decent suction, I would like a quick powerful vacuum burst to prevent the solder from solidifying in the nozzle rather than in the chamber. I figure there must be the equivalent of…
user148298
  • 158
  • 1
  • 10
3
votes
2 answers

What's the difference between a vacuum regulator and pressure regulator?

When browsing through pneumatic parts, I notice that some vendors specify different components for pressure regulator and vacuum regulators. SMC for example does this. I'm curious why vendors would actually need to differentiate vacuum regulators…
Izzo
  • 209
  • 3
  • 6
3
votes
3 answers

How to design a vacuum climbing robot

I'm trying to design a mobile robot which has to climb over flat 60° inclined wet glass surfaces. I was thinking to use a large vacuum system composed by a large fan connected to a brushless motor. By looking on google, I found this photo: As it is…
Marcus Barnet
  • 139
  • 5
3
votes
1 answer

Liquid Vacuum Filler machine using Venturi Pump

We are currently using a liquid vacuum filler machine that vacuum fills nail polish. There is a Gast 1/4 horsepower motor and a Gast rotary vane pump that according to the gast website pulls 20" of vacuum at a flow volume of 4CFM. I wanted to know…
Steve Hawaii
  • 31
  • 2
1
2 3 4 5