Questions tagged [vacuum]
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47
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Why do Nescafe's (and others'?) instant coffee jars have an inner seal with no “grip” for easy removal?
For a number of years now, I have been buying instant coffee products. Since the main brand has been Nescafe, this question is specifically about their products, even though I vaguely recall that the ...
0
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1answer
22 views
Calculating the Thickness of a Glass Tube which contains a Vacuum
I am looking for borosilicate glass tubes which can be used to contain a vacuum, so the top is sealed and then there is a vacuum pump at the bottom where the edges are also sealed, effectively making ...
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2answers
65 views
How fast could a Mini Cooper go in a vacuum?
Lord Evulz just stole the Earth's atmosphere. Our hero must race his trusty old Mini - which he had already prepared to be airtight, to ensure the tires do not explode, with pre-packaged oxygen to ...
0
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1answer
29 views
what is the most optimal cost effective diameter of a hyperloop tube ferrying ALL cargo between the US and EU [closed]
what is the most optimal cost effective diameter of a hyperloop housing vacuum tube housing hyperloops that can ferry ALL cargo currently travelling by air and sea to and from the US and Europe? ...
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10 views
Looking to apply very specific amounts a vacuum to a small chamber in fractions of inches of mercury to manipulate a diaphragm.
I was considering having the container sealed with a one-way valve to apply the vacuum. I then considered that I might have a vacuum Supply chamber connected between the vacuum generator and the ...
0
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18 views
Proper name for this weld adapter/sleeve/stub
I'm studying the design and construction of viewports for vacuum systems. Usually, the window is bonded to a welding ring, which is then welded to a stainless flange. (See the cross section below for ...
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0answers
17 views
Are most vaccum pumps isothermal?
Because adiabatic processes would lead to a high temperature rise due to the high reduction in pressure (from 1 atm to roughly 0 atm).
2
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0answers
17 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 ...
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36 views
Is it possible design a portable high powered vacuum cleaner from a 12V DC motor?
I am currently designing a device that can pick up 20 kid's plastic balls from one box and transfer them all into another box. I have decided to use a vacuuming method to vacuum up the balls as my way ...
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0answers
70 views
Solid-liquid separation of a crystal slurry
Let me preface my question by saying I am a recent chemical engineering graduate and apologize if my inexperience shows.
I have designed a batch process which results in a water slurry stream ...
0
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0answers
20 views
Which diffusion pump oil specification indicates pump temperature for max vacuum?
Of the diffusion pump oil specs listed below, which indicates the temperature the diffusion pump needs to operate at for maximum vacuum pull?
Flash Point, Open Cup: 220°C
Boiling Point @ 0.06 ...
0
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0answers
20 views
giga/tera hertz timer? super fast spinning disc?
How would I go about detecting a very small amount time dilation
I want to accelerate something and measure the time dilation even if I reach 1km/s time dilation is very small but it looks just ...
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0answers
17 views
Technical name for vacuum float liquid shutoff valve?
I am working on a "maker" hobby project involving a vacuum/blower motor. I want to make sure that if the suction pipe is accidentally (or intentionally) placed in water that the liquid will not be ...
2
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0answers
30 views
Dense, non-conductive UHV compatible material?
I'm not sure if this sort of question is appropriate here or not so please let me know if not!
I am designing a UHV vacuum system with a few interesting requirements. Inside of the vacuum chamber ...
5
votes
1answer
67 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
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1answer
43 views
deep vacuum in the 19th century
Nowadays deep vacuum pumps are fairly expensive, so I'm wondering: how could people reach the deep vacuum required for crookes tube or Geissler tubes in the 19th century ? (I'd be interested in ...
1
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2answers
50 views
Low cost feedthrough for an acrylic vacuum chamber
I am currently building myself a "hobby" vacuum chamber from 1 inch tickness acrylic sheets (I am very aware that acrylic is not the proper material). Inner dimensions of the the chamber is 40x40x40mm....
1
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2answers
865 views
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 ...
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0answers
16 views
Matching Output of Two Old Ring Compressors using Larger Single Unit
Disclaimer: I am new in the design of any fluid systems, however the selection of these units is critical for the electrical design I am responsible for this system, so please excuse me if my approach ...
1
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2answers
219 views
Inlet/outlet of a fridge compressor
I'm attempting to convert a fridge compressor into a vacuum pump, but it got me confused. There should be one inlet and one outlet I believe, but instead I have three, with the third being connected ...
0
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3answers
54 views
Vacuum Pump Issues
I seem to be having an issue with my little vacuum chamber I am building where I can only reach a base pressure of 6,000mTorr which is pretty high and am trying to figure out what is wrong. I have a ...
1
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2answers
63 views
Usticking two glass elements fused by vacuum
I have an interlocking set of parts (1 and 2) which are used under vacuum. The last time I used it, the interface was wet with a mixture of water and ethanol. When the vacuum was removed, the two ...
2
votes
1answer
45 views
What is the formula to work out time to remove water from an open vessel with vacuum?
We have an open container sitting at 1000mm off the ground and a receiver tank sitting one metre above it. Container holds 400l of water and is connected to the receiver by 80mm id pipe. I was ...
2
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0answers
54 views
Generating a plasma via induction coil
I am trying to see if I can generate a plasma from an induction coil that is wrapped around a glass jar under vacuum. Tons of induction coil heatering circuits are on ebay for forging that can supply ...
5
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2answers
94 views
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 ...
1
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1answer
220 views
How to backfill vacuum chamber with low pressure gas
I have a vacuum chamber that I would like to backfill with 15 mTorr of argon. The problem with accomplishing this is that most pressure regulators can't do pressures that low. Are there regulators ...
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0answers
28 views
Proper way to power/use a vacuum cylinder?
I'm considering using a vacuum cylinder in my project (like these ones) to lift sheets of cardboard, but being new to mechanical engineering I'm not at all sure what I need to attach to operate one, ...
0
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4answers
151 views
How to quickly equalize pressure in a low pressure container?
Background: This is for a science project I'm creating where I use an airpump connected to a sealed 5gal pail bucket to create a vacuum. That vacuum is then connected to water source to "suck" liquid ...
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2answers
90 views
How does electricity flow through this kind of vacuum tube?
Does the current flow from the bottom left pin to the bottom right pin, or from the bottom pins to the cap on top?
4
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2answers
192 views
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 ...
3
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3answers
758 views
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. ...
0
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2answers
41 views
Vacuum vessel at 10mbar with a diaphragm pump: do I need a venting valve?
I'm working my way through learning vacuum technology.
I have a 10l vessel which I want to evacuate to < 10mbar. I'll use this diaphragm pump.
Do I need to add a (manual) venting valve to the ...
1
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1answer
40 views
Are “Imperial Eastman” compression connections sized the same as regular imperial connections?
I have some high pressure and vacuum lines off of a tool from the 1980s and they are labeled as, for example, "3/8 imperial - eastman," which seems to be different from how normal compression ...
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2answers
111 views
PD pump type for vacuum liquid extraction?
I would like to learn what type of positive displacement pumps are used to remove liquids from vacuum applications. I have been searching for an example application, but it seems to be a rare case.
...
3
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1answer
106 views
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 ...
0
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1answer
34 views
What are some concepts I can look into to aide in creating a 'compression funnel'(?) without the aide of a motor? [closed]
In short I'm designing a 'Humane fly swatter' for my University application into bachelor of Industrial Design.
The idea is to utilise the energy of swatting a fly to capture air through an intake, ...
2
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2answers
2k views
How to regulate a vacuum pump?
I need a vacuum pump to provide at least 21" Hg of vacuum. Looking at the cheap rotary pumps on ebay, this one seems to be way more than fit for the job.
Is there a way though I can regulate it ...
0
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1answer
2k views
Vacuum Pump hg" vs Pa units?
I need a vacuum to provide 21" Hg but looking online many list an ultimate vacuum of 10Pa but 1"Hg = 3300Pa? I know I am missing something and just want to make sure I get it right. Thanks for the ...
2
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2answers
1k views
Series O-ring in Vacuum Application
I am working with a piece of equipment that has a vacuum sealed chamber.
The outer wall (ring) of the chamber is shown in the image below.
This ring is bolted to a bottom plate and a top plate is ...
6
votes
1answer
404 views
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 ...
12
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1answer
250 views
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 ...
0
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1answer
57 views
Spreading vacuum load using stacked perforated sheets
I am thinking of playing around with food in partial vacuum conditions (ie water boiling at room temperature). But, as it is more a curiosity, I'd rather not spend too much money right now. That ...
0
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1answer
465 views
What options are available to create a vacuum with hydraulics? [closed]
What options are available to create a vacuum using hydraulics? I am working on constructing a small planter which needs a vacuum to operate.
Planters operate best at a pressure of 10 PSI. I ...
3
votes
1answer
199 views
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 ...
3
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1answer
315 views
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, ...
4
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0answers
45 views
What is the reason for the instant loss of a vaccum through the sealed glass tube after shuting off a pump? [closed]
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 ...
2
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1answer
7k views
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 ...
