Is an electronic vacuum necessary for creating a vacuum in a vacuum container?

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Discussion Overview

The discussion revolves around the effectiveness of using a hand pump versus an electronic vacuum pump for creating a vacuum in a vacuum container. Participants explore the challenges faced when using a hand pump, including its inability to achieve a sufficient vacuum level for specific applications such as food preservation and sound testing.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Exploratory

Main Points Raised

  • One participant reports that their hand pump creates a vacuum in the tube but fails to create a vacuum in the vacuum container.
  • Another participant suggests that the issue may relate to the position of a non-return valve in the system.
  • Some participants express doubt about the hand pump's ability to achieve a high vacuum level, with one noting that it may not be designed for large volumes.
  • There are inquiries about the level of vacuum desired, with one participant specifying a target of close to 99% vacuum.
  • Participants discuss the possibility of using a liquid to enhance the seal of the rubber lid on the vacuum container.
  • Suggestions are made to check the gauges and ensure valves are functioning correctly during the vacuum process.
  • One participant proposes using a bicycle air pump to initiate the vacuum process before switching to the hand pump.
  • Another participant shares measurements from their own pump, indicating it cannot achieve the desired vacuum level.
  • Concerns are raised about the safety of using oil in vacuum pumps for food preservation.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the effectiveness of the hand pump versus an electronic vacuum pump. There are multiple competing views regarding the best approach to achieve a vacuum, and the discussion remains unresolved.

Contextual Notes

Limitations include the uncertainty about the specific capabilities of the hand pump and the vacuum container, as well as the lack of clarity on the necessary conditions to achieve a proper vacuum seal.

paradisePhysicist
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Hi I purchased a vacuum container on amazon, the type with the glass and rubber lid. I didn't want to spend a bunch of money to buy an electronic air vacuum so I just bought a hand pump instead. Only problem is the hand pump doesn't seem to create a vacuum, even though I verified the hand pump does create a vacuum in the tube itself.

The manufacture told me that the vacuum container is not defective, and that I just must buy an electronic vacuum instead of a hand pump or else it will not create a vacuum. I am wondering is this a common occurrence, and if so, which electronic vacuum should I buy? Ideally it should be cheap and also able to do other things, such as blowing air for cleaning dust from computers.

Another thing I thought of is to somehow put tinted air into the vacuum container, the tinted air would look different from the regular air in order to see what exactly is going on. I just thought of this though and not sure what is the cheapest way to tint air. I thought about boiling water but I don't want to risk damaging the device.
 
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paradisePhysicist said:
Only problem is the hand pump doesn't seem to create a vacuum, even though I verified the hand pump does create a vacuum in the tube itself.
Can you provide links to the vacuum container and to the hand pump.
It may be as simple as the position of a non-return valve.
 
paradisePhysicist said:
I just bought a hand pump instead.
What level of vacuum do you want to pull? What is the application?

I had one of those type of hand pumps and used it for many years to bleed the brakes on my motorcycles. They are not made to pump down a large volume like the vacuum jar you have.
 
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berkeman said:
What level of vacuum do you want to pull? What is the applications?

I had one of those type of hand pumps and used it for many years to bleed the brakes on my motorcycles. They are not made to pump down a large volume like the vacuum jar you have.
Ideally close to 99% vacuum but it doesn't even seem to do anything, after dozens of pumps there is no pressure change. If the hand pump is not strong enough to initiate a vacuum seal, maybe there is some kind of liquid or something I can put on the rubber to create more of an air tight seal? The application is I want to test the effect on sound and also foods.
 
Pull a vacuum with the hand pump connected to the chamber, while you watch the gauges.
Do the gauges agree? If they disagree, check that the valve between the vacuum pump and chamber is open and free to pass air. Check the other valve is closed.
Because the handpump is small it will take quite a bit of exercise to pump out the chamber.
 
You have 346 cubic inches of molecules of air, increasingly hard to catch and remove from the container, by using an increasingly inefficient pump that has a displacement per stroke of a fraction of an inch.
Perhaps your most practical solution is an electric mini oil-less vacuum pump.
 
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paradisePhysicist said:
Ideally close to 99% vacuum
berkeman said:
What is the application?
 
Baluncore said:
Pull a vacuum with the hand pump connected to the chamber, while you watch the gauges.
Do the gauges agree? If they disagree, check that the valve between the vacuum pump and chamber is open and free to pass air. Check the other valve is closed.
Because the handpump is small it will take quite a bit of exercise to pump out the chamber.
How do I pull a vacuum, I am not sure what you mean. I cannot get a vacuum to start in the first place. I have tested that the hand pump is working and the gauge is working, I closed the valve to the main vacuum area and the hand pump was able to create a vacuum in just the tube.
 
  • #10
Lnewqban said:
You have 346 cubic inches of molecules of air, increasingly hard to catch and remove from the container, by using an increasingly inefficient pump that has a displacement per stroke of a fraction of an inch.
Perhaps your most practical solution is an electric mini oil-less vacuum pump.
Hmm which model do you recommend?

Also I looked on the amazon link but didn't find where it lists the displacement per stroke of the hand pump. I got into it with the mindset of "however many strokes it takes" but didn't expect nothing to happen after 50 strokes. I was expecting it to maybe take 500 strokes but notice a change after 50.
 
  • #11
berkeman said:
What is the application?
To test audio and various foods to make food last longer. I am looking for an oil-less pump because I am not sure if the oil is safe for the foods.
 
  • #12
paradisePhysicist said:
To test audio and various foods to make food last longer. I am looking for an oil-less pump because I am not sure if the oil is safe for the foods.
Do you mean like this?

1621698147494.png

https://spy.com/articles/hacks/kitchen/best-vacuum-seal-food-bags-256242/
 
  • #13
paradisePhysicist said:
Hmm which model do you recommend?

Also I looked on the amazon link but didn't find where it lists the displacement per stroke of the hand pump. I got into it with the mindset of "however many strokes it takes" but didn't expect nothing to happen after 50 strokes. I was expecting it to maybe take 500 strokes but notice a change after 50.
Sorry, I have no experience with that type; only with bigger oil vane vacuum pumps.
You may need to prime the manual pump with some pre-vacuum, since the thing contains a check valve that seals better with some pressure differential.
 
  • #15
Lnewqban said:
Sorry, I have no experience with that type; only with bigger oil vane vacuum pumps.
You may need to prime the manual pump with some pre-vacuum, since the thing contains a check valve that seals better with some pressure differential.
Hmm how would I do that, the tube thing I did earlier but then immediately open the valve?
 
  • #16
paradisePhysicist said:
Hmm how would I do that, the tube thing I did earlier but then immediately open the valve?
If you have a bicycle air pump, you could try this:
https://www.wikihow.com/Make-a-Vacuum-Pump
 
  • #17
  • #18
paradisePhysicist said:
Hmm, how much vacuum would that create, could you get 99% vacuum with this?
I don't believe so.
But you could initiate the process with it and then switch to the hand pump you have.
For achieving real high vacuum level, you will need an electric pump running for some time, so all humidity is eliminated.
 
  • #19
  • #20
I have one of that style pump, here are the measurements I just took:

Bore: 0.75in (estimated)
Piston area: 0.44sq.in.
Stroke: 0.95in.
Displacement: 0.42cu.in.

Vacuum pump alone:
1st stroke: -570mmHg
2nd stroke: -680mmHg
3rd stroke: -720mmHg That is maximum vacuum of bare pump.

Vacuum attached to approx. 910ml container:
100 strokes: -400mmHg
200 strokes: -640mmHg That is very close to maximum, needle barely moved.

Conclusion: That pump can not get even close to your target. :cry:

Cheers,
Tom
 
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  • #21
Lnewqban said:
I don't believe so.
But you could initiate the process with it and then switch to the hand pump you have.
For achieving real high vacuum level, you will need an electric pump running for some time, so all humidity is eliminated.
That is a clever suggestion, will try that, thanks.
Tom.G said:
I have one of that style pump, here are the measurements I just took:

Bore: 0.75in (estimated)
Piston area: 0.44sq.in.
Stroke: 0.95in.
Displacement: 0.42cu.in.

Vacuum pump alone:
1st stroke: -570mmHg
2nd stroke: -680mmHg
3rd stroke: -720mmHg That is maximum vacuum of bare pump.

Vacuum attached to approx. 910ml container:
100 strokes: -400mmHg
200 strokes: -640mmHg That is very close to maximum, needle barely moved.

Conclusion: That pump can not get even close to your target. :cry:

Cheers,
Tom
Hmm that's unfortunate, thanks for the data though. Id assume the vacuum would be even less in a larger gallon sized container.
 

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