Workings of a vacuum sealer and help identify a mysterious component

Thread Starter

Yami

Joined Jan 18, 2016
291
Hi I opened up one of those food vacuum sealer machines - it has got the function of sealing things stored in a bag or it could seal things in a jar/bottle.
I was hoping to get some help figuring out on how it works. I thought it was going to be pretty straight forward with a motor sucking the air out like a vacuum cleaner - there is a motor with the pipes connected to the vacuum channel (where the bag mouth is placed). However there is also another pipe going from vacuum channel and which splits one end goes into the bottle/jar inlet and then it goes into a mystery component, the pcb marking says "K1". It looks like a motor it has got a small hole. It needs a voltage across its terminals.
I have attached some pictures and a rough sketch of the vacuum lines.
I hope to understand the mechanics behind how the vacuum sealer works. Thanks in advance.
1.jpg
2.jpg
3.jpg
4.jpg
Sealer sketch.jpg
Sealer.jpg
 
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Reloadron

Joined Jan 15, 2015
5,513
I will venture a guess that K1 is a SPDT pressure activated switch. When the vacuum gets down around 5 - 50 millibar (about 0.150 inHg) to (1.50 inHg) it will pulse the sealer heating element. I see as I typed in my slow fashion paulktreg answered the question. :) That's what I figure.

Ron
 

Thread Starter

Yami

Joined Jan 18, 2016
291
Thanks so much for clarifying, I have never come across a pressure sensor before. Is there anyway to activate the pressure switch manually? - earlier I tried blocking the end of the pipe with my finger to see whether there was a change in the motor, the motor didn't stop.
Just thought of some more questions -
1.Why is the pressure switch in line with the bottle/jar inlet?
2.What happens if a bottle/jar is not connected and when the machine sucks air from the bag wouldn't it also be sucking thorough the bottle/jar inlet? It clearly doesn't but how does it achieve that?
 

Reloadron

Joined Jan 15, 2015
5,513
Just as a simple overview Atmospheric pressure, sometimes also called barometric pressure (after the sensor), is the pressure within the atmosphere of Earth (or that of another planet). The standard atmosphere (symbol: atm) is a unit of pressure defined as 1013.25 mbar (101.325 kPa), equivalent to 760mmHg (torr), 29.92inchesHg, or 14.696psi.[1] The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth.The atmospheric pressure link is from our friends at WIKI.

Yes, you can manually switch the switch but you need to place a vacuum on the switch. There are all sorts of vacuum sensors available including some which are a simple switch and some which are very accurate and expensive sensors. Most inexpensive switches are just a diaphragm with one side vented to atmospheric pressure (small vent hole) and on the other side we introduce a vacuum. When a preset vacuum exist the switch will trip. In your image the vent hole is pretty apparent.

Vacuum sensors surround us everyday, a good example can be found on the engines of today's automobiles. The MAP (Manifold Absolute Pressure) Sensor is a good common example.

1.Why is the pressure switch in line with the bottle/jar inlet?
It looks to me like the vacuum pump runs to a "T" but without actually really seeing your syatem up close I can't tell but the line off the pump serves as a vacuum manifold so the pressure at any point along the line will be the same.

2.What happens if a bottle/jar is not connected and when the machine sucks air from the bag wouldn't it also be sucking thorough the bottle/jar inlet? It clearly doesn't but how does it achieve that?
Again, less a manufacturer's drawing I can't tell how exactly the vacuum is routed.

Ron
 

oz93666

Joined Sep 7, 2010
737
I will venture a guess that K1 is a SPDT pressure activated switch. When the vacuum gets down around 5 - 50 millibar (about 0.150 inHg) to (1.50 inHg) it will pulse the sealer heating element. I see as I typed in my slow fashion paulktreg answered the question. :) That's what I figure.

Ron
That's very low vacum Ron!! ... the pump pictured could never achieve that .... also would mean a pack one foot square would be pushed with a tonne(wt) of force on each side , enough to crush contents ....

I'm only guessing , but I would think the 'vacuum' might be about 50 millibar below atmospheric pressure ... about the vacum a human can get by sucking a tube .

I have vacuum packed by sucking , the results look very impressive, the contents get more crushed than when using a commercial vacuum sealer ... first seal the bag all but 5mm ... push in a tube , suck and seal
 
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Thread Starter

Yami

Joined Jan 18, 2016
291
Just as a simple overview Atmospheric pressure, sometimes also called barometric pressure (after the sensor), is the pressure within the atmosphere of Earth (or that of another planet). The standard atmosphere (symbol: atm) is a unit of pressure defined as 1013.25 mbar (101.325 kPa), equivalent to 760mmHg (torr), 29.92inchesHg, or 14.696psi.[1] The atm unit is roughly equivalent to the mean sea-level atmospheric pressure on Earth.The atmospheric pressure link is from our friends at WIKI.

Yes, you can manually switch the switch but you need to place a vacuum on the switch. There are all sorts of vacuum sensors available including some which are a simple switch and some which are very accurate and expensive sensors. Most inexpensive switches are just a diaphragm with one side vented to atmospheric pressure (small vent hole) and on the other side we introduce a vacuum. When a preset vacuum exist the switch will trip. In your image the vent hole is pretty apparent.

Vacuum sensors surround us everyday, a good example can be found on the engines of today's automobiles. The MAP (Manifold Absolute Pressure) Sensor is a good common example.


It looks to me like the vacuum pump runs to a "T" but without actually really seeing your syatem up close I can't tell but the line off the pump serves as a vacuum manifold so the pressure at any point along the line will be the same.


Again, less a manufacturer's drawing I can't tell how exactly the vacuum is routed.

Ron
Thanks for the detailed explanation Ron, I'm sorting of getting a clearer picture now.

Again, less a manufacturer's drawing I can't tell how exactly the vacuum is routed.
Hehehe I don't even know the correct terminology or the schematic symbols. But the sketch I made is almost how it is - with the "T" indicated. Where can I get more information about this topic, what is this field called?

Thanks
 

Reloadron

Joined Jan 15, 2015
5,513
That's very low vacum Ron!! ... the pump pictured could never achieve that .... also would mean a pack one foot square would be pushed with a tonne(wt) of force on each side , enough to crush contents ....
I agree, the 5 to 50 is just a number I caught for a food vacuum system online. The 50 mb is likely more realistic.

Ron
 
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