Please do not use your vacuum cleaner to speed up your period

[MillCreek]

https://www.iflscience.com/health-and-medicine/two-women-hospitalized-in-a-week-trying-to-end-their-periods-using-a-vacuum-hose-nurse-says/?fbclid=IwAR1jBKZJV_-ciPmXKM3vuMX7sDkj1Grpf0zArXO8wGkSD8VAF5xOgsTnYqg

https://www.vice.com/en/article/xwn537/period-hoover-menstrual-extraction

Bad things can happen.

And lest you think that men would never do something so stupid: https://pubmed.ncbi.nlm.nih.gov/1529397/

[230RN]

Alan Harper calls his Brenda.

[230RN]

Anyone got a ball-park number for the ultimate pressure of regular household vacuum cleaners, where you plug the intake and let it run?

I no longer have instrumentation which would allow me to measure it directly.

I tried looking it up but the numbers seem to deal with "efficiency" in a normal cleaning situation with a normal flow.  Some sites throw "inches of water" into the variable set, which would be OK since conversion to other pressure systems is easy, but that's intermixed with other things such as power consumption and the like --again, under normal use with normal flow.

Obviously, you plug the intake and the motor speeds up since it's no longer pumping anything*, but what is that ultimate pressure you're looking at, ball-parkish?

Terry, 230RN

* Including cooling air, so don't overdo it.

[zahc]

Atmospheric pressure is about 15psi. A standard vacuum will be able to pull something close to that. Further levels of vacuum are about higher and higher grades of "nothing", but even a vacuum cleaner is close to 1 atm...in terms of macroscopic sucking power all levels of vacuum are about the same.

[230RN]

Atmospheric pressure is about 15psi. A standard vacuum will be able to pull something close to that. Further levels of vacuum are about higher and higher grades of "nothing", but even a vacuum cleaner is close to 1 atm...in terms of macroscopic sucking power all levels of vacuum are about the same.

If I'm reading you right, "close to one atmosphere" means a household vacuum will pull near an absolute vacuum.

If that's the case, why do people buy thousands of dollars' worth of diffusion pumps with LN2 cold traps to get down to 10^{-7 or -8} mmHg?

Maybe I just need more coffee this AM.

[Nick1911]

Oddly enough, I had actually measured this at one point, using a manometer.  A shop vacuum provided about the right about of pressure drop for something I was testing, so I needed to know it's performance curve.  That involved bodging a MAF sensor to an arduino as a quick and dirty flow sensor, and hooking up a manometer with a static pressure probe in the air stream.

Unfortunately I don't still have that data.

[230RN]

Oddly enough, I had actually measured this at one point, using a manometer.  A shop vacuum provided about the right about of pressure drop for something I was testing, so I needed to know it's performance curve.  That involved bodging a MAF sensor to an arduino as a quick and dirty flow sensor, and hooking up a manometer with a static pressure probe in the air stream.

Unfortunately I don't still have that data.

Helpful, but once again, that's with an airflow into the shop vac if I'm reading you right. 

I'm talking ultimate pressure with the intake blocked.  As an educated guess, I'd say 2 or 3 psia (103 mmHg to 155 mmHg or  4" Hg to 6.1" Hg) but I could be way off.

What I'm getting at is what kind of tissue damage can be related to "vacuum cleaner pressures."

Obviously it's worse than a Prom Night hickey.

Terry, 230RN

[Nick1911]

Oh, fine.  Don't say I never did anything for you, Terry.



My craftsman 5 gallon shop vac measures an ultimate pressure of 41.2 inWc on my equipment.

[dogmush]

That's hilarious, Nick and I must have walked out to get a vacuum gauge at the same time.

My Hepa Shop Vac tops out at 8 inHg when deadheaded.




ETA:  To save you the DuckDuckGo: 8 inHg is ~101 inWc.  I was using a Clayton Warthog, 11amp commercial shop vac

[Nick1911]

Well I'm clearly not using a good enough shop vac! 

[230RN]

OK, follow me here.  Assume sea level, assume the only meaningful values are in absolute terms, that is starting from an absolute pressureof 0.0 psia and going up from zero, and not values going down from sea level pressure.

Let us also assume that Pascal pressures are nonsensical to the normal human being as having been highly contrived by the French.

Nick1911:

This is with the left port into the vacuum and the right port open to atmosphere, right?

Atmosphere is about 360" of water, right?

(A) So 41.2" water down from atmosphere =13.1 psia, right?

(B) And 41.2" water up from absolute vacuum  is 1.6 psia, right?

A seems like too high an absolute pressure, and B seems to be too low an absolute pressure.

dogmush:

8"Hg.

That's 11psia.

That sounds a lot more reasonable, despite my guesstimate above as 2-3 psia.

The difference could easily be explained by the different equipment and I now have the ball park estimate I wanted.

Call it 12 PSIA for the typical vacuum cleaner ultimate pressure at sea level with a totally clogged intake and no leakage due to hair.

Ta-dahhh!  Thank you, thank you all. You can leave donations with the attendants at the door.

Terry, 230RN

[Nick1911]

OK, follow me here.  Assume sea level, assume the only meaningful values are in absolute terms, that is starting from an absolute pressureof 0.0 psia and going up from zero, and not values going down from sea level pressure.

Let us also assume that Pascal pressures are nonsensical to the normal human being as having been highly contrived by the French.

Nick1911:

This is with the left port into the vacuum and the right port open to atmosphere, right?

Atmosphere is about 360" of water, right?

(A) So 41.2" water down from atmosphere =13.1 psia, right?

(B) And 41.2" water up from absolute vacuum  is 1.6 psia, right?

A seems like too high an absolute pressure, and B seems to be too low an absolute pressure.

dogmush:

8"Hg.

That's 11psia.

That sounds a lot more reasonable, despite my guesstimate above as 2-3 psia.

The difference could easily be explained by the different equipment and I now have the ball park estimate I wanted.

Call it 12 PSIA for the typical vacuum cleaner ultimate pressure at sea level with a totally clogged intake and no leakage due to hair.

Ta-dahhh!  Thank you, thank you all. You can leave donations with the attendants at the door.

Terry, 230RN

A is the correct interpretation.  41.2 inWc below atmospheric.  Atmospheric is running around 400inWc right now here, so that means the vacuum is 358.8 inwc absolute, 12.96 PSI.  A different gauge confirmed this. If nothing else, we've established that there is certainly some variance between vacuum cleaners here.

[zahc]

If I'm reading you right, "close to one atmosphere" means a household vacuum will pull near an absolute vacuum.

If that's the case, why do people buy thousands of dollars' worth of diffusion pumps with LN2 cold traps to get down to 10^{-7 or -8} mmHg?

Maybe I just need more coffee this AM.

I already explained. The fancy vacuum pumps we use at work can get vacuum so high that the individual air molecules never touch each other, and just bounce back and forth in the chamber. But the difference in pressure vs. atmosphere is insignificant to more basic vacuum pumps. If you hooked up a shop vac to the same chamber, the actual pressure on the chamber walls would be about the same--about 1 atmosphere. It's expensive to get those last few molecules out. But those last few molecules don't really create much pressure, so if it's mechanical force or suction you are looking for, it's about the same for all vacuum systems. Even shopvacs. If you could generate shopvac-level vacuum in a room, it would implode the room just about the same a if it were diffusion-pump vacuum.

Diffusion pumps are obsolete btw.

[230RN]

^ Zahc, I thought I took that paragraph out.  Anyhow, I used to work in an ultrahigh vacuum laboratory and your later post explained a lot of what you meant in your first post, so thank you.  When I left, mechanical turbopumps were coming into vogue, I guess because "vacuums" down to 10^-8 Torr pressure were no longer needed for the usual production techniques, but I never followed up on that.  I'm also familiar with mean free paths at those pressure levels. So thanks for the "update."

And thank you., Nick1911 and dogmush as well.  I see my original "educated" guess was in fact way off.

Most folks forget that you can't measure a vacuum, only a pressure.  I live at a pressure of 12.5 psi, not a vacuum of 2.2 psi.  We're just letting the equipment do the subtractions for us.

In the True State Of Nature, the zero and the thirty should be reversed in Nick1911's pic of the Winters gauge.  But what the hell, if we're still using "inches," so big deal anyhow.

Terry, 760 minus 230 = 530RN

[dogmush]

The other factor we are failing to consider is intraabdominal pressure.

The damage to internal organs (or likely hood of their removal) is going to be a function of the total pressure differential.  So the shop-vac is a few PSI less than atmospheric, what is the pressure in the abdomen?  The organs in question are below the diaphragm so it should be pretty steady, but isn't there some abdominal fluid in there with a little pressure on it to hold everything?  Skin, when cut, sure acts like it's higher pressure inside than out.

Millcreek, or one of the med folks, can you chime in?  We'll also need the average uterine circumference so we can go from PSI to actual expelling force.

[RoadKingLarry]

The important question is: Did she self chlorinate her (shallow) end of the gene pool?

Is there a Darwin Award category for stupidity survivors that have lost their ability to reproduce?

[MillCreek]

The normal intra-abdominal pressure ranges from 0-5 mmHg and goes up to 5-7 in critically ill patients and even higher in trauma cases.  The dimensions of a nulliparous uterus is 7-9 cm long, 4.5-6 cm wide and 2.5-5 cm thick.

[230RN]

The other factor we are failing to consider is intraabdominal pressure.

The damage to internal organs (or likely hood of their removal) is going to be a function of the total pressure differential.  So the shop-vac is a few PSI less than atmospheric, what is the pressure in the abdomen?  The organs in question are below the diaphragm so it should be pretty steady, but isn't there some abdominal fluid in there with a little pressure on it to hold everything?  Skin, when cut, sure acts like it's higher pressure inside than out.

Millcreek, or one of the med folks, can you chime in?  We'll also need the average uterine circumference so we can go from PSI to actual expelling force.

I dealt with internal pressure on another matter.  "Normal" systolic blood pressure is supposedly around 120mmHg, which is

(120/760) x 14.7 = 2.3 PSI

so take it from there.

But that's what brought up the question in my original post in this thread although unstated:  What's the pressure differential between a person's internal pressure and the "vacuum" cleaner's ultimate pressure.

Calling it 11 PSI as I concluded above, that brings us to

(14.7PSI -  11PSI) + 2.3 PSI = 6 PSI total pressure differential between the person and the vacuum cleaner hose..

(14.7PSI -  11PSI) is the "vacuum" in the vacuum cleaner hose.

Ick.

The area of application is significant, but I guess you can figure about 1.75 in² for a typical hose diameter.

(1.75/2)² X pi= 2.40 in² area .

So 6 PSI X 2.40 in²  = 14.4 pounds of force on that area.

Seems like enough to do substantial damage to a sensitive area.   Lots more than a Prom Date hickey.   I note you can hold a vacuum cleaner hose against the palm of your hand without leaving much more than a reddish area for a couple of minutes.

Beyond that, we get into force distribution over a diaphragm (the skin), and I don't want to go any further.

My original question has been answered:  Pressure in a closed-off vacuum cleaner hose is approximately 11PSI.

Terry, 230RN

[Bogie]

https://pubmed.ncbi.nlm.nih.gov/3966281/

[230RN]

^ Do any of those links provide real pressure data instead of our estimations here?