Pressure to Blow Out a Candle

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Pressure to Blow Out a Candle

When wildfires occur, wind is a major threat to make them even more dangerous. However, a single breath can blow out a candle. One of the differences is the fuel.

Unlike the forest fire that continues to burn and consume everything in its path, the candle’s gas flame is highly unstable. After fire initially melts the wax, wax is continuously pumped into the wick and turned into combustible gas. Blowing into the flame blows away the gas that is burning. When flame disappears, there is not enough heat left to turn more wax into gas, so the candle goes out.

Blowing Out the Candles (Birthday) | MakingArtFun.com

To blow out the candle, puckering the lips creates a venturi so the airflow is much greater than exhaling or inhaling.  According to Bernoulli’s Principle, as the speed of air increases, the pressure decreases. Blowing against one side of the candle’s flame, creates an area of low pressure. Normal maximal expiratory pressure (MEP) values could be as high as 120 to 150 cm H2O, so the pressure to blow out the candle could be 3 to 5 times this value. However, the impact of air directed at a flame with a small area is sufficient to snuff it out.

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Sinus Pressure – Pop Goes Your Eardrum

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

Sinus Pressure – Pop Goes Your Eardrum

A sinus infection or sinusitis can result in headaches, sinus pressure and other symptoms including ear and teeth pain. There are treatments for sinusitis and immediate approaches for the ears. To relieve the ear pressure, 8 ways to pop your ears, include:

      1. Swallowing
      2. Yawning
      3. Valsalva maneuver
      4. Toynbee maneuver
      5. Applying a warm washcloth
      6. Nasal decongestants
      7. Nasal corticosteroids
      8. Ventilation tubes

Two of these specifically address the pressure aspect.

Diagram of the Inner Ear | Chad Ruffin, MD

Image courtesy of Chad Ruffin, MD

In the Valsalva maneuver, the individual should pinch their nostrils closed with their fingers. With the cheeks in a neutral, or pulled in position, they should blow air gently through their nostrils. This process generates pressure in the back of the nose to help open the Eustachian tube, the passageway that connects the throat to the middle ear.

Inserting ventilation tubes, or pressure equalizing (PE) tubes into one or both ears can drain out excess fluid.

While it might be interesting to know the value of the pressure, in this case, the more important aspect is relieving it.

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The Pressure in an Air Cannon

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

The Pressure in an Air Cannon

A compressed air cannon may sound a little weird, but it’s surprising what a sudden pulse of air can do. For simply having fun, the AirZooka can blow a harmless ball of air up to 20 feet. Also for play is the Zero Blaster that launches 2-to-6-inch diameter non-toxic fog rings, which travel up to 14 feet. The fog allows the user and observers to see the toroid shape of the pressure pulse.

AirZooka Air Gun

Image Source: AirZooka on Amazon

The sudden release of a diaphragm allows pressure to build inside a chamber. With a restriction on the opposite end the pressure is increased according to Boyle’s law (P1 x V1 = P2 x V2).

One do-it yourself website for an air-powered cannon recommends attaching a bicycle pump or air compressor to build up pressure to 50-80 psi on a design that uses water pipe in a sealed chamber with a release valve. Depending on the design, air cannons are also used to launch potatoes, tennis balls and other stuff.

The world’s largest air cannon, built in the Czech Republic in collaboration with the TV show “Wonders of Nature,” can shoot air more than 300 feet. Its effectiveness was demonstrated by knocking down a wall of cardboard boxes. Smoke added to the pulse shows the toroid shape of the moving air.

Popular Mechanics Air Cannon DemoImage source: Popular Mechanics

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The Pressure for Water Conservation

Welcome to All Sensors “Put the Pressure on Us” blog. This blog brings out pressure sensor aspects in a variety of applications inspired by headlines, consumer and industry requirements, market research, government activities, and you.

The Pressure for Water Conservation

A compressed air-assisted flush water tank can consume 20% to 38% less water on average than a 1.6 gallon per flush (gpf) gravity toilet. Pressure-assisted or power flush toilets use a tank-in-tank design to propel additional water (i.e., 70 gallon per minute peak flow) into the bowl with each flush. The pressure-assisted flush system uses the existing pressure energy of the water supply to significantly improve toilet performance and minimize double flushes to clear waste.

In this design, when supply line water fills the compressed air-assisted flush water tank, the air is trapped and compressed. The air pressure builds until it is approximately equal to the water supply line pressure. At this point, the water flow stops and the compressed air-assisted flush water tank is ready for the next flush. Since it uses the same basic water supply pressure (20–25 psi or higher) as a conventional gravity-fed toilet, the developed air pressure is 20–25 psi or higher (minus the height of the water in the gravity-fed tank). The increased pressure pushes waste up to 33% further down the drain than the recommendations set by the American National Standards Institute (ANSI).

Uncompressed vs compressed air mechanism. Image courtesy of Flushmate.

Uncompressed vs compressed air mechanism. Image courtesy of Flushmate.

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