Tekno Training

Impianti intelligenti per un pianeta mig

Tekno Training

Impianti intelligenti per un pianeta mig

Using the toilet flush on the top floor of the Burj Khalifa in Dubai...

2022-01-17 11:00:00

How fast does the water get to the ground floor ???

Imagine being in the Imperial Suite on the top floor of the Burj-khalifa in Dubai, the tallest skyscraper in the world: 828 meters !!

Imagine flushing the toilet ... 12 or 15 liters of water (small button or large button) reach the drain stack and fall to the ground floor.

Which speed the wastewater flow reach? What happens when it arrives at the horizontal pipe section in the basement?

A very high speed water missile that arrives with such force to break any pipe, even the most resistant !!

A very high-speed water rocket that descends with such force that it breaks any pipe, even the toughest!

This is what we would be led to imagine ... but the reality is surprisingly different. It is enough to observe any waterfall to understand that our fears are totally unfounded.

Falling water tends to spread sideways due to friction with the air. Gradually the falling flow widens, nebulizes and slows down its speed! The same thing happens inside a drainage stack:

After the first floors of fall (2-3 floors), the discharge flow ("turbulent flow") tends to widen and adhere to the walls of the stack, forming a so-called "annular flow":

At this point the annular flow, by friction with the walls of the stack and by friction with the central air core, slows down its rate of fall until it reaches a constant value of about 10 m / sec.

Our discharge system is safe! It doesn't matter if we design it for 100, 200, 500 or 1000 floors! There are clearly a whole series of other factors to take into consideration when sizing and choosing the type of ventilation for the stack ... but at least one factor remains constant: the speed of the falling water.



Please note. Source of some images: web



by Marco Colmari