Just imagine the amount of torque that not only the engine has but the fan as well that would incredibly hard to stop while running without using emergency stop
Emergency stops exist on machines like this but they are highly impractical. If something bad happens and the whole thing still runs, there is no point in stopping it. Stops are also always slow, even with active braking.
That's a very cool fan indeed yet it seems kind of strange having the top half open like that I would think the entire blade would be enclosed in a safety cage
That fan blade is so big, the outer edges of the blade are traveling a lot faster than the axle of the motor that's driving it! I would want that big steel cage there in case something breaks off one of the blades and goes flying, wonder why they only half covered it with mesh protection?
i wonder what the specs are on this blower and is this the only fan for the whole tunnel? i would bet this beast at full speed can make some strong wind
I don’t understand the design of this thing, there’s no curvature in o the blades which imply a centrifugal design but the case and everything else isn’t shaped for that either. How does this work? Looks like it would just spin around and create a lot of noise / turbulent air lol.
@@moonprofilepiclol454 Care to elaborate a bit genius? I probably have more time researching and training the aerodynamics and effects of propellers than you'll have in 10 f'ing lifetimes, but sure - unleash your childish youtube zing. The blades AREN'T curved (fine, easier to build) but the blades appear to have nearly two perpendicular surfaces, one of which is in-line with the rotation, which would hint at more of a centrifugal design. With the lighting and camera angle, it's impossible to tell - hence my confusion. If it was a typical fan-type circulation pump, you'd expect a medium-coarse pitch fan blade. Again, feel free to clarify since you obviously know far more about this installation and its engineering specifications than I ever will.
I would say that's not the nominal speed of the impeller, seems too low. Nominal is 132 cubic M /sec (279692.16 cfm) from museum picture in this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dv0BjHNK5W8.html . I think the motor is just for demonstration purposes. Seems to small also for the nominal job. It's a Walker fan impeller. They were commisioned in 1934.
[variable frequency drive intensifies] I'm actually wondering if they hadn't run the optimization routine yet - normally the system will be really loud like this and efficiency may be off till you let it autotune
Most of the noise seems to be from the variable frequency drive, that's the high pitched buzzing, then there's the transmission noise the lower humming noise. The fan itself is almost silent.
I'm glad to see that I don't live in the only country that fills a fan chamber up with people that have no idea what they are looking at, stick shiny yellow hardhats on them, and start the fan. Well done but wow that gearbox is noisy.
I wonder if they 'jog' the motor a few times first as test for fan obstruction or a warning to anyone in the plenum to be prepared. Certainly a fair bit of lash in the transmission.
You have no idea what you're talking about yet you're criticising them? That isn't gearbox noise you're moaning about, it's the VFD's carrier frequency. Certain lifts, trains and trams make that exact same noise.
We have VFD speed controlled trams in Adelaide Australia, they totally smash AM radio broadcasts as well, all you get is a modulated high pitched whine through the radio as the tram goes past.
wow!! Id love to see that... what was on the other side of the fan? and where does it lead.? and how many RPM's does that fan run at. ? Very cool though
The motor is being driven by a VFD (variable frequency drive) and the carrier wave / pulses to "imitate" the wave form (goes from 1 to 50hz slowly for motor "soft start). These pulses cause ringing and harmonics in the motor windings / magnets and vibrate causing the shrill sound.
Under 35, even. I counted approximately 25RPM, when it was full speed (Count the seconds it takes for one blade to do one full revolution, convert from seconds per revolution to revolutions per minute)
I'd appreciate if you could throw that link at me if you could find it. Pretty interesting stuff. Wouldn't be entirely surprised if it could make it up to 60
