“ＩＮＤＥＸ”of Multi-cyclone dust collector 1.( How to make a multi-cyclone dust collector)

In the comments to my channel, there are many questions such as "What are the benefits of having multiple cylinders?" And "What will happen to the suction power?" I reply to the extent that I can answer, but this time I tried to summarize the reply contents that will answer the question with a video.
・ Phenomenon occurring in 4-cylinder dust collector.
1. When used at its strongest, the vortex extends to the bottom of the unit (inside the pail), and as a result, it seems that the accumulated dust inside is rolled up.
2. It seems that when a large amount of dust is sucked in, it does not separate well and leaks to the vacuum cleaner side. These are not serious defects, but there seems to be some room for improvement due to suction efficiency issues. So, we started the two-cylinder serialization initiative. I thought that if you use this method, you can prevent the dust that goes to the vacuum cleaner side.
★ Consideration of the result of dividing the 4-cylinder dust collector into two cylinders and connecting them in series.
・ By separating the piping and separating it into primary and secondary, I think that the pressure difference in suction has disappeared. Moreover, since the chamber is the minimum range due to the shielding unit, it may be efficient. The weaknesses of the cyclone unit (listed below) can't be helped by my own power, so I'd like to leave it to someone who has the ability.
・ About dust separation ability.
As you can see from the verification results of the 2 to 4 cylinder dust collectors, the dust outflow to the vacuum cleaner filter is clearly reduced this time. However, due to the biggest drawback of cyclones, the amount of fine dust leaking into the vacuum cleaner filter could not be reduced to zero.
On the other hand, light dust does not go to the inner wall because it has no mass, but it rotates with the air flow and goes down. The airflow that reaches the bottom end is reversed, but of course you will be caught up in it. This is the main reason why micro dust goes to the vacuum cleaner side.
★ Things we must be aware of. (Weakness of cyclone unit)
1. As in the above supplement, even a high-performance cyclone always leaks a small amount of dust to the outside without being able to separate it.
Why does this happen: As already said by manufacturers, the cyclone unit is because the dust in the container rises up and is discharged to the outside when the vacuum cleaner is turned on and off. In other words, when the airflow is not stable enough to centrifuge, the separation capacity is low. In either case, a "different eddy" will occur in the unit. Also, due to the centrifugal separation by wind power, fine particles such as PM2.5 cannot be separated well. Some fine particles will inevitably escape to the outside by Brownian motion. Particles that are too light will deviate from the flow of airflow.
・ If the flow velocity at the inlet is slow, particles will accumulate at the inlet. On the other hand, if the speed is too high, the pressure loss will increase and the particles will re-scatter from the collection box (pail). If the size of the cyclone is increased while maintaining the same shape, the dust collection efficiency will decrease. If the cyclone is enlarged while keeping the same shape, the dust collection efficiency will decrease. The processing of a large amount of airflow is dealt with by a multi-cyclone in which multiple small cyclones are arranged in parallel, instead of simply increasing the size of the device. by Wikipedia. Dust collector Centrifugal dust collector. (Answer "What is the merit of using multiple cylinders?")
2. It does not mean that the suction power increases even if the number of cylinders is increased. (Answer "What will happen to the suction power?") In terms of suction power, it cannot beat the paper carton vacuum cleaner. The source of suction is the connected vacuum cleaner. Even if you use the cyclone unit, it will not exceed the suction power of the vacuum cleaner. Therefore, what you can do is "how to improve the suction efficiency".
・ Why is the cyclone method weak in suction?
That's because most of the suction power of the connected vacuum cleaner is used for the cyclone (power to rotate). A cyclone is a method with extremely high energy loss, and is a special device for separating things that originally have no other effective method of separation, that is, things like powder. In the first place, when the vacuum cleaner works, the suction power is 100% on the vacuum cleaner side, but when it reaches the suction port through the unit and the connection hose, the suction power will decrease. Also, if you increase the number of cylinders, more energy loss will occur due to the unit. If the purpose is suction power, it is better to suck it as it is with a vacuum cleaner. The measure for using a cyclone is how much the air resistance due to the unit, connecting pipe, etc. can be reduced.
The following is omitted. Please translate Japanese.