Appliances and furniture
How a cyclone vacuum separates dust — centrifugal force is v squared over r
Centrifugal force is v squared over r, so a tenth of the radius is ten times the g — but a tenth of the radius is a hundredth of the airflow, which is why the small cones come in rows
This drawing comes from one YAML file. No shape was moved by hand.
Notes in the source (in Japanese)
接線から入れて、中心から抜く。 壁ぎわを回る空気は外へ振られ、中心は逆に上へ登る。重い粒ほど外へ行くので、中心から抜く空気には軽い粒しか残らない。
遠心力は a = v² ÷ r。 同じ速さなら、径を 1/10 にすると G は 10 倍。速さを 2 倍にすると 4 倍。接線速度 40m/s で、径 200mm なら約 1,600G、径 20mm なら約 16,000G。
ところが細くすると、通せる空気が減る(断面積は r² に比例)。だから細いコーンを並列に何本も並べて、本数で流量を取り戻す。
紙パック式とは詰まり方が違う —— 紙パックは溜まるほど目が詰まる。ただし「フィルタが無い」のではない。分離の主役がフィルタではないだけで、モーターの前後には入っていて、手入れを怠れば吸う力は落ちる。
Source (YAML)
examples/gallery/252-サイクロン掃除機の分け方.zumen.yaml
More in this field
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A fridge does not make cold, it pumps heat out — and it throws away more than it took, because the compressor's electricity comes out as heat too
Heating and cooling swap the roles of the indoor and outdoor coils, and the only part that changes is one valve — which is also why a heat pump briefly runs cooling in the middle of heating, to melt its own frost
Hot and cold spots sit 6.1cm apart because that is half of the 12.2cm wavelength, which no cabinet design can remove — so the food is moved instead
A shelf sags with the cube of its span, so doubling the span sags it eight times — and gluing a 40mm rail under the front edge does more than upgrading the board
The same drum has to stay under 1G to wash and reach 335G to spin, which is why it hangs on springs behind a concrete weight rather than being bolted to the machine