Balanced rotary valve, connects exhaust fan, forming exhaust filter device, used as dust collector. A lëu bï ya looi ka kɛ gas solid separation equipment ye kɛ̈ɛ̈r ye kɛ̈ɛ̈r ye kɛ̈ɛ̈r ye kɛ̈ɛ̈r. A tɔ̈ɔ̈u ka tɔ̈ɔ̈u ka tɔ̈ɔ̈u ka tɔ̈ɔ̈u ka tɔ̈ɔ̈u ka tɔ̈ɔ̈u ka tɔ̈ɔ̈u ka tɔ̈ɔ̈u.