1. dust aspect : moisture of dust to determine dust velocity and material for tube, dust wood made from brushing, wind velocity 4500-5000 fpm. From sew has many size, wind velocity 400-4500 fpm. Dust made from driving velocity 3500-4000 fpm. Sand dust is at 3800-4500 fpm. If we used lower than 3500 fpm. The remaining in the tube is high, sand dust in moisture such as from iron cast, velocity is 4000-45—fpm./ but to design for mixture at least 30% of dust to reduce moisture of water into filter in some case such as dust that has moisture more than 25% will absorb dust more than 50% so dust with the wind more and also depend on design to 2 parts, dried dust 30% and dust with cyclone entrance before D/C dried dust into 20% from Port before D/C at least 30 times of diameter of main tube.