The design guideline for the air suction drawing system with auxiliary air was analyzed,a spunbonding nonwoven system named PADHL1-3200 was designed and polypropylene(PP) spunbonded nonwoven fabrics with excellent pro...The design guideline for the air suction drawing system with auxiliary air was analyzed,a spunbonding nonwoven system named PADHL1-3200 was designed and polypropylene(PP) spunbonded nonwoven fabrics with excellent properties were achieved after many trial runs.On the other hand,the suction air velocity(VA) was calculated and the influence of VA on the bonding strengh of PP nonwoven fabrics was studied as well.It was found that VA is 1.5-2.5 times of the spinning velocity.With the increase of VA,PP fibers become finer and the bonding strength of PP nonwoven fabrics increases as well.展开更多
The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their inst...The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their installation area is demanded to be minimum without losing the high performance. We concentrate our attention on the expansion ratio of the intake as a representative characteristic of the shape of the pumps and investigate the effect of the expansion ratio on pump performance. It is concluded that the optimum expansion ratio ranges in 1.1-1.2 if we take into consideration that the area needed for the installation of the pump should be minimum.展开更多
文摘The design guideline for the air suction drawing system with auxiliary air was analyzed,a spunbonding nonwoven system named PADHL1-3200 was designed and polypropylene(PP) spunbonded nonwoven fabrics with excellent properties were achieved after many trial runs.On the other hand,the suction air velocity(VA) was calculated and the influence of VA on the bonding strengh of PP nonwoven fabrics was studied as well.It was found that VA is 1.5-2.5 times of the spinning velocity.With the increase of VA,PP fibers become finer and the bonding strength of PP nonwoven fabrics increases as well.
文摘The flow structure around the intake of a vertical pump is investigated experimentally and numerically in order to obtain a guideline in designing the optimum shape of the intake of vertical pumps, in which their installation area is demanded to be minimum without losing the high performance. We concentrate our attention on the expansion ratio of the intake as a representative characteristic of the shape of the pumps and investigate the effect of the expansion ratio on pump performance. It is concluded that the optimum expansion ratio ranges in 1.1-1.2 if we take into consideration that the area needed for the installation of the pump should be minimum.
