Blade effective length

It is possible to consider that the corpuscle in twirled shovels of an air swirler will be separated, if it attains a wall of blades. This condition allows to design effective length of blades h m which the corpuscle of the set size is separated (Figure 5.2). 

All calculations obtained earlier are fair at a direction of rotation of blades a<90°. Results of calculation for a>90° show that the effective length of a shovel is slightly less than at a heading a<90°. 

On the basis of the obtained results it is possible to define effective length of twirled blades of the air swirler, necessary for trapping corpus-... 

Calculation on the treated equations has shown that in the accepted limits of change of criterion of Stokes, speed of gas in shovels and angular speed of twirl of an air swirler magnitude of effective length of blades are negative. 

A particle path Criterion of stokes Effective length of blades Operating conditions The absolute motion The kinetic energy... 

The significance of this centrifugal effect is that if can cause a series of fairly stable vortices to be set up between and travel with the blades. Figure 11 shows this effect. This implies that the outer dimension of the vortex is equal to the gap width H and that the mixing length L lies somewhere between H and 2H. Because this is about a tenth of the distance between the blades, the heat transfer should be increased by a factor of 2-3. 

Chipper A machine which reduces logs and tree length wood to small chips by means of a rapidly rotating drum or disc, carrying a series of blades. The chips usually leave the cutting device in an air-stream induced by the fan effect of the chipping mechanism and are thus automatically conveyed into transport vehicles or stockpiles. Power requirements are around 300 horsepower for a machine capable of chipping around 25 ton/hours. 

Although the effect of the mass of the impeller is easy to take account of in air, little notice has been paid to m, , the associated added mass of liquor, which is the amount of liquid that effectively vibrates with the impeller, so increasing its inertia and reducing its natural frequency (and thus critical speed). The general subject of added mass is researched in, and applied to impellers in. The added mass of an impeller has been determined as a coefficient multiplied by the mass of liquid contained within a cylinder of diameter equal to the impeller diameter and of length equal to the projected blade width ... 

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