# SCREW CONVEYOR

## These are employed in transportation of grain material (cereals, oleaceous plants, grape) and farinose components (flour, corn meal, fodder, cement, chalk, sand, etc.).

Its construction ensures its smooth and quiet running and an excellent degree of sealing. The direction of transport may be on one side, “one-way” or in both directions, “reversible”.

The movement of the transported mass may be simultaneous or separated-reversible. These conveyors are made in a trough version and are able to transport a mass with a corresponding correction of the number of revolutions up to a 15-degree angle.

The formula for determining the conveyor’s speed is:

**v=((dx3.14) x n))/60 (m/sec)**

d – screw diameter (m)

n – number of revolutions (min-^{1})

In the transporting process, it is possible to have ventilation of the crawler conveyor with a specific quantity of air, as shown in the table.

The formula for the crawler conveyor is:

**Q = 47 x D ^{2} x S x n x f x Ym x B (t/h)**

D – diameter of the spiral (m)

f – degree of loading

Ym – the specific weight of the bulk

B – correcting factor depending upon the angle of the crawler conveyor

f | 0 | 5 | 10 | 15 | 20 | 25 |

B | 1 | 0,9 | 0,8 | 0,7 | 0,65 | 0,6 |

For the selection of power of the crawler conveyor we recommend the formula:

**P _{0} = ((1,2 x Q) /367 )) ( L x U_{0} x + H ) (KW)**

L-horizontal length of transport (m)

U_{0} – characteristic of the transported bulk(for grain and oleaceous plants U_{0} = 3; for farinose components U_{0} = 2.8 while fir cement, plaster and sand U_{0} = 4 )

H – height of raising or lowering (m)

Power gotten in this way is necessary to divide with the degree of useful action and accept it for the first bigger power of drive reductors.

**P = P _{0}/0.85 (KW)**

Type | a | b | c | d | e | s | L max |

SC 150 | 156 | 170 | 170 | 150 | 85 | 150 | 42 |

SC 200 | 206 | 220 | 220 | 200 | 110 | 200 | 38 |

SC 250 | 256 | 270 | 270 | 250 | 140 | 250 | 36 |

SC 300 | 300 | 320 | 320 | 300 | 165 | 300 | 32 |

SC 350 | 360 | 370 | 370 | 350 | 190 | 350 | 25 |

SC 400 | 360 | 425 | 425 | 400 | 220 | 400 | 20 |

SC 500 | 400 | 525 | 525 | 500 | 270 | 500 | 16 |