The cross sectional capacity Mostof the documentation publishedby belt and conveyor manufacturersrefer toa dynamic triangular angle of reposewith angles from 5 to 20 whencalculatingthe capacity of belts according to the type of trough(V, trapezoidal at 30а or45 etc). It is to be pointed out that: o the triangularangle only relates to slightly Гfluid materials with a highstatic angle of repose. o thesecalculations are valid only for horizontal conveyorswithsmallcentre distances; as soon as the length exceeds a few tens of metres, especially if conventional troughs are used, the settling of the...

Table 1 shows some exemplary results for various angles of repose and belt width. Belt width Circular surface of repose S in m2 for a belt speed of 1m/s [mm] = 0߰ = 5߰ = 10߰ = 15߰ = 20߰ 500 0.02412 0.02683 0.02829 0.02975 0.03120 650 0.04538 0.04783 0.05045 0.05308 0.05570 800 0.07415 0.07832 0.08156 0.08509 0.08864 1000 0.12290 0.12950 0.13500 0.14100 0.14680 1200 0.18050 0.19010 0.19860 0.20710 0.21550 1400 0.24880 0.26220 0.27400 0.28580 0.29760 1600 0.33090 0.34600 0.3615 0.37650 0.39270 1800 0.41950 0.44170 0.46110 0.48110 0.50100 2000 0.52110 0.54860 0.57280 0.59760 0.62280 Table 1: Cross-sectionalca...

Speed and stability of belts and products conveyed The belt speed depends on criteria including: o centring of the belt in operation empty, o stability of the products conveyed. With this in mind, powder or other products with a lowdensity (sawdust or charcoal, flour, cereals, talc, sugar,bulkcement, etc.) must be subject to specialstudies.Thanks to the adjustment of the forward inclinationangle, the VALMEC with automatic variation of this angleaccording to the load conveyed has a positive influence on the stability of the unloaded belt, even if the belt is quite narrow, as well as on the stability...

Spacing of carrying stations Due to the semi-circularshape, the belt supportedby garlandsgenerates a significant beam effectӔwhichdepends on the belt tension in the considered area, the belt width and the load per running metre (product plus belt).Calculationsbased on static tests and experience gained enable to draw up Figure 6.The graph isdrawnupaccording to a load perrunning metre, equal to the maximumcross-sectionalcapacity of the belt, a material with a density of 1.5 t/m andadynamic angle of repose of 15Ӱ, belt tensions of 10 to120N/mm and maximum deflections of 2% between stations. We...

Direction of travel Cable R = Spring or counterweightReturn b V = Electric or pneumatic cylinderwith two directions yp ulle y >

Figure 8: Conveyor with two operating directions:schematic illustrations Carrying section > beltcable Return section > beltcable cablecylinder Figure 9: Conveyor with two operating directions: principle mode of operation Increasingthe slope angle The use of the VALMEC allows the slopeangle of conveyors to be increased.Different tests in variousfields of conveyance and products (cement,sand, salt, wood etc.) confirmed that, comparedto conveyors withtrapezoidal trough, the slopeangle of conveyorswith a VALMEC can be up to 10greater, reaching well into the field of application of profiled belts...

Curved conveyors Thanks to the VALMEC, its higher sectional area capacity, the max. containingeffect of its shape and its naturaltendency to keep the belt centred, a curved conveyor can be easily designed, even with a much shorter curveradius than any other belt conveyor type.The standard carrying VALMEC garland can be used for smooth curve radius, just risingup the innerhookfixation points. For shorter curve radius, alongergarlandside rollerisenough to prevent the natural belt rising on the inner sideof the curve. The length of this longerroller can be calculated with the help of the belt manufactureraccording...

Rulli Rulmeca S.p.A. Via A. Toscanini, 1 Italy 24011 Alm (BG) Tel. +39 035 4300111 Fax. +39 035 545700 [email protected] www.rulmeca.it > 11 size="-1">