Belts designed to be used in bucket elevator plant only. The special construction of the reinforced polyester-nylon fabrics assures the use of such belts also for severe loading requirements. The result are the following:
- Polyester warp assures high resistance to heavy working conditions.
- Nylon weft guarantees transverse tearing strength and strong bolt holding.
All ELETEX are supplied with cut edges because sintetic fabrics used for their production do not need protection against humidity as they can’t absorbe any liquid.
The 2 mm thickness both for top and bottom cover is designed to protect the carcass and at the same time assures the best bucket support without bolt loosening.
Covers Specifications
- OX – Oil resistant quality
- OX is a standard rubber compound designed for elevator belts working at ambient temperature. This compound is antistatic according to ISO 284 and oil resistant too.
- AX – High temperature resistance
- AX is a rubber compound especially designed for textile elevator belts to guarantee good performances with
- abrasive and hot materials up to 150°C. This compound is antistatic according to ISO 284 but not oil resistant.
- BX – Superior temperature resistance
- BX is the rubber cover that assures the maximum heat resistance for a rubber compound. It is designed to work at maximum temperature of 180°C. It is not oil resistant.
- AG – Self extinguish and oil resistant compound
- AG is a nitrile compound typically designed for bucket elevator systems used in cereal silos. It provides superior resistances to vegetable oils and animal fats; it is also selfextinguishing and antistatic according to ISO 340 and ISO 284 or equivalent in order to guarantee high safety into the conveyor plant. The maximum allowed temperature of the conveyed material is 100°C.
For different cover characteristics or particular applications, please contact to our commercial department.
Recommended Pulleys Diametre (mm)
Belt style N/mm | 400/3 | 500/4 | 630/4 | 800/5 | 1000/5 | 1250/5 | 1600/5 |
Drive pulley mm | 400 | 500 | 500 | 630 | 800 | 1000 | 1000 |
Lower pulley mm | 315 | 400 | 400 | 500 | 630 | 800 | 800 |
According to the OEM experience, different choices in the joining system or in the bucket bolts could need higher pulley diameters.
Technical Specifications
Belt style N/mm | 400/3 | 500/4 | 630/4 | 800/5 | 1000/5 | 1250/5 | 1600/5 |
Heat resistant cover AX (150°C)
Cover thick. mm | 2+2 | 2+2 | 2+2 | 2+2 | 2+2 | 2+2 | 3+3 |
Belt thick. mm | 6,8 | 7,8 | 8,4 | 9,5 | 10,7 | 11,7 | 14,7 |
Belt weigth kg/m2 | 8,4 | 9,6 | 10,2 | 11,5 | 13,2 | 14,5 | 18,6 |
SUPER heat resistant cover BX (180°C)
Cover thick. mm | – | – | – | 3+3 | 3+3 | 3+3 | 3+3 |
Belt thick. mm | – | – | – | 11,5 | 12,7 | 13,7 | 14,7 |
Belt weigth kg/m2 | – | – | – | 13,2 | 14,9 | 16,1 | 17,8 |
OIL RESISTANT COVER OX
Cover thick. mm | 2+2 | 2+2 | 2+2 | 2+2 | 2+2 | 2+2 | 3+3 |
Belt thick. mm | 6,8 | 7,8 | 8,4 | 9,5 | 10,7 | 11,7 | 14,7 |
Belt weigth kg/m2 | 8,6 | 9,7 | 10,4 | 11,7 | 13,4 | 14,7 | 19,0 |
Self extinguish and oil resistant AG
Cover thick. mm | 2+2 | 2+2 | 2+2 | 2+2 | 2+2 | 2+2 | 3+3 |
Belt thick. mm | 6,8 | 7,8 | 8,4 | 9,5 | 10,7 | 11,7 | 14,7 |
Belt weigth kg/m2 | 9,1 | 10,2 | 10,9 | 12,2 | 13,9 | 15,2 | 19,7 |
Available special constructions on demand and under technical approval.
Fastening
Metal clamps for ELETEX
Steel clamps with M14 bolts at 50 mm centre distance are available for Eletex belts up to 800N/mm. For higher classes, it is preferable to adopt customized clamps characterized by a third internal metal element isolating the two belts ends for better clamping efficiency.
Elevator Belt Calculator
In this section our method of calculation for elevator belts is described. Various tensions T
[daN] in the belt must be taken into consideration:- T1=P1·H due to belt weight P1
- T2=P2H/p due to bucket weight P2
- T3=P3H/p due to material weight P3
Capacity Q and weight of the handled material for each bucket P3 are connected by
P3calc=Q p/3,6v
If there are inconsistency between P3 and P3calc use in the calculation of T3 the greatest value between the data P3 and the value P3calc coming from the capacity calculation. An investigation on this conflict is suggested.
- T4=DJT3/H due to friction at the loading point.
- T5=MAX(K(T3+T4)-(T1+T2),Fv/2) to guarantee motion transmission.
The therm K(T3+T4)-(T1+T2) represents half of the minimum take-up value that must be applied. Negative values mean that buckets and belt weigth are sufficient to assure the minimum required pretension.
The maximum tension in the belt is the sum of these a.m. values T=T1+T2+T3+T4+T5. For the calculation of the minimum tensile strenght a usefull belt width BU=B-dfnf lower than the real belt width must be considered because of the presence of the hole necessary for the bucket holding.
If at least one of these datas are unknown, we suggest to use a safety factor fs ≥ 15 in the calculation of minimum tensile strength instead of the standard safety factor (fs=12 for Eletex and fs=10 for Elemet).
So, the minimum tensile strength is CRmin= T X fs. / Bu
Chosen a tensile strenght CR greater or equal to the here above calculated value CRm, it is possible to verify the effective safety factor fs’= CRx Bu.
The motor power necessary to move the belt loaded with the material must balance T3+T4 because the tensions T1 + T2 produces autocompensative effects along the whole lenght of the conveyor:
Pa=T3+T4 X r / 1000
Introducing the mechanical efficiency of the transmission and a power surplus of 20%, the minimum motor to apply to the conveyor belt must be Pm=1,2Pa/h.
LEGEND
P1 [kg/m] = Belt weight
P2 [kg/each] = Bucket weight
P3 [kg/each] = Material weight for each bucket
P3calc [kg/each] = Material weight of each bucket necessary to guarantee the capacity Q
Q [Ton/h] = Elevator capacity
v [m/sec] = belt speed
H [m] = Elevation
p [m] = Buckets pitch
D [m] = Lower pulley diameter
J = friction factor on the carter: generally 8, for big lump size 12
K = Friction factor on drive pulley (tipically 0,5)
Fv [kg] = Applied counterweight (including the lower pulley weigth)
T [kN/m] = Maximum belt tension
CRmin [kN/m] = Minimum tensile strength
B [mm] = Belt width
Bu [mm] = Usefull belt width
df [mm] = hole diameter
nf [mm] = hole number for each bucket
ff = Safety factor
fs’ = Effective safety factor
Pa [kW] = Theorical motor power
Pm [kW] = Minimum required motor power
h = Drive efficiency