The tubular conveyor system is designed to allow the belt to wrap around the conveyed material while it remains flat at loading, discharging areas and takeup zone.

Consequently, over the full conveying length, Pipex and Piflex belts are shaped into a tubular section by idler frames properly arranged in hexagonal form. The advanced technology of Pipex and Piflex for tubular conveyor system includes all the typical advantages of traditional trough belts adding further characteristics which make its use suitable under technical and economical profiles. Past unsolved logistic and environmental protection problems can now easily faced and overcome. Main advantages of this technology are:

• Horizontal and vertical curves with reduced bending radius
• Little space requirement by compact plant design
• Reduced spillage of materials loaded from the belt
• Dust free transportation
• Low maintenance

Application Fields

Pipex and Piflex tubular conveyor belts are high technology products designed upon customers specific requests to properly work as per the operational characteristics of the plant where they will be installed.

The rubber covers quality is studied and developed to meet the specific needs of the conveyed materials.

The environmental regulations introduced in the last years require the industries to redraw the use of the plants for the transportation of dusty materials; the tubular belts plants are the most suitable to the handling of those materials where a special care to the environmental protection is needed (developed areas, parks etc.)

Some products affected by the presence of humidity, such as cement, meet in the tubular conveyor belt system the right technology for their transport in open areas such as loading and unloading wharfs.

PIPEX and PIFLEX give the maximum of their potential in the fields of:

• Cement factories
• Power plants
• Ports
• Steel factories and any place where environmental impact must be reduced and/or where obstacles must be got round.

Design Details

• This page shows the layout of the main components of a tubular conveyor belt. Pulleys and take-up devices are the typical one of a standard troughing belt while the development of the plant is totally different because the belt, instead of leaning against the idlers, wraparounds by idler sextines placed perpendicularly to the belt and supported by purpose-made panels. As per the conventional troughing conveyor belts, it is worth to design the conveyor plant in accordance with the characteristics of the belt to adopt, especially keeping into consideration the modulus of elasticity of the carcass material.
• From that derives transition lengths, bending radius as well as the take-up lengths. Where possible, depending on the centre-to-centre distance and the available space for take-up, it is recommended to adopt Pipex textile belts (see also: Texter textile belts) that, because of the reduced modulus of elasticity, allow short transition lengths and reduced bending radius. On the contrary, when the centre-to-centre distance requires an unacceptable take-up run, it is better to choose the Piflex tubular belt (see also: Siderflex steel cord belts) made of a steel carcass requiring wider transition lengths and bending radius.
• A wrong evaluation of transition lengths and/or bending radius may cause an incorrect closure of the belt and its premature damaging.
• To obtain a perfect performance it is furthermore essential to choose the pipe diameter keeping into consideration both the requested capacity and the size of the material; overfilled pipes or too big material lump sizes may determine an obstruction of the materials among the idlers and the damaging of both the belt and the steel structure.

Cover Characteristics

WEAR RESISTANT

• CL (L grade ISO 10247) Standard wear resistant compound.
• CL is a cover rubber recommended for all groundapplications and for the majority of materials, where resistance to abrasion is required. Conveyor belts with CL compound are suitable to handle heavy and/or abrasive materials such as gravel, stone, coal, cement.
• EC (D grade ISO 10247) Extra wear resistant compound.
• EC is a superior quality cover rubber, especially designed where maximum resistance to abrasion is required. The characteristics of resistance to cut, tear and ozone cracking, together with long duration, improve the quality of this cover. EC is expressly designed for steel works and iron mines; however, it is also recommended for heavy lump ore, coke, salt, limestone.

SELF-EXTINGUISH

• BS – Self-extinguish compound.
• BS is a cover rubber designed to service both underground and above ground application where safety is fundamental and fire risk is high. It is recommended in particular for coal and potash applications. As self-extinguish and antistatic compound, BS is designed according ISO 340 and ISO 284 or equivalent.
• AG – Self-extinguish and oil resistant compound.
• AG is a nitrile compound suitable for conveyor belts and bucket elevator systems of cereal terminals and silos. AG cover rubber provides superior resistances to vegetable oils and animal fats; it is also self-extinguish and antistatic according to ISO 340 and ISO 284 or equivalent in order to guarantee high safety to the conveyor plant.

OIL RESISTANT

• OM – Vegetable oil resistance compound.
• OM is a cover rubber that guarantees a good belt resistance against the chemically aggressive effects due to the transport of materials with moderate oil presence, like corn, fertilizers and general vegetable oily materials. OM is expressly designed to resist the terpene of wooden chips and to convey solid urban waste materials.

HEAT RESISTANT

• CX – High temperature resistance.
• CX is a rubber compound assuring a medium degree of abrasion resistance; it is formulated for continuous service at temperature of 130 °C with peaks of 150 °C.
• MX – High temperature resistance.
• MX is a rubber compound assuring good degree of abrasion resistance; it is formulated for continuous service at temperature of 150 °C with peaks of 180 °C.
• TX – Superior temperature resistance.
• TX is a cover rubber that assures the maximum heat resistance for a rubber compound. It is designed to resist at maximum working temperature of 200 °C with peaks of 300 °C.
• All types of conveyor belts produced by SIG SpA are realized according to ISO standards; furthermore they meet also the requirements of equivalent UNI, DIN, BS, NF, ASTM and RMA standards.

For particular applications, please contact our sales dept.

Bài viết PIPEX E PIFLEX® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

Flexobord belts are based on the following main components:

• Base belt
• Sidewalls
• Cleats

The correct choice of each component in relation to the final use is one of the most important contribution to the overall plant performances. The complete range of SIG Rubber Conveyor Belts is produced according to the international standards; therefore the cross reinforcement of the carcass ensures the necessary transversal stiffness and prevents from hitting the full width return idlers.

Sketches on the right show typical but not exhaustive Flexobord layouts; the belt designer must take into consideration these alternatives to guarantee correct plant performances.

Bài viết FLEXOBORD® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

As shown in the drawing of this page, ARABELT® is a rubber conveyor belt characterized by only one ply with a special construction named “straight warp”.

This is a special weaving where the longitudinal filaments (warp) are not braided with the transversal ones (weft); furthermore, the connection between warp and weft is assured by a special nylon binder. In this way, both warp and weft are straight, with two main advantages: no elongation due to the weaving of fibres and possibility to connect big warp and weft filaments with each other.

This second aspect guarantees high tensile strength and superior cutting, tearing and impact resistance thanks to the presence of a double weft realized with high tensile nylon filaments.

SPECIAL TEXTILE CONVEYOR BELTS: THE ARAMID FIBER

The advantages of straight warp construction are emphasized by the aramid fiber forming the longitudinal filaments. Aramid is a sintetic fibre whose molecule is a combination between the rigid aromatic structure of polyester and the chain links of polyamide; the result is an aromatic polyamide with higher strength and very low elongation.

These two characteristics are so stunning for a sintetic fibre that aramid is comparable to steel, but with a very important difference: a density more than five times lower. Two other properties make aramid similar to steel: high heat and flame resistance.

Further considerations on the differences between aramid and steel can be found at section “comparative graphics”.

Bài viết ARABELT® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

Textbind double unit

• Texbind belts have been originally designed as an universal mining conveyor belting to provide maximum flexibility together with high resistance.
• Now, Texbind are available as profitable alternative of EP multiply conveyor belts in case of heavy applications where impacts with big-sized materials are present.
• Texbind is composed of a single ply carcass which provides the mechanical characteristics of the belt, protected by two rubber covers which define the typology of use of the belt.
• In case of extreme applications where high tensions in the textile carcass add to heavy and hard working conditions, with big lump materials falling on the belt surface from considerable heights, a special version with two textile layers is available; with this construction the already superior resistance against impacts, typical of the straight warp construction, is multiplied for a factor higher than 2, thanks to the perfect synergy guaranteed by the intermediate rubber layer specifically designed to distribute the impact energy between the two layers.
• Rubber covers are tipically wear resistant or selfextinguishing; however, also oil proof and heat resistant realizations are available, on request.

Main Advantages

• High impact, tear and cutting resistance thanks to its special double reinforced weft
• Superior longitudinal flexibility that allows smaller pulleys
• Very low permanent elongation guaranteed by straight warp construction
• High efficiency with mechanical jointing

Straight Warp Construction

• The EpP weaving has been introduced for rubber conveyor belts in order to overcome the limitations of standard EP multiply belts of medium-high style: high elongation, weak weft resistance for heavy applications, high thickness with consequent belt stiffness and possibility of ply separation.
• In fact, the straight warp allows to reduce elongation as no weave in the filament is present, the double weft allows to highly improve the fabric resistance against impacts and tears; moreover, the monoply construction makes the belt carcass thinner and deletes any possible ply separation.

Bài viết TEXBIND® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

• Polyester – Nylon carcass
• Reinforced cut edges
• Excellent adhesion between plies and covers
• Complete tension style
• Wide selection of cover compounds
• Very low permanent elongations
• Maximum load support
• High resistance to tear and cutting
• Good impact resistance
• Apt to mechanical fasteners
• Humidity proof

Cover Characteristics

ABRASION SERVICE

• CL (L grade ISO 10247 – Y grade DIN 22102 – RMA II grade) – Standard abrasion resistant compound. CL is a cover rubber recommended for all ground applications and for the majority part of the materials, where resistance to abrasion is required. Conveyor belts with CL compound are suitable to handle heavy and/or abrasive materials such as gravel, stone, sand, aggregates, coal, cement, etc.
• EC (D grade ISO 10247 – W grade DIN 22102 – RMA I grade) – Extra abrasion resistant compound. EC is a superior quality cover rubber, especially designed where maximum resistance to abrasion is required. The characteristics of resistance to cut, tear and ozone cracking, together with long duration, improve the quality of this cover. EC is expressly recommended for steel works and iron mines; however, it is recommended for heavy lump ore, coke, salt, limestone too.
• SC (H grade ISO 10247 – X grade DIN 22102) – Superior cutting resistance compound. SC is a cover rubber designed for specific use when the resistance to cut and tear is the most important requirement. SC also guarantees high abrasion resistance. Main applications are quartz and cullet conveyance.
• AS – Rubber cover for extreme applications. AS rubber cover is studied to offer the maximum abrasion resistance in all the applications, where an increase in the standard abrasion resistant conveyor’s service life is required. Moreover, its excellent mechanical characteristics allow a superior tearing and cut resistance, which permits its use with heavy materials, i.e. big-sized minerals, bauxite, etc. or in critical working situations characterized by atypical loading/unloading systems. AS grants and surpasses grade W – DIN 22102 and D – ISO 10247 assuring an abrasion resistance of 30-50 mm3.

SELF-EXTINGUISH

• BS – Self-extinguish compound. BS is a cover rubber designed to service both underground and above ground application where safety is fundamental and fire risk is high. It is recommended in particular for coal and potash applications. BS compound is self-extinguish and antistatic according ISO 340 and ISO 284, equivalent Grade K DIN 22102.
• TS – Selfexstinguish compound. TS is a product typology designed to service both underground and above ground applications. It is highly recommended for the belt conveyors located in the back areas of the tunnels. TS is designed according to ISO 284 and ISO 340, equivalent Grade S DIN 22102.
• TV – Fireproof compound. TV is a belt typology designed to work in underground applications where it is necessary that the belt does not burn and does not trigger centres of fire. It is recommended for the belt conveyors located close to the permanent work-stations in the tunnels. TV is designed according to ISO 284, ISO 340 and DIN 22100-1.
• AG – Self-extinguish and oil resistant compound. AG is a nitrile rubber suitable for conveyor belts and bucket elevator systems of cereal terminals and silos. AG cover rubber provides superior resistances to vegetable oils and animal fats; it is also self-extinguish and antistatic according to ISO 340 and ISO 284, equivalent to K grade of DIN 22012 in order to guarantee high safety to the conveyor plant.

OIL SERVICE

• OM (G grade DIN 22102) – Vegetable oil resistance compound. OM is a cover rubber that guarantees a good belt resistance against the chemically aggressive effects due to the transport of materials with moderate oil presence, like corn, fertilizers and general vegetable oily materials. OM is expressly designed to resist the terpene of wooden chips and to convey solid urban waste materials.
• OH – High oil resistance compound. OH is a premium quality cover rubber with maximum resistance to oils and characterized by low volume variations after immersion in highly aggressive mineral oils. OH is expressly realized for belts conveying materials sodden with mineral oils, as for example the mechanical manufacturing rejects.
• PL – Oil and heat resistant cover. PL is a covering compound designed specifically for the handling of petroleum coke during the production process where the material can reach temperatures of 120 ° C. The composition of the compound based on nitrile polymer also ensures good resistance to oils.

HEAT SERVICE

• CX – Medium temperature resistance. CX is a rubber compound assuring a medium degree of abrasion resistance; it is formulated for continuous service with hot coarsematerials at a temperature of 130 °C with peaks of 150 °C.
• MX – High temperature resistance. MX is a rubber compound assuring a good abrasion resistance. It is
• designed for continous service at temperature of 150 °C with peaks of 180 °C.
• TX – Superior temperature resistance. TX is a cover rubber that assures the maximum heat resistance for a rubber compound. It is designed to resist with coarse materials at a maximum working temperature of 200 °C with peaks of 300 °C.

All types of conveyor belts produced by SIG SpA are realized according to ISO standards; furthermore, they meet also the requirements of equivalent UNI, DIN, BS, NF, ASTM and RMA standards.

Cover Selection

Bài viết TEXTER® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

Cleat height 15 mm

SIG reserves the right to introduce at any time such modification as would seem justified by continual development and improvement.

Dimensional tolerances: ISO 251

The present edition cancels and replaces the previous ones

SPINATEX G15

Cleat height 15 mm

SIG reserves the right to introduce at any time such modification as would seem justified by continual development and improvement.

Dimensional tolerances: ISO 251

The present edition cancels and replaces the previous ones

SPINATEX G25

Cleat height 25 mm

SIG reserves the right to introduce at any time such modification as would seem justified by continual development and improvement.

Dimensional tolerances: ISO 251

The present edition cancels and replaces the previous ones

Bài viết SPINATEX® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

• 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)

According to the OEM experience, different choices in the joining system or in the bucket bolts could need higher pulley diameters.

Technical Specifications

Heat resistant cover AX (150°C)

SUPER heat resistant cover BX (180°C)

OIL RESISTANT COVER OX

Self extinguish and oil resistant AG

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

• 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

Bài viết ELETEX® đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

Covers Specifications

Rubber covers for elevator belts have two main functions: protection of the carcass against material and moisture aggression, assurance of the perfect bucket holding up without bolt loosening in course of time. In order to guarantee safety and longer life, under hard working conditions too, all type of rubber covers are antistatic and ozone protected.

• SX – Medium temperature resistance
• SX is a rubber compound assuring resistance against abrasion; it is formulated for maximum temperature of 100°C. It is 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.

Recommended Pulleys Diametre

Fastening

Metal clamps for ELEMET

There is not a general purpose clamp suitable for all steel elevator belts as it must be designed in accordance with the tensile strength of the belt, the diameter and the construction of the steel cables, the pulleys diameter, the holes pattern for bucket fixation.

Although ELEMET are realized with very thin and elastic steel cables in order to minimize the effort in the joint bending area, two particulars of these clamps are fundamental for the right performances without breaking of the cords or tearing of the belt:

• Sufficient radius of curvature in order to distribute the tensions along the cords reducing the possibility of cord breaking due to steel fatigue;
• Suitable bolts distribution, steel plates robustness and clamp surface with high friction coefficient to assure perfect clamping with a minimum number of cord breaking.

Elevator Belt Calculator

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.

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= fs. 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’= .

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: .

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

fs = Safety factor

fs’ = Effective safety factor

Pa [kW] = Theorical motor power

Pm [kW] = Minimum required motor power

h = Drive efficiency

P3calc=Q p

3,6v

10T

Bu

CR· Bu

10T

Bài viết ELEMET® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

Covers Specifications

Rubber covers for elevator belts have two main functions: protection of the carcass against material and moisture aggression, assurance of the perfect bucket holding up without bolt loosening in course of time. In order to guarantee safety and longer life, under hard working conditions too, all type of rubber covers are antistatic and ozone protected.

• SX – Medium temperature resistance
• SX is a rubber compound assuring resistance against abrasion; it is formulated for maximum temperature of 100°C. It is 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.

Fastening

Metal clamps for ELEMET

There is not a general purpose clamp suitable for all steel elevator belts as it must be designed in accordance with the tensile strength of the belt, the diameter and the construction of the steel cables, the pulleys diameter, the holes pattern for bucket fixation.

Although ELEMET are realized with very thin and elastic steel cables in order to minimize the effort in the joint bending area, two particulars of these clamps are fundamental for the right performances without breaking of the cords or tearing of the belt:

• Sufficient radius of curvature in order to distribute the tensions along the cords reducing the possibility of cord breaking due to steel fatigue;
• Suitable bolts distribution, steel plates robustness and clamp surface with high friction coefficient to assure perfect clamping with a minimum number of cord breaking.

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.

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= fs. 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’= .

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: .

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
• fs = Safety factor
• fs’ = Effective safety factor
• Pa [kW] = Theorical motor power
• Pm [kW] = Minimum required motor power
• h = Drive efficiency
• P3calc=Q p

Bài viết ELEMET® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.

The carcass of SIDERFLEX belts consists in a brass coated steel fabric (see picture below) with low elongation characteristics which gives to the belt a high tensile strength.

The greatest advantage of the low elongation for rubber conveyor belts with a center distance not extremely long is the possibility to replace textile belts without significant modifications of the conveyor system.

This type of carcass gives to SIDERFLEX belts special qualitative characteristics of:

• Excellent cut and tear resistance
• Low elongation
• High tensile strength
• Good impact resistance
• Excellent longitudinal flexibility
• Very good troughability

WARP CHARACTERISTICS

• Warp refers to longitudinal steel cords which characteristics of resistance and elasticity define the running properties of the belt.
• SIDERFLEX IW – HE series, provided of open type warp cords with increased elongation, have a longitudinal elasticity bigger than the standard steel cord conveyor belts. These performances allow to SIDERFLEX belts an easy replacement both of textile and steel cord belts.
• SIDERFLEX ID serie realized with regular warp cords has the same carcass characteristics of steel cord conveyor belts according to (ex) DIN 22131 and ISO 15236-2 type A1 (see Tab. on page 8).

Equipment Design

LONGITUDINAL FLEXIBILITY

• The presence of a single ply and the special warp cords construction give to the SIDERFLEX IW & HE belts a considerable longitudinal flexibility. At the same condition of fatigue stress this properties allows to use smaller pulleys than equivalent textile multy-ply.
• It means that in existing plants it is generally possible to replace the original textile belts with SIDERFLEX IW & HE without any plant modification.

TROUGHABILITY

• For a long time the majority of trough idlers have been produced with angle of around 20°.
• Due to the increasing demand for higher handling capacity, the angle of the idlers went up in value reaching 30-35° end even more. SIDERFLEX belts, in all series and style, thanks to their transversal flexibility will trough perfectly up to 60° without any problem.

ELONGATION & CREEP

• These mechanical properties refer to the elastic characteristics of cords and to our method of production defined to obtain the best performances of the final product. Low elongation is one of the most important points of SIDERFLEX belts: laboratory tests made on rubbercoated cords give value of elongation as shown in the following table:

Reference load: 10% of nominal tensile strenght

• Creep is the permanent elongation that the belt shows in the first period of life. The great advantage of SIDERFLEX in comparison with textile conveyor belts is a very reduced creep, generally negligible. This property helps maintenance because the belt can be vulcanized just one time on original installation without need of new joint after a certain period of time.

CUT & TEAR RESISTANCE

• Longitudinal cuts and tears are always a cause of belt replacements both in textile and conventional steel cord belts. SIDERFLEX, with its steel weft, is more resistant against this kind of damages. Indicative values of cut resistance in kN for SIDERFLEX IW belts compared with multiply textile belts are shown in the following table:

IMPACT RESISTANCE

SIDERFLEX has high impact resistance. The effect of oversized material falling on to the belt at the loading point is absorbed by the flexible steel carcass and the high quality level of rubber used.

CORROSION PREVENTION

Various properties of our SIDERFLEX assure a superior resistant against corrosion of steel cord:

• The adhesion between steel cord and core rubber is obtained through a chemical reaction during the curing process between special chemical compounds present in the rubber and brass (Cu/Zn alloy) covering the cords. In comparison with other coating method (tipically Zn), brass assures an higher and more constant adhesion to rubber.
• The open cord construction for IW, HE carcass and the special design of regular cord used for ID carcass allow the penetration of rubber up to the center of the cords, virtually eliminating the capillary action of moisture.

During the vulcanizing process, the combined effect of heat and pressure produces the flowing of rubber into the cord center and the top and bottom cover become “one” with the steel carcass locked in the center. In conclusion, no ply separation is allowed.

Bài viết SIDERFLEX® SIG đã xuất hiện đầu tiên vào ngày Công ty Thiết bị công nghiệp và Tự động hóa AUMI.