J320202-JES-ME-SPE-101/A4

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It shall be mounted in such a position that material collected by the scrapper is discharged inmain discharge chute of the conveyor.

4.6.18.3 Internal scrappers (plough scrapper)

Internal V plough type scrapper of suitable design shall be provided on tail side of the conveyorto divert any material that may fall on the clean side of the belt and restrict it from entering intotail pulley. It shall be V-shaped, hinged on one side and pointing towards the head pulleys. Theplough made of mild steel flats and hard rubber strips without any fabric shall be provided withsuitable arrangement to press the wiping edge gently but firmly against the belt. Scrapper bladeof molded rubber shall be adjustable type.

4.6.19 CONVEYOR SUPPORTING STRUCTURE

4.6.19.1 All belt conveyors shall be provided with stringers and supports throughout the length of theconveyor. All head and tail sections shall be designed to resist all loads including belt tensions.

4.6.19.2 All structure like stringers, supports, head and tail frames shall be fabricated fromangle/channel/beam rolled steel section. In case of belt widths1000 mm and above, conveyorsshall have stringers/short supports fabricated from minimum 150 mm depth channel.

4.6.19.3 All cross bracings required for stringers/short supports shall be fabricated from rolled steelsection of suitable size. The base plates, splice plates, gusset plates shall be of minimum 10mm thickness.

4.6.19.4 As a general rule, clearance around all machinery to nearest fixed obstruction shall not be lessthan 1.0 m. There shall be access for belt renewal, vulcanizing and replacement of majorcomponents.

4.6.19.5 The deflection of conveyor girders shall not exceed 1/500th (0-2%) of the supporting span.

4.6.20 SAFETY SWITCHES

4.6.20.1 Belt sway switch

Spacing between two switches shall not exceed 50 m. Switch shall be Form C Single PoleDouble Throw type (SPDT), manual reset type with 2No+2Nc contacts. Minimum two switchesshall be provided. One pair shall be at head end and other shall be at tail end.

4.6.20.2 Pull cord switches

These switches shall be of industrial, heavy-duty type enclosed and vermin proof with indirectarrangement for operation. The switches shall be operable in both directions with automaticlocking arrangement in the operating position and shall be manually reset type with 2No+2Nccontacts. Spacing between two switches shall not exceed 30 m. These switches shall be Form C(SPDT) type. Required shackles shall be provided on each support.

These switches shall be provided along each walkway side of each conveyor.

4.6.20.3 Zero speed switch

zero speed switches shall be provided on tail pulley for each conveyor. These switches shall beForm C (SPDT) type. It shall be proximity non-contact type .The electronic unit for zero speedswitches shall be in FRP enclosure

4.6.21 CONVEYOR DRIVE

BASIS OF DESIGN FOR FERTILIZER&PHOSPHATE CONVEYING SYSTEM - J320202-JES-ME-SPE-101

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