Belt Conveyor
A
belt conveyor system consists of an endless belt of resilient material
connected between two flat pulleys and moved by rotating one of the
pulleys by electric motor. Normally material is fed on the belt near the
other end pulley. The moving belt carrying the material towards the
driver pulley is likely to sag between the two end pulleys due to its
self weight and pay load. That is why the belt is supported both on the
carrying side and the return side by a number of rollers, called the
idlers. As the belt is always under tension, it is prone to elongation
resulting in slackness over the pulleys and loss of tension and power.
That is why some kind of device for tensioning the belt is incorporated
in the system. This tensioning device is known as take up arrangement.
The system is inherently very simple.
Belt
conveyors have attained a dominant position in transporting bulk
materials due to a number of inherent advantages like the economy and
safety of operation, reliability and practically numerous processing
functions while supporting a continuous flow of material between
operations. Low labour and low energy requirements are fundamental with
belt conveyors as compared with other means of transportation. The
reliability of belt conveyors has been proved over decades and in every
industry. Belt conveyors are environmentally more acceptable than other
means of transport. They neither neither pollutes the air nor deafens
the ears. Conveying of a wide variety of materials is possible with belt
conveyor, and belt conveyors are capable of transporting at a hourly
rate much in excess of any practical requirement. Belt conveyors can
deliver materials at a great distance from the loading point covering
all odd terrain.
Essential components of a belt conveyor:
Belt
conveyors consists of a driving pulley at the head end, and take up
pulley at the tail end, both being accommodated in a steel frame. An
endless belt connects the two pulleys on both runs and supported by
suitable roller type supports, called the idlers. At the upper side of
the conveyor also called the carrying side, because the pay load is
carried on this side, the belt is supported by idler. At the other side
also called the return side because usually there is no pay load, the
belt is supported by idlers. In some designs the belt is supported by a
stationery runway instead of idlers. In some special installations both
the upper and lower sides transport loads (usually unit load)
simultaneously in opposite directions. The driving pulley receives its
rotation from drive unit.
The material to be
conveyed is loaded on the belt by one or more feed hoppers mounted over
the conveyor belt line normally placed at the tail end side. The load
conveyed by the moving belt is discharged over the driving pulley into
discharge spout. However discharge can be arranged at any point along
the conveying run by means of special discharge devices. At the tail end
side a device called the take up arrangement is attached with the take
up pulley to keep the belt under a minimum tension so that the belt does
not slip over the pulleys due to extension of its length. Belt cleaner
removes material adhering to the outer belt face. It is usually located
near the driving pulley.
Application of belt conveyor:
Belt
conveyors are employed to convey a great variety of bulk materials and
also unit loads along a horizontal or gently inclined paths. Such duties
can be performed within the factory shed or in outdoor work. Within the
factory shed belt conveyors are also employed to carry articles of
light weight in line production from one operation to another. Belt
conveyors are used to mechanize material handling operations in
foundries to distribute moulding sand, mould cores and cast articles.
Belt conveyors are used for carrying coal, ores, and minerals in power
plants, mining industries, and metallurgical process plants. For
handling food grains and building materials belt conveyors are
frequently employed.
Capacities of a belt conveyor system may range from 500 to 5000 m3
/ Hr. and more. The distance covered for a belt conveyor system may be
as small as 50m (for indoor work) to 5 Km for supplying raw material
from mine area.
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