Bucket chain excavator

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Bucket chain excavator, human for size comparison.

A bucket chain excavator (BCE) is a piece of heavy equipment used in surface mining and dredging. BCEs use buckets on a revolving chain to remove large quantities of material. They are similar to bucket-wheel excavators and trenchers. Bucket chain excavators remove material from below their plane of movement, which is useful if the pit floor is unstable or underwater.[1]

History[]

The first documented use of a bucket chain excavator was in 1859 [2] by Alphonse Couvreux, a French entrepreneur.[2] Several Couvreux BCEs were used in the construction of the Suez Canal.[2]

Overview[]

A bucket chain excavator works similarly to a bucket wheel excavator, using a series of buckets to dig into the material before dumping it in the bucket chute and depositing it through a discharge boom. The primary difference is that the buckets are mounted on a flexible chain similarly to a chainsaw blade rather than on a rigid wheel. BCEs are used primarily to excavate material below the vehicle's superstructure while bucket wheel excavators focus primarily on excavating top soil overburden and/or resources.

BCEs vary in range and size, although the majority of them are extremely large, with some capable of excavating 14,500 m3/h. The average BCE from Tenova Takraf for example, weighs around 1,150 tons and has a combined length of 58.5 meters, with a 23.5 meter long bucket ladder. The speed of the bucket chain is 1.22 m/s with a digging force of 1,170 kN/m2.[3] BCEs such as the RK 5000 from the Czech Republic weigh up to 5,000 tons.[4]

Nevertheless, bucket chain excavators are usually smaller than bucket wheel excavators, dragline excavators or conveyor bridges due to the limitations of excavating materials below the base of the vehicle.

Structure[]

The superstructure of a bucket chain excavator is similar to that of a bucket wheel excavator.

The primary component of bucket chain excavators is the bucket ladder and the bucket-chain. Unlike the buckets on a BWE, the buckets on the chain face downwards, allowing the machine to remove overburden or materials significantly below the bench or travel level.[5]

The excavated materials are deposited through the bucket chute. Material can be transferred to a bench conveyor directly or via a discharge boom or mobile conveyor bridge.[5]

Like the BWEs, bucket chain excavators also feature a fixed or rotating superstructure with a counterweight boom that allows the cutting boom a certain degree of verticality.[6] Likewise have a substructure equipped with either a rail or crawler-mounted undercarriage for mobility and transportation.[5] Some BCEs have 'hopping' pontoons similar to those found on walking dragline excavators.[4]

Gallery[]

  • Two BCEs supporting a conveyor bridge.

  • RK 5000 BCE with walking mechanism.

  • Open pit mining in Cottbus-Nord

  • Bucket dredger Heimdall

  • Bucket dredging

References[]

  1. ^ Tenova TAKRAF. (2007). Tenova Takraf Mining Equipment. Retrieved from http://www.takraf.com/en/products/miningequipment/main.htm Archived 2011-12-06 at the Wayback Machine.
  2. ^ Jump up to: a b c Keith Haddock. Giant Earthmovers : An Illustrated History. MotorBooks International. pp. 173–174. ISBN 978-1-61060-586-1.
  3. ^ "Bucket Chain Excavator ERs (K) 800".
  4. ^ Jump up to: a b Avery Thompson. "How a 5,000 Ton Excavator "Walks" Away When Its Work Is Done".
  5. ^ Jump up to: a b c "Bucket-Chain Excavators".
  6. ^ "Bucket chain excavator".
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