Petrochemical Industry Vessels - Single-Stage Demolition Mast

SCX Special Projects has created a single-stage mast assembly to enable GNAT UK’s robotic deconstruction tooling to access a series of 30m tall reaction vessels.

The brick linings of the vessels become worn during the manufacturing process and regularly need replacing. Manual demolition of the linings is not only time-consuming, but hazardous to health. GNAT UK designed a remotely operated manipulator boom system complete with deconstruction tooling to remove the lining, eliminating the need to expose personnel to the hazardous process.

GNAT UK then required an access system so that their deconstruction boom could be inserted into the vessel from above and remotely controlled. SCX Special Projects designed and manufactured an 18m high mast assembly to enable the manipulator arm to enter and navigate the 12m drop into the vessels.

Diagram of single stage mast assembly

The economical single-stage mast assembly takes advantage of the vessels’ outdoor location with no overhead space restrictions. A lightweight truss construction makes the structure more manoeuvrable without compromising on rigidity. The mast is constructed from galvanised steel to protect against the chlorination process and the truss is finished with saline environment paint.

The manipulator arm features two rotation joints and two elbows to enable access to the upper ceiling as well as the lower internal walls.

Free-running guide wheels of a single stage demolition mast

A 5 tonne pendant-controlled chain hoist raises and lowers the 400 x 400mm-wide mast through the centre of the truss assembly, supported by two groups of eight free-running guide wheels surrounded by safety guards to protect maintenance personnel. These wheels also allow the mast to be stored on its side if required.

Once in position, independent wedge brakes hold the weight of the mast in order to take the load off the hoist and extend its lifespan. A key switch on the pendant prevents unauthorised usage.

Hoses of the hydraulically driven single stage demolition mast

Pressure to the 16 hoses of the hydraulically driven demolition tool is regulated to create a controlled force capable of demolishing the brick lining, but not the structural steelwork. A drag chain feeds the flexible hoses from the top of the structure down the centre of the mast to the manipulator arm, and quick release couplings streamline the connection and disconnection processes when the mast is transferred between multiple vessels.

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SCX Special Projects Ltd

Roman Ridge Road, Sheffield, S9 1GA, United Kingdom

t:  +44 (0)114 262 6199