RotoScrew0 pages

RotoScrew Pneumatic Injector

Introduction
Schenck Process RotoScrew range is designed to effectively inject
solid materials into processes, either continuously or on a batch
basis, to one or multiple points.
This system injects materials with accuracies of 2% by volume
or 0.5% by weight depending on the control method employed volumetric or weight related respectively. Materials can be injected
into processes at distances of up to 500 metres, with back pressure
of up to 30 bar(g).

The dispensing vessel is used to provide a constant
supply of material to the volumetric feeder. When
material is being injected, the dispensing vessel will
be pressurised. The lock vessel is used to periodically
replenish the dispensing vessel with material. In
this way, injection of material to the process can be
continually maintained.
The conveying air will enter the screw auger along with
the material and will leave the auger along with the
other process gases.

®

The vessel utilises the Original Dome Valve and the RotoScrew
pneumatic injection dispensing unit.

The original Dome Valve®
Central to the operating efficiency to all Schenck Process pneumatic
conveying systems, or as a stand alone valve is the original Dome
Valve® which incorporates a unique and highly reliable inflatable
sealing arrangement. The original Dome Valve® was developed
by Clyde Materials Handling* in 1974 for use with pneumatic
conveying systems and as a stand alone product.

The Operation of a RotoScrew

RotoScrew Applications
The RotoScrew system has been widely used in
the power, steel and pig-iron industries, in order to
continuously inject coal into blast furnaces, reducing the
requirements of coke, and allowing fines to be injected
straight into the blast furnace. Injection rates usually
average at 185kg/ton of hot metal, although some
operations have injected up to 210kg/ton of hot metal.
RotoScrew can feed cohesive or irregular and large
materials as well as lightly abrasive materials.

The RotoScrew machine consists of two pressure vesssels, a
rotating screw at the outlet and valves to control the air supply,
material flow and vessel pressure. The feeder will be driven
through a gearbox by a standard induction motor.

*Clyde Materials Handling Ltd was purchased by Schenck Process in 2011 and the original Dome Valve® is part of Schenck Process technologies