Client : Highveld Steel and Vanadium Corporation.
Total value : R 64 559 180 (2005)
Duration : 18 months
Responsibility : Turnkey EPCM contractor
Technologies : 1. Industrial plant layout
                     2. Process Engineering
                     2. Pollution control
                     3. Bag filtration
                     4. Gas dynamics and CFD
                     5. Automation and Control

Type Pulse-jet baghouse
Air volume 1 512 000 Nm³/h
Operating temperature 60 °C
Raw gas dust content 3 200 mg/Nm³
Clean gas dust content < 20 mg/Nm³
Dust density 1,2 t/m³
Number of compartments 36
Dimensions of filter bags Ø160x7 000 mm
Total number of filter bags 5 616 piece
Number of fans 3
Fan Drive Motor 800 kW


The steel plant consists of several batch processes including pouring, shaking ladles and blast oxygen furnaces, all contributing to the emission of particle pollutants. The secondary emission control plant was simulated using advanced CFD modelling to determine the convection patterns. This, combined with detailed gas sampling and particle analyses provided the basis of the design, enabling optimisation of extraction points.

The large diameter ducting is installed on a specially re-inforced roof structure and features automated dampers, a necessity to improve efficiency as a result of the batch processes.

The filter unit utilises pulse-jet technology for cleaning, and features fire detection and fire suppression systems. Cleaning is controlled by proprietary controllers also allowing off-line access to chambers for maintenance purposes. The dust collected is slurried and pumped to a recovery plant.

Three induced-draught centrifugal fans provide flexibility and redundancy, and add to the energy efficiency of the plant. The turnkey contract included amongst others disciplines all civils and structures as well as the total electrical supply from the 22kV feed.