1. Arcelor Mittal Vanderbijlpark Industrial Energy Efficiency
IEE Case Study

2. Company Profile
ArcelorMittal South Africa (AMSA) is the largest steel producer in Africa. AMSA produces 4.8 million tonnes per year of saleable steel. The plant’s steel products are manufactured in an integrated process. Raw materials such as iron ore, coke and dolomite are charged to blast furnaces where they are converted to liquid iron. The liquid iron is refined in basic oxygen furnaces and electric arc furnaces to produce liquid steel. The liquid steel is cast into slabs, which are hot rolled into heavy plate in a plate mill, or into coils in a strip mill. The coils are either sold as hot rolled sheets in coil or processed further into cold rolled and coated products, such as hot dip galvanised, electro-galvanised and pre-painted sheet, and tinplate.

3. Arcelor Mittal VDBP - NCPC / IEEP Journey
First encounter with the Industrial Energy Efficiency Project (IEEP) – Dec 2013 with UNIDO experts becoming a valuable extension of the AMSA energy efficiency team.
Energy management systems (EnMS) expert level training – May 2014.
Compressed air system optimisation (CASO) 2 day training – June 2014
Pump system optimisation (PSO) 2 day training – Mar 2014
PSO expert level training – Jul 2014
Fan system optimisation (FSO) 2 day training – Sep 2014
FSO expert level training – Oct 2014
Steam system optimisation (SSO) 2 day training – Sep 2014
SSO expert level training – Feb 2015
In the process of implementing EnMS – ISO 50001, energy systems optimisation (ESO) assessments and case studies in pumps, fans, steam and compressed air.

4. ESO Assessment Results - Case Study
Compressed air leak detection assessment
R3.6 million
Pump system optimisation assessment (Ph1)
R25 million
Compressed air system optimisation assessment
R36 million
Steam system optimisation assessment
(Incl. power generation)
R175 million
ArcelorMittal VDBP - EnMS implementation results: Electricity and natural gas data on baseline period 2013 Actual Savings 2016 – Approx. R105 million!

5. Status of Energy Phase1 Pump Savings Projects with the assistance of UNIDO / NCPC Funding
Plate Mill
Descaler pump Ph1
Descaler pump Ph1&2
BF- D Furnace cooling pumps
5 Stand South Ph I Cool pump
5 Stand South Ph 2 Cool pump
HSM-HP Pump (after VSD’s)
Savings study mechanism funded by NCPC
Run best out of 3 pumps only after pump efficiency test
Refurbish pumps
Run 1 pump only
Run 1 less pump
Reduce friction
Reduce orifice size at bypass
Automate main pumps on/off
Analyse / optimise in PumpMonitor
Savings
(Rand)
R253,246
R458,557
R1,498,421
R811,992
R900,113
R2,200,000
Energy savings
(kWh p.a)
358,705
649,514
1,971,607
1,014,990
1,125,141
2,820,513
Total equipment
investment VDB (Rand)
None
(completed)
R457,053 (completed)
R 676,640 (completed)
R30,000
R300,000
R508,000
Payback time
N/A
12 months
5.5 Months
<1 month
4 months
3 months
Project status & plant support
Completed
M&V Audit
Implemen - tation
Proposal

6. How the Blast Furnace (BF-D) Pump System Works
Cooling Tower
Motor Data :
Rated Power 315 kW
Voltage V
Full Load Amps 68 A
Speed RPM
Pump Data :
Salweir Centrifugal Split Casing Double suction
Model SDA
Type 400/500
Impeller Diameter 478mm
BF-D
Close
System IN
Sump
BF-D
Close
System
OUT
Heat
Exchangers

7. New Water Level increase
BF-D Pump System - Root Cause Analysis
Pump
Station
BF-D
New Water Level increase
NPSH

8. Pumps to Operate close to BEP

9. BF-D Pump System - Root Cause Analysis
Pump operation outside BEP 2
Inlet cavitation
Low NPSH available
Inline strainers got blocked restricting flow
Plastic cooling tower packing collapsed and contaminated water
Strainers at cooling tower and pump suction were not effective
2.1
Cooling tower fill is in bad state due to ageing. End of life.
2.2
Strainers cause high ∆P even when clean
Design restriction
2.3
Long rusted inlet pipes with elbows increase pipe resistance
Pipes ageing
2.4
One out of two inlet valves stuck in close position restricting half of the flow
Butterfly valve sleeve damaged during installation cause disk to become stuck
Installation is too rigid. Valve had to be forced into position
2.5
Low level in the sump
Water overflows to BF-C sump
Leaking sluices
2.6
No control by operational personnel
2.7
Lack of maintenance & lubrication 1
Grease does not enter the bearings but stays in the bearing cap
Bearings were not greased by supplier
Bearings were not greased by maintenance personnel

10. BF-D Pump System - Root Cause Analysis
Operation outside BEP 2
Outlet cavitation
High back pressure
Blocked heat exchangers increase system pressure
Plastic cooling tower packing collapsed and contaminated water
Strainers at cooling tower and pump suction were not effective
2.1
Cooling tower fill is in bad state due to ageing. End of life.
2.2
Heat exchangers were not cleaned regularly
No maintenance plan for heat exchangers cleaning
2.8
Not effective and unreliable system for monitoring HE pressure drop
2.9
BF-D Pump System - Root Cause Analysis
Recommendations (without large capital) :
Sump level increase to 100%.
Automatic level control for top-up.
Redesign suction pipe in order to reduce pressure loss
Use bigger size pipe;
Regularly clean strainers; and
Remove elbow on inlet.
Regularly clean heat exchangers.
Adjust flow based on temperature.
Confirm ΔT requirements of the ‘BF closed loop’ system and calculate the required flow rate of the ‘open’ loop system.
Compare flow requirements with cooling degree days.
Operate a single pump year round.

11. BF-D Pump System - Root Cause Analysis

12. Effect of Increased Maintenance at the Right Time on Total Operational and Energy Cost

13. Effect of Increased Maintenance on Total Operational and Energy Cost
The Plate Mill makes use of a descaling pump system (1 out of 3 pumps in parallel) that sprays concentrated high pressure water onto the plate, after the heating and rolling process, to remove any scale that has formed on the plate.

14. Plate Mill Descaler PSO
- Worn Pump Reduce Head, Flow, Efficiency at Increase Power

15. Thank You
Questions ?