Science, Technology and Innovation

National Energy Efficiency Project

NFTN has initiated an Energy Management working group in order to consolidate a number of activities that are taking place under this important topic to the industry. The projects reported on below form part of a holistic approach towards supporting foundries in Energy Management.

Eskom, NFTN and SAIF initiated an Energy Management project in November 2010. Eskom presented their Integrated Demand Management Programme (IDM) and the opportunities for foundries within the programme. It was agreed to amalgamate the above project with the German/UJ Effsafound project.

The objective is to register and capacitate Energy Services Companies (ESCOs) with Eskom that can specifically address the savings in foundries in the melting area of the plant. Not many of these companies are available in South Africa. It is through the ESCOs that foundries can apply for IDM funding support from ESKOM.

The joint working group also submitted a project to the CLIENT programme end of August. The aim of the funding measure is to introduce model projects to help establish and expand international partnerships in the research, development and application of environmental and energy management technologies and services and to trigger the competitive improvement of the foundry industry in this area. NFTN has committed funding over a period of two years to this joint project as one of the South African partners. The final joint proposal is available for information. The working group agreed that even if funding is not released in Germany for this project, the South African partners will go ahead with the project.

One aspect that NFTN would like to bring to the attention of government is the disconnection of energy supply by municipalities and ESKOM. 80% of South Africa’s foundries are catagorised as Small and Medium and are receiving their electricity from their respective municipalities. Through the above activities it has become clear that although ESKOM is very helpful and geared towards assistance of the manufacturing sector, when it comes to Energy Management and Savings, this is not the case with the municipalities. In many cases the foundries are the largest users and therefore also largest income stream for municipalities and therefore they do not have any motivation to encourage foundries to save energy. An alternative approach is needed in order to address this problem which affects the targeted foundries of the NFTN. NFTN, SAIF and AFSA has met with the Intensive Energy Usage group that has accomplished a lot in terms of changing policy and making government aware of the impact of electricity costs on the manufacturing sector. This group is in the process of doing a study of 15 municipalities tariffs which would be of interest to the foundry sector. The intent is to join the group more formally.

Plant simulation software promoting energy saving

The dynamic plant modelling software has been successfully adapted and used to simulate energy usage in a foundry operation. The time based modelling approach also allows one to simulate energy and power demand costs. Typically a foundry operation involves batching processes such as storage, melting, liquid metal transfer with level management as well as other processes such as metal conditioning, casting, recycling of gates and cast finishing. All these use energy and are accounted for in the model. The ability to simulate accumulated power demand offers a novel approach to addressing energy efficiency in the foundry environment.

Some of the capabilities of the model include the following:

• Furnace behaviour such as melting, heat lost to the environment, temperature control, insulation, use of lids, recycle streams etc has been successfully modelled using an adapted “Tank” unit model with integrated sub-routine models.
• Different generic models where developed for melting and holding furnaces. Melting furnaces typically use batching to address loading and transfer while holding furnaces are conditioning the metal for subsequent processing. These furnace models also can be reused in the set up of any other similar foundry operation. Different furnace control logic for temperature and level management can easily be integrated into these models.
• Plant control logic has been used in a global sub-routine to simulate the integration of all the foundry operations, such as alloy supply, metal transfer, furnace level control.
• In order to facilitate the quick set up of a model, there is a parallel interface which has been created and incorporated into an Excel environment. This means that the model can be set up independently of the foundry model.
• Power demand and energy time based costing has been successfully captured in a separate “cost management model”. The model was validated with actual energy costs from the PDC brass and aluminium foundry.
• Various model scenarios were used to make comparisons and demonstrate potential energy savings. One of these cases involved determining quantitatively the benefits of using furnace lids. Another was to establish the amount of saving from using fewer holding furnaces.
• The model can also be used to study progressive effects such as slowly increasing the production to determine optimal foundry behaviour or ideal operating conditions.

NFTN would like to monitor the impact of the software after a period of 6 months in the respective foundries before taking a decision on the way forward of looking how it can be rolled out to industry.

Practical Energy Management guideline

The contract with Casting Services who developed a practical energy management guideline for foundries, has been completed. Energy reduction and energy efficiency improvements can yield savings of high monetary value and in certain cases can change a company from a loss situation to a profitable situation and so secure the employment of the current staff of the company. An estimate 20% to 30% savings in energy costs can be made without having to outlay a large amount of capital. The Energy Management manual will be launched at the Energy Management workshop co-hosted with CSIR under the DST TAP programme in November for best impact. Participants to the workshop will receive the manual as part of the workshop package. For a quick preview please see the content page of the manual – Available as a downloadable PDF – click here. Hard copies of the booklet are available at the NFTN office.

Waste management project

NFTN is hosting the Waste Management Working group aimed at consolidating all activities under this important topic to industry. The key objectives are:

1. Development of a first class public testing facility that caters for the foundry industry
2. Engage the authorities on current regulations
3. Pursue secondary uses of waste sand.

Waste management in South Africa is regulated under the National Environmental Management: Waste Act 2008 (Act 59 of 2008) (“Waste Act”). The Waste Act is supported by the National Waste Classification and Management Regulations, the Standard for Assessment of Waste for Landfill Disposal, and the National Standard for the Disposal of Waste to Landfill (these are all in draft format). It is under these regulations that foundry sand is currently classified as hazardous waste. The working group attempts to prove that this is not the case. Green sand has therefore been collected from four foundries to be tested (about 80% of foundries use green sand). An independent laboratory was contracted by CSIR under the DST TAP programme to test the sand. Findings clearly show that green sand is not hazardous. Further samples shall be collected from foundries that are using furan and resin bonded sand. The next step is to engage government on revising the above regulations and standards and possible meetings with the main dumping sites in South Africa. NFTN has reported on this process at the UJ Colloquium, to view click here

In the meeting that was held with DST mentioned under the Technology Assistance Programme this was raised as the greatest bottleneck to the foundry industry in order to solve their waste management problem. It also affects the ability to look at alternative uses for foundry waste sand. DST undertook to assist the industry with engagement with the Department of Environment.

Further to the above, UJ MCTS has been contracted to develop a report that will contain the properties of sand from different sand suppliers across the country in order to assist foundries in determining the type of sand they acquire, the deliverable date for the report is beginning of December. Visits to 11 sand quarries has been completed, the university is currently testing the samples collected from the quarries. The results shall be made available to industry in order to be informed on the quality of sand they use as input in their processes.