Good Foundry Practices

The metal casting industry has been, and continues to be, a key component of the industrial backbone of various nations and countries. The industry gives employment to a large number of people and supplies huge amount of castings thereby impacting almost every other industrial and commercial domain. The metal casting industry is also a major recycler of metal scrap, a major energy user, and an important pollution prevention partner in different countries.

Good foundry practices address critical technology deployment needs, which will help foundries in saving costs and improving profits. These practices help in reducing the energy consumption and environmental impact of the metal casting industry and improve its competitiveness.

Given below are some of the practices that can be adopted for cost savings and increase in profits -

Energy Saving Practices
By adopting following measures and practices, foundries can make significant cost savings -

Upgrade motor drive belts
Using energy efficient cog belts instead of drive belts help in reducing energy requirements. Cogged belts can function on existing v-belt pulleys, but at lower temperatures.

Set variable frequency drives on motors
Getting rid of voltage imbalances helps in reducing losses from vibrations, mechanical stresses, torque pulsations and overheating.

Switch off equipment and lighting when not in use
Specifically place a start-up and shut-down process to control energy usage spikes.

Cut down the compressed air pressure set point by 10%
Maintaining excess air system pressure is very expensive. Set points can be cut down with proper maintenance of system and continual repair of air system leaks.

Install high efficiency lighting
Using fluorescent lighting with magnetic ballasts instead of older ballasts is always cost-effective. Install targeted lighting at inspection points rather than less efficient ceiling lights.

Adopt superior melting practices
Specific recommendations may vary depending on the type of melting system used by the foundry. Furnace manufacturers can be of great help in helping to identify good melting practices for energy savings. The use of preheated air/oxygen and optimized burner designs have found to be good for gas-fired furnaces.

Short cycle heat treatment
Most of the heat treatment practices followed by many foundries are overly conservative and waste energy. High efficiency furnaces and furnace linings are generally cost effective.

Improved compressed air practices
Compressor should be properly sizes, it should not smaller or over-sized. Use air storage systems to limit idling of compressors. Reduce leaks at valves, couplings and pipe joints.

Low Cost Technology Practices
By adopting following measures and practices in different technical domains, foundries can save costs -

Molding
Upgrade the sand testing quality assurance – Better control of sand systems ensure superior mold quality and reduction in scrap. Make consistent use of sand supplier testing capabilities. In various cases, improved molding practices can help in reducing the biggest single contribution to casting scrap.

Melting
Melt cold, pour hot, pour fast – This will reduce the consumption of melting energy to minimum, while at the same time increases the quality of melt and reduces dis-functioning. It is generally much economical in the long run to completely preheat ladles than to melt hot and admit high temperature drops during the transfer of metal.

Scrap Reduction
Improved reporting and analysis of scrap – The single effective way to reduce scrap is to identify the scrap and its root causes in a right manner. Lack of attention to detail in reporting of scrap may badly affect the bottom line; for instance, it is crucial to identify ‘sand’ or ‘slag’ as the causes of scrap instead of simply grouping them together as 'dirt'.

Data Collection
Decisions should be based on sound data collection - Make sure that the data, which you have collected has sufficient gage R&R; it is useless to collect data if you are not going to use it. Employees will be much more accurate and efficient collection of data if they know how that data is going to be used.

Lighting
Good housekeeping & lighting results in improved quality – A little extra KW of energy use, primarily in inspection areas, actually results in money savings. Good housekeeping leads to pride among workers and improved quality of products.

Training
Training helps in improving the skills and productivity of employees – Make use of all internal and external training resources to improve the skills of your employees. If production employees are better trained they are better problem solvers.

Profitability
Superior costing & pricing systems – This is essentially a challenge especially in the jobbing foundry, but is necessary to ensure the long term success of the organization.