Sand conditioning in metal casting using plate heat exchange technology
The metal casting industry is rapidly changing in response to cost pressures, environmental drivers and new technology adoption. The expectation is that the metal casting business model will completely transform over the next few years.
Pressure on customer pricing is forcing metal casters to work hard on reducing their costs and look critically at casting quality and scrap rates. The Occupational Safety and Health Administration is introducing a new lower exposure limit to protect workers from respirable crystalline silica. Metal casters are also dealing with adoption of new technologies such as additive manufacturing.
Foundries are looking for ways to address some of the challenges and ensure that they remain competitive in the changing business environment. To help solve some of the challenges faced in the core mold foundry process, Solex Thermal Science introduced innovative indirect plate heat exchanger technology for sand conditioning.
Figure 1: Heat exchanger design
Challenges in Metalcasting
Consistent temperature control of sand in the core mold process is a challenge. The problem is magnified when disruptions occur in the foundry process that results in the cooling or over heating of sand. Accurate temperature control is vital to binder mixing and efficiency. Not having this control can result in productivity loss, core mold scrap and casting scrap and rework.
Precise sand temperature control is vital to binder optimization. Lack of accurate sand temperature control results in excessive use of expensive binders to compensate. This is a costly and inefficient way to deal with sand control issues in the core molding step of the process.
The current use of fluid bed technology for sand temperature control introduces direct contact between the air heat transfer fluid and the sand product. This highly energetic, blowing air results in silica dusting that contributes to the personnel exposure of respirable crystalline silica. New application of indirect heat exchange technology that reduces the risk of silicosis is advantageous and will contribute to a safer and healthier work environment in foundries.
Solex Heat Exchanger Advantages
By implementing Solex heat exchanger technology our customers achieve precise sand temperature control, which results in the following benefits:
- Reduce scrap and rework of castings
- Reduce rework on core molds
- Reduce the cost of expensive binders and additives
Using indirect heat exchangers and gentle handling of sand reduces the likelihood of silica dusting and wear on any mechanical parts, with the following advantages:
- Lower potential for personnel exposure to respirable crystalline silica
- Prevent sand segregation which helps to maintain the consistency of AFS-GFN (American Foundry Association Grain Fineness Number)
- Zero or minimal maintenance of mechanical components
- Reduced noise as the Solex Plate Heat Exchanger has minimal moving parts and uses indirect heat exchange (does not use air blown through the sand)
Figure 2: Core sand conditioning process
This entry was last updated on June 9, 2020
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