Multi-Cooler Discharge Door Upgrade

The primary design objective of the Simpson Multi-Cooler was to provide sand stability through cooling and preconditioning using less space and more control than any other system.

Users identified several performance issues:

• To maintain optimal performance during major changes in sand demand, operators had to manually reset the inner discharge door mechanism. This required skilled labor and caused downtime. Often, adjustments were skipped, reducing system performance. Such demand changes could result from varying numbers of active molding machines or production schedules.
• Before 2000, most Multi-Coolers were supplied with separate “black box” moisture controls, creating redundant components (panels, PLCs, etc.) and poor integration with process controls—raising training and maintenance costs while reducing efficiency.
• Unbalanced electrical loads and power fluctuations—sometimes up to 15%—lowered drive motor efficiency. Amperage monitoring alone failed to detect these variations, leading to inconsistent control. The older monitoring method, discharge door design, and control logic lacked the precision needed for modern foundries.

The discharge door and its control logic has been updated to meet these challenges. The new discharge door system improves control over door actuation and operation. The new door allows any foundry to easily enhance performance of their Simpson Multi-Cooler.

The new door consists of a single, vertical discharge gate. The door is positioned by an electro-mechanical actuator in response to the three-mode control loop. The actuator, complete with a variable frequency drive for positioning, is designed to quickly respond and locate the door to retain a constant retention time at all times manual intervention. This significantly improves the performance of the Simpson Multi-Cooler during varying foundry conditions. More consistent sand properties result, even when slight fluctuations in sand composition and demand occur. If more dramatic changes in retention time are required (for example, when one of the two or more molding machines on the sand plant are taken off-line), the new discharge door system can be more quickly and easily balanced.