Achieving Melt Shop Safety through Automation

Semi-automation of various foundry equipment, both on and off the melt deck, has been available for more than 15 years, including melt shop computer control, automated material preheating and charging, and automatic pouring systems, as well as many others. However, in the past, the area on the melt deck immediately adjacent to the furnace has always been the most challenging to automate, leaving the furnace operator in a most vulnerable state. The operator is exposed to the risk of molten metal splash areas and water/molten metal eruptions. With the ARMS™ (Automated Robotic Melt Shop) System, the melt deck can be automated, protecting melt deck personnel from these hazards.

This fully integrated system effectively achieves melt shop safety by completely automating the melt deck and relocating the furnace operator to a control room, away from the most dangerous areas. All controls for these automated systems are located in the room, overlooking the melt deck, and the room also contains controls for the furnace induction power supply, and the melt shop computer control systems.

From the control room, the furnace operator remotely controls the movement of the material handling systems, furnace, furnace cover, and slag cart, and initiates the various pre-programmed operations of the robot. Multiple closed-circuit video cameras capture operations on the melt deck and display the images on monitors located inside the control room.

Charging the furnace is a particularly hazardous operation for melt deck personnel, with the constant risk of splashing and explosions caused by moisture getting under the molten bath surface.

Manual charging is slow, labor intensive, and dangerous, but remotely controlled, mechanized material handling moves charge material quickly, efficiently, and more safely. These systems also enhance safety by allowing melt deck workers to be away from the furnace or behind protective barriers during charging. Remote charging from inside a control room is now commonplace, effectively minimizing the furnace operator’s exposure to this hazard.

Dry charge materials are crucial to worker safety, and charge preheating and drying systems are designed for maximum energy efficiency and long system life, significantly increasing productivity in melting operations. These systems help to deliver charge materials to the furnaces as required safely and rapidly, complementing melt deck automation.

When charging is completed, computers with furnace load cell feedback and kWh input can calculate the temperatureof the melt, call for more charge to be added, and prevent temperature overshoot of the melt. Many foundry workers believe these computers to be a luxury; others believe them to be a necessity.

Automated computer control systems, such as Meltminder® or Melt-Manager® Plus®, assist the operator, and avoid accidental superheating of the metal bath, thus saving energy, extending lining life, and increasing safety by minimizing the chances of a runout occurring. Computer control systems also log key operational data and help with various functions, from charge makeup to running sintering programs.

One of the biggest contributors to melt deck productivity and personal safety is the ARMS System. A robot is operated from the control room, performing many duties to tend to the melt: removing slag, taking temperature measurements, taking melt samples, adjusting chemistry by introducing additives to the melt, and bath ground testing.

The robot, upon operator selecting a task on the control screen, begins its fully programmed work by selecting one of five tools from the “Smart” tool rack: slagging tool, thermocouple lance, sample lance, bath grounding probe and a trim material pan. Sensors are used to tell the robot which tools are available.

Another advantage of automated systems is the energy savings that are created. The fast pace of the robotic operations minimizes the time required for the lid to be open, thereby minimizing one of the biggest energy wasters in melting.

After the charge is completely molten, metal is delivered to numerous types of automatic pouring systems. Automatic pouring systems increase casting production and enhance casting quality, while keeping foundry workers at a distance. These advanced systems provide the pouring performance they need to keep pace with automated flask and flaskless molding machines and the precise control required to meet the highest standards of quality. Automatic pouring helps foundries increase productivity, reduce scrap castings, reduce operating costs and improve worker safety.

There are many labor-saving features available to promote safety and efficiency, such as furnace lining push-out systems. They contribute to melt shop automation by speeding up lining removal and limiting the personnel’s exposure to refractory dust.

Automated furnace operations offer a variety of important advantages. Automated processes are precisely repeatable, ensuring consistency and improved productivity melt after melt. Better working conditions, with the most dangerous tasks performed by a robot and other automated equipment, make it easier to recruit and retain foundry workers. But, the primary benefit provided by automated equipment is greatly enhanced worker safety. This allows managers to remove the furnace operator from the most dangerous areas near the furnace, decreasing the potential for injury to their most important asset.