Low energy and non-heat transferring crust breaking system

A system for processing molten metals, comprising:

• a vessel for retaining a mass of molten metal wherein said mass of molten metal periodically forms a crust on a top surface;
• a device operable between first and second working positions for selectively breaking the crust;
• a control system for controlling operation of the device between the first and second working positions, the control system comprising:
• a control actuator selectively actuated to enable fluid communication between the device and a source of pressurized fluid;
• a driving system for selectively driving the device between the first and second working positions in response to the control actuator enabling fluid communication between the device and the source of pressurized fluid;
• a sensing system for identifying either of the first and second working positions of the device and manipulating a flow of pressurized fluid to the device in response thereto;
• and
• a monitoring actuator selectively actuated by the sensing system for relieving the flow of pressurized fluid to a portion of the driving system, wherein the monitoring actuator remains actuated until the control actuator is deactuated.

A pneumatically-operated device comprising:

• a pneumatic cylinder having a piston slidably disposed therein and movable between first and second working positions;
• a pneumatic control system in fluid communication with first and second chambers of said pneumatic cylinder, said pneumatic control system comprising:
• a control actuator selectively actuated to enable fluid communication between the pneumatic cylinder and a source of pressurized fluid;
• a driving system for selectively driving the piston between the first and second working positions in response to the control actuator enabling fluid communication between the device and the source of pressurized fluid;
• a sensing system for identifying either of the first and second working positions of the piston and manipulating a flow of pressurized fluid to the device in response thereto for retaining the piston in the first working position;
• and
• a monitoring actuator selectively actuated by the sensing system for relieving the flow of pressurized fluid to a portion of the driving system, wherein the monitoring actuator remains actuated until the control actuator is deactuated.