Pneumatic system for controlling aluminum bath crust breaker

A pneumatic system for controlling a bath crust breaker, comprising:

• a cylinder defining a piston chamber;
• a piston slidably displaced within the cylinder by a pressurized fluid;
• a crust breaker rod connected to the piston displaced into a bath by displacement of the piston;
• and
• a pneumatic valve system, including:
• a first control valve moved between first control valve first and second positions, the first control valve in the first control valve first position aligned to pressurize a first portion of the piston chamber, and in the first control valve second position aligned to pressurize a second portion of the piston chamber;
• an orifice positioned between a pressure source and the first control valve sized to control a pressurized fluid flow rate per unit time such that a pressure reached in either the first or second portion during a crust breaking cycle is less than a maximum pressure of the pressure source;
• and
• a second control valve moved between second control valve first and second positions, the second control valve in the second control valve first position aligned with a pressure source and the first control valve to pressurize the first portion of the piston chamber, and in the second control valve second position is aligned to isolate the pressure source from both the first control valve and the first portion.

A pneumatic system for controlling a bath crust breaker, comprising:

• a cylinder defining a piston chamber;
• a piston slidably displaced within the cylinder by a pressurized fluid from a pressure source directed to either a first portion of the piston chamber with respect to the piston or a second portion of the piston chamber oppositely positioned about the piston with respect to the first portion;
• a crust breaking member connected to the piston and displaced into a bath when the piston is displaced in the cylinder in a piston drive direction;
• at least one control valve directing the pressurized fluid into either the first or second portion of the piston chamber;
• and
• multiple orifices each positioned in line with individual pressure sources, the orifices each sized to limit a flow rate of a pressurized fluid from the pressure source to the piston chamber such that a pressure within the first and second portions of the piston chamber is limited to less than a maximum pressure of the pressure source.

A method for controlling a bath crust breaker pneumatic system, the pneumatic system including a cylinder defining a piston chamber having a first portion and a second portion, a pressurized fluid, a crust breaker member connected to a piston, and first and second control valves each alignable to a first and second position, the method comprising:

• aligning the first control valve to the first control valve second position to pressurize the second portion of the piston chamber
• causing the piston together with the crust breaker rod to be displaced into a bath;
• during the aligning the first control valve to the second position, passing pressurized fluid flowing from a second portion directed pressure source through the first control valve and into the second portion through a first orifice to control a pressurized fluid flow rate per unit time such that a pressure reached in the second portion during a crust breaking cycle is less than a maximum pressure of the second portion directed pressure source;
• aligning the second control valve to the second control valve second position to pressurize the first portion of the piston chamber causing the piston together with the crust breaker rod to be displaced away from the bath;
• and
• during the aligning the second control valve to the second position, passing pressurized fluid from a first portion directed pressure source through the second control valve and into the first portion through a second orifice to control a pressurized fluid flow rate per unit time such that a pressure reached in the first portion during the crust breaking cycle is less than a maximum pressure of the first portion directed pressure source.