Device for determining the elongation of two chains and associated twin-chain conveyor and method

A method for determining an elongation of a first chain and a second chain of a matched pair of parallel chains of a twin-chain conveyor, the method comprising:

• performing an initialization step comprising:
• driving the first and second chains at a predetermined speed,
• detecting a first instant of passage of a first target element arranged at a first end of a first chain pin of the first chain in front of a first sensor,
• detecting a first instant of passage of a first target element arranged at a first end of a first chain pin of the second chain in front of a second sensor,
• detecting a second instant of passage of a second target element arranged at a first end of a second chain pin of the first chain in front of the first sensor,
• detecting a second instant of passage of a second target element arranged at a first end of a second chain pin of the second chain in front of the second sensor,
• determining a duration between the first instant of passage of the first target element of the first chain in front of the first sensor and the second instant of passage of the second target element of the first chain in front of the first sensor as a first reference duration,
• determining a duration between the first instant of passage of the first target element of the second chain in front of the second sensor and the second instant of passage of the second target element of the second chain in front of the second sensor as a second reference duration,
• after performing the initializing step, performing a conveying step comprising:
• driving the first and second chains at the predetermined speed while a material is conveyed by the twin-chain conveyor,
• detecting a third instant of passage of the first target element of the first chain in front of the first sensor,
• detecting a third instant of passage of the first target element of the second chain in front of the second sensor,
• detecting a fourth instant of passage of the second target element of the first chain in front of the first sensor,
• detecting a fourth instant of passage of the second target element of the second chain in front of the second sensor, and
• determining a duration between the third instant of passage of the first target element of the first chain in front of the first sensor and the fourth instant of passage of the second target element of the first chain in front of the first sensor as a third reference duration,
• determining a duration between the third instant of passage of the first target element of the second chain in front of the second sensor and the fourth instant of passage of the second target element of the second chain in front of the second sensor as a fourth reference duration,
• determining a difference between the third duration and the first duration as a first degree of elongation of the first chain,
• determining a difference between the fourth duration and the second duration as a second degree of elongation of the second chain, and
• determining a differential elongation equal to a difference between the first degree of elongation and the second degree of elongation.