Coiling mandrel and relative procedure for monitoring the condition thereof

A cooling control system of a coiling mandrel for metal products originating from a hot rolling mill plant comprising:

• a coiling mandrel which comprises
• an internal shaft with a plurality of sectors;
• an external drum which as a whole contains coaxially said internal shaft and which is circumferentially subdivided into a plurality of segments arranged in a direct or indirect coupling connection with said sectors, wherein the indirect coupling connection is realized by wedges coupled to anyone of said sectors and interposed between said segments and said sectors;
• an internal and/or external cooling system of the mandrel;
• wherein said segments are movable in a radial direction with respect to said internal shaft by an axial movement of the latter, subsequently to the internal shaft, causing the consequent radial expansion or collapse of the drum;
• and
• wherein said mandrel is provided with
• a group of temperature detection sensors;
• and a control unit adapted to:
• receive temperature data measured in the mandrel,
• and provided with an algorithm which:
• compares said data with temperature nominal values,
• increases, reduces or maintains constant the flow of the cooling liquid based on the difference determined between the measured value of the temperature and the target nominal value of the temperature.