Cryogenic treatment method for large-diameter cold-rolled work rolls and the cryogenic box used

Abstract

The invention discloses a subzero treatment method for a large-diameter cold rolling work roller and a copious cooling box thereof. The copious cooling box comprises a box body with an insulating layer, an insulating box cover and liquid nitrogen spray pipes arranged in the box body. Two liquid nitrogen spray pipes are respectively arranged on the upper side and the lower side, nozzles of the two liquid nitrogen spray pipes on the upper side are inclined downwards, nozzles of the liquid nitrogen spray pipes on the lower side are inclined upwards, and net covers are arranged at the nozzles of the liquid nitrogen spray pipes. The subzero treatment method comprises the steps of enabling the temperature in the copious cooling box to fall to -80 DEG C to -120 DEG C and insulating for 1h-3h, then arranging the large-diameter cold rolling work roller in the copious cooling box, and controlling ultralow temperature electromagnetic valves on pipelines between the liquid nitrogen spray pipes and a liquid nitrogen storage tank to enable liquid nitrogen to be sprayed out of liquid nitrogen spray pipes to cool the large-diameter cold rolling work roller. The subzero treatment method achieves low temperature cooling, enables the low temperature limitation to be about -180 DEG C, can quickly reduce the surface temperature of the roller and improves cooling efficiency.

Description

Technical field [0001] The invention belongs to the technical field of cryogenic treatment, and specifically relates to a cryogenic treatment method for large-diameter cold rolling work rolls and a cryogenic box used in the same. Background technique [0002] Cryogenic boxes are currently the most commonly used equipment for cryogenic treatment of cold rolling work rolls. The existing cryogenic boxes are divided into two types: liquid medium cryogenic boxes and gas medium cryogenic boxes. [0003] The liquid-medium cryogenic box uses n-propanol or similar liquids as the medium, and uses liquid nitrogen or dry ice as the refrigerant to cool down the cold-rolled work rolls. The cooling process curve is as follows figure 2 Shown. The advantage of the liquid medium cryogenic box is that the liquid can be pre-cooled, so as to take advantage of the high heat exchange rate of the liquid to make the surface of the cold-rolled work roll cool rapidly in the early stage of the treatment proce...

AI Technical Summary

Problems solved by technology

Therefore, its initial cooling rate is slow ( image 3 The surface temperature of the middle roll is still about 0°C after 2 hours, and it drops to -40°C after 4 hours), which requires a long time of heat preservation and low heat exchange efficiency

[0006] Therefore, the working efficiency of cryogenically treating large-diameter cold-rolled work rolls with an air-medium cryogenic box is low, and the effect is not ideal

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