Abstract: A gentle start-up device includes: a rotational type hollow pipe body, including an inlet and an outlet, and having an inner wall provided with a plurality of bar-shaped fins; a transmission unit, physically connected to the rotational type hollow pipe body; and a driving unit, physically connected to the transmission unit for driving the transmission unit to rotate the rotational type hollow pipe body in a rotational direction and to achieve a predetermined rotational speed according to a water supply flow value of a water turbine of a hydraulic generator set, whereby water flow which passes through the rotational type hollow pipe body generates rotational flow.

Abstract: A gentle start-up device includes: a rotational type hollow pipe body, including an inlet and an outlet, and having an inner wall provided with a plurality of bar-shaped fins; a transmission unit, physically connected to the rotational type hollow pipe body; and a driving unit, physically connected to the transmission unit for driving the transmission unit to rotate the rotational type hollow pipe body in a rotational direction and to achieve a predetermined rotational speed according to a water supply flow value of a water turbine of a hydraulic generator set, whereby water flow which passes through the rotational type hollow pipe body generates rotational flow.

Abstract: A cooling apparatus includes a convoying unit and a spraying unit. The convoying unit includes a base and a plurality of rollers. The base includes a feeding end and a discharging end in which a convoying direction extends from the feeding end to the discharging end. The rollers are arranged on the base. Each roller includes a convoying portion. The convoying portion has a diameter which reduces from two ends to a center thereof. Each roller includes a shaft. The shaft has an axle direction which is at a diverted angle to the convoying portion. The diverted angle is 15° to 90°. The spraying unit includes at least one nozzle unit arranged between the feeding end and the discharging end. In this arrangement, a cooling operation can be performed on a rod-shaped steel material that is moving and rotating at the same time, attaining uniform and fast cooling effect.

Abstract: A method of heat treatment of a metal material is disclosed. The method of heat treatment includes heating the metal material to a first temperature through a heating fixture, and reducing the first temperature of the metal material to a second temperature through a cooling apparatus performing a fast cooling operation. The fast cooling operation has a high cooling speed of 80° C./sec to 200° C./sec. As such, the processed metal material can have the required mechanical properties.