Abstract: A method of operating a crystallizing vessel assembly, said vessel assembly having a crystallizing vessel, and a rotor comprising a rotor shaft, said rotor including a plurality of rotor arms, said rotor arms having arms attached to the rotor shaft and scrapers attached at the arms. The crystals are grown on the inside of the vessel and the rotor is rotated to scrape said crystals off. To improve liquid flow inside the crystallizing vessel, a plurality of arms of the rotor arms are hollow arms, each arm of the plurality of arms including an inlet opening that is relatively close to the shaft and an outlet opening that is relatively far from the shaft.

Abstract: A method of operating a crystallizing vessel assembly, said vessel assembly having a crystallizing vessel, and a rotor comprising a rotor shaft, said rotor including a plurality of rotor arms, said rotor arms having arms attached to the rotor shaft and scrapers attached at the arms. The crystals are grown on the inside of the vessel and the rotor is rotated to scrape said crystals off. To improve liquid flow inside the crystallizing vessel, a plurality of arms of the rotor arms are hollow arms, each arm of the plurality of arms including an inlet opening that is relatively close to the shaft and an outlet opening that is relatively far from the shaft.

Abstract: A method of performing an operation such as a maintenance operation on a vessel assembly, said vessel assembly having a vessel, such as a crystallizing vessel, a rotor, said rotor including an upright, rotatable shaft, said shaft having a top shaft section extending above a top wall of the vessel, to perform maintenance. The top shaft section includes a first member chosen from a male member and a female member for engaging a device. The device has a top end, and a bottom end. The bottom end includes a complementary second member for the first member. According to the method, the device is connected to the top shaft section of the shaft, the rotor is lifted by lifting the shaft at its top end section using the device, following which the operation is performed.