Metal melt pump with heat insulating hood

A metal melt pump that drives metal melt inside a furnace, the metal melt pump comprising:

• a bottomed cylinder body including a side wall and a bottom wall;
• a melt flow passage body including a melt flow passage that connects a suction port and an ejection port, the melt flow passage body being a body separate from the bottomed cylinder body;
• and
• a melt driving part including a magnetic field device rotatably disposed around a vertically oriented rotary shaft inside the bottomed cylinder body and an electric motor that rotates the magnetic field device, the melt driving part adapted to drive metal melt in the melt flow passage,
• wherein
• the magnetic field device includes a plurality of permanent magnets arranged such that different magnetic poles are alternately arrayed along a circumference of the rotary shaft, and
• the melt flow passage body is removably provided on the bottomed cylinder body at a position around the side wall of the bottomed cylinder body and where a magnetic force line from a first permanent magnet among the plurality of permanent magnets penetrates through the side wall of the bottomed cylinder body and an inner side flow passage wall of the melt flow passage body to reach the melt flow passage and penetrates from the melt flow passage through the inner side flow passage wall of the melt flow passage body and the side wall of the bottomed cylinder body to return to a second permanent magnet adjacent to the first permanent magnet,
• the metal melt pump further comprising:
• a heat insulating hood configured to cover the magnetic field device and the electric motor of the melt driving part and to define a cooling air flow passage for cooling air to flow through the magnetic field device and the electric motor,
• wherein the heat insulating hood comprises:
• a fixed hood fixed to a base plate that defines, together with the bottomed cylinder body, a space that houses the magnetic field device, the fixed hood covering the electric motor and provided with an air intake hole that takes in the cooling air;
• and
• a movable hood attached to the magnetic field device so as to define, together with the fixed hood, the cooling air flow passage and to cover an outer periphery surface of the magnetic field device, the movable hood adapted to rotate together with the magnetic field device,
• wherein a lower end portion of the fixed hood is loosely inserted into an upper end portion of the movable hood or the upper end portion of the movable hood is loosely inserted into the lower end portion of the fixed hood.