Pulverizing device, throat for pulverizing device, and pulverized-coal fired boiler

A pulverizing device, comprising:

• a housing;
• a pulverization table configured to rotate inside the housing;
• and
• a throat, disposed inside the housing on a radially outer side of the pulverization table, for forming an upward air flow,
• wherein the throat includes:
• an inner ring extending along an outer periphery of the pulverization table;
• an outer ring, disposed on a radially outer side of the inner ring so as to form an annular flow passage between the inner ring and the outer ring;
• a plurality of throat vanes disposed between the inner ring and the outer ring, and wherein, following expressions (a) and (b) are satisfied:
• 2.0≤L/d≤4.0 (a)
• 0.5≤H/d≤1.5 (b)
• where H is a gap between the inner ring and the outer ring with respect to a radial direction, L is a length of the throat vanes, and ‘d’ is a distance between
• adjacent two of the throat vanes,
• wherein each throat vane is oblique toward an upstream side, with respect to a rotational direction of the throat, from a lower end toward an upper end of the throat vane, and
• wherein following expression (d) is satisfied:
• H/d≥0.95×(sin θ)−2.0×(L/d)−1.2 (d)
• where θ is an inclination angle of the throat vanes with respect to a rotational center axis of the throat.