CRYOGENIC HOPPER OF BALLS FOR COLD NEUTRON MODERATOR Russian patent published in 2013 - IPC G21K1/00 

FIELD: power engineering.

SUBSTANCE: invention relates to facilities for dosing of loose material in the form of solid balls, in particular, balls from frozen aromatic hydrocarbons, and is designed for supply of a working substance (balls) into a pneumatic tract with cold gas of helium for their subsequent delivery into a chamber of a cold quick neutron moderator of an intense source (a nuclear reactor or a neutron-producing target of an accelerator). The invention is aimed at improvement of temperature stability in a hopper and at provision of controlled speed of balls dosing. In the proposed device walls of the hopper and a part of a helium-feeding pipe are made of copper, and a dosing element represents one thin metal disc with holes of a certain diameter arranged in the lower end part of the hopper instead of the bottom. When the disc is fixed, balls do not drop from the hopper. In the dosing mode the disc is put into step rotation by a controlled step motor, the dropping speed is defined by the pitch size of disc rotation, frequency of steps repetition and the number of holes in the disc. High heat conductivity of copper provides for low temperature in the hopper and on the disc, which is close to helium temperature in the pneumatic tract.

EFFECT: exclusion of forced cooling of a hopper with liquid nitrogen.

1 cl, 1 dwg