| 摘要 |
<p>The invention relates to a method and an installation for the refrigeration by discontinuous charges of objects in bulk which occupy a long thermally-insulated zone, the method comprising essentially the steps of: carrying out the complete refrigeration of the objects located in a longitudinally-restricted portion of the thermally-insulated zone by circulating a main flow of cooling gas longitudinally inside the restricted portion, partly re-cycling the cooling gas outside the thermallyinsulated zone to an injection station for frigorific energy such as refrigerated gas in the liquid or solid state, precooling the objects located in a remaining portion of the insulated zone by the longitudinal circulation of an excess flow of non-re-cycled cooling gas through the remaining portion followed by evacuation to the atmosphere, circulating all the main flow of cooling gas longitudinally through the remaining portion of the insulated zone, and re-cycling an excess flow of said cooling gas outside said zone to the frigorific energy injection station with subsequent direct evacuation to the atmosphere. The operations take place in two stages, the duration of the first stage being such that the cooling gas temperatures at the inlet and outlet of the restricted portion are substantially equal, the duration of the second stage being such that the cooling gas temperatures at the inlet and outlet of the remaining portion of the insulated zone are substantially the same. Application to the cryogenic fragilization of objects for their grinding or separation.</p> |
