摘要 |
A fluid is cooled and liquefied in an apparatus with a heat exchanger (5) having a shell side (78) within its walls (85) and a plurality of flow passages extending through the shell side (78). The plurality of flow passages comprises two or more primary groups (40a, 40b) of one or more primary flow passages, each said primary group for carrying a part of the fluid stream through the heat exchanger (5) and to indirectly cool said part against a refrigerant in the shell side (78) of the heat exchanger (5) to provide a liquefied fluid stream (50, 70). A primary inlet header (6,6′) connects the two or more primary groups (40a, 40b) of primary flow passages to a source of the fluid (10), and arranged to split the fluid stream between the two or more primary groups (40a, 40b) of primary flow passages. Means (25a, 25b) are provided for selectively blocking at least one of the two or more primary groups (40a, 40b) of primary flow passages whilst allowing the fluid stream to flow through the remaining unblocked primary groups of primary flow passages. |