| 摘要 |
<p>1478419 Thermal regenerators AIR PRODUCTS and CHEMICALS Inc 22 Jan 1976 [28 Jan 1975] 3738/75 Heading F4K At each end of the reversing fluids flow path through a system of regenerative heat exchangers (in particular in an air separation plant) is provided an inlet branch and an outlet branch (e.g. 46, 48 and 34, 36) each branch incorporating two valves, such as check valves 24 and 50 in the branch 46 and switch valve 16 and check valve 38 in the branch 34, and a vent pipe being provided between each said two valves, e.g. vent pipe 57 between valves 24 and 50 in branch 46, and means being provided to control fluid flow through the vent pipes. In the operation of the system, the heat exchanging fluids being air and low pressure nitrogen; as each gas flows in turn through the regenerator 12 from its respective inlet branch at one end of the regenerator to its respective outlet branch at the other end of the regenerator, any gas leakage (e.g. through valves which are closed until the fluids are reversed) is vented respectively through the vent pipe associated with the outlet branch at said one end and with the inlet branch at said other end of the regenerator. Each vent pipe has a switch valve such as 66 incorporated therein and these valves as well as the other switch valves, such as 16, in the system are all controlled by a valve timer 80. The intention is to prevent contamination of the nitrogen gas by the air during the steady state operation of the heat exchanger. At the end of a cycle, during which air has been flowing through the regenerator, the regenerator flow path is purged of air via the vent pipe 61 (or 64) before the nitrogen is admitted. Alternatively such venting may be effected through an additional vent (not shown) downstream of the valves 38 and 44.</p> |
