| 摘要 |
1482464 Electric resistance heating BOC INTERNATIONAL Ltd 7 March 1975 [20 March 1974] 12401/74 Heading H5H A through flow fluid heater comprises a fluid permeable mass of electrically conductive material (e.g. carbon fibres or carbon coated fibres) 12 within a tube of electrically non-conducting material (e.g. glass) 2 between fluid permeable electrically conducting plugs 8 (e.g. of sintered metal) which connect the electrical supply with the heating conductor at points as widely spaced as possible on the fluid flow path. A further non-conducting tube 14 may pass coaxially through the first. Electrical connections to plugs 8 are via conductive extensions to one or both tubes, 4, 4, Fig. 1 and 4, 22, Fig. 3. To provide terminals at the same end of the heater, a conductive sleeve 20 may line the inner tube and is connected to the extension of the inner tube. Cold fluid passes through the central tube and is mixed with the heated fluid in a chamber 18. By keeping constant flow late through the heated tube, current supply and voltage, temperature of the mixed fluid leaving chamber 18 can be controlled by altering the rate at which cold fluid is supplied to the inner tube 16. A number of either sort of heater can be used together to give a greater volume of heated fluid. They are connected electrically in series and fluidically in parallel (Fig. 4, not shown). |
