| 摘要 |
The method and the appliance employ at least two parallel coiled pipes (2, 3, 4, 5); the material stream to be heated and/or to be evaporated flows via the coiled pipes in divided form. The temperature Ti of the material stream is measured at the end of each coiled pipe i (13, 14, 15, 16) and the mean value <IMAGE> is calculated (29), where n denotes the number of coiled pipes. Each of the temperature differences T-Ti (34, 33, 32, 31) is used to generate a signal which controls the material flow (17, 18, 19, 20) through the coiled pipes (2, 3, 4, 5) in question in such a way (25+9, 26+10, 27+11, 28+12), that the temperature difference T-Ti decreases. The highest temperature Timax of all the temperatures Ti is employed to calculate the difference Timax-Ts (30), where Ts denotes the temperature set point of the overall material stream leaving the oven. The calculated difference Timax-Ts (35) is used to generate a signal which controls (23) the generation of heat in the oven in such a way that said temperature difference decreases. <IMAGE> |
