| 摘要 |
<p>919,772. Drying paper. SULZER FRERES S.A. June 23, 1960 [July 17, 1959], No. 22030/60. Class 96. [Also in Group XIII] The drying section 1 of a paper-making machine comprises a travelling felt and a closed hood 2, in which warm exhaust air is collected. This air is passed through a pipe 3 and a heatexchanger 4 to heat water stored in a tank 7. The exhaust air then passes through a pipe 14 and a heat-exchanger 15, in which it heats fresh air entering through a pipe 16. The heated fresh air passes, through a pipe 17, a fan 18 and a heater 19, into the base of the drying section to serve as below-felt drying air. Exhaust air from the heat-exchanger 15 is discharged into the atmosphere through a pipe 23 and fan 24. A pipe 10, incorporating a valve 11, connects the pipes 3 and 14 to by-pass the heat-exchanger 4. A pipe 22, incorporating a valve 21, connects the pipes 14 and 23 to by-pass the heatexchanger 15. The valve 11 is actuated by a servomotor 13 controlled by a thermostat 12 in the heated water. The valve 21 is actuated by a servomotor 26 controlled by a thermostat 25 in the heated fresh air entering the drying section. When the temperature of this air falls below a predetermined value, the thermostat 25 overrides the control exerted by the thermostat 12 to limit the extent to which the valve 11 can be closed.</p> |
