| 摘要 |
PURPOSE:To make the easy and continuous measurement of the thickness of dehydrated cake possible in the measurement stage of the thickness of said cake by intercepting a part of a laser luminous flux by means of the cake layer formed on a drum and measuring the intensity thereof. CONSTITUTION:A filter drum 5 is immersed in sludge mixed liq. 7 stored in a liq. tank 6. Since a filter cloth 9 is wound on the outside surface 8 of the drum and the inside of the drum is evacuated to a vacuum through an air release port, the sludge in the sludge mixed liq. is sucked and captured successively by the filter cloth as the drum 10 rotates, by which it is dehydrated and a dehydrated cake layer 11 is formed on the filter cloth. The cake layer is scraped off by a scraper 12. If a luminous flux of a beam diameter larger than the thickness of the cake layer is irradiated to the cake layer from a laser oscillator 13, part of the luminous flux is intercepted by the thickness of the cake layer. Since the quantity of the intercepted light is continuously proportional to the thickness, the thickness of the cake is obtained by measuring the intensity of the luminous flux with a measuring device 14 for luminous intensity. |
