摘要 |
PURPOSE:To shorten the press process time and reduce the running cost, by detecting the filtrate flow rate in the press process to measure the changes in correspondence with time, and giving a command for next process when the variation rate becomes small. CONSTITUTION:In the press process, the filtrate changes in correspondence with time. As the press approaches the end point, the quantity of filtrate DELTAQ per unit time DELTAt decreases. When the ratio DELTAQ/DELTAt reaches a certain point, it is regarded as the end of the press process, and a start command for next dehydrating process is issued. If the condition of the sludge is bad and it takes too much time to reach the specified value, the operation may be advanced to the next process when exceeding the preset backup time Tb. In this operaion control, the service life of the filter cloth of the dehydrating machine may be extended. |