ケミカルタンカーの荷揚後の管内残留貨物量の低減に関する研究

Abstract

To reduce the quantity of remaining noxious liquid substances in piping arrangement after the unloading, the effectiveness of gas blowing which is commonly applied to the chemical tankers is examined analytically. Two different test arrangements are considered for the means to maintain back pressure at the end of horizontal pipe. Back pressure is maintained by 10m. long vertical riser pipe (10mP) or constant pressure valve (CPV) . Model for predicting the quantity of remaining water and pressure in horizontal pipe during the process of air blowing for the test arrangement of CPV is developed, based on physical mechanism presented in previous paper for the test arrangement of 10mP. Results predicted by the present analysis are both compared with experimental data for 4-inch and 6-inch diameter horizontal pipe lines and with the predicted results for the test arrangement of 10mP. Good coincidence with experimental data is obtained and two predictions are in satisfactory coincidence. This suggests that constant pressure valve has an equivalent function to the 10m. long vertical riser pipe.