• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.12
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• pp.1702-1714
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• 1998

Removal of spilled oil over the sea and the river has become one of the urgent problems in these days. Removing oil using mechanical devices was recommended because chemical dispersion could cause the secondary contamination in the environment. In the present study a series of experiments were carried out to study the effect of operating conditions, especially, the angle between the belt and the fluid surface on the rate of recovery for the spilled oil using a belt skimmer. Three different types of operation, namely, upward pickup, downward pickup and up-and-downward pickup situations have been investigated for various contact angles, belt speeds and oil thicknesses to find the effects on the recovery rate. The highest rate of oil recovery was found in the case of a contact angle of $45^{\circ}$ and downward pickup. Furthermore, an optimal belt speed was found to reach the saturated recovery rate for a given oil thickness.

• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.132-143
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• 1997

Removal of spilled oil over the sea and the river has become one of the urgent problem in these days. Removing oil using mechanical devices are recommended because chemical dispersion can cause the secondary contamination in the environment. In the present study a series of experiments were carried out to study the effect of working conditions of a belt type skimmer on the rate of recovery for the spilled oil. The oil chosen for the present experiment was diesel oil. Three different situations, namely, upward, downward, up-and-downward pickup have been investigated for various contact angles, belt speeds and oil thicknesses. The results show that the rate of oil recovery for the case of downward pickup with a contact angle of 45.deg. shows the highest among all the conditions. For the removal of spilled diesel oil the optimal belt speed can be found as the critical value to reach the saturated pickup rate for a given oil thickness. The recovery rate of bunker C oil shows 4-6 times higher than that for diesel oil. And the optimal belt speed for bunker C oil can be found less than that for diesel oil for the same slick thickness.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.4
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• pp.52-66
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• 2003

Generally we have difficulty in removing oil using mechanical devices because recovery rate and recovery efficiency decrease remarkably when operating in thin oil films or in oils of very high viscosity In the Present study a series of experiments were carried out to study the effect of operating conditions on the rate of recovery for the spilled oil using a drum type skimmer. For each set of experiments depth of immersion, oil film thickness and the circumferential speeds were varied systematically to find the effects on the recovery rate. The results shows that recovery rate is dependent on the contact angle for the depth of immersion and the highest rate of oil recovery shows in the case of a contact angle of 45°(h/d=0.15). For the removal of spilled oil the optimal circumferential speed can be found as the critical value to reach the saturated recovery rate for a given oil film thickness and depth of immersion. Even in thin oil thickness we have enough recovery rate and recovery efficiency within critical circumferential speed this way.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.5
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• pp.679-690
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• 1997

Oil spill over the sea and the river become a serious problem in these days. Two different approaches are used to clean up the spilled oil by means of chemical dispersion and mechanical devices. If it is possible, removing spilled oil using mechanical devices are highly desirable in order not to worry about the secondary contamination from chemical treatment. One of the major unsolved problems using mechanical devices has been the recovery of highly viscous oil spill. So, the systematic experimental data for treating very viscous oil are still wanting. In the present study a series of experiments were carried out to study the effect of the rotational direction of the belt skimmer on the rate of oil recovery using Bunker C oil. Three different situations, namely, upward, downward and up-and-downward pickup rate have been investigated for variable belt speed. The results showed that the rate of oil recovery for downward pickup was much higher than that for upward pickup. The major mechanism to recover the oil using a belt skimmer has been confirmed that oil sticks to the belt surface while moving to the water rather than moving upward. For the removal of spilled oil the optimal belt speed under the present experimental conditions was found to be about 200 ~ 270 mm/s just before the starvation started. The present experimental results would provide the basis for understanding the performance characteristics and physics of various types of skimmers.