Design and Control of Deep Sea Bulk Terminals (2008.TEL.7294)
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Summary
Dry bulk products are transported in vast amounts, often from one continent to another, by bulk carriers. Bulk carriers are loaded at ‘export’ bulk terminals and unloaded at ‘import’ bulk terminals. Bulk terminals have two major functions:
• Loading and/or unloading bulk carriers as well as other (hinterland) transport equipment for example trains or barges.
• Temporarily storing bulk in order to decouple differing in- and outgoing flow patterns. For both functions equipment and space is needed.
The growing demand for bulk products is causing a growing demand for higher throughput of bulk terminals.
The increase of bulk terminal throughput can be achieved in three ways:
• Expansion of the terminal: This requires additional space and equipment
• Equipment upgrading: Upgrading equipment with new equipment with higher storage and handling capacity.
• Improving operational control: This is the ‘cheapest’ way of increasing the throughput. In order to better utilize the handling and storage capacity.
After literature research and model design, a generic bulk terminal computer simulation model is created. This model is generic with respect to:
Terminal type, terminal lay-out, distribution of relevant bulk grades over the stockyards, (un)loading equipment, stacking/reclaiming equipment and conveyor lines for transportation of the bulk. All equipment can be assigned with a break down time pattern. Model input should consist of import and export flows, generated on the basis of deep sea bulk carriers and land side batches, for example train loads.
The model can operate on basis of different control methods. That may take into account: • Long travel time of stacker reclaimer
• Bulk mass travel time caused by conveyor belt speed and the distance between stockpile and the position of train or bulk carrier.
• Equipment Availability • Equipment Effective Capacity
As Key Performance Indication (KPI) the average berth time of bulk carriers is chosen.
The results found at an export terminal case by varying control methods and equipment properties are:
• There is a berth time reduction of 50% possible between the best and the worst (unrealistic) control method.
• Comparing 10 different realistic control methods shows a difference of 7% in berth time reduction.
• Doubling the long travel speed of the stacker reclaimers reduces the berth time by 2% • Doubling the conveyor belt speed reduces the berth time by 5%. A throughput rise of 22% is
possible when the berth time is kept the same.
• Reducing the breakdowns to 50% reduces the berth time by 12%. A throughput rise of 67% is possible when the berth time is kept the same.
• Increasing the effective capacity of equipment by 50% reduces the berth time by 35%. A throughput rise of 116% is possible when the berth time is kept the same.
