Can a dock be used to unload oil with a steam reciprocating pump? Seeking experts
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At our company’s dock, oil is unloaded (the medium is residue oil with a dynamic viscosity of m²/s at 20°C; the liquid level in the ship is about 3 meters below the ground level). During the initial stages of unloading, heating was not considered to avoid losses due to vaporization of the oil, so unloading was carried out without heating, which resulted in longer unloading times and frequent damage to the screw pumps used for unloading. To ensure production, the company’s management has proposed installing a steam reciprocating pump for unloading oil. The steam used should be at 0.9 MPA, and the unloading capacity needs to be over 100 m³/h. Could you please advise whether this is feasible? If any of you sea friends have seen it, please give some guidance. Thank you!
Based on our previous experience, pumps used for unloading oil generally have high flow rates; centrifugal pumps, twin-screw pumps, or rotor pumps are typically used, as all of these types can meet the required flow rates. Moreover, twin-screw pumps have advantages when used for transporting residue oil; I can send you some information on that. Reciprocating pumps can also be considered plunger pumps, and their main advantage is high outlet pressure, though the flow rate is not high. As far as I know, a reciprocating pump with a capacity of 100 cubic meters is considered a large-scale pump. The cost is very high; it is recommended to use twin-screw pumps or rotor pumps. If you are interested, I can prepare a proposal for you
Thank you for your reply. We initially used twin-screw pumps and rotor pumps. The biggest problem at present is that the residue oil is not heated during unloading, which results in a very high dynamic viscosity. This leads to high resistance for the pumps during unloading, reduced unloading capacity, a tendency for the pumps to reach vacuum conditions, and a high failure rate. What worries me now is whether the suction lift will be sufficient once the steam reaches the reciprocating pump, and whether it might experience vacuum conditions. Additionally, I am very interested in your oil unloading plan for the centrifugal pump; I would appreciate your guidance.