Issues in selecting oil unloading pumps for oil depots (improving unloading efficiency)
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Dear experts, the oil products in our company are mainly supplied through unloading. Since we don’t have a dedicated unloading area, unloading is carried out by connecting pipeline pumps to the spare ports on the loading platform, and then using pipelines from the platform to reach the pump house before the oil is sent to the storage tanks. At present, the model specifications of the pipeline pump we use for unloading are as follows: flow rate of 50 m3/h, head of 32 m, power of 7.5 kw. A hose with an inlet diameter of DN80 is connected to the vehicle, while a hose with an outlet diameter of DN80 is connected to the spare connection point on the vehicle’s pipeline system; the pipeline leading to the pump room has a diameter of DN100. Storage tanks are generally in the range of 3,000–5,000 m3 in volume, with a safety height of around 15 meters; unloading usually takes place while the tanks are filled with material. However, in actual use, the flow rate only reaches around 30 m3/h, and it takes 2 hours to unload one truck, which has caused great dissatisfaction among customers. The circuit load design for our equipment is relatively low; circuits exceeding 7.5 kw are prone to burning out. Therefore, we would like to ask: (1) Without being able to maintain a power level of 7.5 kw, are there any ways to optimize the selection and choose a pump with more suitable specifications? (The actual flow rate is expected to reach 50 m3/h for operation.) (2) Currently, a vertical pipeline pump with a flow rate of 50 m3/h, a head of 32 m, and a power output of 7.5 kW is being used; the outlet pipe diameter is DN100, and the density of the fluid is around 0.8. The actual flow rate is only about 30 m3/h. Is this normal? (A pipe support is required; the length of the pipeline may range from 100 to 300 meters, with approximately 4 to 6 bends.)
Personally, I think the pump head selected by the poster is too low; the actual pressure drop in the piping is high, which prevents an adequate flow rate. It is recommended to increase the head; a pump with higher efficiency can be chosen. Or take other measures to reduce the pipeline pressure drop.
First, the pump’s performance is insufficient; adding a elbow increases resistance； Second, you can use gas balance unloading; that might be better ； For the third major investment point, installing a low-level trough can solve many problems. The simplest are gas balance and pump replacement. To be honest, there are also problems with the design institute; why would the unloading area have to be that far away? Isn’t this cheating the client, and do the client’s staff also build strictly according to the blueprints?
It’s because the pipeline is too long and there are elbows; as a result, the head pressure is insufficient and no flow occurs. It probably won’t work if you don’t change the motor, or you might need to find a solution by shortening the pipeline
Change the original pipeline length, or adjust the pipeline elbows.
First: Your tank’s safe liquid level of 15 meters is relatively high, and unloading often takes place while there is still oil in the tank, resulting in a high static pressure of the oil inside the tank. Second: I’m not sure how many vehicles your pipeline pump can serve at the same time. If the number of vehicles being unloaded simultaneously exceeds 2, you can choose a pipeline pump with a flow rate of 100 m³, and increase the diameter of the oil collection pipeline to ensure that the pump operates at full capacity.
I agree to adding a zero-position groove on the 3rd floor; a location that meets the safety distance requirements can be found within the factory area to install this groove. At the same time, the pump’s flow rate and head should be increased, and the power cables need to be replaced. It’s not acceptable to continue having inefficient unloading processes – it’s time to take decisive action
Will the oil evaporate, and is a vacuum system required?
If the volume of material to be unloaded is large, it is recommended to modify the unloading system; using a small pump is not a serious solution in such cases
The bottleneck should be at the pump inlet and the pump flow rate; if the pump cannot be replaced, using two pipes in parallel at the pump inlet would be better
For now, we are using two original vertical pipeline pumps in parallel to carry out the unloading process. The inlets of the pumps are connected to the two interfaces on the vehicle via hoses, while their outlets are connected together with pipes, which are then connected to the unloading pipeline on the vehicle bed. The flow rate is increased to around 60 m3/h