1, vacuum oil unloading process the use of vacuum system for oil pump priming, warehouse and suction blow tank oil operations. Equipment is more, the system such as water ring vacuum pump, vacuum tank, vacuum pipelines, etc, and vacuum pump water to consider the winter antifreeze. Additional vacuum pump is working, the exhaust pipe often have a lot of oil and gas discharge, is not safe, so at present this technology has been seldom used in the oil depot.
2, positive displacement pump auxiliary centrifugal pump unloading process using displacement pump instead of the vacuum system, implemented as centrifugal pump oil and sweep the warehouse. The application of this system is more, especially suitable for diesel and jet fuel oil. The positive displacement pump is usually adopted by the vane pump or swinging rotor pump. Application of the system is important to note that in the process of sweeping warehouse, because of the existence of oil-gas mixture lose, sweep the warehouse of the pump outlet pressure will be much lower than the rated capacity of the pump, so you must set up and warehouse or low blow tank, otherwise can't work normally.
3, submersible pump unloading process submersible pump unloading process has two solutions: one is the low uplift Cheng Qian oil pump and main oil pump series oil unloading process. Second, young Cheng Qian pump unloading oil directly into the tank process. The process scheme is unloading the advantages of high reliability, operation time is short, don't worry about the crane tube gas resistance and pump cavitation, especially effective for discharge plateau high temperature gas. The downside is the operation cost is higher, because of the crane tube mouth with submersible pump, operation is not very convenient. Can't omit the scheme and other warehouse system, its way of setting with centrifugal pump unloading process. New technology of oil unloading rotary piston pump unloading process: rotary piston pump is a positive displacement pump, low speed (400 RPM), suction capability (maximum vacuum up to 0.085 MPa), high efficiency (0.7 ~ 0.85), the spirit liquid two phase transfer, filter impurities of the low demand. Because of its strong self-priming capacity, unloading when no longer need to other pump for its oil filling pump; Due to the conveyor belt can be solid particles of liquid, the impurity in the warehouse operations have little impact on it. In the unloading process, need to set a rotary piston pump can be completed unloading, storehouse, pipeline, suction blow tank oil and other operations. So as to eliminate the flicking tank, pump, pipeline equipment facilities such as sweep storehouse, not only can significantly save investment, but also convenient operation management, is a kind of ideal, economical and practical new technology of oil discharge. The oil unloading process there are two alternative: one is all a large crane tube common flow of rotary piston pump; The scheme has the advantage of low investment, less equipment, easy to manage. The scheme is suitable for unloading flow between 100 and 200 m3 / h, unloading time is abundant. 2 is set to the pier under the pump, according to the three crane tube of a group, each group set up a small flow (60 ~ 80 m3 / h) of rotary piston pump. When unloading, all pumps can work at the same time, thus meet the requirements of large flow, rapid unloading, both a train can be discharged three hours; And avoid the unloading to the final, due to insufficient flow pump vibration problems. Apply to the unloading time is short, big flow and head is not high.