Pipeline pumps are the most common equipment currently used in oil delivery systems. However, its biggest problem is low suction, easy to produce air resistance; the same time, if the actual flow in the pipeline and the rated flow more difference between the formation of oil and gas mixed transport, will lead to double the oil transmission time, waste of electricity doubled. Oil tank zero tank is buried in the horizontal tank, pipeline pump installed in the ground pipe. Working pump sucked the oil from the underground horizontal tank into the pump, the vertical height is the pump suction. Gasoline 20 ° C suction over 4.27 meters began to vaporize, suction more than 4.5 meters can not work properly. Negative pressure suction conveying oil, the pipeline in negative pressure working state, when the pipeline at a point the remaining pressure is less than the saturated vapor pressure of oil operating temperature, the oil will be a large number of vaporization, resulting in discontinuous flow or flow Phenomenon, this is gas resistance. Once the air resistance, the entire oil system can not work properly, this also need to support the installation of vacuum systems. The submersible pump is immersed in the pump body at the bottom of the tank directly through the impeller to the oil pressure, the oil will be pushed to the target storage device, to pay the oil or zero tank canning oil. Because it is a positive pressure transmission oil, high flow submersible pump does not produce air resistance, there is no suction problem. The core technology to solve this problem is to submerge the motor or shielded motor. There is a gap between the stator and the rotor of the motor about the thickness of an A4 paper. The oil flows through it and serves two functions: First, to the motor cooling, almost all of the motor can only flow through the motor to achieve the cooling effect, thus protecting the motor life. Submersible pump motor fluid inside the characteristics of this motor doubled the life. Second, the liquid flow through the gap between the stator and the rotor, the bearing play a good role in lubrication. Motor and bearing problems have been effectively resolved, so that submersible pump does not require maintenance, low failure rate. Service life of up to ten years, shelf life of three years. Case 1: "Inner Mongolia Petrochemical Industry" 2009 the 17th published in the weekly and Liu Xiaowei jointly issued entitled "Gas Unloading Crane pipe air resistance problems and solutions" wrote: "... the summer heat or is located in the plateau Low-pressure area, prone to air resistance. Gas resistance is generated, not only to extend the pick and place time, increasing the volatilization loss of oil, resulting in serious flow interruption and can not be unloaded, seriously affecting the normal operation of the oil depot and rail transport .... Case 2: China University of Petroleum teaching materials "finished product crane crane handling system" on the gas resistance solution: 1. until the night temperature drop before operation; 2. to the pipe cooling water to ease the air resistance.
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