三螺杆泵的选型技巧
Selection of the three screw pump technique
三螺杆泵选型时，要尽可能详尽地了解泵的使用条件，除了运行参数，如流量，压力需要清楚以外，输送介质的特性如介质的腐蚀性，含汽量，含固溶物的比率及固体颗粒的大小，以及介质的工作温度，粘度，比重，对材料的腐蚀性等和泵装置的吸入条件，安装条件均要了解，根据我们的经验，三螺杆泵选型时应注意以下几点：
3 screw pump selection, we should pump as much as possible a detailed understanding of the conditions of use, in addition to operating parameters such as flow, pressure, need to clearly beyond the characteristics of transmission media, such as the corrosive medium, containing steam containing solid solution compounds ratio and the size of solid particles, and the medium temperature, viscosity, specific gravity, corrosion of materials, etc. and pump suction conditions, installation conditions are to understand, according to our experience, three screw pump selection should be Note the following points:
1. 泵转速的选择
1. Pump speed selection
1.1 以输送介质粘度和泵的规格确定转速范围：
1.1 in order to transport medium to determine the specifications of viscosity and pump speed range:
输送高粘度介质时，泵应选低转速，若粘度较低，相应可选择高转速：
Transport high viscosity medium, low speed pump to be elected, if the low viscosity, the corresponding high-speed selectable:
介质粘度〉20°E时，对于大规格的泵（主杆外径60mm以上），转速以970rpm或720rpm为宜，如果粘度更高（粘度〉80°E）如粘胶液，可降低转速使用，推荐200-500rpm；
Medium viscosity of> 20 ° E when the pump for the large-size (the main pole diameter 60mm and above), speed to 970rpm or 720rpm is appropriate, if a higher viscosity (viscosity> 80 ° E), such as viscose solution may be reduce the speed using the recommended 200-500rpm;
对于小规格的泵，介质粘度〉20°E时，转速以1450rpm或970rpm为宜，如果粘度更高（粘度〉80°E），可降低转速使用，推荐300-600rpm；
For the small size of the pumps, medium viscosity of> 20 ° E, the rotation speed to 1450rpm or 970rpm is appropriate, if a higher viscosity (viscosity> 80 ° E), can reduce the speed using the recommended 300-600rpm;
1.2 由于泵的转速越高，在相同性能参数下，泵的体积就越小，但由于转速高，摩擦功率高，泵的磨损就大，寿命就短，如果输送介质的润滑性比较差或含有微量杂质，应选择较低转速，以使泵保持较长的寿命，推荐在1450rpm以下。
1.2 due to the higher speed of the pump in the same performance parameters, the smaller size of the pump, but because of high speed, friction-power high, pump wear and tear on the big, life expectancy is short, if the transmission medium relatively poor lubrication or contain trace impurities, should choose a lower speed in order to extend the life of the pump is recommended below 1450rpm.
2. 结构的选择可根据泵的安装和使用条件参考三螺杆泵的系列和型式来进行，原则上：
2. The structure of choice under conditions of the pump installation and use of reference and type a series of three screw pumps to carry out, in principle:
2.1 输送润滑性油类，温度在80°C以下选择内置轴承结构的泵；
2.1 transmission lubrication oil, the temperature at 80 ° C the following options built-in pump bearing structure;
2.2 温度超过80°C或输送介质润滑性差时，选择外置轴承结构的泵；
2.2 The temperature exceeds 80 ° C or transport of poor lubrication medium, select the external bearing structure of the pump;
2.3 输送流动性差，粘度较高的介质或需要所输送介质进行加热或保温时选择双层加热泵体结构的泵；
2.3 The transport mobility is poor, medium or high viscosity media transport needs of the selection of heating or insulation layer structure of heat pump pumps;
2.4 高温输送时，应选择耐高温的材料所制成的泵，请与我厂联系。
2.4 The high-temperature transport, they should choose the material made of heat pumps, please contact me.
3. 泵材料组合的选择：
3. Pump material combinations of options:
详见材料组合。
See material combinations.
4. 关于泵的吸入能力可查阅我厂样本提供的NPSHr或[HS]值。
4. With regard to the pump suction capacity can be found in our plant samples provided by the NPSHr or [HS] value.
5. 配套电机的选配
5. Supporting the motor-matching
泵的选型确定后，根据样本数据可查到泵的轴功率N，该轴功率再加上一定的功率储备后，作为选配电机的依据，一般电机功率Nm应不小于泵轴功率N乘以功率储备系数K后所得值，K值可参照下表取值：
Pump Selection determined, based on the sample data can be found on the pump shaft power N, the shaft power coupled with a certain degree of power reserve, as a basis for matching the motor, general motor power Nm should not be less than the pump shaft power N power reserve factor multiplied by the value of K obtained after, K value can be reference to the following table values:
N（KW) N<5 5 10 N>50
K 1.25 1.2 1.15 1.1
N (KW) N <5 5 10 N> 50
K 1.25 1.2 1.15 1.1
另外，选泵时还常由于样本提供的泵性能参数均以表格形式或特定粘度、转速下性能曲线的形式给出，所需泵的性能值有时不能直接读出，这时可遵循以下原则作粗略估算，若需比较准确的数据可向专业人员咨询。
In addition, the selected pump Shihai often due to the sample pump performance parameters are provided in tabular form or a specific viscosity, the speed given in the form under the performance curve, the required pump performance values can sometimes can not be directly read out, then can follow the following principles to make a rough estimate, For more accurate data can be addressed to professional advice.
三螺杆泵的流量、压力在相同转速、粘度时近似呈直线关系，压力越高，流量越小。
3 screw pump flow, pressure at the same speed, viscosity approximate linear relationship, the higher the pressure, flow rate smaller.
相同粘度、压力下，泵的流量与转速近似成正比。
The same viscosity, pressure, pump flow and speed linearly proportional to.
相同转速、粘度下，轴功率与压力近似成正比。
Same speed, viscosity, the shaft power and pressure approximation is proportional to.
同一粘度、压力下，轴功率与转速近似成正比。
The same viscosity, pressure, shaft power and speed linearly proportional to.
粘度增大时，流量和轴功率均增加，但由于其中关系较复杂，必要时可向专业人员咨询。
Viscosity increases, flow rate and shaft power was increased, but because of the relationship between them is more complex and when necessary to consult professionals.
只要选型得当，维护合理，三螺杆泵就可保证令人满意的运行。
As long as the selection of appropriate, to maintain a rational, three-screw pump can ensure satisfactory operation.
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