三螺桿泵的選型技巧
Selection of the three screw pump technique
三螺桿泵選型時，要盡可能詳盡地了解泵的使用條件，除了運行參數(shù)，如流量，壓力需要清楚以外，輸送介質的特性如介質的腐蝕性，含汽量，含固溶物的比率及固體顆粒的大小，以及介質的工作溫度，粘度，比重，對材料的腐蝕性等和泵裝置的吸入條件，安裝條件均要了解，根據(jù)我們的經(jīng)驗，三螺桿泵選型時應注意以下幾點：
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. 泵轉速的選擇
1. Pump speed selection
1.1 以輸送介質粘度和泵的規(guī)格確定轉速范圍：
1.1 in order to transport medium to determine the specifications of viscosity and pump speed range:
輸送高粘度介質時，泵應選低轉速，若粘度較低，相應可選擇高轉速：
Transport high viscosity medium, low speed pump to be elected, if the low viscosity, the corresponding high-speed selectable:
介質粘度〉20°E時，對于大規(guī)格的泵（主桿外徑60mm以上），轉速以970rpm或720rpm為宜，如果粘度更高（粘度〉80°E）如粘膠液，可降低轉速使用，推薦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;
對于小規(guī)格的泵，介質粘度〉20°E時，轉速以1450rpm或970rpm為宜，如果粘度更高（粘度〉80°E），可降低轉速使用，推薦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 由于泵的轉速越高，在相同性能參數(shù)下，泵的體積就越小，但由于轉速高，摩擦功率高，泵的磨損就大，壽命就短，如果輸送介質的潤滑性比較差或含有微量雜質，應選擇較低轉速，以使泵保持較長的壽命，推薦在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. 結構的選擇可根據(jù)泵的安裝和使用條件參考三螺桿泵的系列和型式來進行，原則上：
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 輸送潤滑性油類，溫度在80°C以下選擇內(nèi)置軸承結構的泵；
2.1 transmission lubrication oil, the temperature at 80 ° C the following options built-in pump bearing structure;
2.2 溫度超過80°C或輸送介質潤滑性差時，選擇外置軸承結構的泵；
2.2 The temperature exceeds 80 ° C or transport of poor lubrication medium, select the external bearing structure of the pump;
2.3 輸送流動性差，粘度較高的介質或需要所輸送介質進行加熱或保溫時選擇雙層加熱泵體結構的泵；
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 高溫輸送時，應選擇耐高溫的材料所制成的泵，請與我廠聯(lián)系。
2.4 The high-temperature transport, they should choose the material made of heat pumps, please contact me.
3. 泵材料組合的選擇：
3. Pump material combinations of options:
詳見材料組合。
See material combinations.
4. 關于泵的吸入能力可查閱我廠樣本提供的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. 配套電機的選配
5. Supporting the motor-matching
泵的選型確定后，根據(jù)樣本數(shù)據(jù)可查到泵的軸功率N，該軸功率再加上一定的功率儲備后，作為選配電機的依據(jù)，一般電機功率Nm應不小于泵軸功率N乘以功率儲備系數(shù)K后所得值，K值可參照下表取值：
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，選泵時還常由于樣本提供的泵性能參數(shù)均以表格形式或特定粘度、轉速下性能曲線的形式給出，所需泵的性能值有時不能直接讀出，這時可遵循以下原則作粗略估算，若需比較準確的數(shù)據(jù)可向專業(yè)人員咨詢。
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.
三螺桿泵的流量、壓力在相同轉速、粘度時近似呈直線關系，壓力越高，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、壓力下，泵的流量與轉速近似成正比。
The same viscosity, pressure, pump flow and speed linearly proportional to.
相同轉速、粘度下，軸功率與壓力近似成正比。
Same speed, viscosity, the shaft power and pressure approximation is proportional to.
同一粘度、壓力下，軸功率與轉速近似成正比。
The same viscosity, pressure, shaft power and speed linearly proportional to.
粘度增大時，流量和軸功率均增加，但由于其中關系較復雜，必要時可向專業(yè)人員咨詢。
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.
只要選型得當，維護合理，三螺桿泵就可保證令人滿意的運行。
As long as the selection of appropriate, to maintain a rational, three-screw pump can ensure satisfactory operation.
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