渣浆泵叶片入口角的选择
  对于抽送均质液体的菜，叶片入口角，厚度和入口边的位置，根据保证很高吸入能力的条件来选取，因此，对于最佳工作状态，采用冲角09=3°~10°。

对于抽送磨蚀性固液混合物的泵，叶片入口角，叶片厚度和入口位置，根据最小可能的磨损量并考虑所抽送固液混合物的磨蚀特性，主要考虑固体颗粒的粒度来确定。
  在选取入角时可以分为两种情况:
(1)泵抽送细颗粒固液混合物，这时入口边磨损强度很小，入口角选取的主要条件是保证所需的吸入能力。对于一般用途泵，下列推荐值是正确的，Pu=18°~25"

(2) 抽送砂砾固液混合物的泵，入口边磨损强度很大，即其磨损量可以预侧叶轮寿命，选取叶片入口角的主要准则是保证磨损量最小。因此，入口边磨损量随着入口角的增大而减小，采用入口角要大于根据据提高泵汽蚀特性条件所要求的角度，一般采用叶片入口角βBn=30°~40。
六、叶片入口边位置的确定
    入口边位置对叶片磨损以及对叶轮后盖板磨损均有重要影响。
  显然，在抽送均质液体的泵上，在入口段叶片很薄，入口边位置在很小的半径上(入口边拉向叶轮入口)，可以改善吸入能力。但是，对于抽送磨蚀性固液混合物的泵，由于入口处叶片增厚，使液流排挤增强并且由于相当宽的过流断面，不可能使入口边处在很小的半径上。通常，入口边与叶轮盖板具有一定角度;同时，前盖板侧入口边位置半径大致等于或者略大于叶轮入口半径。
  根据中间流束，采用下列方法检查叶片入口角Pur选择的正确性:
(1)计算圆周速度u1= Rwn式中半径R1根据所选择的入口边位置由图上求得。
(2)在不考虑排挤的情况下，确定液流在叶片入口的轴面分速Cim.
(3)在不考虑排挤的情况下，绘制入口三角形(图3-9-1）。
(4) 根据公式ψ=1- n/确定液流在入口处的排挤系数。式中，o.为半径R圆周方向上叶片厚度; 01=a/simB.n;t1为叶片入口节距；t1=2rR/z.

    由于抽送磨蚀性固液混合物泵叶轮叶片进行加厚(并且在入口段，叶片不但不变薄，如抽送清水的泵那样。而且在一些情况下甚至要加厚)，对于这些泵，排挤系数变小，大致为0.65-0.75.在确定排挤系数时，根据本章上述推荐值选取入口角并且对于不同，使用条件，这些角度是不同的。
  叶片较厚部分的厚度(除了入口段和出口段以外)，可以根据关系式δ= (0.1~0.13) Dx确定(式中，Dbc为吸入短管半径），根据现有泵结构叶片厚度分析得到上述关系.渣浆泵厂家

Selection of blade inlet angle of slurry pump

For vegetables pumping homogeneous liquid, the inlet angle, thickness and position of the inlet edge of the blade shall be selected according to the conditions ensuring a high suction capacity. Therefore, for the best working condition, the impact angle is 09 = 3 ° ~ 10 °.

For the pump pumping the abrasive solid-liquid mixture, the blade inlet angle, blade thickness and inlet position are determined according to the minimum possible wear amount and considering the abrasive characteristics of the pumped solid-liquid mixture, mainly considering the particle size of the solid particles.

There are two situations when selecting the angle of entry:

(1) Pump pumping fine solid-liquid mixture, when the wear strength of the inlet side is very small, the main condition for the selection of the inlet angle is to ensure the required inhalation capacity. For general purpose pumps, the following recommended values are correct, Pu = 18 ° ~ 25“

(2) For pumps pumping gravel solid-liquid mixtures, the wear intensity at the inlet side is very high, that is, the wear amount can predict the life of the impeller. The main criterion for selecting the inlet angle of the blade is to ensure the minimum wear amount. Therefore, the wear of the inlet side decreases with the increase of the inlet angle. The inlet angle is larger than the angle required according to the condition of improving the cavitation characteristics of the pump. Generally, the blade inlet angle β BN = 30 ° ~ 40.

Vi. determination of the position of the blade inlet edge

The position of the inlet side has an important influence on the wear of the blade and the back cover plate of the impeller.

Obviously, in the pump pumping homogeneous liquid, the blade in the inlet section is very thin, and the position of the inlet side is on a very small radius (the inlet side pulls toward the impeller entrance), which can improve the inhalation capacity. However, for the pump pumping the abrasive solid-liquid mixture, because the inlet blades are thickened, the liquid flow extrusion is enhanced, and because of the quite wide flow passage section, it is impossible to make the inlet edge at a very small radius. Generally, the inlet side has a certain angle with the impeller cover plate; at the same time, the position radius of the inlet side of the front cover plate is approximately equal to or slightly greater than the impeller inlet radius.

According to the intermediate flow beam, the following methods are used to check the correctness of the selection of the blade inlet angle pur:

(1) calculate the circumferential velocity U1 = rwn where the radius R1 is obtained from the figure according to the selected entrance edge position.

(2) determine the axial velocity of liquid flow at the blade inlet, CIM, without considering extrusion.

(3) draw the entrance triangle without considering crowding (Figure 3-9-1).

(4) according to the formula ψ = 1-N / determine the liquid flow at the entrance of the extrusion coefficient. In the formula, O. is the blade thickness in the circumferential direction of radius R; 01 = A / simb. N; T1 is the blade inlet pitch; T1 = 2rr / Z.

Because the impeller blades of the pump are thickened (and in the inlet section, the blades are not only the same thin, as the pump pumping clean water). And in some cases, it even needs to be thickened). For these pumps, the extrusion coefficient becomes smaller, about 0.65-0.75. When determining the extrusion coefficient, select the inlet angle according to the above recommended values in this chapter and for different conditions of use, these angles are different.

The thickness of the thicker part of the blade (except for the inlet section and the outlet section) can be determined according to the relationship δ = (0.1 ~ 0.13) DX (where DBC is the radius of the suction short pipe). The above results can be obtained according to the thickness analysis of the existing pump structure blade.