沃曼公司在选型手册中认为，这类渣浆泵浆体的管路水头损失有如下特点:在同样的管路条件下，当浆体流速为其临界沉降流速的0.7倍(V=0.7V.) 时浆体的水头损失与清水以浆体临界沉降流速流动(v=V2) 时的水头损失相同;当浆体流速为其临界沉降流速的1.3倍(V=1.3V2)时，浆体水头损失与清水以同样流速流动时的水头损失相同。将上述情况示在H V坐标系中，如图1-4- 1所示，用曲线将点C和B连接起来且在点B处相切，就得到浆体管路特性(阻力)出线。
Overview of research on determination method of slurry pipeline loss in slurry pump
The head loss of slurry pipeline varies with the size of solid particles, the relative density of solid and the concentration of slurry. The head loss of slurry pipeline is based on the head loss of clear water pipeline. The following is a brief introduction of slurry pipeline loss determination methods.
1. Method to Determine Head Loss of Homogeneous Slurry Pipeline
All solid particles of solid material are less than 0. lmm, and the slurry with weight concentration C < 30% and volume concentration C < 15%. It belongs to homogeneous slurry and does not need to consider the settling of solid particles. The head loss of pipeline is basically the same as that of clear water. Therefore, the head loss and pipeline characteristic curve can be obtained according to the method of clear water.
2. Determination of Head Loss in Typical Slurry Pipeline
Typical slurry is slurry with solid particle size DSO = 0.1~03mm, weight concentration C less than 40%, volume concentration C less than 20%.
In the selection manual, Walman Company considers that the head loss of slurry in the slurry pipeline of this kind of slurry pump has the following characteristics: under the same pipeline conditions, when the slurry velocity is 0.7 times of its critical sedimentation velocity (V=0.7V.), the head loss of slurry is the same as that of clear water flowing at the slurry critical sedimentation velocity (V=V2); When the critical sedimentation velocity is 1.3 times (V=1.3V2), the head loss of slurry is the same as that of clear water when it flows at the same velocity. The above situation is shown in the H-V coordinate system. As shown in Fig. 1-4-1, the slurry pipeline characteristics (resistance) can be obtained by connecting points C and B with curves and tangential at point B.
3. Research methods of head loss in atypical slurry pipelines
Atypical slurry refers to a body with solid particle size Da > 0.3mm, volume liquid degree C and less than 20%. The method to determine the lock-in loss of slurry pipeline is to take the loss of clear water head as slurry head loss when the flow velocity V-V, and calculate the flow velocity when the slurry loss is the same as that of clear water head (He Xijie has given the specific expression), and then use it. By connecting these two points with smooth curve, slurry pipeline loss curve can be obtained.
Given the parameters C. di.) of slurry and the working conditions on site, the values of V., K and K can be calculated, so that the head loss H. of slurry pipeline at different flow velocities V can be determined according to the above formulas, and then the relevant parameters can be calculated according to the selection program, so that the pump type suitable for the working conditions on site can be selected.