Slurry pump selection calculation slurry pipeline characteristic curve and pump slurry lift curve im is the slurry pipeline hydraulic gradient; v is the pipeline average flow velocity; D is the pipeline diameter; g is the gravity acceleration; m is the slurry density; The density of water; the coefficient of influence on the resistance of water flow turbulence in order to consider the existence of suspended matter, usually = 0.9; s is the friction coefficient, s = 0.37605, related to the nature of the particles; vt is: vt = ni = 1ivti, Vt is the mass-weighted average of the particle settling velocity of each particle size group; i is the mass percentage of the i-th particle, and vti is the sedimentation velocity of the i-th particle: vti=2gdi(s-)3CD, ( 2) wherein di is the average particle diameter of the i-th particle; s is the density of the solid particle; CD is the drag coefficient related to the particle shape and the Reynolds number.
In the selection calculation, the clean water test curve of the slurry pump should be converted into the slurry performance curve. Four calculation formulas are listed in the literature <4>. The most commonly used is the Cave formula: HmHo=1-0.0385CWs-14s+1ln (44d50). In the magnetic pump (3) type, Ho and Hm are the heads when the slurry pump pumps clear water and slurry at the same flow rate, CW is the mass percentage of solids in the slurry; d50 is the median diameter of the solid particles.
The basic function of TH-PUMP software This software uses Borland's newly released Delphi5.0 as the development environment, adopting many advanced features and design ideas of Windows graphical user interface. The use of object-oriented programming makes the software better code reusability and good ability to simulate real-world environments. Delphi provides a set of graphical components and methods, making full use of the system resources provided by Windows, directly calling without having to care about the details of the specific implementation, directly facing the graphical interface for program development.
Entering the slurry characteristics of the stainless steel sewage pump that need to be pumped and the structural conditions of the piping system, the software proposes several available pipe diameters and corresponding heads. After the pipe diameter is selected, the software automatically provides the available pump type, and draws the working point and pipe slurry characteristic curve in a coordinate system and displays it as a thumbnail. The diaphragm pump places the mouse on a small image. The status bar on the bottom of the form shows the pump model and the pipe diameter. Click on the thumbnail to see the enlarged result. The pump selection curve, shape installation size, and specific data of the selection result can be saved as graphic files in bmp or jpg format, and can also be printed.
Selection example A mine tailings conveying system design flow rate Q=680m3/h, slurry volume concentration CV=9%, solid particle size is relatively uniform, is a general abrasive material, d50=0.1mm, density=2.65g/cm3, The slurry temperature is t=20, and the height difference between the two ends of the system is h=31m. The suction pipe is 6m long and placed horizontally. The discharge pipe horizontal pipe length L1=530m, the upward inclined pipe length L2=72m, the inclination angle=12, the vertical upward flow pipe length L3=16m; the valve has one, the opening degree h/d=7/8; 90 elbow 2 , d / R = 0.8; one bend tube, = 35, d / R = 0.6; 1 diffuser, = 12. Pipe imports without shrinkage. The gear pump calculates the slurry pipe head and selects the slurry pump.
The selection steps are as follows: (1) Click the icon of the TH-PUMP application to pop up the main interface of TH-PUMP. The impeller rotates slowly on the interface, and the particles are driven in the impeller. (2) Click the input data shortcut to enter The first interface of the selection calculation, the user inputs the corresponding slurry characteristics and other parameters through the keyboard. There is a relationship between the solid density s, the slurry density m and the concentration (volume concentration CR or mass concentration CW), and only one of the two can be calculated to calculate the other. If the fluoroplastic stainless steel submersible pump does not need to calculate the pipeline characteristics, you can select one of the pipelines in the diagram and enter the required pipeline head in the subsequent box; (3) Click the Next button to enter the tube. Road calculation parameter interface. The pipeline system is divided into two parts: the slurry suction line and the discharge line, the length of the segment input line, the inclination angle, the contraction angle of the inlet line and the diffusion angle of the outlet line, and the material and components of the input line ( (3) Click the Next button to enter the selected pipe diameter interface. TH-PUMP automatically lists the pipe diameter D, the pipe flow velocity v, the critical flow velocity v1 and the required head of the pipeline. The user can click on the box in front of the pipe diameter to select the pipe diameter. If the screw pump is too high, the pump can be operated in series. The series number is set to 2 to 5. However, considering the strength and shaft seal of the pump, under normal circumstances, do not exceed 3 stages in series. Click to make it easier to compare. In this example, the 200Z-XN-570 slurry pump is finally selected. The head balance of the pump is 12m slurry column. At this time, the speed is n=980r/min, which is convenient for the motor to run directly. Parameter input to the end of the selection is about 12min.
The software also allows you to view all slurry pump characteristics of the relevant series. Enter the relevant parameters of the slurry, and the software automatically converts the pump's fresh water characteristic curve into a slurry characteristic curve. And compare the two on the screen. The software has intelligent functions such as data memory, and has a dynamic demonstration of the flow pattern of the slurry pump. It can also be added to the multimedia demonstration of the pump factory products. Self-priming pump In order to adapt to the technical progress of the slurry pump, the software can modify the data of any pump type, or add the parameters of the new pump, or delete the old pump type that is no longer used.
Conclusion The selection software has been used in several units, saving time and effort, and being affirmed by relevant technical personnel. It can be used for the selection and calculation of pumps such as ordinary pumps, chemical pumps and shield pumps.
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