The design and selection of mixing devices are closely integrated with the purpose of mixing operations. Various mixing processes require the operation of different mixing devices. When designing and selecting, the mixer type, motor power, and mixing speed should be determined based on the purpose and requirements of the mixing operation according to the process. Then, various components such as reducer, frame, mixing shaft, and shaft seal should be selected. The specific steps and methods are as follows:
1. According to the process conditions, mixing purposes, and requirements, select the type of mixer. When selecting the type of mixer, it is necessary to fully understand the dynamic characteristics of the mixer and the causal relationship between the flow state generated by the mixer during the mixing process and various mixing purposes.
2. Based on the determined type of mixer and the flow state generated by the mixer during the mixing process, the control requirements of the process for mixing time, settling speed, and dispersion are determined through experimental methods and computer simulation design to determine the motor power, mixing speed, and mixer diameter.
3. Select the reducer model from the reducer selection table based on the motor power, mixing speed, and process conditions. If the gearbox is selected based on the actual working torque, the actual working torque should be less than the allowable torque of the gearbox.
4. Select a frame and coupling with the same model and specifications as d according to the output shaft head d of the reducer and the support method of the mixing shaft system
5. Select the shaft seal type based on the dimensions of the mixing shaft head, installation capacity, working pressure, and working temperature of the rack
6. According to the installation form and structural requirements, design and select the mixing shaft structure type, and check its strength and stiffness. If designed according to a rigid axis, n/nk ≤ 0.7 under strength conditions; If designed according to a flexible axis, n/nk>=1.3 under strength conditions
7. Choose to install the bottom cover, flange base or flange flange according to the nominal diameter DN of the rack, the type of shaft support and pressure rating of the mixing shaft
8. Determine whether to configure auxiliary supports based on the supporting and anti vibration conditions.
In the above selection process, the combination and configuration of the mixing device can refer to the schematic diagram of the mixing device design selection process. The key dimension for connecting various components during the configuration process is the shaft head size. Components with consistent shaft head size are generally interchangeable and combined.