In engineering, it is often reflected that the output of bucket elevator can not meet the design requirements, which affects the normal production of the whole process line. This paper briefly analyzes various factors affecting the output of bucket elevator, hoping to influence and help relevant personnel to solve such problems in the future. Before we start, please make sure that the output really can not meet the design or promised output. In other words, we must find out what is the basis (data) for the failure of production to meet the requirements? Are these bases (data) taken out to prove whether the problem is reasonable? You should know that the output data that can really explain the field bucket elevator must be generated under the following three conditions: first, the feeding amount of the upper link is continuous and sufficient; second, the material flow of the lower link is smooth; third, the equipment operates normally (without blocking and shutdown). So do these data meet the above three conditions? This requires us to carefully check and verify the data on site.
After it is clear that the output of on-site equipment can not meet the requirements, we can start the following cause analysis and search process.
1: Confirm the physical characteristics of the lifting material.
The physical properties mentioned here mainly refer to the bulk density, particle size and fluidity of materials. Because the output of bucket elevator is mostly reflected by the quality output, and the quality output measured on site is also more realistic, the design quality output is different according to the different proportion of the actual lifted materials. The output data we provide in various materials are based on granular material 0.75 and powder material 0.5. It can be seen that the data on the data can not be taken directly, and it can be comparable only after corresponding correction. The particle size and fluidity mainly affect the filling coefficient of the hopper. For convenient and intuitive comparison, we often use corn as the granular material and corn flour as the reference material. Therefore, when upgrading other materials, please correct the output based on the reference materials. (this analysis and search method comparing the particle size and fluidity is only used when there is little difference between the measured output and the designed output, because for our industry, the characteristics of materials are not very different, so the influence of material characteristics on output is not very great.)
If the upgraded material itself is a standard material or the corrected output still cannot meet the requirements, we must continue to find the reason in the next step.
2: Check the relevant configuration of the equipment.
Relevant configurations mainly refer to the model of motor and reducer, the number of driving and driven sprocket teeth (chain drive), the model of dustpan, the spacing of dustpan, etc.
Check whether the configured motor frequency of the bucket elevator on site is consistent with the grid frequency; Confirm whether the speed ratio of the reducer meets the standard configuration. In case of chain drive, the number of teeth of the driving and driven sprockets must be verified at the same time to find out whether the comprehensive reduction ratio of the reducer and sprocket is consistent with the reduction ratio of the standard reducer. The above work is to eliminate the impact of speed on output. The speed is directly proportional to the output. When the speed is reduced, the number of dustpans lifted per unit time is reduced, resulting in the reduction of lifting volume, resulting in the reduction of output. At the same time, due to the reduction of speed, the unloading mode of bucket elevator will also be changed, resulting in the increase of return material, so as to further reduce the output. Under certain limits, increasing the speed will increase the output, but it will also increase the impact of materials on the machine wall, so as to increase the wear of the machine wall and improve the crushing rate of materials. Due to the early throwing of materials, the return quantity may also be increased. Therefore, the lifting speed can be configured according to the requirements to meet the long-distance travel of the equipment in the optimal state and ensure the output.
The purpose of checking the model and spacing of the dustpan is to exclude the influence of the lifting volume per unit time on the output under the same line speed. The effect of lifting volume on yield is obvious. The reasonable model matching of the dustpan also fully takes into account the factors such as the maximum loading capacity, good material receiving and throwing performance and filling rate.
Therefore, if you want to meet the design output, the above configuration must meet the design requirements. The configuration problem may be caused by the process selection and configuration error caused by the negligence of process personnel, or the installation error caused by the wrong delivery of configuration model or the confusion of installation site caused by other reasons. When the bucket elevator leaves the factory from the manufacturing workshop, it is only a part of the equipment, and the completion of the equipment is really announced only after the on-site installation. Such a long process leads to many uncertain factors, and configuration errors are inevitable.
If the above parameters are found to be different from the standard configuration, please take measures or replace them in time. If no abnormality is found, please go to the next step.
3: Observe the overall process layout and whether there is any problem with the on-site installation interface.
It's a little difficult to make an accurate judgment on this point, but this is often the point of frequent problems. The judge needs to have a certain understanding of the bucket elevator and have some handling experience.
Here, only a few points that often appear on the site are put forward for comparison and reference.
Influence of feeding mode: the bucket elevator base is provided with multiple feeding ports, the relatively high one is the reverse feeding port, and the low one is the forward feeding port. It is recommended to feed powder in the forward direction and reverse direction. However, sometimes due to process requirements, the pellets may also adopt forward feeding, but the output of forward feeding is only 80% of that of reverse feeding. In this case, our design output must also be corrected accordingly.
Incorrect arrangement of feed chute: the incorrect arrangement of feed chute here refers to that when the material flow enters the feed inlet due to the arrangement problem of feed chute, it can not be evenly spread along the width direction of the feed inlet, but offset to a certain side, so as to offset the material receiving of the dustpan, reduce the filling rate of the dustpan, and deposit the residual materials on the base, resulting in material blockage. If you encounter this problem, it is recommended to correct the feed chute. If the space is not enough, adding a small variant bucket on the feed inlet can also achieve good results.
The chute corner at the discharge port is too large: the problem here is mainly due to the insufficient space position of the process, resulting in too large chute corner, poor material flow and material deposition, which eventually leads to a huge increase in the amount of returned materials and material blockage.
The problems of on-site process installation may be strange and unpredictable, but we only need to grasp one fundamental principle: the material flow entering the material inlet must be evenly spread in the width direction of the material inlet without deviation, and the material flow at the material outlet must be smooth without material retention. We can respond to changes with invariance.
Finding out that the output of bucket elevator can not meet the design requirements on site is a comprehensive analysis process, which can not simply analyze the problem from one aspect. We should not only focus on the single equipment in front of us, but also need to analyze and consider the problems at the level of the whole process. A lot of knowledge here needs us to constantly learn and summarize in practice.
