How to improve the efficiency of concrete mixing plant

  Concrete mixing plants have been formed and developed in China for a long time, and various production technologies have gradually matured, concrete mixing technology has been significantly improved, concrete mixing plants have been spread in almost every city in the country, with government policies and the development of the construction industry has gained a new opportunity. However, behind such a gratifying result, we must be aware of some problems, such as old equipment and shrinking market, which have brought some negative effects on the development of concrete mixing plants in China.

1 Theoretical workflow of mixing plant

  As the working principles of concrete mixing plants are different, it is impossible to describe them all here. The water is accurately measured by means of special measuring tools and mixed with a number of additives before the mixture is finally fed into the mixer by means of an over-loading hopper and conveying pipes; the mixer is then switched on and mixed; the finished product is finally put into the concrete transport vehicle. In order to simplify the process, the author has simplified the whole process of concrete mixing into a series of processes. We can divide the process into several time periods. The transport phase before the raw materials are placed can be called preparation, the process of placing the raw materials is called feeding, the next formal mixing process is called mixing, and the final concrete product ready for transport is called discharging. Another point to note here is that the reason for the presence of a medium storage hopper in a concrete mixer is to allow the various raw materials to enter the mixer when they have all been prepared, thus ensuring that the preparation time is less than the mixing time and discharge time. If this condition holds, then the preparation time of the transport truck is shorter than the sum of the mixing time and the discharging time, which means that during the whole concrete mixing process, the time relationship can reach a dynamic equilibrium, the equilibrium process is as follows: preparation time (first tray of material) → feeding time → mixing time → discharging time → feeding time → mixing time → discharging time, and so on and so forth, finally reaching a continuous Work target

2 Analysis of the causes of low working efficiency

  The main reason for the delay in the work of concrete mixers to improve efficiency lies in the following two aspects: ① Preparation time is longer than the mixing and discharging time. As a variety of raw materials need to wait for the completion of the preparation time before they can be carried out, in this case the entire process there is a lot of time idle, this time can only wait for the preparation work to be carried out, greatly reducing the efficiency of work, the unit of time can not be completed within the corresponding workload. ②The preparation time is less than or equal to the sum of the two. The denominator of the calculation of the work efficiency in the production process of concrete is relatively large, which means that the total production time is too long and the whole balance of concrete production is broken, which ultimately results in low work efficiency. In general, too much time is wasted in the preparation phase, which means that the weighing of raw materials or the transport process is too long. Generally speaking, materials such as gravel and pebbles are very difficult to transport to the mixer because of their special characteristics, so it takes basically the longest time, during which the weighing and transport of cement and curing agent and water agent can be finished, so it is said that whether the weighing and transport of gravel and pebbles can be completed according to the standard time will directly determine the efficiency of the concrete mixing plant. In practice, we can control the rate of the weighing tools so that the transport equipment can maximise the transport work, which is very beneficial to reduce the transport time of the pebbles and gravel.

3 Measures to improve the efficiency of concrete mixing plants

3.1 Feeding efficiency improvement measures

  The feeding stage to improve the efficiency of concrete mixing needs to be divided into three stages to carry out, they are sand and gravel pebbles put, cement curing agent put and water agent put. In fact, specifically, the capacity and discharge rate of the equipment for temporary storage in the middle will have almost no efficiency problems if they are scientific and the valves in them do not have stagnation problems. Water dosing is even simpler, as long as there are no blockages or leaks in the transfer pipes. The factors affecting the placing of the powder are more complex, and whether this process can be completed successfully and on time directly determines whether the concrete mixing work can be completed efficiently and smoothly. The author has also carefully studied and analysed this project during the actual work. The final reasons for the long powder dropping time are summarised as follows: ① The angle of the powder dropping tool is too small for the powder to descend properly by gravity to the next step, causing the powder to clog and affecting the overall result. In order to solve this dilemma, the angle of the dropping tool needs to be corrected or a vibrating knocking device needs to be adopted to provide power for the powder to fall, while the specific practical operation of how to make adjustments and how to determine the data needs to be based on the actual situation and amended according to different requirements. ②The exit valve of the powder hopper is not working due to rust or weathering, in this case even if the powder can pass through the storage hopper above, it cannot be discharged smoothly, and the work efficiency will also be reduced in this case. In order to solve this dilemma, we need to organise special staff to carry out regular maintenance, and once the above two problems are found, rectify and adjust them immediately to ensure that the whole process can be completed smoothly and successfully.

3.2 Mixing efficiency to improve countermeasures

  Specifically, the effectiveness of the mixer can directly determine the length of time required to work, the work is effective, the probability of needing to repeat is smaller, the time wasted will be shorter. The effectiveness of the mixer is influenced by a number of factors, including the integrity of the blade liner inside the mixer, the position of the raw material, the time of day and the presence of the shaft clutching phenomenon. In order to solve the blade liner breakage, we need to regularly check and monitor the actual operation, and need to clean the tank, only good cleaning and maintenance work to ensure that the blade liner does not appear broken, always maintain in the best working condition. In addition, as the powder is generally adherent, it is not easy to place it smoothly, so the timing of the powder placement needs to be determined by the staff according to their practical experience and operational standards to minimise the probability of shaft clamping. Shaft clutching is a very common problem in concrete mixing and if ignored, it can eventually lead to a reduction in mixing capacity and ultimately have a detrimental effect on production efficiency.

3.3 Discharge efficiency improvement measures

  The efficiency of the discharge time is most affected by the size of the concrete truck's inlet, if the inlet is too small then the finished concrete will not flow smoothly into it, causing the discharge speed to slow down, then a series of production mixing work will not be able to speed up, ultimately leading to a decline in overall efficiency. In practice, although there is a way to improve the capacity of the concrete hopper, but fundamentally this solution can be said to treat the symptoms but not the root cause, even if there is an improvement is only a relatively small part, so you also need to start from the root cause of the solution, the specific operation involves the manufacture of transport vehicles, the main object of this paper is to study the work of the concrete mixing plant, this is not one by one The main focus of this paper is on the work within the concrete mixing plant and will not be discussed in detail.

4 Conclusion

  In conclusion, the efficiency of concrete mixing plants has a certain impact on the development of the construction industry, so we need to think about and analyse how to improve the efficiency of concrete mixing plants. Based on the specific reasons and experience in the actual work, the author has analysed the actual methods of improvement in the hope that the efficiency can be effectively improved. Start from the processing of powder, its regular inspection and cleaning, and ultimately achieve the development goals.