Classification and composition of concrete mixing plant and selection principle of equipment

As we all know about concrete mixing plants, what are the classification and composition of concrete mixing plants? What are the selection principles of concrete mixing plant equipment?

For these problems, today, Huihong will give you a detailed explanation

1、 Classification of concrete mixing plant

1. Classification according to control system

Concrete mixing plant can be divided into standard concrete mixing plant and simple concrete mixing plant according to different control systems The simple concrete mixing plant adopts a centralized control system, while the standard concrete mixing plant adopts a fully automatic control system The centralized control system is a "simple" control system. The simplicity mentioned here does not mean the simplicity of the quality or accuracy of the centralized control system, but refers to the degree of automation. The centralized control system belongs to semi-automatic control Click the operation of the full-automatic control system, and the materials will be automatically transported from the warehouse to the weighing bucket through the screw, and then automatically unloaded into the mixer. The whole process is fully automatic, convenient and fast

2. Classification according to production volume

Concrete mixing stations can be divided into: HZS25 concrete mixing station, HZS35 concrete mixing station, HZS50 concrete mixing station, HZS60 concrete mixing station, HZS75 concrete mixing station, HZS90 concrete mixing station, HZS120 concrete mixing station, HZS180 concrete mixing station, hzs240 concrete mixing station, etc. according to the production volume

2、 Composition of concrete mixing plant

The concrete mixing plant is mainly composed of five systems and other auxiliary facilities, including material storage system, material weighing system, material conveying system, mixing system, powder storage system, powder conveying system, powder metering system, water and admixture metering system and control system

1. Mixing machine mixing machine is divided into forced mixing and self dropping mixing according to its mixing mode Forced mixer is the mainstream used in mixing plants at home and abroad. It can mix a variety of concrete, such as fluidity, semi dry and dry hard The self - dropping mixer is mainly used to mix mobile concrete, which is rarely used in the mixing plant

2. Material weighing system material weighing system is a key component that affects the quality of concrete and the production cost of concrete. It is mainly divided into three parts: aggregate weighing, powder weighing and liquid weighing Generally, the mixing plant with less than 20 cubic meters per hour adopts the superposition weighing method, that is, the aggregate (sand, stone) is weighed with a scale, the cement and fly ash are weighed with a scale, and the water and liquid admixture are weighed respectively, and then the liquid admixture is put into the water bucket for pre mixing In the mixing plant with more than 50 cubic meters per hour, the method of independent weighing of each weighing material is often used, and all weighing is controlled by electronic scales and computers The weighing accuracy of aggregate is ± 2%, and the weighing accuracy of cement, powder, water and admixture is ± 1%

3. Aggregate conveying in material conveying system: there are two ways of conveying in mixing plant: hopper conveying and belt conveying The advantages of hopper lifting are small floor area and simple structure The advantages of belt conveying are large conveying distance, high efficiency and low failure rate Belt conveyor is mainly applicable to the mixing plant with aggregate temporary storage bin, so as to improve the productivity of the mixing plant Powder conveying: the available powder for concrete is mainly cement, fly ash and mineral powder The commonly used powder conveying method is screw conveyor, and pneumatic conveying and scraper conveying are used in large mixing plants Screw conveyor has the advantages of simple structure, low cost and reliable use Liquid transportation: mainly refers to water and liquid additives, which are respectively transported by water pumps

4. The storage methods of materials available for concrete in the material storage system are basically the same Aggregates are stacked in the open air (there are also closed silos for urban large-scale commercial concrete mixing plants); The powder is stored in a fully enclosed steel structure silo; Admixtures are stored in steel containers

5. Control system the control system of the mixing plant is the central nervous system of the whole set of equipment The control system has different functions and configurations according to the different requirements of users and the size of the mixing plant. Generally, the small-scale mixing plant control system available on the construction site is simpler, while the large-scale mixing plant system is relatively complex

3、 Selection principle of concrete mixing plant equipment

1. Production scale

Judge the production capacity of concrete mixing equipment according to the size of production scale Annual output 200000 m? Below, the productivity of concrete mixing equipment is generally not less than 90m/ h; The annual output is 200000-300000 m?, The productivity of concrete mixing equipment is generally 120m/ h; Annual output 30m? Above, the productivity of concrete mixing equipment is generally 180m/ H or 240m/ h.

2. Construction site

According to the size of the construction site, concrete mixing plant or concrete mixing plant can be selected The concrete mixing plant is selected, and the aggregate is increased at one time. The production efficiency of the mixer with the same capacity is higher than that of the mixing plant. The overall shape is neat and beautiful. The area of the material plant is small, and the production environment is good, but the manufacturing and installation cycle is long, and the one-time investment cost is high When selecting concrete mixing plant, the aggregate needs to be lifted twice, with flexible layout, short manufacturing and installation cycle and low one-time investment cost. However, the stockyard covers a large area and the production environment is relatively poor

3. Supporting equipment

Select the specifications and working dimensions of concrete mixing equipment according to the supporting equipment The loading capacity of the mixer truck should match the discharge capacity of the mixer. Improper matching will affect the work efficiency The loading capacity of the loader shall match the loading height of the batching plant of the concrete mixing plant

4. Management function

If intensive network management is adopted, the network management function of concrete mixing equipment should be considered to avoid difficulties in future upgrading

5. Technical performance of equipment

Mainly consider the progressiveness, reliability, excellence and versatility of the equipment Concrete mixing equipment should have the characteristics of advanced working principle, high degree of automation, powerful management function and good environmental protection performance The concrete mixing equipment shall be well configured, with reliable control mode, strong adaptability and good maintainability In addition, we should also consider high measurement accuracy, good mixing quality, high production efficiency, low energy consumption, large use of standard parts, and good interchangeability

6. Supplier reputation

Mainly including whether the installation and commissioning are strict; Whether the technical guidance and training are in place; Whether the after-sales service is timely; Whether the supply of spare parts is sufficient

7. Performance price ratio

It is unwise to pursue the technical performance of concrete mixing equipment in an all-round way, which will increase unnecessary investment, but only pursuing low investment and reducing the technical performance of equipment will increase the use cost, which is also undesirable At present, the comprehensive performance of imported equipment in the domestic market is higher, but the price is also more expensive The comprehensive performance of domestic concrete mixing equipment may be lacking, but the main working performance is not much worse than that of imported equipment, but the price is much lower, which is a high cost-effective choice