Composition of mixing plant:

The concrete mixing plant is mainly composed of 5 major systems: material storage system, material weighing system, material transportation system, mixing system, powder storage system, powder transportation system, powder measurement system, water and admixture measurement system and control system. And other ancillary facilities.

Mixing host

The mixing host is divided into forced mixing and self-falling mixing according to its mixing method. 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 rigidity and dry rigidity. The self-falling mixing machine is mainly used for mixing liquid concrete, which is rarely used in mixing plants.

Forced mixers are divided into main shaft planetary mixers, single-horizontal mixers and double-horizontal mixers according to their structural forms. Among them, the double-horizontal-shaft forced mixer has the best comprehensive performance.

Weighing system

Material weighing system is a key component that affects the quality of concrete and the cost of concrete production. It is mainly divided into three parts: aggregate weighing, powder weighing and liquid weighing. Under normal circumstances, mixing plants below 20 cubic meters per hour adopt superimposed weighing, that is, a scale for aggregate (sand, stone), a scale for cement and fly ash, water and liquid admixtures are weighed separately , Then put the liquid admixture into the water weighing bucket to pre-mix. In mixing plants above 50 cubic meters per hour, most of the materials are weighed independently. All weighings are controlled by electronic scales and computers. Aggregate weighing accuracy is ± 2%, and the weighing accuracy of cement, powder, water and admixtures is ± 1%.

Conveyor system

Material handling consists of three parts:

Aggregate conveying: There are two ways of conveying in the mixing plant: hopper conveying and belt conveying. The advantages of hopper lifting are small footprint and simple structure. The advantages of belt conveying are large conveying distance, high efficiency and low failure rate. The belt conveyor is mainly suitable for mixing plants with temporary storage bins to increase the productivity of the mixing plants.

Powder transportation: The available powders for concrete are mainly cement, fly ash and mineral powder. The commonly used powder conveying method is screw conveyor. Large-scale mixing buildings use pneumatic conveying and scraper conveying. The advantages of spiral conveying are simple structure, low cost and reliable use.

Liquid transportation: mainly refers to water and liquid admixtures, which are transported by water pumps.

Storage system

The material storage methods available for concrete are basically the same. Aggregates are stored in the open air (there are also closed silos for large-scale commercial concrete mixing plants in cities); powders are stored in fully enclosed steel structure silos; admixtures are stored in steel structure containers.

Control System

The control system of the mixing plant is the central nerve of the whole set of equipment. The control system has different functions and configurations according to the different requirements of the user and the size of the mixing plant. Generally, the control system of the small mixing plant available at the construction site is simpler, while the system of the large mixing plant is relatively complicated.