Understanding of concrete batching plant

What is a concrete batching plant? Concrete batching plant, also known as concrete mixing plant, is a project used for concrete construction, mainly for mixing and mixing concrete. Concrete batch plant is mainly used for centralized mixing of concrete. Mixing plant can also be called concrete prefabrication plant or ready-mixed concrete plant. Concrete batch plant is equipped with a mixing host, which can automatically batch water, cement, aggregate (sand, stone, etc.), admixtures, admixtures and other raw materials according to a certain proportion, and use machinery to mix them evenly.

Importance of concrete batch plant

The construction industry is inseparable from the participation of concrete. The unique properties of concrete batch plants enable batch plant concrete to be used in the construction of skyscrapers, roads, highways, sidewalks and bridges. The application of these materials requires the participation of concrete batch plants.

Concrete batch plants equivalent name

Finished concrete batching plant types

Concrete batching plant products are installed in various forms. Generally, they can be divided into mobile concrete batching plant, fixed batching plant, ship-mounted batching plant, and foundation-free batching plant according to the fixed form.

Mobile Concrete Batching Plant
Fixed Concrete Batching Plant
Ship-mounted Concrete Batching Plant
Foundation-free Concrete Batching Plant

Mobile batching plants have good mobility and can be moved at any time. They are suitable for various construction sites with small concrete consumption and short construction period, so they usually need to be equipped with walking devices.

Mobile batching plants specification

Fixed batching plants are fixed on the equipment foundation by bolt connection or welding, etc. They are mainly used in large prefabricated component plants, commercial concrete plants and water conservancy project sites. Such batching plants generally have large production capacity.

Ship-mounted batching plants are generally used for the construction of cross-river bridges and large-span cross-sea projects. This type of mixing equipment is suitable for concrete construction in wide waters far away from land. It can move with barges in the construction waters, and various types of concrete can be mixed.

The base frame of the foundation-free batching plant equipment is not connected to the foundation of the equipment site where it is located. The equipment is disassembled and installed quickly, and the foundation construction volume is small. It is generally fixed on the installation base frame.

Structure of concrete batching plants

Concrete mixing station is an equipment system used for centralized production of concrete. It measures and mixes raw materials such as cement, sand, stone, water and admixtures according to the set ratio, and finally forms concrete that meets the engineering requirements. Each part plays an important role:

Mixer

The mixer is the core part of the concrete mixing station. Its main function is to mix cement, aggregate (sand, stone, etc.), water and other materials to form uniform concrete. The mixer usually adopts a twin-shaft forced mixer, which has the characteristics of high mixing efficiency, good mixing uniformity and strong wear resistance.

Batching System

The main function of the batching system is to deliver raw materials of different proportions into the mixing station according to the formula requirements. The batching machine realizes the precise proportioning and transportation of various raw materials through belt conveyors, steel frame structures, transmission motors, weighing buckets and storage silos.

Material Conveying System

The material conveying system is responsible for conveying various materials from the storage silo to the mixer. The system includes aggregate conveying, cement conveying, water conveying and other parts. Aggregate conveying usually uses belt conveyors or bucket elevators, cement conveying uses screw conveyors or pneumatic conveying systems, and water conveying is achieved through water pumps and pipes.

Material Storage System

The material storage system of the mixing station is used to store materials such as cement, aggregates, additives, etc. These silos usually use steel structures or reinforced concrete structures, with sufficient strength and sealing performance to ensure that the materials are not damp, agglomerated, or contaminated during storage. Common storage equipment includes cement tanks and aggregate silos.

Weighing System

The weighing system of the mixing station is responsible for accurately weighing various materials according to the set mix ratio. The system is usually composed of electronic scales, sensors, controllers, etc., which can achieve accurate measurement of various materials such as cement, aggregates, water, etc. to ensure the stability of concrete quality.

Control System

The mixing station control system is the brain of the concrete mixing station and is responsible for the operation control of the entire mixing station. The control system usually uses a PLC programmable controller or a touch screen control system, which can achieve automatic and intelligent control and improve the operation efficiency and stability of the mixing station. At the same time, the system can also realize functions such as remote monitoring and fault diagnosis, which is convenient for users to manage and maintain equipment.

Each component of the concrete mixing plant plays an important role and works together to complete the concrete production task.

Principle of concrete batch plants

Concrete mixing plant is a kind of equipment used to produce concrete. Its working principle is to mix cement, sand, gravel, water, admixtures and other raw materials in a certain proportion to make concrete that meets the requirements of the project.
The working principle of concrete mixing plant mainly includes the following steps: raw material storage and transportation, metering, mixing and discharging.

Raw material storage and transportation

1. Raw material storage:

Aggregate (sand and gravel): usually stored in an open-air aggregate silo. The aggregate silo is divided into multiple grids according to needs to store sand and gravel of different particle sizes.
Powder (cement, fly ash, etc.): stored in a sealed powder silo. The powder silo is usually a vertical cylindrical structure with dust removal equipment on the top to prevent dust from overflowing.
Liquid (water and admixture): water is stored in a water tank, and admixtures are stored in a special admixture tank.

2. Raw material transportation:

Aggregate transportation: Aggregates are transported from the aggregate silo to the batching machine by a loader or a belt conveyor.
Powder conveying: The powder is conveyed from the powder silo to the metering hopper through a screw conveyor.
Liquid conveying: Water and admixtures are conveyed to the metering device through a water pump and a pipe.

Batching metering

Metering is a key link in a concrete mixing plant, and accurate metering is a prerequisite for ensuring the quality of concrete. The metering system includes aggregate metering, powder metering, and liquid metering.

1. Aggregate metering:

Aggregates are metered by a batching machine, which weighs aggregates of different particle sizes according to the set weight or volume and then transports them to the mixing main machine.
The aggregate metering accuracy is generally ±2%.

2. Powder metering:

– Powders such as cement and fly ash are weighed by a metering hopper, which is equipped with a high-precision weighing sensor that can accurately measure the weight of the powder.
– The powder metering accuracy is generally ±1%.

3. Liquid metering:

– Water and admixtures are metered by a flow meter or a weighing sensor, with a high metering accuracy, generally ±1%.
– The metering accuracy of water and admixtures has an important influence on the workability and strength of concrete.

Mixing process

Mixing is the core link of the concrete mixing plant, and its purpose is to fully mix various raw materials to form uniform concrete.

1. Mixing main machine:

The mixing main machine is the core component of the concrete mixing plant. Common mixing main machines include twin-shaft forced mixers and planetary mixers.

– The twin-shaft forced mixer is the most widely used mixing main machine at present. It uses the mixing blades on the two horizontal shafts to force the materials to mix, with high mixing efficiency and good mixing quality.

– The planetary mixer drives the mixing blades through the planetary gear mechanism, which makes the mixing more uniform, but the cost is higher.

2. Mixing process:

– The raw materials enter the mixing main machine in the set order and time, and the mixing main machine mixes according to the set mixing time and speed.

– The mixing time is generally 30 seconds to 1 minute, and the specific time depends on the mix ratio of the concrete and the performance of the mixing main machine.
– During the mixing process, the mixing blades shear, flip and mix the materials, so that the cement, sand, water and admixtures are fully mixed to form uniform concrete.

Concrete unloading and transportation

After mixing, the concrete enters the transport vehicle or concrete storage tank through the discharge port of the mixing main machine, and then is transported to the construction site.