System Operation Steps of Commercial Concrete Mixing Plant Production Process

System Operation Steps of Commercial Concrete Mixing Plant Production Process

Concrete mixing plant is composed of aggregate batching, aggregate feeding, powder storage, powder feeding, water admixture pipeline, batching and discharging system, mixing and discharging system, air system, control and other systems and structural components, want to produce good, understand certain production process is essential, today to share the production process of commercial concrete mixing plant system operation steps, come to see.

The steps of the system operation of the commercial production process.

1. Aggregate batching system

  Aggregate batching system is a set of sand and stone and other aggregate storage, metering output and other functions in one. Generally there are storage hopper and metering hopper composition.

  Due to the production of concrete gradation is different. Storage hopper can be set as 3 hoppers, 4 hoppers, 5 hoppers and so on. With 4 buckets as a typical. Can adapt to various grades of aggregate storage. The capacity of the hopper generally depends on the production capacity of the station. The storage hopper discharge adopts pneumatic control door opening method.

  Aggregate measurement is distinguished according to the measurement method. There are two kinds of sand, stone vertical measurement and cumulative measurement. Standing metering is set up under each storage hopper weighing hopper, and open the pneumatic door of metering hopper after finishing counting alligator. Aggregate falls to the horizontal belt machine below. It is output by horizontal belt machine. Cumulative metering is in the horizontal belt machine without spring stall and the belt to form a metering trough, the aggregate falls into the metering trough with the belt machine to complete the cumulative metering. Both kinds of measurement methods adopt electronic weighing form, dynamic measurement accuracy can meet the standard specification requirements.

  Aggregate feeding is to send the aggregates into the mixer after the completion of metering. Generally through the belt conveyor. Also available to pull bucket elevator. Belt type of the belt machine according to the site conditions to choose, in general. When the angle of inclination ≤ 22. choose plain belt. Inclination 22. a 30. choose herringbone shallow pattern belt, inclination 300 a 60. choose skirt belt, angle greater than 600 can be used to pull the cattle hoist. Belt speed of the belt machine is generally selected 1.6m / s, 2.0 or 2.5 a s. The common specifications of the belt width are 650, 800, 10 (10, 1200ma, etc.). Inclined belt machine conveying capacity Qmax (t & ) should be able to meet the actual output flow of the horizontal belt machine Q. (kg / s) requirements.

  The permitted range of belt conveyor conveying capacity is large and can be adapted to various specifications of mixing machine. And the belt machine can also be equipped with additional protective canopy. The corridor for maintenance and repair can be fully enclosed if necessary.

3. Powder material storage

  Powdered raw materials such as cement, fly ash, slag powder, etc. are stored in powder silo (silo). Powder silo can be designed for 100t, 200t, 300t, etc. The capacity of powder silo is also designed according to the requirements of users. The smaller the capacity of the powder silo, the higher the requirement for the flow of powder supply channel when the mixing plant continuously produces concrete. The number of alligator bins is determined by the type of powder required for concrete.

4. Powder feeding

  Powder feeding is to feed cement, fly ash and other powders into the corresponding powder weighing hopper. The conveying of powder must be carried out in a completely sealed cavity. In order to avoid pollution of the environment and moisture of the conveyed materials, the widely used is 0-shaped cross-section screw conveyor. Its casing is made of seamless steel pipe, common specifications are 'p219, 'P273, 'p325, etc. The casing tail inlet is connected to the powder bin butterfly valve through the universal ball, and the head outlet is softly connected to the powder weighing hopper through the canvas bag. The length of the spiral should not exceed 14 m. Different total lengths of the spiral can be obtained by replacing the middle section. Longer conveying distance can be achieved by means of spiral relay, and two feed ports are set for the relay spiral.

5. Water, admixture pipeline

  Water admixture pipeline includes water and liquid admixture feeding device and pipeline components, through the pipeline, water and liquid admixture are sent to the corresponding liquid weighing hopper in the station. The water tank with water pump is usually purchased in the engineering station. Commercial mixing station generally build their own storage tank with submersible pump water supply, admixture pump should be selected with corrosion-resistant pump. Water supply pipeline should be set up to circulate network water branch, so as not to stop the pump on the water pipe shrinkage deformation, especially when the pump discharge alligator and the use of hose on the water is more necessary. Water pump and corrosion resistant pump discharge scenery should meet the mixing station water (admixture) requirements, the pump head should be greater than the height of the water (admixture).

6.Batching and unloading system

  This system is a variety of materials required for concrete (aggregate, powder, water, admixtures, etc.), according to the ratio, through the precise measurement of alligator and then sent to the mixer. At present, the mixing plant batching measurement with electronic weighing measurement. The general weighing hopper adopts three-point type. Belt machine with metering slot adopts four-point type, weighing hopper weighing value is small (such as liquid admixture) can also use one-point type, according to the installation form of measuring device to choose the tension or pressure sensor.

  After the dosage is finished. After receiving the signal of material release, the arc gate (butterfly valve) of various materials will be opened in turn. The material will be sent into the mixer to complete the unloading procedure.

7. Mixing and discharging system

  Mixing system is the core system of concrete mixing plant. It is the mixer that mixes the various materials received into homogeneous concrete. The mixer can be divided into two types: forced type and self-falling type according to the mixing principle. In the forced type, the tank is not moving. The mixing shaft rotates, and the mixing vanes are driven by the mixing arm to force the material in the tank to guide the mixing; the self-falling mixing cylinder rotates, and with the help of the mixing vanes installed in the mixing cylinder, the material is lifted, and the material falls by its own gravity, and produces axial crosstalk. So as to achieve the mixing effect. Compared with the two, the forced mixing effect is strong, generally in 30-60 seconds of mixing time to mix the mixture into homogeneous concrete. When preparing special or special concrete, it takes a longer time; self-falling mixing time needs to be doubled or even longer, mixing special concrete is difficult or even impossible. At the same mixing capacity, the driving power of the mixer is larger for the forced type compared to the self-falling type. The corresponding total installed power of the equipment and power distribution facilities to increase, but the work cycle is shorter, so the production of concrete unit energy consumption is not increased significantly. Comprehensive mixing efficiency, function, quality and energy consumption of all factors. The mixing plant should choose the forced mixer as the host. Only when the aggregate particle size is larger such as 150ram or more crushed stone is preferred to the self-falling mixer.

8. Gas circuit system

  Air system includes kiln compressor, storage tank, air supply pipeline and gas-water separator, oil mist, pressure reducing valve, electromagnetic gas valve air accessories, used to provide compressed air to the mixer discharge door, storage bin bottom door, metering hopper bottom door or butterfly valve, discharge hopper bottom door and other devices to perform the switching action of the cylinder and powder silo arch breaking device.

  The technical specifications of the air compressor exhaust volume according to the cylinder and other executive components specifications and data optional, to the cylinder air supply pipeline should be equipped with gas and water separator and oil mist device. The pipeline supplying air to the arch-breaking device should be equipped with gas-water separator and pressure reducing valve, and cannot be equipped with oil mist. The pressure of pressure reducing valve is about 0.2MPa.

9. Structure

  The structure of the main station is divided into top to bottom: batching layer, upper row frame, mixing layer, lower row frame, etc. The design of the main station structure should consider material weight, self-weight, wind load, live load, vibration coefficient and earthquake intensity, etc. The whole mixing station can be enclosed with color sandwich panel or color steel plate, which can prevent dust spillage in the mixing station. It can also play the effect of heat preservation and decoration.

10. Control system

  All controls are located in the control room (including the control and monitoring of loading and discharging of aggregate, powder, water and admixture). The control room adopts a centralized control system centered on computer control, which can control and manage the whole process of concrete production in the control room on the control panel.