SHANDONG HONGDA Asphalt Mixing Plant Production capacity 240t/h

1. The original modular design of the mixing plant makes transport and installation work quick and convenient. It can separate extra-large flotsam from usable stuff.

2. The loop belt feeder for the measuring hopper has a frequency-conversion speed regulator which can provide high and low speed. Its original structure facilitates belt change and makes material feeding more fluent, which reduces power consumption. Besides, there is a warning light which will remind the user when the machine uses up raw material.

3. The high-efficiency and heat-preservation drying drum and the special vanes make heat exchange more sufficient. Moreover, the high-efficiency and energy-saving imported burner can use both heavy oil and diesel, which reduces energy consumption.

4. The vibrating screen adopts the linear and completely-closed design with the vibrator placed outside. The sieving efficiency is high, the maintenance and changing of screen is easy, and the imported bearings are more reliable.

5. The hot aggregate bin is equipped with a continuous level indicator which enables the operator to know the level of material at a glance. The measurement of aggregate is conducted twice through large and small doors, which greatly improves the measuring precision. The unique structure of the material emptying door reduces the chance of blockage and will work more reliably.

6. The main mixing machine designed with European technology has double reducers with a high-speed synchronization capacity. Accurately-weighed asphalt can be directly pumped into the agitating kettle and powder material can be conveyed into the agitating kettle through the helix, which makes agitating more even and speedy. Besides, it has an opening to add wood fiber and an inlet to add used material to be recycled.

7. The dust-removing system adopts imported NOMEX bags which limit the density of dust discharged into the air within 50mg/m³, which is completely up to the national standard of environmental protection. The dust blown down will be collected into the collection tank through the dust lifter for reuse to avoid secondary pollution.

8. The control system adopts the SIEMENS integrated solution which plays a leading role in the industrial automation field. It also uses the PROFIBUS field bus to form a large and medium-sized distributed automatic system. In operation, the equipment adopts the technology of double hot standby on the industrial computer, dynamic display and buttonless design. All operations are done through the mouse. It has the real-time fault monitoring and control system with functions like parameter setting, data management and fault diagnosis. It measures precisely and can be controlled automatically, semi-automatically and manually, showing a stable and reliable performance.

Functions and features of control system

 The system adopts SIEMENS S7-300 medium programmable controller as main control unit for its superior features fully satisfying site industrial control. We adopt SIEMENS PROFIBUS to form a typical distributed computer control system, improve greatly on key factors concerning systematic performance index like batching decision-making speed, batching control computation, operation pattern. For system structure, we adopt separation model of site real time control and operation management to completely prevent impact caused by uncertainties like computer virus and sudden shutdown on system stability. For system operation, we use “no button” operation mode. Operators can use mouse to fulfill all equipment operation (except for safety operation components such as emergency stop, key switch).

For design of control software, we use latest flow adaptive computation. By dynamic analysis of current material batching process, the batching method determines proper change point and change traditional control system’s adoption of ex post facto data, to make it more suitable for construction environment of great change in material characteristics like asphalt and concrete.

[Main technical parameters of LB series asphalt aggregate mixing equipment]