Asphalt Mixing Plant

Shanghe Asphalt Mixing Plant

An asphalt mixing plant is an industrial facility that produces hot mix asphalt (HMA) by heating and precisely blending aggregates, liquid bitumen, and additives. This material is essential for constructing and maintaining durable pavement on roads, runways, and other critical infrastructure.

Its output is essential for numerous applications:

1. Primary Construction: Supplying high-quality mixtures for highways, urban roads, airport runways, and bridge decks.
2. Maintenance & Rehabilitation: Producing material for pothole repair, asphalt overlays, and eco-friendly recycled (RAP) mixtures.
3. Commercial & Specialized Surfaces: Paving parking lots, industrial zones, sports surfaces, and farm roads.
4. Building & Waterproofing: Manufacturing materials for roofing shingles, membranes, and foundational moisture barriers.

Asphalt Mixing Plant Types

1. By Mixing Method

• Batch Mix Plants: These produce material in precise, discrete cycles. Aggregates are dried, screened, and weighed separately before being mixed with bitumen. This allows for superior quality control and flexible recipe changes, making them ideal for high-specification projects.
• Drum Mix Plants: In these plants, all materials are continuously fed, dried, and mixed in a single rotating drum. This design offers higher output and lower operating costs, making it suitable for large-scale projects requiring a consistent mix.

2. By Mobility

• Stationary Plants: Permanently installed for stable, high-volume, long-term production at a fixed site.
• Mobile Plants: Mounted on trailers for quick relocation and setup, ideal for temporary or remote projects. Both batch and drum types come in mobile configurations.

3. By Capacity

Large (>400 t/h): For major infrastructure like expressways and large-scale government projects.

Small (<40 t/h): For minor repairs and small local roads.

Medium (40-400 t/h): For standard city and regional road construction.

Advantages

Advantages by Plant Type

• Batch Mix Plants (for Precision):
  • Superior Quality: Each batch is individually weighed for exact material proportions.
  • Mix Flexibility: Quick changeover between different asphalt recipes.
  • Enhanced Emissions Control: Typically feature advanced baghouse filtration systems.
• Drum Mix Plants (for Efficiency):
  • Continuous Output: Uninterrupted production ideal for large-scale projects.
  • Lower Operational Costs: Simpler design reduces initial investment and maintenance.
  • Energy Efficient: Consumes less fuel by avoiding frequent start-stop cycles.
• Mobile Plants (for Flexibility):
  • Rapid Setup: Can be operational in days without permanent foundations.
  • On-Site Production: Drastically cuts material transportation costs.
  • Project Adaptability: Perfect for remote locations or multiple short-term sites.

Modern Plant Benefits
Contemporary plants integrate key advancements:

• Automation: PLC and IoT systems enable precise real-time control and remote monitoring.
• Sustainability: Capable of incorporating high percentages of recycled asphalt pavement (RAP).
• Durability: Advanced mixing and temperature control produce longer-lasting pavement.
• Safety: Built-in sensors, alarms, and suppression systems enhance operational safety.

Working Principle

1. Shared Operational Stages

All plants follow these fundamental steps:

• Cold Aggregate Feeding: Sized aggregates are stored in separate Cold Feed Bins and precisely metered onto a gathering conveyor according to the mix design.
• Drying & Heating: Aggregates enter a rotating Drying Drum equipped with a burner, where they are heated to 160°C–180°C to remove moisture.
• Pollution Control: Exhaust gases are cleaned by a Dust Collection System (e.g., cyclone and baghouse filter) to meet environmental standards.
• Binder & Filler Supply: Liquid bitumen is stored in heated tanks, and mineral filler (e.g., lime) is held in silos, ready for precise addition.

2. Mixing Process by Plant Type

Batch Mix Plant Process:

1. After drying, hot aggregates are lifted to a Vibrating Screen and sorted into compartmentalized Hot Bins.
2. Each component (aggregates, filler, bitumen) is individually weighed for a single batch.
3. Materials are discharged into a twin-shaft Pugmill Mixer and blended for 30-60 seconds.
4. The complete batch is then discharged, and the cycle repeats.
   • Advantage: Superior precision and flexibility for changing mix recipes.

Drum Mix (Continuous) Plant Process:

1. Weighed aggregates enter the drying drum continuously.
2. Drying and mixing occur in a single, uninterrupted process within the same rotating drum; bitumen and filler are injected into the drum’s mixing zone.
3. Finished HMA is discharged in a constant flow.
   • Advantage: Higher efficiency and output for large volumes of a consistent mix.

3. Final Output & Control

The finished HMA is discharged directly into trucks or conveyed to Insulated Storage Silos to maintain temperature. The entire operation is managed and monitored through a Centralized Control Panel (PLC/SCADA system) for precision and real-time adjustments.

Specification

Stationary Asphalt Mixing Plant

* Productivity based on aggregate water content of 5%.

Mobile Asphalt Mixing Plant

Simple Asphalt Mixing Plant

Continuous Asphalt Mixing Plant