Double Shaft Concrete Mixer

Shanghe Concrete Mixer

A double-shaft (twin-shaft) concrete mixer is a forced-action mixer engineered for rapid, high-volume production. Its two horizontally aligned, counter-rotating shafts create a vigorous mechanical mixing action that ensures a complete and uniform blend of all components, delivering consistent, high-quality concrete batches ideal for commercial and industrial use.

Designed for efficient, consistent, and cost-effective concrete production, it is an ideal solution for diverse applications including urban construction sites, roadworks, housing projects, and remote or temporary installations.

Advantages

Unmatched Mixing Performance

At the core of its design are two counter-rotating shafts that create a powerful, turbulent mixing zone. This forced mechanical action guarantees a rapid and perfectly homogenous blend of all components—from large aggregates to fine powders and additives—in as little as 30 seconds. This process eliminates segregation and ensures every batch meets precise specifications, making it ideal for everything from standard plastic concrete to specialized mixes like Self-Consolidating Concrete (SCC) and dry-hard formulations.

Built for Efficiency & Long-Term Reliability

These mixers are synonymous with high-capacity output and robust construction. Engineered with wear-resistant alloys and intelligent design features that minimize abrasive contact, they are built for longevity in continuous operation. This durability is further enhanced by integrated systems, such as automatic lubrication, which streamline maintenance, reduce downtime, and protect critical components, thereby lowering the total cost of ownership over the machine’s lifespan.

Operational Advantages for Modern Production

Beyond mixing excellence, the design delivers significant operational benefits. It provides unparalleled batch-to-batch consistency, which is critical for precast manufacturing and large-scale projects requiring uniform quality. Quick-discharge mechanisms and seamless integration into automated batching plants further maximize production throughput, making it a versatile and productivity-focused solution for ready-mix facilities, precast yards, and major infrastructure projects.

Application

1. Large-Scale Infrastructure & Civil Engineering
In these sectors, the mixer’s capacity for continuous, high-volume output of exceptional quality is critical. It is the preferred solution for:

• Major Hydro & Civil Works: Essential for producing the massive volumes of Roller-Compacted Concrete (RCC) for dams and high-strength mixes for foundational structures.
• Transportation Infrastructure: Powers the construction of highways, bridge decks, and airport runways where consistent quality and rapid placement are non-negotiable.
• Tunnel Boring & Linings: Provides the reliable, high-performance concrete required for tunnel segments and linings in demanding subsurface environments.

2. Precision Precast & Product Manufacturing
Here, batch-to-batch consistency and the ability to handle stiff mixes are paramount. The twin-shaft mixer is vital for:

• Precast/Prestressed Elements: Ensures uniform density and strength in structural components like beams, columns, and hollow-core slabs.
• Brick, Block & Paver Production: Delivers the homogeneous color and texture required for high-quality masonry units and paving stones in automated production lines.

3. High-Efficiency Commercial Ready-Mix
As the heart of modern batching plants, it enables the reliable, on-demand production of commercial concrete, capable of efficiently producing everything from standard ready-mix to specialized formulations like self-consolidating or fiber-reinforced concrete.

4. Specialized Industrial & Environmental Processing
The mixer’s robust, thorough blending action extends its utility beyond traditional construction into industrial realms:

• Waste Stabilization & Landfill Engineering: Used to solidify contaminated soils or blend stabilizing agents for secure landfill caps.
• Mining & Industrial Backfilling: Prepares consistent, pumpable backfill materials for mining operations.
• Chemical & Material Blending: Adapted for processing where intensive, uniform mixing of dry or semi-dry materials is required.

Working Principle

The double shaft concrete mixer is a forced-action mixer engineered for intensity and speed. Its core mechanism consists of two parallel, horizontal shafts that rotate in opposite directions at synchronized speeds. This counter-rotation, combined with strategically angled blades arranged in a staggered spiral pattern on each shaft, creates a powerful three-dimensional mixing flow. Materials are simultaneously lifted, folded, and thrust laterally through a central “turbulent zone” where the paths of the two shafts overlap. This vigorous compulsory action eliminates dead spots, ensures every aggregate particle is fully coated with cement paste, and achieves a homogeneous mix in a remarkably short cycle time. A precisely controlled water injection system sprays directly into this active zone for immediate and even hydration.

Key System Components

The mixer integrates several specialized subsystems to execute this process reliably:

1. Mixing System (The Core): Comprises the two heavy-duty shafts, arms, and wear-resistant alloy steel blades engineered for optimal material shearing and movement.
2. Drive & Transmission: A high-torque electric motor delivers power through a belt and heavy-duty gearbox (often planetary) to the shafts. An open-gear mechanism guarantees their precise, synchronized counter-rotation.
3. Material Handling Systems:
   • Feeding: Typically a skip hopper or conveyor that charges aggregates, cement, and powders into the drum.
   • Water Supply: A metered pumping and nozzle system for accurate, evenly distributed water addition.
   • Discharge: A centrally located, hydraulically or pneumatically operated gate allows for rapid and complete emptying of the batch.
4. Support & Control Systems:
   • Lubrication & Sealing: An automated greasing system protects critical wear points like shaft seals and bearings from the abrasive environment.
   • Electrical Control: Manages the entire operational sequence—from batching and mixing time to discharge—and incorporates safety interlocks, overload protection, and emergency stops.

Specification