Double Shaft Mixer for Cement, Fly Ash & Powder Mixing
Twin Shaft Paddle Mixer for Cement, Fly Ash, Dry Mortar and Bulk Powder Handling
What Is a Double Shaft Mixer?
A double shaft mixer, also called a twin shaft mixer or twin shaft paddle mixer, is an industrial mixing machine designed for uniform blending, conditioning and moisture control of cement, fly ash, lime powder, dry mortar and other bulk powder materials.
It uses two counter-rotating shafts with mixing paddles to create strong material movement inside the mixing chamber. Compared with simple single-shaft mixing equipment, a double shaft mixer provides higher mixing intensity, shorter mixing time and more stable output for continuous powder handling systems.
For cement plants, fly ash handling projects and dry mortar production lines, the mixer is often installed together with screw conveyors, air slide conveyors, dust collectors, storage silos and discharge valves to form a complete bulk material mixing system.
One important feature of LVRUI double shaft mixer is the bottom aeration design. Compressed air is introduced from the bottom of the mixer to help fluidize fine powders, reduce material buildup, and improve discharge stability, especially when handling cement, fly ash, lime powder and other materials that may become compacted during mixing or discharging.
For industry safety standards, refer to OSHA guidelines on combustible dust hazards.
How Does a Double Shaft Mixer Work?
A double shaft mixer works by using two parallel shafts rotating in opposite directions. The paddles mounted on the shafts push, lift and turn the material continuously inside the mixing chamber.
The typical working process includes:
✅ Powder or granular material enters the mixer through the inlet.
✅ Two counter-rotating shafts move the material in opposite directions.
✅ Mixing paddles create strong cross-mixing and axial movement.
✅ Bottom aeration supplies compressed air from the mixer bottom to fluidize fine powder and reduce material buildup.
✅ The mixed material is discharged through the outlet or pneumatic discharge gate.
✅ Downstream conveyors transfer the mixed material to the next process.
This working principle makes the double shaft mixer suitable for cement blending, fly ash conditioning, dry mortar mixing, lime powder treatment and other bulk powder processing applications.
Features
✅ Two high-intensity parallel shafts for fast and uniform mixing
✅ Suitable for cement, fly ash, lime powder, dry mortar
✅ Bottom aeration design helps fluidize fine powders and improve discharge stability
✅ Wear-resistant paddles for abrasive bulk materials
✅ Sealed body structure helps reduce dust leakage during operation
✅ Compatible with pneumatic discharge, gravity discharge or conveyor connection
✅ Low-maintenance structure for continuous industrial operation
✅ Can be integrated with screw conveyors, air slide conveyors, silos and dust collectors
Explore related dust control solutions for cleaner, safer, and more efficient powder and granular material blending operations.
Key Components of a Double Shaft Mixer
| Component | Function | Why It Matters |
|---|---|---|
| Mixing Chamber | Holds material during mixing | Determines capacity and mixing stability |
| Twin Shafts | Provide counter-rotating movement | Improves mixing intensity |
| Mixing Paddles | Push, lift and turn the material | Affects mixing uniformity and mixing time |
| Drive Motor | Provides mixing power | Ensures stable operation under load |
| Gear Reducer | Controls shaft speed and torque | Protects the transmission system |
| Wear Liner | Protects the chamber from abrasion | Important for cement, fly ash and mineral powder |
| Moisture Addition System | Adds water or liquid when required | Useful for fly ash conditioning and dust suppression |
| Bottom Aeration System | Supplies compressed air from the mixer bottom | Helps fluidize fine powders, reduce buildup and improve discharge stability |
| Discharge Gate | Controls material outlet | Supports continuous or batch discharge |
| Sealed Cover | Reduces dust leakage | Improves site cleanliness |
Technical Specifications
The following double shaft mixer specifications are commonly used for preliminary selection. Final model selection should be confirmed according to material bulk density, required capacity, moisture content, particle size, abrasiveness and downstream conveying method.
| Model | DSG100 | DSG150 | DSG200 |
|---|---|---|---|
| Capacity (t/h) | 50–100 | 80–150 | 120–200 |
| Mixing Time (s) | 60–120 | 60–120 | 60–120 |
| Power (kW) | 11–18.5 | 18.5–22 | 22–30 |
| Moisture Content | 5–12% adjustable | 5–12% adjustable | 5–12% adjustable |
| Discharge Gate | Pneumatic | Pneumatic | Pneumatic |
| Wear Liner | High manganese / alloy steel | High manganese / alloy steel | High manganese / alloy steel |
*Technical specifications are for reference only and can be customized upon request.
The final mixer model, paddle configuration, liner material, bottom aeration layout, compressed air requirement and drive power can be customized according to different powders, fly ash properties, cement mixing requirements and production capacity.
Common Applications of Double Shaft Mixer
✅ Cement powder mixing in cement plants
✅ Fly ash conditioning before conveying or loading
✅ Industrial dust conditioning and recycling
✅ Bulk powder mixing before screw conveyor discharge
✅ Cement and fly ash processing lines in Southeast Asia
✅ Bulk material handling systems with bottom aeration discharge assistance
To build a complete powder mixing and conveying line, the double shaft mixer can be integrated with an Air Slide Conveyor for efficient powder transfer.
For controlled powder feeding and discharge, the system can also be combined with a Screw Conveyor.
How to Choose the Right Double Shaft Mixer
Selecting the right double shaft mixer requires more than choosing a capacity model. The mixer should match the material properties, moisture requirement, discharge method, compressed air condition and downstream conveying system.
| Selection Factor | What to Confirm |
|---|---|
| Material Name | Cement, fly ash, lime powder, dry mortar, sludge or mineral powder |
| Bulk Density | t/m³ or kg/m³ |
| Required Capacity | t/h |
| Moisture Requirement | Dry mixing or moisture conditioning |
| Material Abrasion | Whether wear-resistant liner is required |
| Feeding Method | Screw conveyor, air slide conveyor, silo outlet or manual feeding |
| Discharge Method | Pneumatic gate, gravity discharge or conveyor connection |
| Bottom Aeration Requirement | Whether compressed air aeration is required from the mixer bottom |
| Compressed Air Data | Air pressure, air volume and available air source |
| Motor Power | Based on capacity and material load |
| Dust Control | Whether sealed cover or dust collector interface is required |
| Site Layout | Inlet height, outlet height and maintenance space |
For fine powder materials such as cement, fly ash and lime powder, bottom aeration is especially useful when the material may become compacted or difficult to discharge. The air pressure and air volume should be confirmed according to material flowability, mixer model and site operating conditions.
FAQs About Double Shaft Mixers
What is a double shaft mixer used for?
A double shaft mixer is used for uniform mixing, conditioning and moisture control of powders and granular materials such as cement, fly ash, dry mortar, lime powder and industrial solids. It is commonly used in cement plants, dry mortar production lines and bulk material handling systems.
Is a twin shaft paddle mixer the same as a twin shaft mixer?
Yes. A double shaft mixer is also known as a twin shaft mixer. Both terms describe the same mixing principle using two counter-rotating shafts with high-intensity paddles, providing fast and uniform mixing for industrial powders and granular materials.
Why is a dual-shaft mixing system suitable for dry mortar production?
Dual-shaft mixers provide high mixing intensity, short mixing time, and uniform distribution of cement, sand, and additives in dry mortar production lines. They ensure consistent quality, low-maintenance operation, and reliable output for industrial applications.
Can a double shaft mixer handle fly ash and fine powders?
Yes. Double shaft mixers are widely used for fly ash conditioning and fine powder mixing, especially when combined with dust control systems and proper feeding mechanisms. They are ideal for cement plants, mortar facilities, and bulk material processing industries.
How do I choose the right double shaft mixer model?
Mixer selection depends on required capacity, material characteristics, moisture content, and production process. LVRUI engineers can recommend the optimal double shaft mixer model based on your specific application for cement, dry mortar, lime powder, or fly ash processing.
What is the difference between a double shaft mixer and a single shaft mixer?
A double shaft mixer uses two counter-rotating shafts to create stronger material movement and faster mixing. It is more suitable for high-capacity cement, fly ash, dry mortar and bulk powder mixing applications.
Can a double shaft mixer be used for fly ash conditioning?
Yes. A double shaft mixer can be used for fly ash conditioning when moisture addition, dust suppression or stable discharge is required before conveying, storage or loading.
What information is required before selecting a double shaft mixer?
Normally, the required information includes material name, bulk density, required capacity, moisture content, abrasiveness, feeding method, discharge method, voltage and site layout.
Does the double shaft mixer need bottom aeration?
For fine powder materials such as cement, fly ash and lime powder, bottom aeration can be used to fluidize the material, reduce buildup inside the mixer, and improve discharge stability. The air pressure and air volume should be confirmed according to the material properties and mixer model.
Need a reliable double shaft mixer for cement, fly ash or dry mortar mixing?
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