Central Scraper
المواصفات الفنية
Key Attributes
| Product Name | Central Scraper / Bottom Trough Discharge Scraper |
| Material Grade | Cr26 High-Chromium Alloy, PTA Tungsten Carbide Overlay (W2C/WC) |
| Hardness Rating | 62 – 66 HRC (Tungsten Matrix 68–72 HRC / 1800–2200 HV) |
| Boundary Clearance | 3.5mm – 5.0mm Slotted Hole Precision Tuning |
| Primary Function | Bottom Trough Clearing & Rapid Batch Discharge Sweeping |
| Machine Compatibility | BHS, SICOMA, Liebherr, Teka, SIMI, ELKON, MEKA, Linz |
| Casting & Hardfacing Process | Vacuum Sand Casting & Plasma Transferred Arc (PTA) Weld Overlay |
| Brand Name | VOTNE |
| Place of Origin | China |
| Scraper Thickness | 18mm, 20mm, 25mm (Customized) |
| SEO Keywords | central scraper, bottom trough scraper, BHS scraper blade, SICOMA central scraper, concrete mixer scraper, high chromium wear blade, concrete wear parts |
Product Overview
VOTNE Central Scrapers are heavy-duty wear-resistant blades engineered specifically to clear heavy aggregate settlement and cement paste buildup from the central bottom trough apex and discharge gate region of industrial twin-shaft, planetary, and pan concrete mixers.
Mounted on central mixing arms directly above the main discharge door, central scrapers operate in the heaviest material compression zone. During mixing, heavy coarse aggregates settle to the bottom trough floor. When the discharge door opens, the central scraper acts as a sweeping squeegee, forcing out sticky concrete in seconds without leaving aggregate residue inside the mixer. VOTNE central scrapers utilize ultra-hard Cr26 high-chromium alloy casting metallurgy (62 to 66 HRC), forming a dense concentration of discontinuous M7C3 eutectic carbides (1500 to 1800 HV) bound inside a tempered martensitic matrix. For severe high-abrasion applications mixing crushed granite or silica sand, VOTNE offers optional Plasma Transferred Arc (PTA) Tungsten Carbide (W2C/WC) hardfacing along the bottom scraping edge.
Designed with CNC-milled slotted mounting holes for precise 3.5mm to 5.0mm bottom liner clearance tuning, VOTNE central scrapers deliver up to 3 times longer wear life, ensuring 100% complete batch discharge and lowering your total wear cost per cubic meter.
Material & Hardfacing Selection
| Alloy Grade | Hardfacing Tech | Hardness | Microstructure | Best Application |
|---|---|---|---|---|
| VOTNE PTA Tungsten Carbide | W2C/WC Carbide Matrix | 68 - 72 HRC (2200 HV) | Tungsten Carbide Particles in Ni-Cr | Extreme Silica Sand & Granite Bottom Trough Scouring |
| VOTNE Cr26 Super High-Cr | Solid Cast High-Cr | 63 - 66 HRC (1800 HV) | Discontinuous M7C3 Carbides | Commercial Ready-Mix & Precast Concrete Plants |
| VOTNE Cr20 Standard High-Cr | Solid Cast High-Cr | 62 - 64 HRC (1500 HV) | Primary Chromium Carbides | Light-Duty Batching Mixers & Mortar |
Technical Specifications & Dimensions
| Mixer Brand / Model | Scraper Blade Position | Standard Thickness | Mounting Bolt Hole Spec | Approx. Weight (kg) |
|---|---|---|---|---|
| BHS DKXS 2.0 / 3.0 | Central Bottom Scraper | 20mm / 25mm | M16 Slotted Hole (2 Holes) | 11.8 kg |
| SICOMA MAO 2250 / 3000 | Central Discharge Scraper | 18mm / 20mm | M16 Slotted Hole (2 Holes) | 9.8 kg |
| Liebherr DW 2.25 / 3.0 | Central Floor Scraper | 20mm / 25mm | M20 Slotted Hole (2 Holes) | 13.5 kg |
| TEKA TPZ 1500 / 2250 | Planetary Central Scraper | 18mm / 20mm | M16 Slotted Hole (2 Holes) | 8.9 kg |
| Custom OEM Drawings | Custom Central Scraper | 15mm - 25mm | As Per CAD Drawing | Custom |
Key Advantages for Plant Operators
Rapid Complete Batch Discharge
Sweeps the bottom trough apex and discharge gate, ensuring 100% material evacuation without leaving aggregate residue behind.
Superior Scratching & Abrasion Resistance
High-density M7C3 carbides (or optional PTA Tungsten Carbide hardfacing) resist severe bottom aggregate scouring and sliding friction.
Slotted Hole Clearance Tuning
CNC-milled slotted mounting holes allow easy 3.5mm to 5.0mm clearance adjustments to compensate for progressive drum liner wear.
Prevents Bottom Cake Packing
Continuous scraping prevents cement paste from compacting into a rock-hard layer over the discharge gate mechanism.
Standard & Custom OEM Stock
Direct replacement central scrapers in stock for major European and Asian mixer brands, with rapid custom casting available.
Applications & Field Use Cases
VOTNE Central Scrapers are widely specified across heavy-duty industrial concrete mixing operations:
- Commercial Ready-Mix Concrete Batching Plants (Twin-Shaft Mixers 1.0m³ to 4.5m³)
- Precast Concrete Production Facilities (Planetary and Counter-Current Pan Mixers for pipe, beam, and precast slab casting)
- High-Impact Infrastructure & Dam Construction Projects (Mass concrete mixing with 40mm aggregate)
- Cold Recycled Pavement & Road Base Mixing Plants
- Mining Paste Fill & Underground Backfill Preparation
- Heavy Refractory & Industrial Chemical Mixing Equipment
Frequently Asked Questions (FAQ)
1. What is the primary operational function of a Central Scraper in twin-shaft mixers?
While side scrapers clean vertical end walls, the Central Scraper sweeps the bottom curved drum trough directly above the discharge door. It prevents coarse aggregates from packing into a dead cake at the bottom apex, speeding up batch discharge when the door opens.
2. What is the recommended bottom trough clearance setting for central scrapers?
Maintain a 3.5mm to 5.0mm clearance between the central scraper edge and the bottom drum liners. Adjust using the slotted bolt holes every 20,000 m³ of output to prevent metal drag while keeping the floor clean.
3. When should I choose PTA Tungsten Carbide hardfacing over solid Cr26 alloy?
Solid cast Cr26 high-chromium (63–66 HRC) is ideal for standard commercial ready-mix concrete. For heavy precast or dam concrete using crushed granite, basalt, or crushed sand, PTA Tungsten Carbide overlay (68–72 HRC) extends bottom edge service life by 2x to 3x.
4. What clamp bolt torque should be applied during scraper installation?
For M16 Grade 10.9 countersunk bolts, torque to 210–230 N·m. For M20 bolts, torque to 410–430 N·m. Always use polyurethane backing washers and nylon lock nuts to absorb aggregate impact vibration.
5. What are your lead times and trade terms for export orders?
Standard replacement central scrapers for BHS, SICOMA, and Liebherr mixers are kept in stock for immediate shipment. Custom casting orders take 15 to 25 days. We support EXW, FOB, CIF, and DDP trade terms with global delivery.