Conical Screw Mixer, Doebritz Industrial Mixer, 304 Stainless Steel / ATEX Certified

Product Summary

The Doebritz Conical Screw Mixer is a high-performance, heavy-duty industrial blending system engineered for precision mixing of powders, granules, and pastes. With capacity ranges from 50L to 30,000L and a robust conical vessel design, it guarantees 99.9% discharge rate and minimal residual material. Certified for ATEX Zone 21/22 and equipped with a dual-screw orbital mixing motion, it delivers homogeneous blends in as little as 5-15 minutes while maintaining product integrity even for fragile or abrasive materials.

Why Source Doebritz Conical Screw Mixer

Choose Doebritz for unmatched process reliability and long-term ROI. Here is why global OEMs and plant operators trust our mixing technology:

• Superior Mixing Precision: Patented conical screw geometry generates both convective and diffusive mixing actions, achieving CV < 5% in most applications.
• Minimal Contamination Risk: Crevice-free welding and mirror-polished internal surfaces (Ra ≤ 0.4µm) enable rapid changeover and CIP/SIP compatibility.
• ATEX Explosion-Proof & Sealing Safety: Fully certified for explosive dust/gas atmospheres; multiple air purge sealing systems prevent product ingress to bearings.
• Lowest Lifecycle Cost: Heavy-duty gearbox with helical-bevel gears, plus wear-resistant screw flight hardfacing, delivers 100,000+ hours MTBF under full load.
• Global Engineering Support: Doebritz provides on-site commissioning, FEA-validated custom nozzles, and RFID-enabled spare parts tracking for all markets.

Housing & Rotor Engineering

The Doebritz Conical Screw Mixer features a fully seam-welded, dished head conical vessel constructed from 304 or 316L stainless steel as standard, with Hastelloy and duplex options for corrosive processes. The conical shape eliminates dead zones while the bottom discharge valve ensures complete emptying. The mixing screw assembly consists of a precision-machined single or twin continuous spiral screw mounted on a cantilevered swing arm. The screw rotates on its own axis while the arm orbits the conical vessel interior, creating a 3D material flow pattern. All screw flights undergo CNC contour grinding to maintain a tight clearance of 3-5 mm from the vessel wall, ensuring efficient wiping action without metal-to-metal contact. The drive system incorporates a double mechanical seal with nitrogen purge, preventing dust leakage and prolonging bearing life in fine powder applications.

Technical Specifications

Below are standard engineering parameters for Doebritz Conical Screw Mixers. Custom configurations (jackets, spray bars, high-speed choppers) are available upon request.

Specification	Detail
Vessel Material	304 or 316L Stainless Steel (Hastelloy / Duplex optional)
Working Capacity	50L to 30,000L
Screw Design	Single or Twin continuous spiral, CNC ground clearance 3-5 mm
Drive Power	4 kW to 160 kW, IE3 premium efficiency motor
Mixing Speed (Screw)	40 – 150 RPM (variable via VFD)
Orbital Speed	3 – 10 RPM
Sealing System	Double mechanical seal + Nitrogen purge (ATEX compliant)
Surface Finish	Internal Ra ≤ 0.4µm (Mirror polish), External 240 grit
Max Temperature	Standard 200°C / Optional 400°C with jacket
Explosion Protection	ATEX II 2/2D c T4, Zone 21/22

Heavy-Duty Application Scenarios

Powder & Granule Blending for Pharmaceuticals & Food

Gentle mixing prevents particle degradation while achieving blend uniformity for API/drug compounds, nutritional powders, and bakery premixes. Fully washdown-compliant design meets GMP standards.

Chemical & Pigment Dispersion

Conical screw motion effectively disperses liquid additives or colorants into dry powders with minimal agglomerates. Available heating/cooling jacket enables temperature-sensitive reactions.

Plastic & Masterbatch Homogenization

Blend virgin resins, regrind, and color concentrates at low shear to preserve pellet integrity. Optional stainless steel lining prevents cross-color contamination.

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Frequently Asked Questions

What is the typical lead time for a Doebritz Conical Screw Mixer?

Standard capacities (500L to 5,000L) are delivered within 8-10 weeks. Larger or custom-engineered units (with jackets, ATEX instrumentation) require 12-14 weeks. We offer expedited machining for urgent projects.

Can you customize the inlet/outlet flange standards and sizes?

Yes. Doebritz provides flanges to ANSI, DIN, JIS, or BS standards. We also support sanitary tri-clamp connections, slide gates, and rotary airlock discharge adapters based on your pneumatic conveying layout.

Is the mixer fully ATEX certified for Zone 0/20 dust explosions?

Our standard ATEX design is certified for Zone 21/22 (dust) and Zone 2 (gas). For Zone 20/0 applications, Doebritz offers a specialized inert gas purge system and brushless motors with full certification documentation.

What maximum operating temperature can the mixing vessel withstand?

With a standard 304 SS shell, max temperature is 200°C (392°F). With optional heat transfer jacket and high-temperature gaskets, we support up to 400°C (752°F) for chemical reactors and calcined powder blending.

Do you provide spare parts globally and what is the warranty?

Doebritz provides a 24-month warranty on gearbox and main shaft. Spare parts (screw flights, seals, bearings) are stocked regionally in EU, USA, and Asia for 24-48h dispatch. We also offer preventive maintenance contracts.