Under-driven Cone Mill, Doebritz Industrial Cone Mill, 316L Stainless Steel / CIP Capable

Product Summary

The Doebritz Under-driven Cone Mill is a precision size reduction machine engineered for the most demanding continuous bulk solid processing lines. Designed to achieve output capacities from 50 kg/h up to 10,000 kg/h while maintaining a low operation temperature, this unit excels in deagglomerating, granulating, and pulverizing powder, granules, and friable flakes. ATEX certified for dust explosion protection (Zone 20/21), the Doebritz cone mill ensures safe, dust-tight operation for both chemical API synthesis and food powder production. The vertical, under-driven motor design eliminates top-shaft contamination risks, making it ideal for sanitary applications with full CIP (Clean-in-Place) capability.

Why Source Doebritz Under-driven Cone Mills

• Ultra-Low Residual & Gentle Milling: The unique cone rotor and stator screen design produces a narrow particle size distribution (D90) with minimal fines, preserving product integrity for heat-sensitive materials. No metal-to-metal contact reduces spark risks and wear particle contamination.
• True 24/7 Industrial Durability: CNC-machined 316L stainless steel housing and a heavy-duty outboard bearing assembly with a permanent air purge seal prevent process gas or dust ingress, extending bearing life to over 50,000 operational hours.
• Rapid Changeover & Validation Ready: Quick-release clamps and a hinged door allow screen and rotor inspection in under 2 minutes. All wetted parts are polished to Ra ≤ 0.4µm, meeting strict FDA, cGMP, and EC 1935/2004 standards.
• Global OEM Supply Chain Advantage: As a direct manufacturer, Doebritz provides full traceability, 3.1 material certificates, FAT/SAT protocols, and global after-sales support with 48-hour spare parts dispatch.

Housing & Rotor Engineering

The Doebritz under-driven cone mill is built around a one-piece cast or fabricated 316L stainless steel housing with a removable liner for easy refurbishment. Unlike top-driven mills, the integral under-drive motor is directly coupled to a precision-balanced cone rotor with a specialized helical blade pattern. This rotor design creates a centrifugal force that presses product against the perforated or abrasive screen, shearing particles uniformly. The cartridge mechanical seal with a silicon carbide face is rated for ±0.5 bar differential pressure and temperatures up to 150°C (302°F). A dry-running labyrinth seal above the bearing housing guarantees zero product contamination from lubricants. The entire assembly is designed to be CIP-SIP compatible with automated spray balls.

Technical Specifications

All Doebritz cone mills undergo 100% factory load testing before dispatch. Standard specifications are listed below, and full custom engineering is available for your process line integration, including inlet/outlet flanges to DIN, ANSI, or JIS standards.

Specification	Detail
Body Material	316L Stainless Steel (EN 1.4404) / Electropolished
Rotor Design	Helical Cone Rotor (Under-driven, 0.5-20mm screen gap)
Motor Power	2.2 kW to 22 kW, IP55, F-class insulation
Speed Range	1500 RPM (standard) / Optional VFD to 3000 RPM
Capacity (Powder)	50 – 10,000 kg/h (depending on screen & material)
Seal Type	Single Cartridge Mechanical Seal (SiC/SiC) / Optional Double
Max Operating Temp.	150°C (302°F) Standard / 200°C (392°F) Optional
ATEX Rating	II 2/2 D c T4 (Zone 21/22) / Optional II 1/2 G c
Finish	Ra ≤ 0.4µm wetted parts / Ra ≤ 0.8µm non-wetted

Heavy-Duty Application Scenarios

API & Chemical Powder Milling

Wet or dry milling of paracetamol, ibuprofen, and chemical intermediates. The under-driven design eliminates overhead clearance needs and prevents shaft sweep, achieving yield rates >99.5%.

Food & Beverage Granulation

Deagglomerating cocoa powder, breaking up dried milk chunks, or sizing breadcrumbs. The low heat generation preserves flavor and vitamins, and the stainless steel finish meets EHEDG guidelines.

Plastic & Rubber Pulverizing

Size reduction of PVC, PU, and recycled rubber flakes. The replaceable abrasion-resistant screens and a rotor with a hardened edge ensure long intervals between re-tipping.

Frequently Asked Questions

What is the typical lead time for a Doebritz under-driven cone mill?

Standard models (stainless steel 316L, 2.2kW to 15kW) are shipped within 4-6 weeks. Custom-engineered units with special screens, ATEX/IECEx certificates, or motor brand requirements typically require 8-10 weeks. Express service is available for critical breakdowns.

Do you offer non-standard inlet/outlet flanges and customized screens?

Yes, Doebritz specializes in custom interface engineering. We can provide ANSI 150#, DIN 2633, or JIS 10K flanges, as well as slot, round, or square hole screens from 0.5mm to 20mm. We also design special rotor geometries for extremely sticky or friable materials.

Is the Doebritz cone mill ATEX certified for Zone 0/20 gas/dust environments?

Absolutely. Our standard construction with earth-bonded housing and a non-sparking rotor option is available with an EC Type Examination Certificate for Zones 0, 1, and 2 (gas) and Zones 20, 21, and 22 (dust). We can also provide a Conformity Assessment for your whole system.

Can the under-driven cone mill be operated under pressure or vacuum? What about high temperatures?

Yes. The standard cartridge mechanical seal handles pressure up to 2 bar and full vacuum. With our high-temperature seal package (graphite/PTFE), the mill can continuously operate at 200°C (392°F) for hot milling processes. A purged nitrogen connection is available for inert operation.

How do you validate cleanability and what documentation do you provide for Pharma?

The Doebritz under-driven cone mill is designed with a drainable, sloped outlet and no crevices. We provide full validation packages including 3-A Sanitary compliance, material traceability, surface roughness certificates (Ra), and a custom FAT/SAT protocol. A blanket label is included as part of our standard quality documentation.