Feeding screws for powders and granules

Name: Doseerschroeven
Brand: HECHT
Availability: PreOrder

Dosing

Description

Feeding screws — definition: A feeding screw (screw feeder) conveys bulk materials via a rotating screw shaft with a consistent throughput per revolution (volumetric) or coupled to a weighing system for exact mass dosing (gravimetric, ±0.1–0.5% per OIML R76). HECHT feeding screws are available in hygienic design (EHEDG), quick-disassembly versions and ATEX-certified variants for pharmaceuticals, chemicals, food and battery production.

HECHT feeding screws are particularly suitable for dosing free-flowing bulk materials. For poorly flowing bulk materials, an upstream discharge aid, such as an agitator, can ensure a uniform product feed. Depending on the product and the required accuracy, the appropriate screw geometry and drive are selected.

Key points — feeding screws

Volumetric or gravimetric dosing, batch or continuous
Quick-disassembly for thorough cleaning; CIP-compatible
EX/ATEX version and hygienic design available
Uniform material flow without pulsation — ideal for weighing and filling systems
Seamless integration with PLCs, scales and Industry 4.0 architectures

Customer benefits

Quick-disassembly versions as an option for fast and thorough cleaning of the screw
Optional trickle protection
EX version possible
Various materials
Various sizes depending on the application
Volumetric or gravimetric dosing
Easy integration into various process systems
Optionally available in hygienic design

Frequently asked questions about feeding screws

What is the difference between volumetric and gravimetric dosing?

Volumetric dosing delivers a consistent material throughput per screw revolution — suitable for stable products and processes. Gravimetric dosing couples the feeding screw to a weighing system (OIML R76) for exact mass dosing with real-time dose feedback. HECHT feeding screws support both principles and can be integrated with PLC and instrumentation/control systems for recipe management, mixing and controlled feed to reactors or packaging machines.

How is OPC-UA used for process integration in pharmaceutical bulk handling?

OPC-UA (IEC 62541) provides secure, platform-independent machine-to-machine communication between PLCs, SCADA, MES and ERP systems. In pharmaceutical bulk handling it enables: real-time weighing data transfer (OIML R76 certified), electronic batch records (21 CFR Part 11), alarm management and audit trail according to ALCOA+ principles. HECHT systems are supplied with a built-in OPC-UA server, validated against ISA-88 batch models.

Which GAMP 5 category applies to a bulk handling control system?

A configured PLC/SCADA system for pharmaceutical bulk handling falls under GAMP 5 category 4 (configurable software). Custom-developed MES integration modules are category 5. Category 4 validation requires: supplier assessment, configuration specification, functional testing (IQ/OQ), risk assessment per ICH Q9 and change control. HECHT provides complete GAMP 5 validation packages including URS, FS, DS, IQ/OQ protocols and a traceability matrix.

What are the key EHEDG design requirements for pharmaceutical bulk handling equipment?

EHEDG Class II certification requires: dead-angle-free internal geometry, surface roughness Ra <0.8 µm (electropolished 316L), self-draining >3° slope, full CIP/SIP cleanability, no crevices (butt-welded and Tri-Clamp connections) and material traceability (EN 10204 3.1). HECHT bulk handling systems meet EHEDG Class II as standard and are validated for CIP cleaning cycles.

How do you plan preventive maintenance for ATEX-certified dosing equipment?

ATEX equipment requires annual inspection by a qualified body (NEN 3140), including: verification of antistatic continuity (<10⁶ Ω, NEN-EN 60079-32), inspection of Ex-certified motors and sensors, checking of gaskets and seals, and logging in the equipment record. HECHT Technology B.V. offers annual maintenance contracts with ATEX recertification and GAMP 5-compliant maintenance records.

How does predictive maintenance with IIoT sensors reduce downtime?

IIoT sensors monitoring vibration (bearing wear), temperature (motor overload), differential pressure (filter clogging) and flow (line blockage) detect deviations 2–4 weeks before failure. OPC-UA integration with MES/ERP systems (ISA-95) enables automatic work-order generation. HECHT systems are IIoT-ready with standardised sensor mounting points — this reduces unplanned downtime by 30–50%.

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Technology

Depending on the bulk material and application, dosing screws can be used for volumetric or gravimetric dosing
Bulk materials are conveyed in a controlled manner via a rotating screw shaft from an upstream buffer or, for example, directly from a big bag emptying unit
Compact design, uniform material flow, high dosing accuracy and easy to clean - also available in ATEX or hygienic design versions
Seamless process integration: dosing screws can be precisely coupled with scales and/or control systems to ensure precise dosing results

Areas of application

Doseerschroeven van HECHT zijn ontworpen om te presteren in uiteenlopende industriële sectoren zoals farmacie, chemie, voedingsmiddelen en batterijproductie. Ze spelen een cruciale rol waar:

continue procesintegratie vereist is;
volumetrische of gravimetrische dosering moet worden gegarandeerd;
materiaalstroomcontrole in combinatie met meet- en regelsystemen nodig is;
zoals vaak bij recepturering, mengen of gecontroleerde toevoer naar reactors, verpakkers of weegmodules.

Technical characteristics & functionality

Depending on the bulk material and application, dosing screws can be used for volumetric or gravimetric dosing
Bulk materials are conveyed in a controlled manner via a rotating screw shaft from an upstream buffer or, for example, directly from a big bag emptying unit
Compact design, uniform material flow, high dosing accuracy and easy to clean - also available in ATEX or hygienic design versions
Seamless process integration: dosing screws can be precisely coupled with scales and/or control systems to ensure precise dosing results

Process integration & control

Depending on the bulk material and application, dosing screws can be used for volumetric or gravimetric dosing
Bulk materials are conveyed in a controlled manner via a rotating screw shaft from an upstream buffer or, for example, directly from a big bag emptying unit
Compact design, uniform material flow, high dosing accuracy and easy to clean - also available in ATEX or hygienic design versions
Seamless process integration: dosing screws can be precisely coupled with scales and/or control systems to ensure precise dosing results

Design and maintenance considerations

Depending on the bulk material and application, dosing screws can be used for volumetric or gravimetric dosing
Bulk materials are conveyed in a controlled manner via a rotating screw shaft from an upstream buffer or, for example, directly from a big bag emptying unit
Compact design, uniform material flow, high dosing accuracy and easy to clean - also available in ATEX or hygienic design versions
Seamless process integration: dosing screws can be precisely coupled with scales and/or control systems to ensure precise dosing results

Voordelen voor engineering & operations

Depending on the bulk material and application, dosing screws can be used for volumetric or gravimetric dosing
Bulk materials are conveyed in a controlled manner via a rotating screw shaft from an upstream buffer or, for example, directly from a big bag emptying unit
Compact design, uniform material flow, high dosing accuracy and easy to clean - also available in ATEX or hygienic design versions
Seamless process integration: dosing screws can be precisely coupled with scales and/or control systems to ensure precise dosing results