PEGE Loss-in-Weight Feeder for Food Grade Fine Powder Proposal

1.Material and Process Details-Request

• Material Name: M1 (Proprietary Powder)
• Material Form: Fine Powder
• Bulk Density: 0.20 – 0.35 g/cm³
• Specific Powder Resistivity: > 1 × 10¹² Ohm-m (Classified as RESISTIVE per ASTM D257 / IEC 62631-3-1)
• Static Discharge Sensitivity: YES – material is sensitive to static discharge
• Combustibility: Combustible dust – fine dust dispersed in air can form explosive concentrations
• Required Maximum Feed Rate: 20 kg/hr
• Accuracy Required: ±0.5% or better

2. Project Overview-PEGE Proposal

This document sets out the customized technical specification for a loss-in-weight feeder designed exclusively for Demolis Foods’ M1 proprietary fine powder, which presents unique handling challenges: low bulk density, ultra-high electrical resistivity, high electrostatic discharge (ESD) sensitivity, and combustible dust properties.

Every design element and component selection is centered on complete static elimination and high-precision metering, in full compliance with EU ATEX 94/9/EC directives and international food-grade safety and sanitation standards.

Core anti-static engineering includes low-speed screw operation, a fully conductive stainless-steel structure, and zero-contact screw design to eliminate static buildup, friction sparks, and discharge risks entirely.

This technical proposal outlines the customized loss-in-weight feeder configuration tailored for handling Demolis Foods’ M1 proprietary fine powder, which is characterized by low density, ultra-high resistivity, high ESD sensitivity, and combustible dust hazards. All design upgrades and component selections prioritize static electricity elimination and accurate metering, fully complying with EU ATEX directives and international food processing safety and hygiene standards. Key anti-static optimizations include low-speed screw operation, full conductive stainless-steel structure, and zero-friction screw design to eliminate static buildup and discharge risks.

3. Technical Parameters and Structure Design

Model: PG-FT-22    Twin screw feeder, 5-30kg per hour

1.       Weighing Frame & Support Structure

Cantilever suspension-style load cell support frame for the storage hopper, constructed entirely from food-grade stainless steel 316 to boost electrical conductivity and enable consistent static dissipation. Engineered with advanced shock absorption and anti-horizontal interference capabilities, this structure effectively blocks non-weight interference from the agitator, ensuring stable, high-accuracy real-time flow calculation and dynamic loss-in-weight metering.

The full stainless-steel build removes all insulating parts, supporting continuous static discharge to meet strict ESD safety requirements for high-resistivity powders.

2.       Feeding & Drive System

Precision twin-screw feeder with an integrated gearbox that combines gentle material agitation and feeding functions, built with a detachable split structure for easy maintenance, disassembly, and thorough cleaning to meet food-grade sanitation standards.

The feeding flow range is calibrated to 5–30kg/h (extended above the required 20kg/h maximum rate), allowing the screws to run at a lower rotational speed during standard operation.

Reduced screw speed significantly cuts friction-induced static generation, a critical design adaptation for this ESD-sensitive, high-resistivity fine powder.

3.       Storage Hopper

Standard 30L capacity hopper, with a maximum material load of approximately 8kg, sized to match the M1 powder bulk density range of 0.20–0.35 g/cm³.

4.       Feeding Motor

Servo explosion-proof motor with dual gas and dust explosion protection function.
- Explosion-proof rating: Ex db IIC T4 Gb / Ex tb IIIC T130°C Db
- Power supply: AC220V
- Rated power: 400W

5.       On-Frame Electrical Components

 Explosion-proof junction box mounted on the main equipment frame, fully compliant with ATEX field wiring requirements for combustible dust and gas environments.

6.       Load Cell

Mettler Toledo MT1022 high-precision weighing sensor, ATEX-certified for explosion protection, delivering stable and accurate dynamic weighing performance for loss-in-weight operation.

7.       Electrical Control Cabinet

Standard non-explosion-proof design as specified.  If require cabinet to be explosion proof too, client should inform the supplier in advance.

8.       Twin-Screw Anti-Static Precision Design

Custom-machined twin-screw assembly with a tightly controlled 0.1mm clearance between the two screws to eliminate direct contact and friction.

Each screw’s front end is fitted with specialized low-friction PTFE (Teflon) positioning bearings, which produce almost no static during operation.

There is no contact between the two screws, nor between the screws and the inner barrel wall, fully eradicating friction-related static buildup and potential deflagration risks from friction sparks to address the material’s high ESD sensitivity.

9.       Product Contact Materials

All product-wetted surfaces (hopper, screws, barrel, discharge port) are made from SUS316 food-grade stainless steel. The full stainless steel weighing frame and contact structure ensure consistent conductivity for fast, continuous static discharge, preventing static accumulation while meeting food manufacturing standards for corrosion resistance and non-contamination.