PVC & Calcite Silos

Storage for PVC Resin and Mineral Fillers

VOLDE PVC & Calcium Carbonate Silos are designed for the storage and process feeding of PVC resin, calcium carbonate (CaCO₃) and other fine bulk solids used in PVC dry blend production. Because PVC resin and mineral fillers behave very differently during filling, storage and discharge, silo design must consider more than volume alone. Silo geometry, construction material, filling method, vent filtration, discharge equipment and downstream conveying are engineered together according to material characteristics, required storage capacity and production demand. This allows each silo to operate as an integrated part of the PVC raw material handling and mixer feeding system

| Storage Capacity & Silo Design

Silo capacity is selected according to daily raw material consumption, mixer capacity, delivery frequency and the required production reserve. Depending on plant layout and logistics strategy, systems can be configured as individual silos or multi-silo storage groups for PVC resin, calcium carbonate and other fillers.

PVC resin typically has relatively low bulk density and generates considerable dust during pneumatic handling, while micronized calcium carbonate is denser and can be more prone to compaction and difficult discharge. These differences directly influence silo geometry, structural design and discharge arrangement.

• One-piece silos up to approximately 150 m³, subject to transport and project conditions
• Multi-silo and modular storage concepts for larger requirements
• Carbon steel or stainless steel construction
• Product-specific cone and outlet geometry
• Internal surfaces selected according to material and process requirements
• Level monitoring and overfill protection
• Load-cell weighing options
• Silo vent filtration
• Integration with bulk tanker and pneumatic filling systems

Separate storage routes for PVC resin and mineral fillers also simplify material identification, inventory management and recipe-based production.

Silos ⇢

| Reliable Discharge for Different Flow Behaviors

The discharge section is one of the most critical parts of a powder storage silo. PVC resin, micronized calcium carbonate and coated fillers can show different tendencies toward ratholing, bridging, compaction or irregular flow, depending on particle characteristics, moisture, storage time and silo geometry.

VOLDE selects the silo cone, outlet dimensions and flow-assistance technology according to the actual material. Where gravity discharge alone is insufficient, mechanical or pneumatic flow-aid systems can be incorporated directly into the silo bottom.

• SILOCONE Bin Activator for vibration-assisted discharge
• EASYFLOW Silo Flow Cone for air-assisted discharge
• Aeration and fluidizing elements
• Product-specific cone angles and outlet dimensions
• Rotary valves, screw feeders or isolation valves at the silo outlet
• Level and process instrumentation
• PLC-controlled discharge sequences

The objective is to provide a consistent and predictable feed to downstream weighing, dosing and conveying equipment rather than relying on a standard silo geometry for every material.

Silo Discharge Systems ⇢

| Filling, Venting & Pneumatic Conveying

A raw material silo performs effectively only when filling, venting and discharge are considered as one complete system. During pneumatic filling, displaced air is released through a correctly sized silo vent filter while entrained dust is retained within the filtration system.

At the outlet, the conveying method is selected according to material characteristics, required capacity, conveying distance and destination. PVC resin and mineral fillers can be transferred to weighing systems, mixer feed bins, intermediate silos or other process equipment through vacuum, pressure or dense-phase pneumatic conveying.

• Bulk tanker unloading and silo filling
• Big bag-to-silo transfer
• Silo vent filters with pulse-jet cleaning
• Vacuum pneumatic conveying
• Pressure conveying
• DENSPLUS dense-phase conveying
• Rotary valve and screw feeder discharge
• Automatic material and conveying-line selection
• Mixer and dosing system integration
• PLC/SCADA and inventory monitoring

By engineering storage, discharge and conveying as a connected process, VOLDE provides PVC and calcium carbonate silo systems that integrate directly with dry blend preparation, dosing and mixer feeding lines.

Silo Filling ⇢ Dense Phase Conveying ⇢