Efficient bulk material handling is the backbone of industrial production. From cement and minerals to biomass and food-grade products, facilities rely on engineered systems to move, store, and control the flow of dry bulk solids safely and reliably. With that complexity comes a specialized vocabulary.

This glossary defines the essential terms used in conveyors, silos, loadout systems, and storage equipment, providing clear explanations that help engineers, operators, and procurement teams align on technical details.

Use this section to:

  • Understand the terminology behind system design, capacity, and flow control
  • Learn how components such as silos, pneumatic conveying systems, and loadout facilities fit into integrated operations
  • Connect key terms to IAC’s expertise in designing, fabricating, and maintaining complete bulk handling solutions

For more detail on engineered solutions, explore Bulk Material Handling & Storage or see our Construction Services for turnkey installation and commissioning.

Core Equipment

Silo
A vertical structure used to store bulk materials such as cement, fly ash, lime, biomass, or grains. Silos can be bolted, slipform, or dome-style, each with unique benefits for capacity, durability, and material flow. Proper design accounts for bulk density and angle of repose to ensure reliable discharge.
See also: Storage Solutions

Bin Vent Filter
A compact dust collector installed on top of silos or bins to capture displaced air and dust during loading. Bin vents protect air quality, reduce emissions, and prevent over-pressurization during material transfer.
See also: Baghouse Equipment

Bucket Elevator
A vertical conveyor that uses a series of buckets attached to a belt or chain to move bulk materials upward. Commonly used in cement, minerals, and grain facilities where vertical lift is required.

Screw Conveyor
A rotating helical screw within a tube or trough that moves bulk materials horizontally or at a slight incline. Screw conveyors are efficient for powders, granules, and other free-flowing materials.

Belt Conveyor
A continuous conveying system that moves bulk solids over long distances using a belt supported by rollers. Belt conveyors are widely used in mining, minerals, aggregates, and bulk loading operations for high-capacity transport.

Airslide Conveyor
A gravity-assisted pneumatic conveyor that moves fine powders such as cement or alumina. Material flows on a thin cushion of air through a fabric membrane, allowing for low-energy, dust-tight transport.

Conveying Systems

Pneumatic Conveying
A system that uses air pressure or vacuum to transport bulk materials through pipelines. Two primary methods are:

  • Dilute Phase – high-velocity, low-pressure air moves lighter materials in suspension.
  • Dense Phase – low-velocity, high-pressure air moves heavier or abrasive materials in slug form.
    Pneumatic systems are widely used for cement, fly ash, and fine powders.
    See also: Pneumatic Conveying Systems

Blower Package
An integrated set of blowers, filters, silencers, and controls that supply the air required for pneumatic conveying. Proper sizing ensures system efficiency and prevents material blockages.

Feeder
A device that controls the rate of bulk material entering a conveying system or process. Examples include rotary airlock feeders, screw feeders, and vibratory feeders.

Hopper
A funnel-shaped container that temporarily stores bulk material and directs it into a process or conveyor. Hopper design must prevent bridging and ratholing to ensure consistent material flow.

Chute / Spout
A gravity-driven pathway that guides material flow from one point to another, often connecting conveyors, hoppers, or silos. Proper lining or wear-resistant materials extend chute life when handling abrasive products.

System Design & Operation

Bulk Density
The mass of a bulk material per unit volume, typically expressed in pounds per cubic foot (lb/ft³) or kilograms per cubic meter (kg/m³). Bulk density directly impacts conveyor sizing, silo design, and loadout capacity.

Angle of Repose
The steepest angle at which a bulk material can be piled without slumping. This property affects hopper, bin, and silo design, ensuring smooth discharge and preventing bridging.

Flow Aids / Assisters
Mechanical or pneumatic devices that improve the discharge of materials from bins and hoppers. Examples include vibrators, air cannons, and fluidizing pads, which reduce downtime caused by bridging or material hang-ups.

Live Bottom / Screw Live Bin
A bin discharge system that uses multiple parallel screw conveyors or drag chains to move material evenly. Live bottoms are designed to prevent arching and ratholing in cohesive or sticky materials.

Dust Collection at Transfer Points
The integration of dust control equipment, such as bin vents or capture hoods, at conveyor transfer points, loadout stations, and silos. This reduces emissions, protects worker health, and helps maintain regulatory compliance.

Loadout & Storage

Truck Loadout System
An automated system designed to fill bulk trucks quickly and accurately. Often integrated with weighing scales and dust collection to ensure precise loading and environmental compliance.

Rail Loadout
A facility or system engineered for transferring bulk materials into railcars. Rail loadouts frequently include batch weighing, dust suppression, and automated controls for high-capacity transport.

Weigh Bin / Scale Hopper
A vessel equipped with load cells or scales to measure material weight during batching or before loadout. Ensures accuracy in process control, inventory management, and shipping operations.

Domes vs. Silos
Both are used for long-term bulk material storage, but with key differences:

  • Domes: extremely high capacity, self-supporting, often used for cement or fly ash terminals.
  • Silos: vertical storage, bolted or slipform, suited for modular or integrated plant layouts.

Bulk Bag (Super Sack) Handling
Systems for filling or unloading flexible intermediate bulk containers (FIBCs). Includes bag unloaders, fillers, and dust-tight connections to reduce spillage and exposure.

Safety & Compliance

NFPA Compliance
Standards developed by the National Fire Protection Association to prevent fire and explosion hazards in facilities handling combustible dusts. Includes requirements for system design, housekeeping, and explosion venting.

Explosion Protection
Safety systems such as explosion vent panels, suppression equipment, or isolation valves installed on silos, bins, and conveyors. These mitigate damage and protect personnel in the event of a combustible dust ignition.

Confined Space Entry
A safety protocol for entering silos, bins, or hoppers where oxygen deficiency, dust buildup, or structural hazards may exist. Requires permits, training, and monitoring under OSHA regulations.

Dust-Tight / Sealed Systems
Design features that prevent dust leakage from conveyors, hoppers, and storage vessels. Dust-tight construction improves safety, reduces housekeeping, and helps maintain regulatory compliance.

Material Spillage Control
Engineering practices and equipment—such as skirting, belt cleaners, and transfer point enclosures—used to prevent material loss, reduce cleanup costs, and maintain a safer work environment.

Frequently Asked Questions (FAQ)

Silos are vertical, modular storage vessels that can be bolted or slipform constructed, making them ideal for plants requiring multiple, smaller capacity units. Domes offer extremely high storage capacity in a self-supporting structure, often used for terminals handling cement, fly ash, or other high-volume bulk materials.

Dilute phase is best for lightweight, non-abrasive materials and longer conveying distances.

Dense phase is suited for abrasive, fragile, or heavy-density materials, as it uses lower velocity and higher pressure to move product gently in plugs or slugs.

Common issues include bridging, ratholing, and material buildup caused by cohesive or sticky products. Solutions include properly designed hopper geometry, flow aids (vibrators, air cannons, fluidizers), and live bottom discharge systems.

Bulk density is the mass of a bulk solid per unit volume. It’s a critical factor for designing conveyors, sizing silos, and determining loadout capacity. Incorrect assumptions about bulk density often lead to undersized or overbuilt equipment.

Installing bin vent filters, capture hoods, and localized dust collectors at conveyor transfer points prevents fugitive dust from escaping, protecting workers and keeping the facility in compliance with air quality regulations.

NFPA standards address combustible dust hazards in silos, hoppers, and conveyors. Requirements may include explosion venting, suppression systems, housekeeping, and confined space safety procedures.

Yes. Retrofits may include adding new conveyors, upgrading blower packages, automating truck/rail loadouts, or reinforcing silo structures. Retrofitting can extend the life of existing facilities while improving throughput and safety.

Modern loadout systems integrate weigh bins, dust collection, and automated gates or spouts. Operators can load trucks or railcars quickly and precisely, often from a centralized control system that ensures compliance with weight and emission limits.