Bulk Material Conveyor Systems — Moving the Heavy, Abrasive, and Unpredictable
Bulk materials don’t behave like manufactured parts. Gravel shifts and settles. Wood chips bridge and hang up in hoppers. Sand flows like water until it doesn’t. Glass cullet is heavy and sharp enough to destroy conveyor belts in weeks. Steel chips arrive soaked in cutting fluid, creating a corrosive slurry that attacks standard components. Every bulk material has its own density, moisture content, abrasiveness, and flow characteristics — and a conveyor system that ignores any of these properties will underperform, wear out prematurely, or fail outright.
Custom Conveyor & Equipment Corporation has been engineering bulk material handling systems since 1984. Over four decades, we’ve moved everything from fine seed and granular chemicals to heavy aggregate and razor-sharp glass cullet. That breadth of experience means we approach each bulk material application based on what the material actually does on a conveyor — not what a density chart says it should do.
Why Bulk Material Conveyor Design Is Different
Most conveyor engineering starts with the product — how much does it weigh, how fast does it need to move, how far does it travel. Bulk material adds a layer of complexity because the “product” isn’t a discrete object. It’s a flowing mass with properties that change based on moisture content, temperature, particle size distribution, and how long it’s been sitting.
Material Flow Behavior
Some bulk materials flow freely — dry sand, plastic pellets, clean grain. Others are cohesive and prone to bridging, ratholing, and plugging — wet clay, fine powders, materials with high moisture content. Many materials fall somewhere in between, behaving differently depending on conditions. A conveyor system designed for free-flowing material will jam when moisture increases during a rainy season. One designed for worst-case conditions will be oversized and inefficient during dry weather. We design for the range of conditions your material actually presents, not a single laboratory measurement.
Abrasion Rates
Bulk material abrasion varies enormously. Fine sand is moderately abrasive. Crushed granite is highly abrasive. Glass cullet combines abrasion with sharp edges that cut as well as wear. Steel chips and metal turnings add hardness that accelerates wear on every contact surface. We select belt grades, liner materials, chute surfaces, and wear components based on the actual abrasion characteristics of your material — information that comes from experience with similar materials, not from generic abrasion tables.
Loading and Transfer Challenges
The points where bulk material enters a conveyor, transitions between conveyors, or discharges from a conveyor are where most problems occur. Impact damage at loading points. Spillage at transfer points. Carryback that fouls return rollers. Dust generation that creates environmental and housekeeping issues. Each of these problems has engineering solutions, but they need to be addressed in the design phase — not discovered during commissioning.
Bulk Conveyor Types for Different Applications
Troughed Belt Conveyors
The workhorse of bulk material handling. A flat belt supported by troughing idlers forms a channel that carries material at high volumes over long distances. We engineer troughed belt systems for the full range of bulk applications — from lightweight, dry materials on standard-duty frames to heavy, abrasive materials on reinforced structures with impact-resistant loading zones. Belt width, speed, trough angle, and idler spacing are all calculated for your specific material and throughput requirements.
Cleated and Sidewall Belt Conveyors
When material needs to travel up steep inclines — angles beyond what a smooth troughed belt can maintain without material rollback — cleated belts and sidewall belts keep material in place. Our sidewall belt conveyors, including beltwall configurations, transport bulk materials at angles up to vertical. Cross-cleats between corrugated sidewalls create pockets that hold material regardless of incline angle. These systems are particularly effective for moving bulk materials between significantly different elevations in a compact footprint.
Drag Flight Conveyors
For materials that are too abrasive for belt conveyors, too hot, or too corrosive, drag flight conveyors offer a fully enclosed alternative. Steel flights on a chain drag material along a trough — no belt to wear through, no exposed material surface generating dust. We build drag flight systems for metal chip handling, hot material transport, and applications where material containment is critical. The flights and trough liners are the wear components, and they’re designed for replacement access that doesn’t require disassembling the entire conveyor.
Magnetic Conveyors
Ferrous bulk materials — steel chips, iron filings, metal turnings — can be transported using permanent magnet conveyors that hold material against a slider bed through magnetic attraction. No belt is required, which eliminates belt wear in applications where sharp metal would destroy conventional belts quickly. Our magnetic chip conveyors are a proven solution for machine shops and metalworking facilities dealing with chip management from CNC machining operations.
Screw Conveyors and Feeders
For controlled metering of bulk materials into processes — feeding a mixer, dosing a reactor, metering material onto a scale — screw conveyors provide the volumetric control that belt conveyors can’t match. We integrate screw feeder sections with belt conveyor systems to provide precise feed rates at process input points while using belt conveyors for the longer transport runs between those points.
Material-Specific Engineering
We’ve handled enough different bulk materials to know that general-purpose design doesn’t work. Here’s how material characteristics drive our engineering:
Glass cullet is one of our specialties. It’s heavy (80-100 lb/ft³), extremely abrasive, and has sharp edges that slice through standard rubber belting. We use cut-resistant belt compounds, impact-absorbing loading zones with sacrificial wear liners, and enclosed construction that contains the glass fragments and dust that cullet handling generates. Our cullet conveyor systems are backed by decades of glass industry experience.
Wood chips and biomass are lightweight but bulky, with a tendency to bridge at transitions and build up on conveyor components. Low density means you need wide belts and high speeds to achieve meaningful throughput. Moisture content varies seasonally, changing material behavior from free-flowing dry chips to clumping, heavy wet material. We design for the wet condition so the system works year-round.
Sand and aggregate combine high density with significant abrasion. Wet sand sticks to everything — belts, idlers, chutes, hoppers. Our aggregate handling systems use belt cleaning stages at every transition, self-cleaning return idlers, and chute designs that promote material flow rather than accumulation.
Metal chips and turnings arrive mixed with cutting fluid, creating a corrosive, oily slurry that attacks unprotected steel and contaminates standard bearings. Our chip handling systems use corrosion-resistant construction where the material contacts the conveyor, sealed bearings rated for fluid exposure, and coolant separation features that recover cutting fluid for reuse.
Loading Zone and Transfer Point Engineering
The loading zone is where bulk conveyors take the most abuse and where most operational problems originate. We treat loading zone design as a critical engineering exercise:
Impact absorption — Impact cradles and cushion idlers at every loading point absorb the energy of material drops and distribute forces across a wide belt area
Skirt sealing — Adjustable skirt boards contain material during the settling zone after loading, preventing the edge spillage that creates housekeeping problems and material loss
Dust containment — Enclosed loading zones with dust curtains and settling distance contain the airborne particles that bulk material loading generates
Wear protection — Replaceable liner plates at impact and sliding contact zones protect structural components from the abrasion that would eventually wear through permanent frame members
Transfer points between conveyors receive similar attention. Chute geometry, drop height, belt speed matching, and material trajectory all affect whether a transfer works cleanly or creates a maintenance headache at every shift change.
Built for Bulk in Cedar Rapids
Bulk material conveyor projects require heavy fabrication — structural frames that support loaded belt weight across long spans, thick-walled chutes that resist abrasion, and robust drive assemblies that start loaded conveyors reliably. Our Cedar Rapids, Iowa facility handles this work in-house with our 3kW fiber laser, 300-ton press brake, certified welding capabilities, and complete assembly floor. Every system is assembled and tested before shipping to verify structural integrity, belt tracking, and drive performance under load.
Tell Us About Your Bulk Material
The first question we’ll ask is what you’re moving. The second is how it behaves. Every bulk material project starts with understanding the specific material characteristics — density, moisture, abrasion, particle size, temperature, corrosiveness — that determine how the conveyor needs to be designed. Call (319) 449-3322 or visit our contact page to start that conversation. We’ll bring four decades of bulk material handling experience to your specific application.
