If you’ve ever stepped into a grain processing facility, a mining yard, or a recycling plant, chances are you’ve seen that workhorse of bulk material handling—scraper conveyors. I’ve been in this game for over 12 years, helping facilities move everything from wheat to construction aggregate, and more often than not, when a client calls me, they’re not just shopping for any conveyor—they’re looking for the right scraper conveyor for their exact mess (and I mean that in the best way). But here’s the thing: scraper conveyors aren’t one-size-fits-all. There are different types, each built for a specific job, and if you mix them up, you’re looking at downtime, wasted product, or even safety hazards down the line.
Today, I want to break down the main types of scraper conveyors I work with daily, how they’re different, and when to pick each one. I’ll also toss in a few quick comparisons to other conveyors we offer—like [Grain Scraper], [Screw Conveyor], [Bucket Elevator], and [Flat Belt Conveyor]—just to give you context on where scrapers fit in the big picture. Let’s dive in.
First, let’s get the basics straight, because even if you think you know, it’s easy to gloss over. At their core, scraper conveyors move material along a trough with a set of rigid scrapers (think flat metal plates or molded plastic blocks) attached to a chain, belt, or cable that loops around end sprockets. Unlike, say, a [Flat Belt Conveyor] that carries material on top and relies on gravity to keep it from falling off, scrapers push material directly along the trough—perfect for sticky, dusty, or free-flowing stuff that would slip on a smooth belt. Now, let’s get into the specific types you’ll encounter.
1. En-Masse Scraper Conveyors (The Workhorse for High-Volume, Fine Materials)
This is the most common type of scraper conveyor, and it’s what I sell most often for grain handling, flour mills, and bulk mining. En-masse means “mass” in French, and that’s exactly what these do—they move material in a continuous, dense plug, not individual pieces. How? The scrapers are short, closely spaced, and mounted to a heavy-duty chain that runs in a sealed, U-shaped trough. As the chain pulls the scrapers, they pinch the material between them and the trough walls, creating that tight plug that doesn’t separate, spill, or create a ton of dust.
I recently worked with a small grain co-op that was using an old [Screw Conveyor] to move corn from their dryer to storage. They kept having issues with corn flour building up in the screw’s gaps, which caused clogs and meant they had to shut down for cleaning every 2 hours. We swapped in an en-masse [Grain Scraper], and now they only need a deep clean once a week. Why? The sealed trough keeps dust contained, and the en-masse design means there’s nowhere for fine material to get stuck between parts.
The catch with en-masse conveyors? They work best with fine, free-flowing materials like grain, flour, sugar, or fine mineral ore. They’re not great for big, chunky stuff like 4-inch rock or whole logs—those would jam the tight scraper spacing. Also, because they seal so well, you don’t want to overfill the trough—if you do, that plug gets too tight and puts extra strain on the chain, leading to premature wear.
2. Redler Scraper Conveyors (The Precision Workhorse for Difficult Materials)
Wait—you might hear redler and en-masse used interchangeably, but they’re actually slightly different. Redler is a brand name that’s become generic, but technically, redler scrapers are designed with a slightly different chain and scraper profile for materials that are extra sticky, abrasive, or prone to compacting. Think wet sawdust, wet grain, cement slurry, or even food stuffs like dough or cookie dough bits that would gum up a regular en-masse.
I had a client in the concrete recycling business who was moving crushed concrete (which is super abrasive and full of sharp chunks) and using a standard en-masse scraper. The sharp bits were wearing through the scrapers in 6 months, and the chain was stretching so fast they had to adjust it every week. We swapped in redler scrapers—they have thicker, hardened steel plates and a chain that’s designed to handle higher friction. After a year, they still haven’t had to replace the scrapers.
Another plus for redlers? They can handle both horizontal and vertical inclines (up to around 30 degrees) better than regular en-masse, because the scraper profile is shaped to keep material from sliding backward when moving uphill. That’s a big deal if you need to move material between floors in a plant without adding a separate [Bucket Elevator]—it saves on space and cost. The downside? They’re a bit pricier than en-masse, and you have to match the scraper material to your material: steel for abrasive stuff, food-grade plastic for grain or food products, so you can’t just grab a one-size set.
3. Drag Scraper Conveyors (The Low-Profile Workhorse for Short Runs)
Drag conveyors are the scraper conveyor you’ll see in small warehouses or farm storage, usually for short, horizontal runs (like moving grain from a bin to a truck). They’re simpler than en-masse or redler—just a single chain with scrapers (usually spaced a bit farther apart than en-masse) that pulls along a shallow trough, usually open or semi-open (not fully sealed).
I installed a small drag scraper for a local hay farm last year—they needed to move baled hay scraps from their processing table to a collection bin. A [Flat Belt Conveyor] would’ve been too wide and expensive for their short 10-foot run, and a [Bucket Elevator] would’ve been overkill for bulky, light scraps. The drag scraper works perfectly: the scrapers push the hay along the shallow trough, no jams, and it’s easy to clean out at the end of the day.
Drag conveyors are also great for materials that don’t mind a little spillage—like wood chips, mulch, or loose feed for livestock. The tradeoff? They don’t handle fine dust as well, and they’re not sealed, so you can’t use them in food processing or mining where dust is a safety hazard. Also, they’re not designed for long runs—more than 50 feet and the chain starts to sag, which makes the scrapers drag unevenly and cause wear.
4. Enclosed Scraper Conveyors (The Dust-Free Workhorse for Confined Spaces)
If you’re in a facility that needs zero dust, like a pharmaceutical plant or a grain elevator where dust explosions are a real risk, enclosed scraper conveyors are your go-to. These are similar to en-masse, but the entire trough is enclosed in a metal or plastic housing, so there’s no way dust or material can escape. They also have access ports every few feet for cleaning, which is mandatory for industries like pharma where cross-contamination is a problem.
I worked with a vitamin manufacturer last month that was moving powdered vitamin B12—super fine, super potent, and they couldn’t afford any cross-contamination. They were using a [Screw Conveyor] but the gaps in the screw let a tiny bit of powder seep out, which was causing them to lose product and risk mixing batches. We installed an enclosed scraper conveyor with food-grade scrapers and a fully sealed trough. Now, they don’t have a single spill, and their cleaning time is cut in half because the access ports let them brush out the trough without disassembling the whole unit.
The only downside of enclosed scrapers? They’re bigger and heavier than open types, so they take up more space and are more expensive to install. But when you’re dealing with hazardous or high-value materials, that cost is worth it.
5. Vertical Scraper Conveyors (The Elevator Workhorse for Uphill Movement)
Wait, you already know [Bucket Elevator]s, right? They’re the big bucket things that carry material up vertical shafts. But vertical scraper conveyors do the same job, just differently. Instead of buckets, they use two vertical chains with scrapers that pull material up a closed trough.
I’ve had a few clients ask me to choose between a bucket elevator and a vertical scraper, and here’s the breakdown: vertical scrapers work better for sticky, compacted materials that would fall out of a bucket—like wet grain, wet sand, or clay. Bucket elevators work better for fine, free-flowing stuff like flour, where buckets can scoop up material easily. I recently had a construction company moving wet concrete aggregate up to a mixer—they tried a bucket elevator and the wet stuff was sticking to the buckets, so they switched to a vertical scraper and it’s worked flawlessly. The scrapers push the aggregate up, so there’s no sticking. The downside? Vertical scrapers are slower than bucket elevators, so they’re not ideal for very high-volume jobs.
How to Pick the Right Scraper Conveyor (Or Any Conveyor) for Your Job
Let’s wrap this up with a quick cheat sheet, since I know you don’t want to spend weeks reading specs (I’ve been there). First, ask yourself three questions:
- What material am I moving? Fine/dry grain = en-masse. Sticky/abrasive = redler. High-value/hazardous = enclosed. Chunky/bulky = drag. Vertical = check if it’s sticky or free-flowing.
- How far do I need to move it? Short runs (<50ft) = drag. Long runs = en-masse or redler. Vertical = choose between vertical scraper or bucket elevator.
- Do I need dust control or zero cross-contamination? If yes, go for enclosed or sealed en-masse—skip the open drag conveyors.
And for context, if you’re still not sure if a scraper is the right call, I always compare to the other conveyors we offer: [Screw Conveyors] are good for small, low-volume, horizontal runs but they jam easily. [Flat Belt Conveyors] are great for light, non-sticky stuff but can’t move uphill with material that slips. [Bucket Elevators] are perfect for vertical, high-volume, fine materials but not for sticky stuff. Scraper conveyors fill that gap for all the in-between jobs.
Final Thought
At the end of the day, a conveyor is only as good as how well it fits your specific material and facility. I’ve seen too many facilities waste thousands on the wrong conveyor because they picked the cheapest option instead of the right one. If you’re dealing with bulk material and need a scraper conveyor, or even if you’re just comparing to other conveyors, don’t guess—reach out to someone who’s been in the game long enough to know the difference between an en-masse and a redler. Whether you’re moving grain, concrete, or vitamins, the right conveyor will cut your downtime, save you money, and keep your operation running smooth. If you have questions, just get in touch with our team to walk through your needs and find the exact scraper conveyor that works for you.
References
- Bulk Material Handling: Scraper Conveyor Design and Application Guidelines, Material Handling Industry Association (MHIA)
- "Scraper Conveyors vs. Other Bulk Handling Equipment," Global Bulk Solids Magazine, 2022
- "En-Masse Conveyors for Grain Handling: Best Practices," American Grain Merchants Association (AGMA), 2021
- "Redler Conveyors for Abrasive Materials," Mining Engineering Journal, Vol. 74, No. 3, 2022
[Grain Scraper], [Screw Conveyor], [Bucket Elevator], [Flat Belt Conveyor], [Scraper Conveyor]
