In short: on September 24, 2026, a custom-built WTS0820 mobile trommel screen left our Zhengzhou workshop for France. It is not a soil screener with a new coat of paint - it is a two-stage separation system for peanut shells and peanut kernels: an 800 × 2000 mm screening drum sizes the material, and an integrated winnowing fan then splits kernels from shells by density. Rated up to 20 m³/h, fully towable, total machine weight up to 1,100 kg.
Most screening projects are about particle size: soil, sand, compost, aggregate. This one was not. Our client's raw material is peanut shells mixed with whole and broken peanut kernels straight out of the shelling process, and the target was simple to say but hard to achieve - get the peanuts out of the shells, cleanly, with as little kernel breakage as possible. A drum screen alone cannot do it. That is why this WTS0820 was redesigned around a second separation principle: air.
Custom WTS0820 mobile trommel screen with winnowing fan for peanut shell separation before shipment
Why peanut shells are one of the hardest materials to screen
Peanut kernels and peanut shells are close to each other in size after shelling, and that single fact breaks the usual screening logic. A trommel screen separates material by aperture: anything smaller than the hole falls through, anything larger travels to the discharge end. When your two products sit in the same size band, the screen cannot tell them apart - kernels and shell fragments pass the same apertures and come out mixed on both sides.
Three more material behaviours make it worse in practice:
- Shells are light and bulky. Peanut shells are roughly a quarter to a third of the harvested weight and barely weigh anything for their volume, so they behave very differently from mineral feed in a rotating drum - they float, tumble and drift rather than settle.
- Shells are fibrous and flaky. Unlike rounded sand or gravel, shell fragments are flat, hooked and interlocking. They bridge over screen apertures, blind the mesh, and reduce open area within minutes if the drum is not configured for them.
- Kernels are fragile. The usual "cure" for difficult screening - more drum speed, more lift, more agitation - cracks and splits peanut kernels. Aggressive screening solves the shell problem by creating a second, more expensive problem.
Add seasonal moisture, dust in dry conditions, and the fact that the client needed to move the machine between storage yards and field-edge sites, and it becomes clear why the brief could not be answered with a standard catalog model.
Peanut kernels and peanut shells feed sample used to configure the WTS0820 trommel screen mesh and air flow
The engineering answer: screen for size, winnow for density
The solution we designed for this client separates in two stages, in one pass, on one machine.
Stage 1 - Drum screening: clean the feed and set the particle window
- Material enters through the hinged feed hopper, whose folding design widens the loading aperture so a small loader can feed the machine quickly. Inside the 800 mm diameter × 2000 mm long drum, spiral blades lift and convey the material along the 5 m² screening surface. This stage does three jobs at once: it lets fine dust and broken shell powder fall out early, it carries stones, stalk pieces and unthreshed pods over to the oversize discharge, and it presents a reasonably uniform kernel-and-shell mix to stage two.
Stage 2 - Winnowing fan: separate by density, not by size
- This is the part that makes the project work. After the drum, the material falls through a winnowing chamber fed by an adjustable fan. Air is the second separating principle: a controlled air stream lifts the light, flat, high-drag shell fragments and carries them into the shell discharge, while the denser, rounder peanut kernels keep enough momentum to drop through the air column into the kernel chute.
- Because the cut point between "carried away" and "drops through" depends on the client's specific variety, moisture level and broken-shell ratio, the fan is fitted with an adjustable air damper. Instead of re-engineering the machine every season, the operator tunes one setting. That is a deliberate design choice: it moves the variability of a natural product out of the steelwork and into an adjustment the client can make themselves.
Peanut shell separation flow on the WTS0820: size in the drum, density in the winnowing chamber.
Requirement communication: how "peanut shells" became a winnowing design
Custom screening projects rarely fail in the workshop - they fail in the brief. Before any steel was cut, we worked through the material with the client one question at a time, and each answer changed the drawing. This is that record.
| Communication point | Input / specification | What it changed in the design |
|---|---|---|
| Target material | Confirmed Peanut shells mixed with whole and broken peanut kernels, straight out of the shelling process | This is not a mineral or compost feed. Kernels and shells sit in the same size band, so a single size-based separation cannot split them - a second separation principle had to be engineered in. |
| Separation goal | Confirmed Peanuts separated from the shells - two clean streams, not one mixed pile | Output was designed as two streams from the very first sketch: a kernel discharge chute, plus a separate shell outlet on the air chamber. |
| Agreed technical route | Confirmed Add a winnowing structure with a fan to the mobile screening machine | An adjustable-air winnowing chamber was designed in after the drum - separation by density instead of separation by size. |
| Machine platform | Confirmed Mobile WTS0820 | All custom work was engineered onto the mobile WTS0820 chassis: towable frame, traction device, swivel wheels and hinged feed hopper, with total machine weight kept to max. 1,100 kg. |
| Material behaviour | Engineering assessment Shells are light, bulky, fibrous and easily airborne; kernels are dense and fragile | Winnowing was selected over higher-speed or vibrating screening, and the drum was specified with low-lift spiral blades to limit kernel breakage. |
| Hourly throughput | Standard specification WTS0820 is rated up to 20 m³/h on a 5 m² screening surface | If a higher throughput is required, the same two-stage concept scales to the WTS1022 / WTS1230 / WTS1550. |
| Site power supply | Standard specification Total drum drive power 2.2 kW | A small generator or an ordinary site supply is sufficient - no heavy electrical works on site. |
| Dust control | Standard specification Dry shell handling generates fine dust | The air-separation chamber is enclosed, with a dust hood over the outlet, so the fine shell dust can be captured instead of spreading across the yard. |
How the communication ran
- Client brief - material: peanut shells with whole and broken kernels; goal: separate the peanuts from the shells.
- Material review - shelling output assessed for shell fraction, kernel size band and kernel fragility.
- Solution proposed - drum screening alone judged insufficient; a winnowing stage put on the table.
- Design confirmed - winnowing structure with a fan integrated onto the mobile WTS0820.
- Build & test - mesh aperture and air-damper settings set and verified during the factory test run.
- Dispatch - container loading and shipment to France.
Custom engineering highlights
| Configuration module | Custom solution | Operational benefit |
|---|---|---|
| Drum screening stage | 800 × 2000 mm drum with a 5 m² screening surface; mesh aperture selected for this client's peanut / shell size split | Removes dust, fines and oversize before air separation, and presents a uniform kernel-and-shell mix to the winnowing stage. |
| Winnowing fan assembly | Integrated fan feeding an enclosed air-separation chamber, with an adjustable air damper | Separates by density where size screening alone cannot - the cut point is tuned to variety, moisture and broken-shell ratio. |
| Spiral internal drum | Low-lift spiral blades convey material steadily along the drum | Cuts kernel breakage compared with high-agitation or vibrating screening. |
| Dual discharge | Kernel discharge chute + separate shell outlet with dust hood | Two clean product streams in a single pass, with no re-handling or secondary sorting. |
| Hinged feed hopper | Folding hopper that widens the loading aperture | Faster feeding with a small loader, while staying compact for transport. |
| Mobile chassis | Traction device and swivel wheels on a towable frame | One tow and one operator - the machine works at the field edge, the yard or the warehouse. |
| Drive system | 2.2 kW motor with reducer driving the carrier rollers | Low power draw, few wearing parts, easy local maintenance. |
Adjustable winnowing fan and air separation chamber on the WTS0820 peanut shell separating machine
WTS0820 specifications as configured for this project
| Parameter | WTS0820 |
|---|---|
| Trommel diameter | 800 mm |
| Trommel length | 2000 mm |
| Screening surface | 5 m² |
| Capacity | up to 20 m³/h |
| Total power | 2.2 kW |
| Weight | max. 1,100 kg |
| Mobility | Mobile - traction device and swivel wheels |
| Screening media | Customisable mesh aperture; final aperture set for the peanut kernel / shell split |
| Air separation | Winnowing fan with adjustable damper - custom addition for this project |
| Options | Side conveyor for stockpiling |
Standard WTS series capacities for reference: WTS1022 (1000 × 2200 mm, 8.2 kW), WTS1230 (1200 × 3000 mm, 10.6 kW), WTS1550 (1500 × 5000 mm, 20 kW). Full details on the WTS0820 mobile trommel screen page.
Trommel drum mesh and spiral blades configured for peanut shell screening in the WTS0820
What the two output streams are actually worth
Separating is only half the value. What leaves this machine is not "processed waste" - it is two products the client can sell or use.
- Clean peanut kernels - low-breakage, shell-free peanuts ready for roasting and snack production, oil pressing, seed selection, peanut butter or confectionery, depending on grade.
- A clean peanut shell stream - usable as biomass fuel, animal bedding or feed filler, growing media and soil conditioner, and as feedstock for further processing. Peanut hulls make up roughly a quarter of the harvested crop by weight, over 10 million tonnes a year worldwide, and are still widely burned in the field or left as waste.
That second stream is usually where the business case lives. A client who can sell or reuse a clean shell fraction - instead of paying to handle a mixed residue - is recovering value from a material that previously cost money to deal with, and the same machine that cleans the peanuts is doing it.
Separated peanut kernels and peanut shells discharged by the WTS0820 mobile trommel screen with winnowing fan
Core advantages of this configuration
- Two separation principles, one pass. Size in the drum, density in the air stream - the machine solves a problem that a screening-only machine physically cannot.
- Kernels protected. A gentle spiral drum plus air-based separation means the split is made by airflow, not by beating the product against a screen.
- Tune it, don't rebuild it. The adjustable air damper absorbs changes in variety, moisture and shell ratio - one setting, no new machine.
- Genuinely mobile. Max. 1,100 kg on a towable chassis with traction device and swivel wheels, so one unit serves several yards or field-edge sites.
- Low running cost. 2.2 kW total drive power and no heavy electrical works - a small generator is enough.
- Custom mesh and custom airflow. Both variables are set to the client's material rather than to a catalogue default.
- Serviceable. A simple motor-reducer drive and carrier rollers, backed by repair service and 24/7 spare parts support.
Custom WTS0820 mobile trommel screen with winnowing fan loaded into a container for shipment to France
Frequently asked questions
Q: Can a trommel screen actually separate peanut kernels from peanut shells?
A: Not on its own. Kernels and broken shell fragments frequently fall within the same size range, so an aperture-based screen passes both and comes out mixed. On this project the trommel drum handles the size-based work - dust, fines and oversize - while an integrated winnowing fan makes the real kernel/shell split by density.
Q: Why add a fan instead of simply fitting a smaller mesh?
A: A smaller mesh only narrows the size window; it does not separate two products of similar size. It also accelerates blinding, because fibrous shell fragments bridge small apertures, and it pushes kernels harder against the screen. Air separation works on a different physical property, so it succeeds where size alone cannot.
Q: Will this machine break the peanut kernels?
A: Keeping kernels intact was a design constraint from the first sketch. The drum uses low-lift spiral blades that convey material rather than throw it, and the final separation is made by airflow instead of mechanical agitation against the screen.
Q: How much does the WTS0820 process per hour?
A: The WTS0820 is rated up to 20 m³/h on a 5 m² screening surface, with 2.2 kW total power and a machine weight of max. 1,100 kg. Actual throughput on peanuts and shells depends on bulk density, moisture and how clean the kernel stream must be, so the working figure is confirmed on your own material.
Q: Can it be configured for my peanut variety and moisture level?
A: Yes. Two variables are customized per project: the drum mesh aperture and the air-damper setting on the winnowing fan. Varieties that differ in kernel size and shell thickness are handled by changing those two values rather than replacing the machine.
Q: Is it mobile enough to serve several sites?
A: Yes. The WTS0820 sits on a towable chassis with a traction device and swivel wheels, uses a folding hinged hopper that keeps it compact in transit, and stays at max. 1,100 kg - so one unit can move between yards, warehouses and field-edge sites behind a normal vehicle.
Q: What power supply does the machine need?
A: Total drive power is 2.2 kW, so a small generator or an ordinary site supply is sufficient. No dedicated high-power electrical installation is required, which matters when the machine is used at remote locations.
Q: What are the separated peanut shells good for?
A: A clean shell stream can be used as biomass fuel, animal bedding or feed filler, growing media and soil conditioner, or sold on as feedstock for further processing. Peanut hulls make up roughly a quarter of the harvested crop by weight - over 10 million tonnes a year worldwide - and are still widely burned in the field or discarded as mixed waste.
Tell us your material - we will design the separation around it
Every customized screening project starts from the material, not from the catalogue. Send us these three things and our engineers will come back with a recommended model, mesh specification, air-flow setting and quotation - the same way this peanut shell separation machine was specified.
STEP 1
- Your material and what you need separated - for example "peanut shells mixed with kernels", "wet compost", "topsoil with stones".
STEP 2
- Condition and target - moisture level, and the output per hour you need to reach.
STEP 3
- Site conditions - mobile or fixed installation, and the power available on site.
Zhengzhou Sinolion Machinery Co., Ltd. manufactures mobile and stationary trommel screening machines, waste sorting plants and gold wash plants, with every unit built in-house and configured around the material it will handle - as this peanut shell separation machine was. Whether you are separating kernels from shells, upgrading a compost line or specifying a complete plant, our engineering team is ready to work from your material sample. Reach us at +86 15515531291 or zzsinolion02@163.com.
