Horizontal bead mill · RWM series

0.5 to 300 litres — one horizontal bead mill family.

A lab result you can trust and a production machine that keeps it. Every RWM is a horizontal bead mill — the same machine many buyers call a sand mill — built on one rotor family, one set of separator options and one cartridge seal, so scaling from 0.5 L to 50 L is a calculation rather than a new experiment.

How the machine works

Product is pumped from the bottom into a horizontal, water-jacketed chamber packed with grinding beads. A shaft driven by the motor carries pins or discs that put the beads into a controlled turbulence field. Solids are ground between the beads, then the slurry passes a separator at the outlet that keeps the beads inside.

Schematic, not a dimensioned drawing. You get the certified general-arrangement drawing with foundation, port and panel details after the order is confirmed — that drawing is yours to keep.

Chamber. Double-walled, water-jacketed, with a tapered bead-discharge port so the chamber empties fully when you stop.
Rotor. Pin or turbine-disc style, 42CrMo hardened or in 316L / SiC, keyed to the shaft so it cannot walk under load reversal.
Separator. Dynamic screen with a flush-liquid back-pulse; slot size matched to the smallest bead you intend to run.
Seal. Double cartridge, oil-buffered, factory preset. Detailed below, because this is the part that decides your downtime.
Drive. IE3 TEFC motor, VFD on lab machines, star-delta or soft-starter on production machines unless you specify otherwise.
Frame. Welded and stress-relieved, machined in one setup so the motor and shaft stay aligned after transport.

The range, as it is actually built

Five series, 0.5 L to 300 L of grinding chamber. Every figure below is taken from the builder’s own catalogue: chamber volume, motor options, flow or batch range, and footprint in millimetres.

All sixteen models, one tableChamber volume, motor, output and footprint exactly as the builder’s catalogue publishes them. Green row = the model we most often quote for that job.
Series	Model	Chamber	Motor	Output / batch	L × W × H, mm
RWM-N	RWM-N5	0.5 L	3 kW	5–60 L batch	800 × 600 × 800
	RWM-N10	1.0 L	4–5.5 kW	5–60 L batch	800 × 600 × 800
RWM-P	RWM-P5	5 L	7.5 / 11 kW	0–2 L/min recirc.	1100 × 600 × 1200
	RWM-P10	10 L	11 / 15 kW	0–2 L/min recirc.	1100 × 550 × 1300
	RWM-P20	20 L	15 / 18.5 kW	0–10 L/min recirc.	1200 × 700 × 1300
	RWM-P30	30 L	15.5 / 22 kW	0–10 L/min recirc.	1400 × 700 × 1300
RWM-B	RWM-10B	10 L	12–18.5 kW	80–300 L/h through	1250 × 950 × 1300
	RWM-20B	20 L	22–30 kW	100–500 L/h through	1400 × 1000 × 1600
	RWM-30B	30 L	37–45 kW	200–800 L/h through	1500 × 1000 × 1600
	RWM-50B	50 L	55–75 kW	500–2000 L/h through	1800 × 700 × 1600
RWM-C	RWM-C50	50 L	30 kW	0–60 L/min recirc.	1800 × 700 × 1600
	RWM-C80	80 L	37 / 45 kW	0–60 L/min recirc.	1900 × 800 × 1800
	RWM-C100	100 L	45 / 55 kW	0–60 L/min recirc.	2000 × 950 × 1900
RWM	RWM-100	100 L	55 / 75 kW	500–2500 L batch	2000 × 950 × 1900
	RWM-200	200 L	75 / 90 kW	1000–10 000 L batch	2800 × 1200 × 2200
	RWM-300	300 L	90 / 110 kW	to 72 000 L batch	3200 × 1300 × 2300

Where the catalogue lists two motors, both are shown. Everything that depends on your product — bead size, screen slot, liner material, seal arrangement — is quoted separately, and we will tell you which of those we would not let you skip.

“Recirc.” is how fast the loop turns over, not what leaves the machine. Your net number is recirculation divided by the number of passes you need — which is exactly why we ask for the five numbers before we quote.

The three dishes under each machine are typical feed stocks for that series, not a promise about your formula.

RWM-N · 0.5 – 1 L chamber · 5–60 L batch

Laboratory nano bead mill

Built for scale-up: run the formula here, then re-run it on a P, B or C chamber with the same bead and screen choice.
Accepts 0.1–2 mm media, and the same disc rotors used on the pilot machines.
Stepless or inverter speed control; explosion-proof motor available for solvent-based work.
Self-circulating rotor pump built in, plus an external pump loop when the product gets thick.

Ceramic and battery slurry · cosmetic pigment · food paste

RWM-P bead mill with a horizontal stainless chamber, green guard panels, local control box and a separate inverter cabinet

RWM-P · 5 – 30 L chamber · 0–10 L/min

Pilot and small-production bead mill

The workhorse for colour, coating and additive pastes where the week is measured in hundreds of litres, not tens of thousands.
Runs the Φ215 × 50 × 12 and Φ190 × 50 × 12 disc rotors, so a formula proven on the lab machine transfers without re-development.
Skid-mounted with a separate inverter cabinet, which keeps the electrics out of a hot or wash-down area.

Detergent paste · iron-oxide pigment · sesame and peanut paste

RWM-B rod-pin bead mill: vertical motor, touch-panel controller and stainless grinding chamber on a green base frame

RWM-B · 10 – 50 L chamber · 80–2000 L/h · down to D97 < 100 nm

Rod-pin nano bead mill

Rod-pin rotor in a short, large-diameter chamber: less flow inertia, so 0.1 mm media stays suspended instead of blocking the outlet.
The catalogue figure is D97 < 100 nm on 0.1 mm media. That is a statement about the machine, not a promise about your formula — send a sample and we will report what it actually does.
Long, large-diameter separator; cooling on the grinding shaft, with an optional external heat exchanger on the line and in the feed tank.
One pass or several. At the same tip speed, the smaller machine loses less product when you change over.
Touch-panel control, and extra ingredients or additives can be dosed into the circulation loop mid-grind.

Ceramic and battery slurry · cosmetic micropigment · fine pigment concentrate

RWM-C · 50 – 100 L chamber · 0–60 L/min

Ultra-fine bead mill

A medium-duty horizontal closed chamber, revised from the earlier series: same floor space, more throughput, easier wear-part access.
0–60 L/min recirculation, which is where detergent bases, suspension-concentrate fertilisers and food pastes normally sit.
Ex-rated control box available, as photographed.

Detergent base · fertiliser suspension concentrate · food paste

RWM · 100 – 300 L chamber · batches to 72 000 L

Large-flow bead mill

For high-yield lines: 100–300 L of chamber, 500 L through to a 72 000 L batch, on a single rigid frame.
Continuous running, low contamination and self-controlled operation — the reason paint and pesticide plants buy at this size rather than running three smaller machines.
Check the footprint against your own floor before you order: the 300 L unit is 3200 × 1300 × 2300 mm, and it will arrive as one piece.

Fertiliser SC at volume · coating pigment paste · detergent base

Sizing honestly

If you tell us “I want 2000 L/h”, the answer is not automatically an RWM-C80. It depends on solids, viscosity, target fineness, how many passes you accept and how hot your climate runs. A machine sized from a flow number alone either blocks its screen or wastes 40 kW. Send the eight numbers from the quote form and we will show you the calculation.

The mechanical seal is the machine

Ask any plant manager in China which part of a bead mill they hate, and they will not say the motor. In our first years repairing other people's machines, almost every breakdown we were called to was a seal that had been scored by dried slurry. We stopped treating the seal as an accessory.

CONSTRUCTION

What is actually fitted

Double cartridge seal, factory preset — no setting gauges, no guessing at the correct working length on site.
SiC against SiC faces, lapped flat to within one light band and matched as a pair rather than picked from the shelf.
Barrier-oil pressure is held 0.5–1.5 bar above chamber pressure, so anything that crosses the faces is oil going into your product — never slurry coming out into the bearing. That is why the barrier oil is on the materials list we send you: NSF H1 white oil on food and cosmetic builds, VG 46 elsewhere.
Water-cooled seal chamber; faces held under 60 °C at rated speed.
Splash collar and labyrinth ahead of the faces to take the bulk of the abrasive load first.

SERVICEABILITY

Why cartridge matters

Reached from the drive side: undo the coupling spacer and the cartridge pulls away without taking the chamber apart or pulling the rotor.
Two people, roughly 30–45 minutes, standard tools. No lifting the machine.
Every machine ships with the seal drawn to your shaft stamp number, so the replacement you buy in three years is the right one.
Barrier-oil level and pressure are both visible at the front of the frame and both alarmed on production models.

Seal grade selectionStandard fitment is the highlighted row unless your process says otherwise. Upgrades are cheap at order and expensive after a shutdown.
Duty	Faces	Elastomers	Barrier fluid	Notes
Water-based pigment paste, neutral detergent base, pH 5–9	SiC / SiC	FKM (Viton)	ISO VG 32	Our standard build. FKM is the right elastomer here; it stops being the right one above pH 11 or in aromatics.
Solvent-based coatings & inks	SiC / SiC	FFKM	ISO VG 46	FKM swells in aromatics. Do not skip this one.
Food & cosmetics contact	SiC / SiC	FDA-listed FKM or EPDM	NSF H1 white oil	Bearing-side lubricant also H1.
Alkaline agro slurries, pH above 11	SiC / SiC	EPDM or FFKM	ISO VG 46	Hot caustic etches silicon carbide, not carbon. This build is honest to about pH 11 and 60 °C — beyond that tell us, because the face material has to change and the life expectation with it.
Fine bead duty, 0.1–0.3 mm	SiC / SiC + ceramic sleeve	FKM (Viton)	ISO VG 32 + 5 µm filter	Fines get into the oil; the filter saves the faces.
Hot or rapidly cycling product	SiC / SiC	FFKM	VG 46, cooled	Tell us the peak temperature, not the average.

Four signs your seal is about to tell you something

Barrier-oil level dropping without visible wetness outside — the inner face is leaking into the product.
Barrier oil turning milky — water has got into the reservoir. Either the outer face is weeping, or the seal-chamber gasket is passing cooling water. Change the face set now, not next month.
Drip at the weep hole that increases with chamber pressure rather than with shaft speed — seat problem, not face problem.
Seal chamber temperature climbing while cooling water flow is normal — the flush is partly blocked; clean the screen first.

The parts that decide whether it runs

A bead mill is a motor, a chamber and two wear systems: the mechanical seal and the separator. Everything else is steel. This is what goes into those two, and what we will ask you to choose.

Mechanical seal arrangementsThe part that decides whether the machine is running or leaking
Type	Duty	Notes
Single face, standard	Water-based, near-neutral	What most suppliers fit as default. Honest duty for detergent bases and food pastes; expect to replace it early under solvent, heat or continuous running.
Double face, loose	Pigment pastes, occasional solvent	Two faces, no cartridge. Cheaper to buy and slower to fit — the setting gap gets established by hand on your floor, which is where most of these seals die.
Double face, cartridge	Solvent, high solids, 24/7	Pre-set on a cartridge at the workshop and exchanged as one piece in under an hour. This is the arrangement we quote first, and the one we will defend in a price negotiation.

Separator systemsHow the beads stay in the chamber and the product leaves
Type	Notes
Static separator ring	No moving parts, tolerant slot, easy to flush. Used where batches change often and where the machine has to be washed between them.
Dynamic separator ring	A counter-rotating gap that self-cleans at speed. Holds 0.1–0.3 mm media without blocking, but needs the flow the RWM-B and RWM-C actually provide.

Rotor disc sizes built for these chambers: Φ215 × 50 × 12 · Φ190 × 50 × 12 · Φ250 × 70 × 12

Rod-pin grinding rotor: a stainless cage with pressed pins, shown beside its wear sleeves — Rod-pin rotor — the fine-grind rotor on the RWM-B, RWM-C and large-flow machines

Conical outlet screen with machined slots, standing on the bench — Cone outlet screen — the part that keeps 0.1 mm beads inside

Three disassembled disc rotors, each disc carrying the tangential slots that drive the beads — Disc stack — the Φ190 / Φ215 / Φ250 sizes the catalogue builds

Mechanical seal cartridges and separator rings laid out on the assembly bench — Seal cartridges and separator rings — the two things we will ask you to specify

Grinding media we stockChemistry, density, fracture load and self-wear as published by the bead maker
Grade	Chemical composition	Density	Bulk density	Crushing load	Hardness	Self-wear	Roundness
Z80 · 75–80% zirconia	ZrO₂ 75–80% · Al₂O₃ 5–10% · SiO₂ 7–12% · 1.0%	> 5.4 g/cm³	≥ 3.3 g/cm³	> 1.5 kN (Φ2 mm)	> 1050	< 1 ppm/h	—
95 · fully stabilised zirconia (Y-TZP)	ZrO₂ 94.8 ± 0.2% · Y₂O₃ 5.2 ± 0.2%	> 6.05 g/cm³	≥ 3.7 g/cm³	> 2.0 kN (Φ2 mm)	> 1200	< 0.5 ppm/h	≥ 0.98

Z80 · 75–80% zirconia

The default bead. Good wear, materially cheaper, and enough for detergent bases, suspension-concentrate fertilisers and most coatings. Reach for this one first.

95 · fully stabilised zirconia (Y-TZP)

Higher density, higher fracture load, ≥ 0.98 roundness and under 0.5 ppm/h self-wear. This is what we pack for nano grinds, cosmetic and food colours, and any product where a worn bead ends up in the drum you ship.

Rotor and separator

The separator is where a cheap bead mill reveals itself. A screen that is too coarse lets beads into your product; one that is too fine blocks, and a blocked screen in a running machine is a pressure event.

ROTOR

Rod-pin or disc stack

A disc stack is the simpler machine: fewer parts, cheaper to rebuild, and it is happy on coarse media and high solids. A rod-pin rotor puts energy across the whole chamber cross-section, which is what keeps 0.1–0.3 mm media suspended instead of letting it pack against the outlet — that is why our fine-grind machine, the RWM-B, is a rod-pin. 42CrMo hardened as standard; 316L, SiC or tungsten carbide on request.

SEPARATOR

Dynamic screen with back-pulse

Screen slot is set against the smallest bead you will run — roughly one third to one half of its diameter on a static screen, and finer on a dynamic separator, because there the rotating gap does the separating and not the aperture. A small flush line puts liquid back across the screen face, which is what actually keeps it open in a sticky grind. A mesh on the outlet side catches a torn screen before it reaches your tank.

CHAMBER FLOW

Rotor-stator gap and jacket

The rotor runs clear of the liner by a machined gap, which keeps the high-energy zone off the wall — that is where wear and metal pick-up come from. Cooling water enters at the outlet end and returns at the feed end, so the hottest part of the chamber sees the coldest water and the jacket cannot run part-full of air.

Bead size sets everything else

Bead diameter versus achievable finenessTypical for a single pass with adequate residence time. Sub-micron targets usually need two passes or a recirculating loop.
Bead Ø	Achievable D50	Static screen slot	Tip speed	Typical job	Bead material
0.1 mm	0.2–0.5 µm	35–50 µm	10–14 m/s	Nano TiO₂, agro SC, battery slurry, ceramic tape	ZrO₂ (YTZ)
0.3 mm	0.5–2 µm	100–150 µm	8–13 m/s	Pigment concentrate, printing ink, toothpaste	ZrO₂
0.8 mm	2–8 µm	270–400 µm	6–11 m/s	General paint, detergent paste, food paste	ZrO₂ / glass
1.5–2.0 mm	8–25 µm	500–1000 µm	4–8 m/s	Coarse pre-grind, mineral fillers, seed coating	ZrO₂ / alumina
2.5–3.0 mm	25–60 µm	830–1500 µm	4–7 m/s	Breaker grinding, high-solids paste, slag	Alumina / steel

Choose the bead first. It decides the screen slot, the tip speed, the motor, the outlet temperature and how long the liner lasts.

White zirconia grinding beads photographed in mass against a grey background — Zirconia media, 0.1 mm upward

Steel beads are listed only where iron contamination is irrelevant. On a white product, a steel bead is a defect, not a saving.

Materials, and the iron question

If your product is white or near-white, or if it is eaten or applied to skin, metal contact is a specification problem rather than a preference. On those jobs we move the chamber liner, the rotor and the separator off the steel list and quote it as a ceramic line. If your spec carries an iron limit, send us the number — we will tell you which build can hold it, which one cannot, and we will not publish a figure we have not measured on your own product.

Wetted material combinations we buildOutside frame and guard are painted carbon steel in every grade unless you ask for stainless cladding.
Build	Chamber liner	Rotor	Separator	Best for
A · Economy	Carbon steel + epoxy	42CrMo	SS304	Industrial pigment, mineral slurry, non-white filler
B · Standard	SS304 or SS316L	316L / hardened	SS316L	Detergent paste, general water-based work, mild agro
C · Food & cosmetic	SS316L polished Ra 0.4	316L polished	SS316L	Food paste, cosmetics, high-pH or chloride-bearing product
D · White product	ZrO₂ ceramic	ZrO₂ pins on steel core	Ceramic frame + PU	TiO₂, toothpaste, sunscreen, ceramic and battery paste
E · Ultra fine	ZrO₂ or SiC	SiC / carbide	SiC	0.1–0.3 mm bead duty, abrasive carriers, long campaigns
F · Easy clean	PU replaceable liner	PU / ceramic	SS316L	Small workshops changing colour or flavour often

Ceramic chambers are modular: individual tiles and pins replace singly, so a cracked liner is a part order and not a new machine.
Polish level is stated as Ra on the wetted surface, and we measure it before shipping on food and cosmetic builds.
Where a product must not see iron at all, the flow path from hopper to outlet goes PU or zirconia ceramic end to end — including the pump head, the fittings and the sample valve. 316L is the step below that: low pick-up, not zero. Tell us which one your spec is and we will write it into the contract.

Voltage, electrics and the nameplate

Getting the supply wrong is the most common avoidable mistake on an export order. We confirm it twice, in writing, before winding. And we will push the inverter on a production machine: a chamber full of beads should be started up slowly, not dropped straight onto the line.

Electrical and control optionsStandard is the middle column. Anything in the right column is priced as a line item, not smuggled into a total.
Item	Standard fitment	Available on request
Supply	380–415 V, 50 Hz, 3-phase	220 / 380 / 400 / 415 / 440 / 460 / 480 / 660 V, 50 or 60 Hz. Lab RWM-N5 and RWM-N10 in 110 or 220 V single-phase.
Motor	IE3 TEFC, Chinese tier-1	ABB, Siemens, WEG. Inverter-duty insulation if you run a VFD.
Speed control	Star-delta or soft starter (production); VFD standard on lab	VFD 0–100 % with torque control, Delta / Schneider / Siemens.
Panel	IP54 painted steel, English labels	IP65, SS304 enclosure, Spanish / Portuguese / French / Arabic labels.
Explosion protection	Not fitted	Ex d IIB T4 motor and panel for solvent-based coatings and ink rooms.
Instrumentation	Inlet and outlet PT100, chamber pressure gauge, flow switch on cooling water	Seal-oil pressure and level, vibration probe, dry-run cut-off, torque limit, RS485 / Modbus to your DCS.
Interlocks	Cooling-water flow stops the shaft	Full sequence: temperature high, pressure high, seal failure, product flow loss.
Plugs & spares	Hard-wired terminals	Your country's plug on the lab machine, plus a spare fuse and contactor set.

Options and the spares kit we recommend

Machine options

Feed pump: peristaltic / screw / diaphragm
Automatic bead charging
CIP spray ball & drain slope
Recirculation loop kit
Second chamber liner
Static mixer on outlet
Deaeration tank
Trolley base (lab)
SS304 drip tray
PLC + 7″ HMI, recipe storage
Dust cover
Fork pockets & lifting lugs

Recommended spares to buy with the machineTwo years of running at 20 h/day. Buying these with the new machine costs you one freight movement instead of three air shipments.
Item	0.5–30 L	10–50 L	80–300 L
Seal cartridge	1	2	2
O-ring / gasket set	1	1	2
Bead screen	2	2	3
Rotor pins	20 %	20 %	15 %
Beads, one charge	1×	1×	1×
Coupling element	1	1	2
Bearing set	—	1	1

What we need from you to quote

Product name and what is in it — solids, carrier, pH, solvent percentage.
Solids content by weight and viscosity at your feed temperature, in cP or Pa·s.
Target fineness: D50 and D90, or Hegnor / grind gauge if that is how you measure.
Quantity: litres per hour, or litres per batch and batches per day.
Inlet temperature available, and your cooling-water temperature and pressure.
Supply voltage, frequency, phase, and whether the room is classified for solvent.
Any metal-contamination limit in your specification, and whether the product is eaten or applied to skin.
Destination port and whether you take FOB Qingdao or want a landed price.

Put it in the quote form Send by WhatsApp

Want a test grind first?

Send 3–5 kg of your product. We return the ground sample, the fineness curve, the power draw and the machine we would sell you — with the cost of each option shown separately.

Start a test grind Read the FAQ