A cyclone separator is a no-moving-parts vessel that uses centrifugal acceleration to separate dispersed phases — gas-solid, liquid-solid, or liquid-liquid — with the cut-size (d50) typically ranging from 2 µm to 200 µm depending on body diameter, inlet velocity (commonly 15–25 m/s), and pressure drop (1.5–10 kPa) [S5].
Specifying one for an industrial duty requires locking the duty type, throughput range, separation target, material of construction, and integration footprint, then matching the body geometry and connection standard to the upstream/downstream equipment.
Duty Families and Matching Geometry
Three duty families dominate the catalog pages of 27 to 76 manufacturers in the active DirectIndustry indexes, each with a different geometry sweet spot [S1][S2]. Gas-solid dust collection favours tall, narrow reverse-flow cyclones with body diameters typically 200–1,200 mm; liquid-solid dewatering hydrocyclones use short, wide cones (10–30° cone angle) with overflow diameters sized for 50–100 m³/h per unit; and liquid-liquid de-oiling cyclones pair a tangential inlet with a reject-orifice ratio tuned to the oil-water density differential [S3]. Siebec's ATMOS 64 module, for example, uses 64 parallel small-diameter cyclones in a single housing to remove over 99 % of entrained oil at 500 m³/h [S1].
The functional split is direct: reverse-flow gas cyclones separate on Stokes-number-driven particle inertia, while de-oiling and de-sanding hydrocyclones separate on density-difference settling in a swirl, with the same governing constant (Stk·Fr) defining the efficiency curve across both [S5].
Five Spec Gates Engineers Use
Specifiers typically run five gating checks: (1) gas/liquid volumetric flow at operating and design temperatures, (2) particle or droplet size distribution with density, (3) allowable pressure drop against fan/pump head, (4) material of construction against corrosion/erosion/ATEX 2014/34/EU zone classification, and (5) discharge-handling interface — rotary valve, screw conveyor, or sealed pot. A precision filter selection spec sheet follows the same gate pattern, and on a cyclone duty the same gates collapse to flow, d50, ΔP, MOC, and discharge. [S1]
For gas-solid service, the European ATEX 2014/34/EU and IEC 60079 series govern dust-explosion protection when the particulate is combustible; the cyclone body, when used as a primary collector ahead of a bag filter, must dissipate static charge to a bonded ground point, and conductive carbon-black-loaded rubber liners or 304/316L stainless construction are common [S1]. For liquid duty, the wetted material must withstand the abrasive solids — polyurethane, high-alumina ceramic, or natural rubber liners are typical for hard-rock mining hydrocyclones.
Headline Numbers from the 2026 Catalog
Published operating envelopes across 36 cyclone-filter and 100 cyclone-separator catalog entries cluster in four bands: small inline units handle 0.5–24 m³/min (Mattei Ciclone condensate series at 90–120 mm width and 0.6–4.5 kg weight), mid-range dust cyclones reach 3,000–12,000 l/min (UFI FAB series, fluid temperature 95 °C), high-pressure gas-sample cyclones operate to 100 bar at 200 °C (Membrane GmbH MERLIN MGCS, 1/4" FNPT inlet), and large process separators span 3,000 m³/h and 12" hydrocyclone diameters (Kosun KD-100, FLSmidth KREBS) [S1][S2].
The same data set shows a typical secondary-cyclone dedusting load absorbing roughly 90 % of incoming particulate at the pre-separator stage, leaving the downstream HEPA/bag filter to handle the fines — Dustcontrol's C 5500, at 27 kg, is rated to lift that pre-separation load and extend filter life on construction-site extraction [S2].
Comparison: Reverse-Flow Gas Cyclone vs De-Oiling Hydrocyclone vs Pre-Separator Module
Three options cover most industrial line items: (a) a reverse-flow gas cyclone with cut-size 5–20 µm, pressure drop 1.5–2.5 kPa, 304SS or carbon-steel body, used ahead of a bag filter on woodworking, grain, or welding-fume lines; (b) a de-oiling hydrocyclone with reject-orifice ratio 0.3–0.7, body pressure rating 10–100 bar, 316L/FRP/duplex wetted, used on produced-water, compressor-condensate, and refinery desalters; and (c) a multi-cyclone pre-separator module (e.g. 64-element ATMOS 64) with 99 %+ removal at 500 m³/h, used as a primary stage on oil-mist extraction [S1][S3]. The decision rule: dust loads at low pressure and ambient temperature point to (a), liquid-liquid density splits point to (b), and high-volume oil-mist or welding-fume air at moderate pressure points to (c). For a steam-side parallel, see the steam separator spec map — gas/liquid cyclones and steam separators share the same Stk·Fr efficiency logic but differ in MOC and pressure envelope.
Integration and Standards Footprint
Field integration uses flanged connections matched to the upstream line class — DIN/ANSI PN10–PN40 for gas service, ASME B16.5 Class 150–300 for liquid — and the body is selected against the same ASME/EN vessel code as any pressure-containing equipment. A gas cyclone is not a pressure vessel in the strict sense on low-pressure dust service, but at 100 bar gas-sample duties (MERLIN MGCS) the body is treated as a Category IV PED/ASME BPVC item [S1]. CFD validation, used routinely on new designs, predicts collection efficiency and erosion patterns in Autodesk CFD and ANSYS Fluent for new geometries before fab [S6].
For ATEX-classified dust-handling, a grounded 304/316L cyclone upstream of an explosion-isolated filter is a common arrangement in European grain and wood plants; the same body geometry, with the inlet relocated and a reject pot added, serves as a hydrocyclone upstream of a dewatering screen on a mineral-processing line. Inventory under HS code 8421.39 covers both gas and liquid cyclones and is the customs reference for cross-border shipment [S1].
Limitations and Failure Modes
Cyclones do not handle sticky or fibrous material, and d50 below 2 µm is uneconomic — efficiency falls off sharply and pressure drop climbs into fan-head range above 10 µm cut on fine duties. Erosion at the inlet and cone apex is the dominant wear mode, and abrasive feed accelerates liner replacement cycles from years to months. On a gas duty with hygroscopic dust, condensation in the cone can plug the discharge; on a liquid duty, gas-coring in the apex kills separation and shows up as pulsating overflow. [S2]
A second recurring failure is improper scroll/hopper seal on gas duty — a 1–2 % air leak at the rotary valve drops efficiency by 10–15 percentage points and is the first thing a maintenance team should check when outlet loading rises.
Selection Workflow and Trackable Signals
Run the selection in this order: define duty (gas-solid, liquid-solid, liquid-liquid), lock volumetric flow at design temperature, set d50 and efficiency target, fix pressure-drop budget, choose MOC against chemistry/abrasion, then size body diameter from the Stk·Fr correlation and verify with CFD on any non-standard geometry. Cross-check with a process instrument downstream for ΔP verification and an isolation valve on the reject line for service lock-out. Verifiable next signal: monitor the supplier index — 27 cyclone-filter and 76 cyclone-separator active manufacturers, 36 and 100 product lines respectively, on DirectIndustry as of 2026-06-03 and 2026-05-29 [S1][S2].