Hydrocyclone Classification Patents: Leaders & White Space 2026
- Filing has cooled from its 2019 peak of 240 records. annual filings for the complete-year window fell from 81 in 2021 to 42 in 2024, a 48% drop, though 2025-2026 figures are still filling in.
- No single company dominates. the leader holds 131 records and the top 5 assignees combined account for just 14.8% of all 3,141 records in scope — this is a fragmented field, not a walled garden.
- Cyclone separator claims dwarf everything else. B04C covers 46.3% of records, while adjacent branches like flotation (B03D, 5.3%) and paper-stock treatment (D21D, 5.6%) sit far thinner.
Filing growth compares 2021 (81 records) with 2024 (42) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 3,141 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Hydrocyclone classification patents span the mechanics of separating particles by density and size using centrifugal flow — vortex finder geometry, apex spigot and underflow design, feed pressure control, and the wear behaviour of liners under abrasive slurry. The search set pulls records that combine hydrocyclone hardware terms with process-control concepts such as bypass fraction, roping discharge and classification sharpness, which is what separates process-tuning patents from pure equipment claims. Coverage runs from 2015 through the 2026-07-31 data cut-off.
The corpus totals 3,141 published records, all captured in a single assignee ranking of 3,141 patent families. Filing offices skew toward the United States, Australia and WIPO/PCT routes, consistent with a technology tied to mining, oil and gas, and water treatment operations concentrated in those jurisdictions.
Filing trend and technology composition
Two views of the same 3,141-record dataset: how filing volume has moved year over year, and which IPC subclasses carry the claim density.
Filings rose to a 2019 peak, then declined
Annual filings climbed from 205 in 2017 to a peak of 240 in 2019, then declined through the complete-year window, falling from 81 in 2021 to 42 in 2024 — a 48% drop. Because publication lags filing by roughly 18 months, 2025 and 2026 counts are still incomplete and should not be read as a continuing slide.
Cyclone separator claims carry the bulk of the field
B04C (cyclone separators) touches 46.3% of the 3,141 records, with B01D (general separation processes) close behind at 28.2%. Water treatment (C02F), wet solids separation (B03B) and drilling applications (E21B) each sit in the 6-12% range, marking where hydrocyclone technique crosses into adjacent process industries rather than dominating them.
Shares are the percentage of the 3,141 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Hydrocyclone Classification with Eureka
This page is one run against one query. Ask Eureka your own question about hydrocyclone classification and every answer comes back with the patent numbers behind it.
Try EurekaThe document that still anchors the field
GB726683A — hydrocyclone apparatus with dual concentric vortex finders
Filed by STAMICARBON N.V. and granted in 1955, this patent claims a hydrocyclone with two vortex finders forming concentric discharge passages for light and intermediate fractions, plus a heavy-fraction aperture sized at no more than 0.6 times the vortex-finder diameter, with a conical section apex angle fixed between 50 and 90 degrees.One of the earliest geometry-defining filings in this dataset; its specific ratio and angle constraints still frame how later apex and vortex-finder claims are drafted.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20160045841A1 | New and improved system for processing various chemicals and materials | 857 |
| 2 | US5316664A | Process for recovery of hydrocarbons and rejection of sand | 415 |
| 3 | US5340467A | Process for recovery of hydrocarbons and rejection of sand | 390 |
| 4 | US4279743A | Air-sparged hydrocyclone and method | 251 |
| 5 | US3130157A | Hydro-cyclones | 221 |
| 6 | WO2014153570A2 | New and improved system for processing various chemicals and materials | 219 |
| 7 | US20070253874A1 | System, method and apparatus for treating liquids with wave energy from plasma | 185 |
| 8 | US20110257788A1 | Mobile station and methods for diagnosing and modeling site specific full-scale effluent treatment facility r… | 148 |
| 9 | US5478484A | Apparatus and method including a hydrocyclone separator in combination with a tubular filter | 140 |
| 10 | US4838434A | Air sparged hydrocyclone flotation apparatus and methods for separating particles from a particulate suspensi… | 138 |
Ranked by citation count within this searched corpus. Older records accumulate citations simply by being available longer, so treat this as a signal of influence, not of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three patterns worth weighing before drafting claims or scoping freedom-to-operate in this space.
No single assignee controls the field
The leading assignee holds 131 records against a total of 3,141, and the top 5 combined reach just 14.8% of all records in scope. That leaves a long tail of single- and few-filing entrants rather than a small set of blocking incumbents.
Filing volume has genuinely cooled
Complete-year filings dropped from 81 in 2021 to 42 in 2024. Several previously active assignees show zero filings in the latest tracked year, which is consistent with a maturing claim landscape rather than a data artefact, since the decline predates the publication-lag window.
Core cyclone geometry is heavily claimed
Nearly half of all records carry a B04C cyclone-separator classification, while flotation (B03D) and paper-stock (D21D) applications each sit under 6%. New filings that combine core geometry with a thin adjacent branch face less prior art than pure B04C filings.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to hydrocyclone classification, with the prior art for and against each one.
Who is filing, and where the gate is thinnest
The ranked leaders span mining equipment makers, oil and gas process licensors, and chemical processors — reflecting how widely hydrocyclone technique has spread across industries.
The largest single filer still holds a modest share
At 131 records out of 3,141, the top assignee's position is influential but far from exclusive. Fifth place holds 55 records and tenth place holds 41, showing a gradual taper rather than a cliff.
Multiple established filers have gone quiet
Several of the most active historical assignees, including mining-equipment and industrial-chemical filers, show zero filings in the latest tracked year and year-on-year drops as steep as -100%. This tracks the broader 2021-2024 decline rather than signalling exit from the space.
Joint filing is limited but concentrated
Only 10 co-assignee pairs appear in the dataset, and the strongest pairing appears 11 times. Co-filing here tends to link a specialty chemical or process partner with an equipment or research entity rather than reflecting broad industry consortia.
| Assignee | Recent year | YoY |
|---|---|---|
| Vulco | 0 | — |
| Eastman Chemical Company | 0 | — |
| Foret Plasma Labs LLC | 0 | — |
| Metso Minerals Industries, Inc. | 0 | — |
| Conoco Specialty Products Inc. | 0 | — |
| Weir Minerals Australia Ltd | 0 | -100% |
| CALTEC | 0 | — |
| Stamicarbon B.V. | 0 | — |
Where to take this analysis
The dataset points to specific next steps depending on whether you are scoping freedom-to-operate or looking for a filing angle.
Map claims against the thin branches
Cross-reference specific claim language in flotation and paper-stock applications, where IPC density sits under 6%, against your own process parameters before assuming the core B04C art blocks you.
Explore in Eureka →Watch for renewed filing activity
The 2021-2024 decline is real, but 2025-2026 figures are still incomplete due to publication lag. Track whether filing resumes once those years fill in before concluding the field has plateaued.
Set up a monitor in Eureka →Common questions about hydrocyclone classification patents
The dataset ranks 100 companies by patent family count, with the leader holding 131 records out of 3,141 total. The top 5 assignees combined account for only 14.8% of all records, so no single company controls the field the way a leader might in a more concentrated technology area. The ranking spans mining equipment manufacturers, oil and gas process licensors, and chemical processing firms, reflecting how broadly hydrocyclone technique is used across industries.
Filing peaked at 240 records in 2019 and declined through the most recent complete year, falling from 81 in 2021 to 42 in 2024 — a 48% drop. Because patent publication typically lags filing by about 18 months, the partial figures for 2025 and 2026 understate actual filing activity and should not yet be read as confirmation the decline is continuing. Several previously active assignees show zero filings in the latest tracked year, consistent with this broader cooling.
Cyclone separator design, classified under IPC subclass B04C, appears in 46.3% of the 3,141 records in scope, making it the single largest technology cluster. General separation processes (B01D) follow at 28.2%. Adjacent applications — water treatment, wet solids separation, drilling, paper-stock treatment and flotation — each account for roughly 5-12% of records, marking where hydrocyclone technique crosses into other process industries rather than dominating them.
The thinnest IPC branches relative to the core are flotation applications (B03D, 5.3% of records) and paper-stock treatment (D21D, 5.6%), both far below the 46.3% carried by core cyclone-separator claims. Specific sub-areas worth examining include liner wear-rate sensing, self-adjusting apex spigot geometry, and closed-loop feed pressure control, none of which show the claim density of core vortex-finder and underflow geometry patents. A first filing combining core hydrocyclone hardware with one of these thinner branches faces less crowded prior art than a pure B04C filing.
GB726683A, granted to STAMICARBON N.V. in 1955, claims a hydrocyclone with two concentric vortex finders for separate discharge of light and intermediate fractions, a heavy-fraction aperture sized at no more than 0.6 times the vortex-finder diameter, and a conical section with an apex angle between 50 and 90 degrees. As a granted patent from 1955, its original term has long expired, so it does not itself block current filings. It remains relevant as a reference point because its specific geometric ratios still frame how later vortex-finder and apex-angle claims are drafted and distinguished.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.