{
 "version": "2026-10-20",
 "license": "Dimension sheets: CC BY 4.0. Standard and published-size files: CC BY 4.0. Xem Studio's own designs (files_license = Xem Studio Design License): free to use and sell things from, not to redistribute as files — https://xemstudio.com/license/. Other publishers' files: their own license, linked beside them.",
 "slug": "cyclone-separator-proportions",
 "name": "Cyclone separator proportions: Stairmand high-efficiency and Lapple conventional",
 "kind": "standard",
 "category": "Tools & garage",
 "group": "Bench & craft machines",
 "year": null,
 "question": "What are the standard cyclone separator dimensions (Stairmand, Lapple) as ratios of the barrel diameter?",
 "tags": [
  "cyclone",
  "dust collection",
  "separator",
  "shop vac",
  "equations",
  "standard"
 ],
 "aliases": [
  "cyclone separator dimensions",
  "stairmand cyclone",
  "lapple cyclone",
  "cyclone design ratios",
  "dust separator stl",
  "cyclone dust collector design",
  "shop vac cyclone",
  "cyclone inlet size",
  "vortex finder diameter",
  "cyclone cone angle"
 ],
 "overall_mm": {
  "length": null,
  "width": null,
  "height": null
 },
 "official_cad": false,
 "xem_status": "free-files",
 "les": false,
 "free_files": 4,
 "url": "https://xemstudio.com/objects/cyclone-separator-proportions/",
 "sheet_txt": "https://xemstudio.com/objects/cyclone-separator-proportions/sheet.txt",
 "sheet": {
  "basis": "Published ratios: Stairmand 1951, Lapple 1951, as tabulated in Utikar et al. 2010, Grave et al. 2021 and Dartmouth ENGS 37 notes",
  "overall_mm": {
   "length": null,
   "width": null,
   "height": null
  },
  "notes": [
   "Reference geometry from published ratios; no efficiency claim. A reverse-flow cyclone is sized by its barrel diameter D: every other dimension is a fixed ratio of D for a given family. Gas enters tangentially through a rectangular inlet, spirals down the barrel and cone, and leaves upward through the vortex finder; the separated dust leaves through the bottom outlet.",
   "Stairmand (1951) high-efficiency and Lapple (1951) conventional ratios as tabulated by Utikar et al. (2010, after Leith & Licht 1972), Grave et al. (2021, Stairmand only) and Cushman-Roisin (Dartmouth, after Cooper & Alley). Utikar et al. print the Lapple cylinder height as 1 D; the other tabulation prints 2 D with a 2 D cone and H = 4 D, which is what is used here.",
   "Files: D = 100 and 150 mm for both families. D, a, b, De, S, h, H and B are gas-side (inside) sizes; the wall is added outside them. The wall (2 mm, normal to the cone too) and the inlet duct run (1 D from the barrel centre plane, open end) are example parameters, not part of the published ratios. The vortex finder is a plain tube De inside, flush with the top of the roof; the inlet's outer wall is tangent to the barrel and its top is level with the roof.",
   "Material-neutral: the files are shapes. Wall thickness, joints and outlet connections are yours to choose."
  ],
  "table": {
   "columns": [
    "dimension",
    "Stairmand HE",
    "Lapple",
    "Stairmand at D = 100 / 150",
    "Lapple at D = 100 / 150"
   ],
   "rows": [
    [
     "a: inlet height",
     "0.5 D",
     "0.5 D",
     "50 / 75 mm",
     "50 / 75 mm"
    ],
    [
     "b: inlet width",
     "0.2 D",
     "0.25 D",
     "20 / 30 mm",
     "25 / 37.5 mm"
    ],
    [
     "De: vortex finder (gas outlet) diameter",
     "0.5 D",
     "0.5 D",
     "50 / 75 mm",
     "50 / 75 mm"
    ],
    [
     "S: vortex finder length below the roof",
     "0.5 D",
     "0.625 D",
     "50 / 75 mm",
     "62.5 / 93.75 mm"
    ],
    [
     "h: cylinder (barrel) height",
     "1.5 D",
     "2 D",
     "150 / 225 mm",
     "200 / 300 mm"
    ],
    [
     "H: overall height, roof to dust outlet",
     "4 D",
     "4 D",
     "400 / 600 mm",
     "400 / 600 mm"
    ],
    [
     "B: dust outlet diameter",
     "0.375 D",
     "0.25 D",
     "37.5 / 56.25 mm",
     "25 / 37.5 mm"
    ],
    [
     "cone height (H − h)",
     "2.5 D",
     "2 D",
     "250 / 375 mm",
     "200 / 300 mm"
    ]
   ]
  }
 },
 "sheet_text": "Cyclone separator proportions: Stairmand high-efficiency and Lapple conventional — dimension sheet\nSource: Xem Studio, https://xemstudio.com/objects/cyclone-separator-proportions/  (sheet CC BY 4.0)\nBasis: Published ratios: Stairmand 1951, Lapple 1951, as tabulated in Utikar et al. 2010, Grave et al. 2021 and Dartmouth ENGS 37 notes\nCatalog version: 2026-10-20\n\nSizes: see table below\n- Reference geometry from published ratios; no efficiency claim. A reverse-flow cyclone is sized by its barrel diameter D: every other dimension is a fixed ratio of D for a given family. Gas enters tangentially through a rectangular inlet, spirals down the barrel and cone, and leaves upward through the vortex finder; the separated dust leaves through the bottom outlet.\n- Stairmand (1951) high-efficiency and Lapple (1951) conventional ratios as tabulated by Utikar et al. (2010, after Leith & Licht 1972), Grave et al. (2021, Stairmand only) and Cushman-Roisin (Dartmouth, after Cooper & Alley). Utikar et al. print the Lapple cylinder height as 1 D; the other tabulation prints 2 D with a 2 D cone and H = 4 D, which is what is used here.\n- Files: D = 100 and 150 mm for both families. D, a, b, De, S, h, H and B are gas-side (inside) sizes; the wall is added outside them. The wall (2 mm, normal to the cone too) and the inlet duct run (1 D from the barrel centre plane, open end) are example parameters, not part of the published ratios. The vortex finder is a plain tube De inside, flush with the top of the roof; the inlet's outer wall is tangent to the barrel and its top is level with the roof.\n- Material-neutral: the files are shapes. Wall thickness, joints and outlet connections are yours to choose.\n\ndimension  Stairmand HE  Lapple  Stairmand at D = 100 / 150  Lapple at D = 100 / 150\na: inlet height  0.5 D  0.5 D  50 / 75 mm  50 / 75 mm\nb: inlet width  0.2 D  0.25 D  20 / 30 mm  25 / 37.5 mm\nDe: vortex finder (gas outlet) diameter  0.5 D  0.5 D  50 / 75 mm  50 / 75 mm\nS: vortex finder length below the roof  0.5 D  0.625 D  50 / 75 mm  62.5 / 93.75 mm\nh: cylinder (barrel) height  1.5 D  2 D  150 / 225 mm  200 / 300 mm\nH: overall height, roof to dust outlet  4 D  4 D  400 / 600 mm  400 / 600 mm\nB: dust outlet diameter  0.375 D  0.25 D  37.5 / 56.25 mm  25 / 37.5 mm\ncone height (H − h)  2.5 D  2 D  250 / 375 mm  200 / 300 mm\n\nFiles elsewhere (not hosted by Xem Studio; license as stated by the publisher):\n- InTech (open access): Utikar et al., Hydrodynamic Simulation of Cyclone Separators, in Computational Fluid Dynamics (2010), Table 1 — web — Open access chapter; ratios are facts — https://cdn.intechopen.com/pdfs/6738/InTech-Hydrodynamic_simulation_of_cyclone_separators.pdf\n- EPJ Web of Conferences (open access): Grave, Paulo, Petit, Irassar, Optimal design of cyclones in series ..., EPJ Web Conf. 249, 12003 (2021), Table 1 — web — CC BY 4.0; ratios are facts — https://www.epj-conferences.org/articles/epjconf/pdf/2021/03/epjconf_pg2021_12003.pdf\n- Dartmouth College (ENGS 37 course notes): B. Cushman-Roisin, Cyclones: standard cyclone dimensions (Stairmand 1951, Lapple 1951, Swift 1969) — web — Publisher's page; dimensions are facts — https://cushman.host.dartmouth.edu/courses/engs37/Cyclones.pdf\n\nFree files (CC BY 4.0, Xem Studio; STEP + STL, 4 parts): https://xemstudio.com/files/hardware/cyclone-separator-proportions/index.json\nAPI: https://xemstudio.com/api/geometry?object=cyclone-separator-proportions\n",
 "sources": [
  {
   "publisher": "InTech (open access)",
   "title": "Utikar et al., Hydrodynamic Simulation of Cyclone Separators, in Computational Fluid Dynamics (2010), Table 1",
   "url": "https://cdn.intechopen.com/pdfs/6738/InTech-Hydrodynamic_simulation_of_cyclone_separators.pdf",
   "formats": [
    "web"
   ],
   "license": "Open access chapter; ratios are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "EPJ Web of Conferences (open access)",
   "title": "Grave, Paulo, Petit, Irassar, Optimal design of cyclones in series ..., EPJ Web Conf. 249, 12003 (2021), Table 1",
   "url": "https://www.epj-conferences.org/articles/epjconf/pdf/2021/03/epjconf_pg2021_12003.pdf",
   "formats": [
    "web"
   ],
   "license": "CC BY 4.0; ratios are facts",
   "license_verified": true,
   "hosted": false
  },
  {
   "publisher": "Dartmouth College (ENGS 37 course notes)",
   "title": "B. Cushman-Roisin, Cyclones: standard cyclone dimensions (Stairmand 1951, Lapple 1951, Swift 1969)",
   "url": "https://cushman.host.dartmouth.edu/courses/engs37/Cyclones.pdf",
   "formats": [
    "web"
   ],
   "license": "Publisher's page; dimensions are facts",
   "license_verified": true,
   "hosted": false
  }
 ],
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 },
 "related": [
  "schedule-40-pipe",
  "silicone-tube"
 ],
 "fits": [],
 "dimensions": "exact (nominal, no printing tolerance)",
 "dimension_rule": "All geometry on Xem Studio is exact (nominal, true size) with no printing tolerance. Where a part meets another part, the object lists its mating features (feature, exact size, what it mates with, fit class: press, slide, run, socket, clamp or designed). Apply your process's allowance to those features only; 'designed' gaps are part of the design and stay as drawn.",
 "mating": [],
 "faq": [
  {
   "q": "What are the Stairmand high-efficiency cyclone proportions?",
   "a": "Inlet 0.5 D high × 0.2 D wide, vortex finder 0.5 D diameter and 0.5 D long, barrel 1.5 D, overall 4 D, dust outlet 0.375 D."
  },
  {
   "q": "How does the Lapple cyclone differ?",
   "a": "Wider inlet (0.25 D), longer vortex finder (0.625 D), taller barrel (2 D), smaller dust outlet (0.25 D); same 0.5 D inlet height, outlet and 4 D overall."
  }
 ],
 "files_license": null,
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   "file": "cyclone-stairmand-d100",
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   "stl": "https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-stairmand-d100.stl",
   "note": "Stairmand high-efficiency proportions at D = 100 mm (inside): tangential rectangular inlet, vortex finder, cone to the dust outlet; example wall 2 mm, inlet duct run 1 D; reference geometry, no efficiency claim"
  },
  {
   "file": "cyclone-stairmand-d150",
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   "stl": "https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-stairmand-d150.stl",
   "note": "Stairmand high-efficiency proportions at D = 150 mm (inside): tangential rectangular inlet, vortex finder, cone to the dust outlet; example wall 2 mm, inlet duct run 1 D; reference geometry, no efficiency claim"
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  {
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   "stl": "https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-lapple-d100.stl",
   "note": "Lapple conventional proportions at D = 100 mm (inside): tangential rectangular inlet, vortex finder, cone to the dust outlet; example wall 2 mm, inlet duct run 1 D; reference geometry, no efficiency claim"
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   "stl": "https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-lapple-d150.stl",
   "note": "Lapple conventional proportions at D = 150 mm (inside): tangential rectangular inlet, vortex finder, cone to the dust outlet; example wall 2 mm, inlet duct run 1 D; reference geometry, no efficiency claim"
  }
 ],
 "markdown": "https://xemstudio.com/objects/cyclone-separator-proportions/index.md"
}