# Cyclone separator proportions: Stairmand high-efficiency and Lapple conventional

> What are the standard cyclone separator dimensions (Stairmand, Lapple) as ratios of the barrel diameter?

- Category: Tools & garage › Bench & craft machines
- Kind: Standard part
- Basis: Published ratios: Stairmand 1951, Lapple 1951, as tabulated in Utikar et al. 2010, Grave et al. 2021 and Dartmouth ENGS 37 notes
- Page: https://xemstudio.com/objects/cyclone-separator-proportions/ · JSON: https://xemstudio.com/api/geometry?object=cyclone-separator-proportions · Plain text: https://xemstudio.com/objects/cyclone-separator-proportions/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## 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.

## Sizes

| dimension | Stairmand HE | Lapple | Stairmand at D = 100 / 150 | Lapple at D = 100 / 150 |
|---|---|---|---|---|
| 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 |

## Where the files are

- InTech (open access): [Utikar et al., Hydrodynamic Simulation of Cyclone Separators, in Computational Fluid Dynamics (2010), Table 1](https://cdn.intechopen.com/pdfs/6738/InTech-Hydrodynamic_simulation_of_cyclone_separators.pdf) — web — Open access chapter; ratios are facts
- EPJ Web of Conferences (open access): [Grave, Paulo, Petit, Irassar, Optimal design of cyclones in series ..., EPJ Web Conf. 249, 12003 (2021), Table 1](https://www.epj-conferences.org/articles/epjconf/pdf/2021/03/epjconf_pg2021_12003.pdf) — web — CC BY 4.0; ratios are facts
- Dartmouth College (ENGS 37 course notes): [B. Cushman-Roisin, Cyclones: standard cyclone dimensions (Stairmand 1951, Lapple 1951, Swift 1969)](https://cushman.host.dartmouth.edu/courses/engs37/Cyclones.pdf) — web — Publisher's page; dimensions are facts

## Free STEP/STL (4 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/cyclone-separator-proportions/index.json

- cyclone-stairmand-d100: [STEP](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-stairmand-d100.step) · [STL](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-stairmand-d100.stl) — 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
- cyclone-stairmand-d150: [STEP](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-stairmand-d150.step) · [STL](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-stairmand-d150.stl) — 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
- cyclone-lapple-d100: [STEP](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-lapple-d100.step) · [STL](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-lapple-d100.stl) — 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
- cyclone-lapple-d150: [STEP](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-lapple-d150.step) · [STL](https://xemstudio.com/files/hardware/cyclone-separator-proportions/cyclone-lapple-d150.stl) — 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

## Questions

**What are the Stairmand high-efficiency cyclone proportions?**

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.

**How does the Lapple cyclone differ?**

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.

## Fits with

- [Schedule 40 pipe and PVC fittings, 1/2 to 2 inch](https://xemstudio.com/objects/schedule-40-pipe/)
- [Silicone tube 1 × 3 to 10 × 14 mm (ID × OD)](https://xemstudio.com/objects/silicone-tube/)