Thermoacoustic heat exchangers, hot and cold, parallel plate, for 1.5, 2 and 3 in tri-clamp spools — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/thermoacoustic-heat-exchanger/  (CC BY 4.0)
Basis: Parallel-plate heat exchangers on both stack faces (Swift), plate gap and thickness equal to the spiral stack's channel; disc drawn at the 16 ga tri-clamp spool bore (1.5 in = 34.8 mm, 2 in = 47.5, 3 in = 72.9)
Catalog version: 2026-10-20

Sizes: see table below
- A thermoacoustic stack only holds the temperature gradient; the heat exchangers on its two faces move heat into and out of the gas. The hot exchanger sits against the stack's hot face (the closed-end side of a λ/4 resonator), the cold one against the cold face, both inside the same spool bore.
- Each exchanger is a disc Ø34.8 / Ø47.5 / Ø72.9 (the 1.5 / 2 / 3 in spool bore, exact) × 10 mm long: a 1.0 mm outer ring holding parallel plates 0.4 mm thick at 1.4 mm pitch, one plate on the axis, 1.0 mm gas gaps between them. That is the spiral stack's 1.0 mm gap and 0.4 mm wall (stack-spiral-*-g1.0), so the gas channel keeps its width from stack to exchanger.
- The hot and cold files of a size are the same geometry; there are two so each stack face has its own. What they are made of, and how heat reaches the ring and plates, is the maker's choice: the file is the geometry.
- Exact dimensions: the disc OD is the spool bore with no allowance, listed under Mating features with its fit. Plate thickness, gap and ring width are design dimensions and stay as drawn.
- LES: I drew these for the stacks on this shelf: same spools, same 1.0 mm channel.

spool  bore_mm (= exchanger OD)  length_mm  ring_mm  plate_mm  gap_mm  pitch_mm  plates  open_area_pct
1.5  34.8  10.0  1.0  0.4  1.0  1.4  23  63.5
2  47.5  10.0  1.0  0.4  1.0  1.4  33  65.5
3  72.9  10.0  1.0  0.4  1.0  1.4  51  67.5

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Thermoacoustic heat engine — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine
- G. W. Swift (LANL): Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (textbook; DeltaEC software free) — web, software — LANL [verify license at link] — https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/
- Long Earth Society: Engine builds — web, video — LES site — https://longearthsociety.com/engineering/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 6 parts): https://xemstudio.com/files/hardware/thermoacoustic-heat-exchanger/index.json
API: https://xemstudio.com/api/geometry?object=thermoacoustic-heat-exchanger