Fig 1.
Structure of Helmholtz-type pulse combustor.
Fig 2.
Working cycle of Helmholtz-type pulse combustor.
Fig 3.
Structure of the steam boiler.
(a) Overall structure; (b) Detailed structure. 1. fuel tank 2. spark plug 3. carburetor 4. high-voltage generator 5. air pump 6. throat 7. combustion chamber 8. base frame 9. tailpipe 10. water inlet 11. drainage port 12. decoupling chamber 13. bellows 14. maintenance hatch 15. left end cap 16. water level gauge 17. steam outlet 18. steam dome 19. tank body 20. right end cap 21. water.
Fig 4.
Heat transfer pathway.
Fig 5.
Three stages of heat transfer.
Fig 6.
(a) Front cutaway view; (b) Left cutaway view; (c) Photo. 1. connection flange 2. branch pipe 3. main pipe 4. spark plug mounting base.
Fig 7.
Structure diagram of tailpipe.
Fig 8.
Optimal parameters.
Fig 9.
Optimal parameters range.
Table 1.
Nodes coordinates.
Fig 10.
Mesh of optimal parameters range.
Fig 11.
Three sets of meshes of Group l.
(a) Coarse mesh; (b) Medium mesh; (c) Fine mesh.
Fig 12.
Results of the mesh sensitivity analysis: Evolution of the volume-weighted average temperature.
Fig 13.
Deviation in heating duration (Δt) from the mean value across 12 simulation group, with the 95% confidence interval of the overall mean duration.
Fig 14.
Temperature distribution in Group i.
(a) 100s; (b) 200s; (c) 300s; (d) 400s.
Fig 15.
Temperature distribution in Group k.
(a) 100s; (b) 200s; (c) 300s; (d) 400s.
Fig 16.
Structure diagram of soil steam disinfector.
Fig 17.
(a) Single-layer needle; (b) Double-layer needle; (c) A-A direction, B-B direction, C-C direction. 1. steam piping 2. needle base 3. sealing gasket 4. spacer 5. conical tip 6. steam outlet 7. needle tube.
Fig 18.
Layout of temperature measuring points.
(a) Depth direction; (b) Horizontal direction.
Fig 19.
Field experimental setup.
Fig 20.
Temperature profiles under 3-minute steam injection protocol.
(a) Single-layer needle treatment; (b) Double-layer needle treatment.
Table 2.
Duration maintained within specific temperature ranges.
Table 3.
Two-way ANOVA results for the effect of needle design and treatment time on the duration of temperatures ≥80 °C.
Table 4.
Ranges of soil-borne pathogens and pests controlled by different techniques.