| 165 / | HD | HEAT EXCHANGE |
| DIG 9 | DD | HAVING A SOLID HEAT STORAGE MASS FOR ABSORBING HEAT FROM ONE FLUID AND RELEASING IT TO ANOTHER (I.E. REGENERATOR) {5} |
| DIG 30 | | .~ Mass formed of modules arranged in three dimensional matrix ("Checkerwork") {4} |
| DIG 31 | DD | .~.~> Gradated flow area, heat capacity or conductivity |
| DIG 32 | DD | .~.~> Having gas supply or exhaust manifold structure {2} |
| DIG 35 | DD | .~.~> In casing |
| DIG 36 | DD | .~.~> Distinct passages formed in individual modules |