Fiat Societa Per Azioni

Centro Ricerche Fiat S.p.a.

Giacomo Grasso

The characteristics of a gas-liquid heat exchanger are described, for particular use in the production of hot or superheated water by means of the exhaust gases emitted through the chimneys of a thermal treatment furnace, comprising an internal tubular element, for the passage of the gases, surrounded by an external tubular element which defines an annular chamber through which a liquid flows in counter-current to the flow of the gases in the internal tubular element. The latter is provided on its external surface and on its internal surface with radial fins, angularly equidistant from each other, extending axially for a substantial portion of the length of the internal tubular element. The height of each radial fin decreases linearly, both on the side exposed to the gas, and on the side exposed to the liquid, in the opposite direction to that of the flow of the fluid intended to come into contact with the fin, so as to enhance the heat exchange, while the same time avoiding damage through overheating of the said fin and of the wall of the internal tubular element.

Gas-liquid heat exchanger

A recuperator for recovering heat from hot exhaust gases flowing through a flue comprises inner and outer cylindrical walls coaxially surrounding a portion of the flue to which a plurality of fins are fixed, the fins extending longitudinally of the flue and being grouped such that fins spaced circumferentially around one section of the flue are angularly staggered with respect to fins spaced circumferentially around an adjacent section of the flue, the recuperator being arranged such that cold gas can be passed into, and is preheated as it flows along, an outer annular space between the said walls, the gas passing into an inner annular space containing the fins which cause turbulence and increase the heat-transfer by convection and radiation to the gas, and the heated gas being emitted through an outlet.

Growing community of inventors

Moncalieri, Italy

Giacomo Grasso