În industria actuală, există o mare varietate de schimbătoare de căldură ; având în vedere reducerea distribuţiei transferului termic între purtători cu temperaturi de până la 1800 0 C şi presiuni până la 5 bari, se propune un nou schimbător, unul recuperativ gaz-gaz, în contracurent, construit din beton. Funcţionarea sa poate fi extinsă chiar la agenţi sub 100 0 C. Investiţia în schimbător se recuperează în 4 luni de funcţiune, costul fiind 20 % din cel al unui schimbător metalic echivalent

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... nă la 500 0 C) şi doar cu 30 % mai mare. Pentru temperaturi înalte, schimbătorul propus nu are rival. Există o arie largă de aplicare. In the actual industry, there is a great variety of heat exchangers and in order to reduce dramatically the distribution of heat transfer between carriers with temperatures up to 1,800˚C and pressures up to 5 barr, we propose a new one-a recuperative gas-togas heat exchanger in counterflow, made by concrete. Its operation can be extended down below 100˚C. The investment in this exchanger is recovered in less than 4 months of operation, being 20% of the amount requested by an equivalent metallic exchanger (up to 500˚C) and its size is only 30% larger. For higher temperatures, there is no rivalry. It can find a wide range of applications. The proposed heat exchangers might be surprinsing for specialists, because it is made with concrete, a material considered unsuitable for gas-togas heat exchangers. However, a closer investigation finds it usable in a wide range of temperatures, with different types of cement. It is well known that, in the majority of cases, the global thermal resistance of a wall against gases on both faces is higher than 40-1 K·m 2 / kW [1][2], while the one of a concrete wall 15 mm thick is 12-1 K·m 2 / kW. Therefore the heat transfer through the surface of a metallic wall is comparable to the one through a