Patent ID: 7909005

Claim:
Condensation heat exchanger, associated with a gas or fuel burner, which comprises two tubular bundles, one called a “primary” bundle, and the other called a “secondary” bundle, wherein each of said two bundles consists of a tube, or a group of tubes, with a generally cylindrical shape, which two bundles are arranged side-by-side, with their axes (A-A′, C-C′) parallel, and are mounted securely inside a gas-tight casing, and communicate with one another, with means being provided for circulating a fluid to be heated, in particular cold water, between the tube(s) constituting the secondary bundle and the tube(s) constituting the primary bundle, which casing surrounds the two tubular bundles, and has a discharge sleeve for burned gases, wherein a cylindrical burner is housed coaxially inside the primary bundle, which exchanger is thus arranged so that the hot gases generated by the burner pass radially, or approximately radially, first through said primary bundle, from the inside to the outside, then said secondary bundle, this time from the outside to the inside, so as to then be discharged from the exchanger through said sleeve, characterized in that: it comprises a third primary tubular bundle, called an “additional” bundle, consisting of a tube, or a group of tubes, with a generally cylindrical shape, arranged next to the secondary bundle, with their axes parallel (B-B′, C-C′), and securely mounted inside said casing; a cylindrical burner is housed coaxially inside the additional primary bundle; this additional primary bundle communicates at least with the secondary bundle, means are provided for circulating the fluid to be heated, in particular cold water, between the tube(s) constituting the secondary bundle and the tube(s) constituting the additional primary bundle, which exchanger is thus arranged so that the hot gases generated by the burner pass radially, or approximately radially, first through said primary bundle, from the inside to the outside, then said secondary bundle, this time from the outside to the inside, so as to then be discharged from the exchanger through said sleeve; said casing is subdivided at the level of the secondary bundle by means of a partition that extends both inside and outside of said bundle, with the arrangement being such that a circumferential section of the secondary bundle only is capable of being contacted and traversed by the hot gasses generated by the burner of the primary bundle, while the remaining section is capable of being contacted and passed through only by the hot gases generated by the burner of the additional primary bundle.