Patent ID: 8475728

Claim:
A mixing and distributing device for a first gas and a second gas located upstream of a catalytic zone having an inlet section Ωr, said device comprising: a plurality of internal chambers (I) each with a diameter D 1 , an external chamber (II) with a diameter D 2 enveloping the plurality of internal chambers (I), the density of internal chambers (I) being in the range 10 to 500 per m 2 of the external chamber (II), each internal chamber (I) having an enlarged lower (III) zone terminating in an outlet section Ωs, each internal chamber (I) being provided with an inlet pipe (E 1 ), and the external chamber (II) being provided with an inlet pipe (E 2 ) and a perforated plate having orifices, the perforated plate ( 1 ) positioned at a lower distance H 2 in the range 20 mm to 300 mm with respect to the inlet pipe (E 2 ), and with a pitch between the orifices in the perforated plate ( 1 ) being in the range of D′/3 to D′/10, wherein D′ is defined as the difference between the pitch of the distance separating the internal chambers (I) and the diameter D 1 of each internal chamber (I), the external chamber (II) communicating with each of the internal chambers (I) via a series of orifices ( 2 ) pierced in the wall of each internal chamber (I) in a zone located at a distance H 1 with respect to the inlet pipe (E 2 ), H 1 being substantially equal to twice H 2 ; and the angle (α) of the walls of the enlarged lower zone (III) with respect to vertical being in the range 5° to 45°; and wherein the sum of the outlet sections Ωs of the internal chambers (I) is less than the inlet section of the catalytic zone Ωr, in which case the device further comprises a distribution chamber (IV) interposed between the outlet sections Ωs and the inlet section Ωr of the catalytic zone, said distribution chamber (IV) having a height H 3 in the range of 2 (D 1 ) to 50 (D 1 ), and when the sum of the outlet sections Ωs of the internal chambers (I) is less than the inlet section of the reaction zone Ωr, the distribution zone (IV) contains a jet breaker positioned at a height H 4 below the outlet section Ωs of each internal chamber (I) such that H 4 is in the range (D 1 )/4 to 2 (D 1 ).