Oxidation synthesizing reactor for e.g. synthesis of phthalic acid anhydride, comprises diagonal-action impeller wheel with heat medium throttle gap parallel to shaft

摘要

Oxidation reactor (1) has a bundle of tubes (2) for flowing ingredients, surrounded by a heat chamber containing a heat medium. The upright heat chamber ends have inlet and outlets linked by a ring-flow (4, 5) pipes a pump (8) driven by a vertical shaft (9). Oxidation reactor (1) has a bundle of tubes (2) for flowing ingredients, surrounded by a heat chamber containing a heat medium. The upright heat chamber ends have inlet and outlets linked by a ring-flow (4, 5) pipes a pump (8) driven by a vertical shaft (9). The pump has diagonal-action impeller (10) blades with a heat medium (3) throttle gap (11) parallel to the shaft (9), on the pressure side of the pump. Some of the hot medium is drawn from the upper ring pipe (4), passes through one or more external heat exchangers, and is then returned to the lower ring pipe (5). The gap produces a leak current of preferably 5 to 10% of total flow (3). Some of the leaked (11) hot medium is surrendered to the pump inlet side. On the pump inlet side the impeller seal acts as a hydrodynamic bearing (13). The pump has a spiral egress. The reactor heat chamber incorporates a number of baffle plates (12).