SECTION I(b)
(13) New Reactor Design
(b) Lurgi M.P. Oven. (See reference I(b)/42 at end of this section).
The use of Fe catalysts required the construction of ovens which could stand the 20-30 atm. pressure on the catalyst side and at the same time the somewhat higher pressure on the steam side (up to 60 atm.). The arrangement proposed by Lurgi consisted simply of the conventional LP plate oven installed on a horizontal HP drum. One head of the drum is flanged and the cooling coil is connected to that head. For filling and removal of the catalyst, the flange is opened and the head with the entire catalyst and cooling system is drawn out of the pressure drum.
The plate bundle itself is enclosed in a thin sheet jacket to prevent flashing of the pyrophoric catalyst, when the bundle is drawn. The same difficulties in filling and removing of catalyst usually experienced in the LP oven will have to be met in this design.
A pilot unit of this type, containing 7 m3 catalyst and operating at 20 atm. was installed at the gasworks near Boehlen-Rotha. The unit was to be studied to possible use in detoxification of city gas (and of course, FT). Only one run had been made at the unit and the oven apparently performed well. No detailed operating data were available, but the pilot unit had been designed to operate at space velocities up to 400 FV/H/V (including recycle gas). The gas enters the top of the basket containing the catalyst and passes down through the bed. The bottom of the basket is connected to the exit nozzle of the pressure vessel by means of a special expansion joint.