Arrangement for producing a gas flow which is enriched with the vapor of a low-volatile substance

Claim 1

A heatable arrangement for producing a gas flow which is enriched with the vapour of a low-volatile, pulverulent substance, and which gas flow comprises an inert gas, the arrangement comprising: a vessel having an interior space (12) for holding a powder bed a powder bed (13) comprising said low-volatile pulverulent substance positioned in said interior space a feed pipe (6) for the gas flow and a discharge pipe (19) for discharging the enriched gas flow into a reactor, the feed and discharge pipes each having a valve and the pipes ending in the vessel in such a manner that when the arrangement is operative, the gas flows through the powder bed, the vessel (1) and the discharge pipe (19) being provided in a thermostatically controlled bath (2), the powder bed (13) including at least one additional solid inert component, the interior space (12) having two walls which are arranged transversely of the gas flow (4, 16) and are formed by a gas inlet plate (10) and a gas outlet plate (14) both of said plates (10, 14) being gas permeable porous plates the outer walls of the interior space being impermeable to gas, characterized in that, the cross-sectional area of the interior space (12) is at least a hundred times larger than the cross-sectional area of the feed and discharge pipes (6, 19), the gas inlet plate (10), is arranged between the orifice of the feed pipe (6) and the powder bed (13), the gas outlet plate (14) is arranged between the powder bed (13) and the orifice of the discharge pipe (19), at least one of the two plates is movable in a manner such, that, the arrangement being operative, it is pressed into the powder bed (13), the thickness of the gas inlet plate (10), the thickness of the gas outlet plate (14), the pore size of the two plates (10, 14) and the spacing between the two plates (10, 14) or the thickness of the powder bed (13), respectively, in the interior space (12) are chosen such that, the arrangement being operative, the pressure drop in the gas inlet plate (10) exceeds the pressure drop in the powder bed (13), the pressure drop in the powder bed (13) is much higher than the pressure drop in the gas outlet plate (14), and the pressure drop in the gas outlet plate (14) is much less than the pressure in the reactor.