| 摘要 |
<p>A method of direct heating of a liq. medium contg. solid substances at high temps. by using heat of condensn. comprises partly vaporising the heated liq. medium by expansion in one or more stages and immediately condensing the vapour in the medium to be heated brought countercurrent, without using heat transfer agents foreign to the system. An appts. incorporates a reactor under pressure one or more heat exchange stages comprising an expansion receiver and a condensn. column which is in contact with the vapour compartment of the expansion receiver and which has distribution elements in it; a feed pump giving a rate regulated as a function of the level of the liq. at each heat exchange stage and at the reactor; a final cooling stage realised in the form of an expansion stage or a recuperator. Esp. applicable to pptn. or leaching reactions in aq. media at 150-250 degrees C, e.g. hydrolysis of iron, chromium and aluminium in aq. solns. of their sulphates in which heat must be recovered. Heat and material exchange processes take place immediately on the phase sepn. surfaces. The good heat transfer conditions allow a very compact construction. The appts. allows continuous treatment of solns which contain large quantities of incrustation forming agents.</p> |
