| 摘要 |
<p>Solns. esp. of sugar, are crystallised continuously in a vacuum vaporising process, the soln. being force fed through a heating chamber, whilst the mass formed and the steam produced are drawn off continuously. The whole of the mass and the vapour are brought together behind the heating chamber, and divided into two sections. The crystals of the required size finished granulate, are sepd. from the smaller granules with the mother liquor and steam, the vacuum being regulated so that the crystals can be isolated. The smaller granules with the syrup are returned to the heating chamber whilst the vapours from the chamber are vented. The grading is effected by passing the mass from the boiler across a perforated surface, so that the finished granulate remains above, whilst the smaller matter, fluid, steam, passes through teh screen to be recycled. The mixt. after sections have been withdrawn is re- introduced into the heating chamber at the bottom, and preformed crystals may also be added. Process makes better use of the reactor capacity and ensures a higher throughput of uniform and good crystal quality. Control can be exercised over the crystal growth so that its character can be suited to subsequent operations and a crystal size within a definite range be guaranteed.</p> |
