| 摘要 |
<p>The system comprises a shell and tube heat exchanger in which the exhaust air is passed through the tubes to transfer heat to fresh air on its way to the air heater of the spray dryer. The tubes are set in an inlet tube plate so that each tube axis passes through a corner of an equilateral triangle having its other corners similarly occupied by adjacent tube axes. The entry coaxially with the tube. The major dia. of each countersink lies on a circle, real or imaginary, having a radius equal to between 0.500 and 0.577 times the length of a side of the equilateral. The conical countersink pref. has an apex angle of 90 degrees (pref. 60 degrees). Air exhausted form the gaseous heat exchanger is pref. further cooled by passage through a liq. spray heat exchanger which washes out fine into a liq. which is warmed prior to evapn. in the spray dryer. The entries of the tubes in the shell and tube heat exchanger are no larger subject to blocking by damp powder. The liq. spray heat exchanger reduced loss of heat and fines to atmos., improving prod. yield and saving energy.</p> |
