抄録
(1) Residence time distribution function E(t) in continuous degassing reactor was theoretically derived from the assumption that mixing in vessel was expressed as recirculation model with plug flow and perfect mixing.
The equation was shown as follows:
E(t)=d∑∞n=0bn/n!{t-(h+nc)}n·e-a{t-(h+nc)}
t≥h+nc
The constants were determined by flow rate at inlet υ, circulating rate υ1, real flow rate in flow bath υ2, volume of vacuum bath V1, and volume of flow bath V2; The constants are shown as follows:
θC=V1/υ1, θB=V2/υ2, a=1/(1-p)θC, b=υ2/υ1(1-p)θC
c=pθC+θB, d=υ/υ1(1-p)θC, h=pθC
p is plug flow ratio in vacuum bath.
(2) Mixing characteristics in model apparatus were measured by concentration pulse response under similarity of Fr number and Re number.
The results of measurement of pulse response and tracing of flow pattern showed the presence of minor part of by-passing and dead space, and showed relatively close agreement with the above-mentioned theoretical equation.
(3) From these results, percent conversion of continuous degassing under assumption of perfect mixing in reators was estimated and it was in approximate agreement with the results of RH degassing process when mean residence time was properly selected and at least two unit reactors were connected in series.
