The sparging of {TAIL ~ the gas bubbles} is the main mechanism for mixing, catalyst suspension, and {HEAD ~ dispersion} 
The sparging of { TAIL ~ the gas bubbles } is the main mechanism for mixing , catalyst suspension , and { HEAD ~ dispersion }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD