Abstract: This incinerator circulates fumes to be incinerated through a heat exchange chamber; feeds the fumes into a combustion chamber; directs the incinerated fumes through heat exchange tubes to heat incoming fumes; scavenges fume leakage; and recirculates the scavenged fumes for incineration. Leakage of unincinerated fumes is controlled by use of a plurality of scavenging tubes positioned such that their orifices are proximate the hot end tube sheet within the combustion chamber to collect leaking fumes found near the hot end tube sheet and to feed those fumes back to the inlet for incineration.