Autoclave Flash Vapour Condensers are designed similar to direct contact hot water heaters. AHL’s autoclave flash vapour condenser technology is a direct development of our 60 years of experience in the design and supply of vent gas heat recovery and batch blow heat recovery to the pulp and paper industry. The unit can be provided for counter-current gas flow or co-current downward flow orientation. The system may include a venturi scrubber to precede the condenser if particulate is an issue.inclined horizontal position, to accommodate safe removal of any gases possibly released from the chlorine dioxide solution.