EN-RU: chimney hat stage

[adelaida]

Прошу подсказать вариант перевода для "lower chimney hat stage" описания процесса грануляции карбамида:

UREA GRANULATION OPERATING MANUAL
...
Local purified process condensate supply valves for initial filling of the sump 1 and sump 2 of the
scrubbing system are provided. XXX should be open to supply flow via these local valves.

The lower demister package is placed above the sump 1 and sump 2. The lower chimney hat stage is
installed right above this lower demister package. These parts are installed in order to prevent excessive slip of concentrated urea droplets upward into the MMV stage. The lower chimney hat stage has a drain pipe to allow lean urea solution to pass to the sump 2 in the bottom of the column.

Этот "chimney hat stage" также встречается далее:
"The lower chimney hat stage has a drain pipe to allow lean urea solution to pass to the sump 2 in the bottom of the column."

"Above the venturi stage, an orifice plate, the middle demister package, followed by the upper chimney hat stage are installed."

Спасибо за любые идеи.
Спасибо.