dam ring

[A_Anton]

Пожалуйста, помогите перевести dam ring
Словосочетание встречается при описании конструкции цементной мельницы:
...mill terminates in a high dam ring provided with a central outlet opening
When passing this opening the cement will contain a small number of Minipebs, but these are allowed to separate in a small chamber located between the dam ring and the end of the mill
или
the fine-grinding compartment can have a classifying lining with dam rings,

Заранее спасибо