scroll case（蜗壳）是什么意思？音标发音+图解场景

蜗壳 /ˈskɹeɪpə ˈbɑː ˈhəʊldə/ n

English: scroll case · 蜗壳

释义：Duct shaped like a spiral staircase that is used to distribute water uniformly around the turbine to make it turn smoothly.

这个词出现在以下图解场景（1）