Furnace and back-end enclosurewall all adopt membrane wall structure. The outside of tube wall is insulation material and is covered with trapezoid corrugated outer protection plate.
炉膛及尾部包墙均采用膜式壁结构，管壁外侧为保温材料并罩上梯形波纹外护板。
2
This enclosure was so vast that the outermost wall could hardly be seen.
这块圈地大得几乎看不见它最外面的围墙。
《柯林斯英汉双解大词典》
3
The entrance is shielded by a long, heavy, elevated wing wall that not only forms part of the ground floor and sideboard enclosure but also embraces an interior courtyard with an entry pond.