Tube bundle fix the drooped structures through welding for both ends of upper header and make fly ash drop by rapping the end plate of lower header.

锅炉中的管束是上部集箱的两端通过焊接固定垂下的结构，通过锤打下部集箱的端板，振落飞灰。

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A multitude of ring-shaped cracks and three water leakage points were discovered in the right side lower header of a boiler together with a cave-in of the boiler roof water-cooled wall.

锅炉右下集箱产生了很多环状裂纹和三个渗水点，同时顶棚水冷壁管塌陷。

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This means that routers strip off the Ethernet header upon reception of a packet, and then add a new lower layer header-ethernet or otherwise-when the packet is forwarded.

这意味着路由器在收到数据封包时就会去除以太网的数据头信息，加上低一层的数据头信息(以太网层或者其他层的)，然后发送给下一方。

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