两个height如何理解(保护床)? at the bottom of d-1234 is packed with catalyst (zno) support with 600mm height from ground, it is made of norton denstone 57 or equal, the appearance likes ball with diameter 25mm. above the catalyst support is the zno catalyst bed with the height of 2000mm. (关于硫保护床) 600mm height 应该是catalyst (zno) support 的高度, the height of 2000mm应该是the zno catalyst bed 的高度! 仅供参考!查看更多