The flow sheet and structure of 2 axial and 1 radial type and paralleled triple casing pipe type inner parts of converter are introduced.

Author has introduced the structure and process for ammonia converter internal with one axial and two radial beds, described process of the trouble occurred during start-up of the converter, analyzed the caused reason of trouble, and also introduced the maintenance/disposal method and improvement measures.

Design principle and structure characteristic were discussed for reformation of internals of ammonia converter with one axial and three radial beds, the filling of catalyst and its heating and reducing processes were introduced, summarization was also made for running situation of production and economic benefit after reformation.

This paper has carried out the non-contact measurement and relative measurement for the shaft diameter according to the property of the laser and the v-type block s centering automatically based on Fraunhofe single-gap diffraction principle .