Abstract: A refining process includes steps of subjecting crude caprolactam to a first evaporative crystallization and a first solid-liquid separation to obtain a first caprolactam crystal and a first crystallization mother liquor; washing the first caprolactam crystal to obtain a second caprolactam crystal; optionally concentrating the first crystallization mother liquor to perform a second evaporative crystallization and a second solid-liquid separation to obtain a third caprolactam crystal and a second crystallization mother liquor; subjecting the third caprolactam crystal to a second washing to obtain a fourth caprolactam; optionally concentrating the second crystallization mother liquor to perform thermostatic crystallization, performing separation to obtain a fifth caprolactam crystal and a third crystallization mother liquor; washing the fifth caprolactam crystal to obtain a sixth caprolactam crystal; and subjecting the second caprolactam crystal to a hydrogenation reaction.

Abstract: A refining process includes steps of subjecting crude caprolactam to a first evaporative crystallization and a first solid-liquid separation to obtain a first caprolactam crystal and a first crystallization mother liquor; washing the first caprolactam crystal to obtain a second caprolactam crystal; optionally concentrating the first crystallization mother liquor to perform a second evaporative crystallization and a second solid-liquid separation to obtain a third caprolactam crystal and a second crystallization mother liquor; subjecting the third caprolactam crystal to a second washing to obtain a fourth caprolactam; optionally concentrating the second crystallization mother liquor to perform thermostatic crystallization, performing separation to obtain a fifth caprolactam crystal and a third crystallization mother liquor; washing the fifth caprolactam crystal to obtain a sixth caprolactam crystal; and subjecting the second caprolactam crystal to a hydrogenation reaction.

Abstract: The present disclosure discloses a MFI topological structure silicon molecular sieve, a preparation method thereof and a catalyst containing the MFI topological structure silicon molecular sieve, wherein the molecular sieve containing a silicon element, an oxygen element and a metallic element, the ions of said metallic element have a Lewis acid characteristic; the content of the metallic element in the molecular sieve is within a range of 5-100 ?g/g based on the total amount of the molecular sieve; the BET specific surface area of the molecular sieve is within a range of 400-500 m2/g.

Abstract: An inspection system and method with a variable-diameter traveling robot for inspection of a natural gas pipeline. The inspection system includes a pipeline inspection robot, a cable reel, a hydraulic pump and an information acquisition control terminal. The pipeline inspection robot includes an electronic cabin and a traveling mechanism. The electronic cabin includes a first digital camera, a second digital camera, a first digital camera mounting plate, a second digital camera mounting plate, a drum, a printed circuit board, a magnetic flux leakage probe, and a backup battery. The traveling mechanism includes a first traveling part, a second traveling part, an inner ratchet, an inner ratchet base, a slider, a long shaft, a hydraulic cylinder, and a hydraulic pipe. The cable reel includes a power line, a conversion module, and a communication line. The information acquisition control terminal is a mobile terminal having an analysis module and a control module.

Abstract: An inspection system and method with a variable-diameter traveling robot for inspection of a natural gas pipeline. The inspection system includes a pipeline inspection robot, a cable reel, a hydraulic pump and an information acquisition control terminal. The pipeline inspection robot includes an electronic cabin and a traveling mechanism. The electronic cabin includes a first digital camera, a second digital camera, a first digital camera mounting plate, a second digital camera mounting plate, a drum, a printed circuit board, a magnetic flux leakage probe, and a backup battery. The traveling mechanism includes a first traveling part, a second traveling part, an inner ratchet, an inner ratchet base, a slider, a long shaft, a hydraulic cylinder, and a hydraulic pipe. The cable reel includes a power line, a conversion module, and a communication line. The information acquisition control terminal is a mobile terminal having an analysis module and a control module.