The second large-scale fertilizer plant in a factory was purchased and rebuilt in the early 1990s. It was repaired and matched, and after some expansion and transformation of some important static equipment, it was officially built and put into operation at the end of 1999. Its ammonia plant is based on natural gas and has a design capacity of 907 Kellogg process. Because the meteorological conditions, cooling water temperature, and natural gas conditions of the plant are significantly different from the original place of origin, the production capacity cannot meet the original design requirements. Among them, 101J air compressor is the bottleneck restricting the production of ammonia. In the case that changing operating conditions cannot be achieved, it can only be achieved through structural modification. To this end, on the basis of the structural transformation of the same type of equipment from another domestic manufacturer, the author proposes to achieve the purpose of transformation by replacing the impeller and adjusting the position of the baffle assembly on the premise of retaining the existing structural arrangement of the compressor. Therefore, capacity calculation and redesign of the compressor is required.
According to the original installation, operation and overhaul of the air compressor, the limiting factor for its inability to achieve design capability is that the plant is subject to geographical constraints, the local atmospheric pressure is 8713 kPa (a), the air is relatively thin, lower than the design conditions; It can be seen from the impeller blades that they are limited by the design and manufacturing conditions at that time; the micro-deformation of the cylinder caused by long-term idleness causes internal leakage and leakage. The 101J air compressor supplies process air to the ammonia converter reforming furnace. The characteristics are: steam turbine (101JT) drive, high and low pressure cylinders with gear speed increaser (101JG); high and low pressure cylinder impellers Straight row, balanced drum balance axial force; both use vaneless diffuser, the width is slightly smaller than the impeller exit blade width; all gas seals, shaft seals, oil seals are labyrinth seals; Sliding bearing, forced oil lubrication; In addition, in order to find out the ability of the air compressor under the current conditions, in addition to the operational assessment, it must theoretically calculate the capability from the above theoretical and practical analysis and calculation. It is known that the air compressor cannot meet the production needs in the existing environment.