Study And The Corresponding Measures On Problem Existing In Primary Reformer Of Braun Process Ammonia Plant

The primary reformer is used to reform material gas steam into process gas (H2 included).As to large ammonia plant, the capital of primary reformer is 30% of total investment. It is also the key equipment that has an effect on operation of the whole system with safety, stability and supper operation load in good conditions in a long term, therefore, the primary reformer plays an important role on either investment or the whole manufacture program.Jianfeng Chemical Ammonia Plant is designed with capability output 1000t liquid ammonia per day, adopted American energy-saved type Braun technology and the primary reformer is the ladle and stag type one supplied by French Fostee Wheeler Co..This article introduces the Braun ammonia technology process at first ,emphases on the primary reformer process and characteristics of frameworks of equipment, and also introduces the failtures which have ever happened in the primary reformer since the factory put into stream 12 years ago and the reasons of the failures and corresponding measures etc..This article discusses the condition at present and the problem existing in primary reformer in Jianfeng Chemical Plant. The problem focus on the temperature of bottom convection part of primary reformer and the reformer pipe surface is high and not distributed evenly, and the total heat efficient is so low thatit is not compatible for supper operation load operation, etc. Making use of the relevant software (main Braun process ammonia technology calculation software) to carry out theory calculation of the quantity of materials and quantity of heat,on the basis of the calculation results, the author analyze the problem existing in primary reformer, and draw a conclusion that the designation is very different from the actual status; it is distributed unreasonably that the gas from air compressor turbine enteres the radiation part and convection part; the heat loss is large in radiation part of the primary reformer; and the ability of attraction air machine is not sufficient and so on . According to these details of analysis, the corresponding measures are given out: replacing the fireproof materials in primary reformer with high quality and high efficient ones to reduce the heat loss; setting up a dust filter on waste gas pipeline and brushing the pipeline at regular intervals to get the surface temperature of reformer down; optimizing process operation to get the bottom temperature of convection part down; choosing suitable catalyst type and scientific filling method to make the surface temperature of reformer pipe distribute evenly; adding a guided plate in transition section to make the bottom temperature of convection part distribute evenly; and adding a pre-reformer before the primary reformer ,which can increase 10% operation load in safe and stable conditions.At the end of this article, some relevant suggestions are advanced for the normal maintenance of the primary reformer during daily operation.