Manufacturing Process And Material Selection Of Nitrate Equipment

Nitric acid is one of the commonly used chemical materials in industry.In the production process of nitric acid,due to its strong oxidation and corrosion resistance,it has great harmful to the production equipment.Pipes,fittings and valves,which have the same problems that is short lives and have an effect on the normal production.The most advanced production method of nitric acid is Dual – pressure,but it also has many problems,Experts of various countries are constantly studying to solve this problem.Taking the nitric acid production plant of Hubei San Ning Chemical Co.,Ltd as our research target,the nitric acid equipment is designed by Tianjin Huajing Chemical New Technology Development Co.,Ltd.This company developed the latest Dual-pressure Nitric Acid production technology.Although the crafts is the most advanced,the absorber cooling coils and trays still have corrosion problems,the Low pressure reactor Water Cooler also has the same problem.This paper firstly describes the traditional production of nitric acid plant process and equipment,proposed the dangerous of nitric acid production.Secondly,it introduced the operating conditions and characteristics of Nitric acid absorption tower and low pressure reaction water cooler in Dual-pressure Nitric Acid production.By analyzing the two devices,we found that the stress corrosion of Claccumulation,temperature stress corrosion,the erosion of high temperature condensate acid and other corrosion damage are eventually leading to the cooling coil,trays and heat transfer tubes,tube sheet corrosion leaks.At the same time there is not convenient to repair and the maintenance costs is too high.Finally,this paper proposes a cooling water quality assurance,re-select high quality raw materials,optimizing the structure of the infrastructure,the use of advanced manufacturing technology and a series of optimized and improved measures to effectively solve the current absorber and low reaction water coolers corrosion,extended the lives of many devices.Through the process optimization and transformation,it has greatly improve the production efficiency of the nitric acid plant,while ensuring product quality andyield,reduced equipment maintenance costs,Lay the foundation for the further promotion of industrialization.