Ammonia storage tank (also called ammonia tank) is a special fixed pressure vessel for liquid ammonia. The saturated vapor pressure of storage medium is less than or equal to 2.03MPa at 50℃. And the design pressure is generally 2.16MPa. It is mainly used for indoor static storage of liquid ammonia. STRENGTH can produce ASME, CE(PED), GB150 (Chinese standard) liquid ammonia storage tanks. The tanks are generally used in desulfurization and denitrification projects of larger coal-fired boilers and biomass boilers, or in chemical enterprises that use ammonia as raw materials, etc.
During the use of liquid ammonia storage tank, reliable measures should be taken in all links of the whole quality assurance system from design, manufacture to use, as follows:
① Material selection. Practice has proved that the higher the material strength, the greater the possibility of stress corrosion. In order to prevent stress corrosion, the steel with lower strength should be selected as far as possible under the condition of comprehensive consideration of operating pressure, residual stress, safety and economy.
②The liquid ammonia storage tank adopts reasonable structure and welding process. Structurally, stress concentration caused by excessive welds, excessive concentration, asymmetric welds, intersection of welds and unreasonable welding sequence should be avoided. Manufacturing should avoid strong welding, to prevent biting side, wrong side and other defects, to ensure that the surface contact with the medium as smooth as possible. After fabrication, annealing treatment should be carried out to remove residual thermal stress after welding. Proper post-weld heat treatment can greatly reduce the residual stress in the manufacturing process and reduce the peak hardness of the weld heat affected zone.
③The air in the new liquid ammonia storage tank should be completely cleared before it is put into use. For example, in the process of filling, discharging and maintenance, take certain measures to avoid bringing in any air. As for large tanks, ammonia vapor should be continuously condensed. while the non-condensing gas is mostly air, which should be discharged. For smaller ammonia tank, air is removed from tanks by extraction or transpiration. In short, stress corrosion can be effectively prevented by eliminating air pollution in storage tanks.
④For the newly put into use liquid ammonia storage tank, internal and external inspection and periodic periodic inspection shall be carried out according to the provisions. Then the liquid and gas phase interface, arc starting and closing, type joint and other corrosive parts should be inspected. All welds below the liquid level should be tested by MT or UT. If conditions permit, all welds should be tested by MT.
⑤Regularly check the ammonia concentration and water content of liquid. If the water content is lower than the critical concentration, water should be added in time to keep the water content within the range.
Liquid ammonia storage tank often adopts dual system control, local instrument display and remote signal acquisition combined, including the application of MIOT system, leakage alarm, low liquid level alarm, misoperation alarm, emergency cut-off system and so on, a complete set of intelligent control system has the characteristics of simple operation, low failure rate, high safety.
About STRENGTH Equipments
Taian STRENGTH Equipments Co., Ltd is the professional pressure vessel designer, manufacturer and exporter dedicated in supplying finest quality industrial autoclave, storage tank and dish head products and solutions to worldwide customer over 20 years. We have over 80 talented research and development experts, 2 million square meters manufacturing factory and more than 50 sets large-scale manufacturing machines. Our annual industrial autoclave and storage tank output can reach over 300 sets, dished head output can reach over 3000 sets.
STRENGTH Equipments is not only manufacturing high quality industrial autoclaves, storage tanks and dished ends but also providing custom product design, fabrication and after-sale service. ODM, OEM are also available. If you have any questions or inquiries, please fill and submit the following form, we will reply as soon as possible.
