Ammonia synthesis process, ammonia separation equipment, process parameters, thermal insulation

1. The selection of the design temperature usually requires taking into account the lowest and highest temperatures that the equipment may encounter during operation. For ammonia separators, -10°C is likely the lowest ambient temperature that the equipment may experience during winter or when it is shut down, while 70°C takes into account the high temperatures in summer, or the fact that the equipment may need to undergo maintenance tasks such as steam purging or chemical cleaning, which can raise the temperature inside the equipment to around 70°C. This temperature range ensures safe operation even under the most adverse conditions. 2. The value of the design pressure is generally determined based on the following considerations: – Maximum operating pressure: the pressure at which the equipment operates under normal conditions. - Safety factor: The design pressure is usually higher than the maximum operating pressure to provide a certain safety margin. - Regulations and standards: It is necessary to refer to relevant **or international standards and regulations, such as ASME, GB, etc. - Special operating conditions: situations such as startup, shutdown, emergency shutdown, and pressure surges during operation that may cause the instantaneous pressure to exceed the normal operating pressure. - Other engineering experience and manufacturer’s recommended values. Special operating conditions that need to be considered may include the system’s startup process, emergency shutdowns, process control failures, and the impact of external fire sources; all of these situations can lead to sudden and severe fluctuations in pressure and temperature. 3. Polyurethane foam (PU Foam) is a commonly used insulation material, featuring excellent insulating properties and a low thermal conductivity. It is suitable for various temperature ranges, especially in applications with negative and low temperatures. For the insulation of ammonia separators, considering their operating temperature and environment, polyurethane foam may be a suitable choice. However, the waterproofing and moisture resistance of polyurethane, as well as its stability under high-pressure conditions, also need to be considered. Polyurethane insulation can be applied on-site through foaming, or it can be prefabricated into modules. On-site foaming construction is typically suitable for situations with complex shapes or high requirements regarding on-site conditions, as it ensures that the insulation layer fits more closely to the surface of the equipment. Prefabricated modules, on the other hand, may be suitable for devices with standard shapes; they allow for quality control of the modules in a factory environment and reduce the time and difficulty of on-site construction. The appropriate construction method must be selected based on the actual project requirements, site conditions, and cost-benefit analysis. .