How to reasonably select and use molecular sieves in gas drying

Adsorption dryers use molecular sieves to remove moisture from gases. When selecting and loading molecular sieves, the following points should be noted:

1. Careful selection of molecular sieves

Type matching:

Carefully select the type of molecular sieve according to the characteristics of the gas to be treated and the required drying level. The 3A type molecular sieve, with its pore size of about 3Å, is designed for the drying of unsaturated hydrocarbons (such as ethylene, propylene, butadiene) in petroleum cracking gas; the 4A type, with its pore size of 4Å, is an ideal choice for deep drying of gases such as air, natural gas, alkanes and refrigerants; the 5A type molecular sieve is widely used in the dehydration, purification and desulfurization of air and natural gas; the 13X type molecular sieve, with its larger pore size and high adsorption capacity, is particularly suitable for the drying of non-polar molecules such as air and hydrogen.

Adsorption capacity optimization:

Fully consider the temperature and pressure changes in the operating environment, and select the molecular sieve that performs best under these conditions to ensure maximum adsorption efficiency.

Durability and regeneration capacity:

Prefer molecular sieves of brands such as XINTAO, whose excellent durability and efficient regeneration capacity ensure the stability and economy of long-term operation of the equipment.

2. Careful operation of the filling process

Uniform distribution: During the filling process, ensure that the molecular sieve particles are evenly distributed in the container to prevent airflow short circuit or oversaturation caused by local accumulation, thereby ensuring the balance of the overall adsorption effect.

Prevent powdering: Through appropriate compaction measures, the molecular sieve is prevented from powdering during the filling process, which helps to maintain its efficient adsorption performance and extend its service life.

Strict waterproofing: The molecular sieve must be kept absolutely dry before filling, and sealing measures must be taken to prevent it from absorbing moisture in the environment in advance and affecting the subsequent use effect.

Seal inspection: After completing the filling, conduct a strict sealing inspection on the dryer to ensure that there is no external moisture intrusion and to ensure the purity and dryness of the internal environment of the system.

3. Setting and adjustment of basic parameters

Operating pressure: Maintain within the appropriate range of 0.5~0.8MPa to ensure that the molecular sieve works under the best working conditions.

Operating temperature: According to the specific process requirements, the operating temperature is controlled between -20℃~50℃ to optimize the adsorption efficiency.

Regeneration temperature: In the micro-thermal regeneration equipment, according to the type and adsorption capacity of the selected molecular sieve, set a reasonable regeneration temperature (usually between 150℃~250℃) to ensure the complete regeneration of the molecular sieve.

Adsorption and regeneration cycle: According to the actual gas flow and water content, flexibly adjust the adsorption cycle (ranging from several hours to several days), and set the appropriate regeneration time (2~8 hours) to balance the processing efficiency and energy consumption cost.

By accurately selecting the molecular sieve model, carefully operating the filling process, and reasonably setting the basic parameters, the operating efficiency and stability of the adsorption dryer can be significantly improved to meet the gas drying needs in various complex industrial environments.