How to choose the cold dryer and suction dryer

When choosing a cold dryer and a suction dryer, a number of factors need to be considered, including the degree of drying, environmental adaptability, operating costs, maintenance costs, and equipment characteristics. The following is a detailed analysis and selection recommendations for the two dryers:

1. drying degree

• cold dryer:

  • degree of drying: The cold dryer condenses the moisture in the humid air into liquid through condensation technology and then discharges it. The degree of drying is greatly affected by the ambient temperature and intake temperature. Generally, the pressure dew point of the cold dryer can be controlled above 3 ℃ td, but when the ambient temperature is too high or too low, the drying effect may be reduced.

• suction dryer:

  • degree of drying: The suction dryer uses adsorbents (such as silica gel, molecular sieve, etc.) to absorb moisture in the air to achieve a deeper degree of drying. Its pressure dew point can reach -20 ℃ to -70 ℃, which is suitable for occasions where the drying degree of compressed air is extremely high.

2. environmental adaptability

• cold dryer:

  • environmental Adaptability the cold dryer has weak adaptability to the environment, especially when the ambient temperature is too high or too low, its operating effect will be affected. The ambient temperature is too high may lead to refrigeration dryer refrigerant condensation pressure increases, cooling capacity decreased, increase the equipment outlet pressure dew point; and the ambient temperature is too low is prone to ice blocking phenomenon.

• suction dryer:

  • environmental Adaptability: The suction dryer has relatively strong adaptability to the environment and can maintain a stable drying effect in a wide temperature range. However, it should be noted that the influence factors of high dew point value of compressed air pressure caused by high outlet temperature of air compressor at the highest ambient temperature should be considered when selecting the equipment.

3. operating costs

• cold dryer:

  • operating costs the cold dryer mainly consumes electric energy during operation, and its energy consumption is relatively low. In addition, the cold dryer does not need to consume compressed air for regeneration, so its operating cost is low.

• suction dryer:

  • operating costs: The suction dryer needs to consume a certain amount of compressed air for regeneration during operation, which will increase its operating cost. At the same time, the adsorbent of the suction dryer needs to be replaced regularly, which will increase the maintenance cost.

4. maintenance costs

• cold dryer:

  • maintenance costs the maintenance cost of the cold dryer is relatively low. Its main components such as refrigerant system, air system and electrical parts are relatively simple, and the failure rate is low. However, it is necessary to regularly clean the filter screen of the automatic drain to maintain the normal operation of the equipment.

• suction dryer:

  • maintenance costs: The maintenance cost of the suction dryer is relatively high. The adsorbent needs to be replaced regularly, and the valve may also be worn due to frequent action. In addition, the suction dryer needs to consume compressed air and electricity during the regeneration process, which also increases its maintenance costs.

5. device characteristics

• cold dryer:

  • equipment characteristics cold dryer has the advantages of no compressed air consumption, low noise, and effective air supply can reach 100%. However, it is greatly affected by the ambient temperature, and the dew point of the gas supply can only reach about 3 ℃.

• suction dryer:

  • equipment characteristics: The suction dryer has the advantages of deep drying degree and is not affected by ambient temperature. However, it has disadvantages such as compressed air consumption, regular replacement of adsorbents, and large operating noise.

6. selection recommendations

• select according to the requirements of drying degree: If the drying degree of compressed air is extremely high, a suction dryer should be selected; if the requirements are not particularly strict, the cold dryer can meet the demand.
• Considering environmental adaptability: Choose the appropriate dryer according to the temperature conditions of the use environment. If the ambient temperature changes greatly, the suction dryer should be given priority.
• Weighing Operation and Maintenance Costs: Comprehensively consider the operating cost and maintenance cost of the equipment, and choose a dryer with higher cost performance. If the pursuit of lower operating costs, the cold dryer may be a better choice; but if there are higher requirements for the degree of drying and the budget allows, the suction dryer is also an option worth considering.

To sum up, the cold dryer and the suction dryer have their own advantages and disadvantages, and the selection should be considered comprehensively according to the specific use scenario and needs. In chemical plants and other occasions that require high drying degree of compressed air, suction dryer may be more suitable; and in the drying degree requirements are not particularly strict and hope to reduce operating costs, cold dryer may be more suitable.