Aerobic fermentation needs constant sterile air supply. The heat compressed air cannot directly into the fermentation tank, and mixed bacteria and cell in the air stream must be removed. Based on the requirement of aseptic membrane filters, the compressed air must be pretreated. Usually, it be cooled below the pressure dew point, and separated from oil, water and other impurities, then it will be heated to reduce the relative humidity. In a relative cool and dry condition the air goes into the membrane filter, so that the filter can perform its function to the maximum.
Traditional fermentation air pretreatment system generally adopts two-stage cooling, two-stage dewatering and steam heating with excessive auxiliaries and a complex configuration. Due to low equipment efficiency, it requires large cooling and heating amplitude, leading to high energy consumption, high pressure loss and high power consumption; In addition, as fermentation aeration rate changes, separation efficiency of traditional separator fluctuates, leading to low dewatering effect and low air quality. In that case, processed air is difficult to meet the operational requirements of aseptic air, affecting the service life of downstream aseptic filters and production stability.
System of sterile air pretreatment (SAS) consists of advanced new finned-tube cooler, high efficient horizontal gas-liquid separator and air circulatory heater. With several state key patents, it solves above-mentioned problems, provides good air quality, improves production stability, saves water, electricity, steam, and reduces system capital cost and operational cost dramatically.
|Enery-saving system||Trational system|
|Outlet pressure of air compresssor （MPa，G）||0.15～0.25||0.25～0.4|
|Air temperature after cooling （℃）||20～35||15～20|
|Air temperature after heating （℃）||40～60||50～70|
|Heat source||Hot compressed air||Steam|
|System pressure loss （MPa）||0.005～0.01||0.01～0.05|
|Unit power （kW/ (m3/min)）||2.5～3.5||3.5～5.0|
- Finned-tube to strengthen heat transfer, high efficiency, durable.
- Low flow velocity in the shell, low pressure loss.
- Multi-stage cooling arrangement, able to use multiple coolant (circulating water, chilled water, etc.)
- Tubes vertically deployed, drain outlet at bottom of every stage to release impurities.
- Patent technology design, stainless steel precisely manufactured.
- Parallel separation units, separation efficiency 98%~99.99%, good adaptation to aeration volume rate fluctuations.
- Remove aerosol by collision and centrifugation completely, reduce impurities dramatically and improve air quality.
- Separation efficiency 20% higher than cyclone (only 60%~80), 15%~25% higher than folded plate separator. Compared to screen separator, more reliable, far less pressure loss, and no clog.
- No wearing parts, free of maintenance, extended life.
- Use compressed hot air as heat source, no steam needed, energy-saving, free of disruptions from steam system malfunction.
- Specially designed: make up defects of traditional gas-gas heater, with low resistance and high heat transfer efficiency.
- No pressure difference between tube an shell in gas-gas heat transfer, eliminate tube crack and leakage; great reliability.
- Durable finned tube with strengthened heat transfer.