This article is to introduce the application of vacuum pumps for tobacco industry.
Vacuum pumps are used in vacuum rewetting which is the first process of cigarette production.
In the tobacco manufacturing industry, the moisture content of tobacco leaves is strictly limited to a certain range. The required moisture is usually about 21%. If the water content is too low, the tobacco leaves will be powdered after drying. It results that the leaves cannot be made into cigarette rolls. On the contrary, the tobacco leaves will form a sphere when pinched, if there is too much moisture. The leaves are not fluffy, difficult to roll and not easy to light.
In the process, the tobacco leaves are firstly delivered into a rewetting box. The box is then sealed and the air inside is displaced by a vacuum pump to achieve the required ultimate pressure (vacuum). The odor of the gases and moisture inside the tobacco leaves are removed and the leaves dry and shrink gradually, forming numerous pores. After a period of time, water vapor will be introduced. At this point, it’s required by the vacuum pump to maintain a certain air volume and proper vacuum to allow the vapor to gradually fill the pores and moisten the tobacco. Once the specified water content is reached, the vacuum pump and the water pipe are turned off. The rewetting process is completed.
Limitations of liquid ring vacuum pumps
It’s quite natural to choose liquid ring vacuum pumps for this vapory application. However, the shortages of such pumps are also obvious:
- High energy consumption and low efficiency
- Unstable air flow while the liquid temperature fluctuates
- Costly legal disposal of waste water
- Inevitable environmental pollution
- Extra cost for additional controlling equipment
- Flexible option with air cooling & water cooling version
- Integrated inverter for significant efficiency improvement and energy saving
- Stable performance
- Low noise and low pollution