Selection principle of humidifier for tobacco factory
Features of the workshop: The machine in the workshop has a large amount of heat, and tobacco leaves and shreds have high requirements for humidity. The general humidity φ≥80% RH
Humidification process requirements:
Winter: Isothermal or warming humidification
Spring and Autumn: Hope to cool down and humidify
Summer: hope to cool down and humidify
Selection of humidifier:
Use dry steam humidifier in air conditioning unit in winter
Use wet film evaporative cooling humidifier or spray room humidification in air conditioning units in spring and autumn
In summer, use a wet film evaporative cooling humidifier or a spray room humidifier in an air-conditioning unit, and use direct humidification in the plant when the humidity of the supply air cannot be met (generally a centrifugal humidifier)
1. Does the tobacco grading plant need humidification?
In the tobacco production process, in order to improve the grade of cut tobacco required for the production of cigarettes, the tobacco leaves need to be classified before processing. Because the tobacco leaves become very dry after re-baking, the tobacco leaves are particularly fragile, and the flying dust phenomenon is more serious during the classification of tobacco leaves, which will cause harm to the human body and cause economic losses. A cigarette factory in Yunnan once conducted a simulation test in a workshop to control the humidity of the workshop at about 80% RH. In this way, the damage rate of tobacco leaves can be reduced by more than two thousandths. Loss of four million yuan due to broken tobacco. It can be seen that humidity control plays an important role in the production process of cigarettes.
2. How to humidify the tobacco classification plant without central air conditioning?
Because many tobacco leaf grading plants are only used within a few months of a year (how many in Yunnan are in September-October), many plants do not have central air-conditioning installed, but only install a number of exhaust fans in the plant to perform indoor air fresh air replacement.气 处理。 Gas processing. In this environment, if the indoor temperature can be maintained, the smoke and dust will be greatly reduced, and the tobacco crushing rate will be greatly reduced. Under these conditions we recommend:
1. If the area of the tobacco leaf classification plant is large, and the tobacco plant already has a large air compressor station, the gas-water mixed humidification scheme is preferred. For details about the gas-water mixed humidification scheme, please refer to the "Humidification Engineering Manual" of Beijing Hanning Air Technology Co., Ltd. ". For the advantages and disadvantages of air-water mixed humidification scheme, please refer to "Comparison of Several Humidification Methods".
2. If the area of the tobacco leaf classification plant is small (area less than 200 square meters), please choose the centrifugal humidification scheme. For details about the centrifugal humidification scheme, please see the "Centrifugal Humidifier Sample". For the advantages and disadvantages of centrifugal humidification solutions, please see "Comparison of Several Humidification Methods".
3. How to humidify the tobacco grading plant with central air conditioning?
For a tobacco leaf classification plant with a central air conditioner, in winter or spring and autumn, users can choose a humidification scheme in the air conditioning unit (generally this scheme has a smaller investment), such as a wet film circulating water humidification scheme, high pressure spray + wet film baffle plate humidification Scheme or dry steam humidification scheme. However, it should be noted that the temperature of the air supply in the summer is low (generally, the air supply temperature is about 12 ° C). At this time, no matter what kind of humidification method is adopted in the air conditioning unit, even if the humidification reaches a saturated state, it cannot meet the indoor temperature of 20- Air condition at 24 ℃ and relative humidity 70-80% RH.
Under these conditions, the scheme of direct indoor humidification must be used to achieve the above requirements.
Summer humidification of a cigarette factory silk bank
First, do we need to humidify the silk warehouse of the cigarette factory?
In the process of making tobacco, the damage rate and quality of cut tobacco has an important relationship with the humidity of the air during storage. When the air is too dry during storage, the cut tobacco is easily broken into smoke, and the odor is volatilized, which reduces the quality of the cut tobacco. Generally, the temperature of the silk storage needs to be maintained between 18 and 25, and the relative humidity must be maintained above 70% RH. Under this environmental condition, the shredded tobacco is not easily broken, the dust phenomenon is lighter, and the smoke taste is more pure. The relative humidity of the air in the general silk storage is difficult to meet this requirement.
Therefore, in order to improve the quality of cut tobacco, the storage tank must be humidified.
2. Why is the humidification of the silk warehouse of the cigarette factory based on central air conditioning in summer impossible?
When it comes to humidification, many people think of using a central air conditioning system for humidification! In winter, the use of a dry steam humidifier in the central air-conditioning system can achieve the required relative humidity in the silk storage, but in summer, because the temperature in the silk storage is too high, the central air conditioner must send cooler cold air to make the silk storage. The temperature in the storage room has decreased (generally maintained at about 24 to 26 ° C). At this time, no matter what kind of humidification scheme is used in the central air conditioner, even if the relative humidity of the supply air is saturated (100% RH), it can be caused by the supply air. The water content is small, and the relative humidity decreases due to the temperature rise after entering the silk storage, which causes the relative humidity in the silk storage to still not reach 70% RH.
Conclusion: When the temperature of the central air conditioner is too low in summer, no matter what kind of humidification method is used in the central air conditioner (such as dry steam type, spray room type, high pressure spray type, etc.), it cannot meet the 70% RH of the silk storage. Storage silk * best humidity requirements.
3. The best summer humidification scheme for the silk storage in the cigarette factory.
Since the silk storage of the cigarette factory in summer cannot rely on central air conditioning to meet the silk storage requirements, people must directly humidify the silk storage to achieve the purpose!
l Generally speaking, people do not adopt the method of directly spraying steam in the silk storage, because this will not only cause a significant increase in the temperature in the storage, but also cause a series of problems such as condensation and dripping on the top of the storage, and moisture falling off the wall!
l From the perspective of reducing the cooling load of the refrigerator, we recommend the use of cooling methods such as centrifugal humidification, air-water mixed humidification, or high-pressure micro-mist humidification! For performance comparison of several humidification methods, see the attached page "Comparison of Several Humidification Methods"
Generally: a) The area of silk storage is less than 200㎡, and a centrifugal humidification scheme is recommended;
b) When the air volume of the compressed air station of the tobacco factory is sufficient, it is recommended to use a gas-water mixed humidification scheme;
c) When the storage area is> 300㎡ and there is no compressed air station, it is recommended to use high-pressure micro-mist humidification.