There is a lot of knowledge needed for equipment installation, such as the calculation of chimney height. What factors should be considered? What formula do you need to use? I don't know how much you know. Today, Shandong Baolan small editor will introduce to you how to calculate the height of industrial waste gas dedusting chimney.

 

1. The influence of height diffusion parameters and upper inversion of industrial flue gas dedusting stack

 

In the calculation of chimney height, generally 0.5 ~ 1.0 is taken as the value of ó Z / ó y, which has a great influence on the chimney height.

 

The above formula for the height of industrial flue gas dedusting chimney is derived at the same time of temperature stratification. For high and strong heat source, the effect of upper inversion must be considered. The results show that when the effective source height h is equal to the mixed layer thickness D, the ground concentration is equal to 2 times of the general case. According to this condition, the height of chimney will be greatly increased. Therefore, in order to ensure safety, the thickness and frequency of the mixed layer should be investigated to avoid the situation that the effective source height is equal to the thickness of the mixed layer with the highest or higher frequency. In many cases, the effective height is required to break through the inversion layer when the inversion layer is low.

 

2. About avoiding the downwash or sinking of industrial waste gas dedusting flue gas

 

In order to avoid downwash of flue gas, according to gb3840-83, the height of chimney shall not be less than 1.5-2.5 times of the height of its affiliated buildings, the outlet velocity of flue gas u shall not be less than 1.5 times of the average wind speed at the outlet height of chimney, that is, US / ú ≥ 1.5 is required. The proper increase of the velocity of flue gas emission is conducive to the improvement of dynamic lifting. However, if the velocity of flue gas is too high, a negative pressure area will be generated behind the windward side of the flue gas outlet, which will cause some air to be entrained into the flue gas, and the effective height will be reduced instead. In order to avoid this phenomenon, some chimneys are provided with a flat water round plate with a brim shape at the outlet, and the size of the round plate extending outwards is at least equal to the diameter of the chimney outlet. In order to improve the ejecting speed, the chimney mouth can also be designed as a mound nozzle structure, but it should be noted that the increase of resistance should not be too large.

 

3. Increase the dust removal and exhaust volume of industrial waste gas and increase the exhaust temperature

 

If there are several smoke sources in the accessories, it is better to concentrate on one chimney for emission. Considering that the equipment has been put into operation successively, or the smoke exhaust speed is not too low when some of the equipment is stopped running, the multi barrel integrated discharge can be adopted.

 

The temperature of flue gas is very important for lifting, but heating flue gas will increase the economic burden. Therefore, it is beneficial for flue gas lifting to adopt dry dedusting, or to minimize the heat loss of flue and chimney in chimney design.