Condensing type drying method

Abstract

The invention discloses a condensing type drying method, and relates to the drying technology. The method comprises the following steps: A) hot smoke exhausted from a boiler and materials to be dried are respectively introduced into a wall-mounted heat exchanger, and the hot smoke exhausted from the boiler contains more than 30% vapor; B) the smoke is cooled in the heat exchanger to dew point so as to condense the vapor in the smoke; and the materials to be dried absorbs sensible heat released by cooling the smoke and latent heat released by condensing the vapor so as to rise the temperature, evaporate the water and dry the materials; and C) the dried materials, the smoke, the vapor evaporated from the materials and condensate of the smoke are respectively led out of the heat exchanger. The method adequately utilizes waste heat of the smoke and achieves the purposes of saving the energy and reducing the cost.

Description

technical field [0001] The invention relates to the technical field of drying, and relates to a material condensation drying method. Background technique [0002] Thermal drying is a commonly used drying method. With the shortage of energy supply and the rise of energy prices, its energy consumption has become one of the keys to technological development. [0003] In the prior art, waste heat is often used to provide heat for the thermal drying process. For example, the heat exchange medium is used to absorb heat from the boiler flue gas and release heat in the dryer to heat up and dry the material. However, most of the existing boiler flue gas waste heat utilization only utilizes the sensible heat of the flue gas. After the flue gas cools down, the temperature is still higher than the dew point of the water vapor. Take a lot of latent heat of vaporization. [0004] Although the temperature of the flue gas can be reduced below the dew point by using cold media, such as co...

AI Technical Summary

Problems solved by technology

Therefore, the limitation of utilization methods is the main obstacle in the deep utilization of flue gas waste heat.

[0005] At the same time, because the fuel used by ordinary boilers contains sulfur, if the exhaust gas temperature drops below the dew point, it will cause low-temperature corrosion. Compared with the increase in the cost of using corrosion-resistant materials to make heat exchangers, the recovered flue gas waste heat seems to be outweighed.

Images