Energy-saving anti-freezing dehumidifying system and method for spray drying tail gas

Abstract

The invention discloses an energy-saving anti-freezing dehumidifying system and method for spray drying tail gas. The energy-saving anti-freezing dehumidifying system comprises a drying fan, an air reheater, a spray drying tower and a primary dust remover which are arranged in sequence. The system further comprises a dehumidifying tower, an energy-saving device and an anti-freezing device. The dehumidifying tower comprises a tower body, and a secondary dust remover, a water accumulation disc, an energy-saving packing layer, a dehumidifying packing layer and an outlet fan are sequentially arranged in the tower body from bottom to top; the energy-saving device comprises an energy-saving air collecting cover and an energy-saving fan, the energy-saving air collecting cover is located above theenergy-saving packing layer, the energy-saving fan is connected with the energy-saving air collecting cover and the drying fan, and an air inlet of the drying fan is further communicated with ambientair; the anti-freezing device comprises an anti-freezing air collecting cover and an anti-freezing fan, the anti-freezing air collecting cover is located above the dehumidifying packing layer, and the anti-freezing fan is connected with the lower portion of the anti-freezing air collecting cover and the lower portion of the energy-saving packing layer. Heat in the tail gas can be effectively recycled, the operation energy consumption of the spray drying process is reduced, and the operation stability of the dehumidifying system in winter can be improved.

Description

technical field [0001] The application relates to the field of resources and environmental protection, in particular to an energy-saving antifreeze and dehumidification system and method for spray drying tail gas. Background technique [0002] Spray drying is a drying process that has been widely used in industrial production processes. The spray drying process uses an atomizer to disperse the raw material liquid into droplets, and uses hot air to dry the droplets to obtain a drying method. In the spray dryer, when the hot fluid (drying medium: such as air) flows through the dryer, the moisture or solvent in the dried object is evaporated to obtain a powdered product. The liquid removed by spray drying is usually water, and the drying medium used is generally high-temperature dehumidified air. The material passes through the filter and is pumped to the atomizer at the top of the spray dryer to be atomized into mist droplets. At the same time, the air enters the blower and ...

AI Technical Summary

Problems solved by technology

However, there are certain limitations in the treatment of spray drying tail gas by gas condensation and heat exchange with plastic packing membranes, and it is difficult to popularize and apply them on a large scale. The details are as follows:

[0004] (1) The investment cost is high. The spray drying tail gas is unsaturated high-temperature tail gas. The relative saturation humidity of water vapor in the flue gas is about 80%-95%. The exhaust gas temperature is 50°C-90°C. The tail gas needs to be condensed to a saturated state first. , the water vapor in the flue gas can be condensed to form liquid water after the exhaust gas reaches a saturated state and continues to condense, resulting in ineffective condensation in the first stage of condensation, which increases the volume of the condensation heat exchange system;

[0005] (2) It is difficult to operate stably in cold weather in winter. Under low temperature conditions in winter, during the heat exchange process between the ambient air and the plastic diaphragm, it is easy to cool the temperature of the air inlet end of the plastic diaphragm packing to below 0°C, causing condensation in the packing. Water freezes and freezes, cracks the packing and blocks the condensate outflow channel, making the system unable to operate stably

[0006] Therefore, the use of plastic membrane packing to perform gas-gas heat exchange and condensate water collection on spray-dried high-humidity tail gas must solve technical problems such as excessive heat transfer packing volume and winter antifreeze. Heat exchange and energy saving antifreeze technology is still in the blank

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