Fluidization, crystallization and drying system and method for wastewater concentrated solution capable of being directly discharged in air

Abstract

The invention discloses a fluidization, crystallization and drying system and method for a wastewater concentrated solution capable of being directly discharged in air. According to the system and method, air enters an air inlet unit and is heated into hot air through a heat exchanger, the hot air is taken as carrier gas and enters an air inlet of a fluidization, crystallization and drying tower,and a filling between inner and outer cylinders of a roller is blown into a micro-floatation fluidization state; a preheated wastewater concentrated solution is distributed to an atomizer on the innercylinder of the roller and is atomized and sprayed to the surface of the filling to generate heat and mass transfer with hot air, moisture is carried away by hot air, wet saturated air is obtained, salt in the concentration solution is crystallized, dried and hardened on the surface of fluidized salt, falls off due to the grinding and collision among spherical particle fillings through the rotation of the inner cylinder and the flow of hot air and sinks to a crystallization collection cone hopper at the bottom of the tower through a mesh sieve of the outer cylinder, wet saturated air is condensed and dehumidified through phase-change heat transfer of a preheater, and dehumidified air is directly discharged in air. Air is carrier gas or gases such as smoke, helium gas, argon gas, nitrogengas, CO2 or steam.

Description

technical field [0001] The present invention relates to the field of waste water treatment, relates to the terminal solidification of waste water, in particular to a system and method for fluidized crystallization and drying of waste water concentrate which is directly discharged by hot air. The waste water concentrate can be desulfurization waste water concentrate, air or flue gas Helium, Argon, Nitrogen, CO 2 or steam and other gases instead. Background technique [0002] The desulfurization wastewater zero discharge system generally includes three parts: a pretreatment unit, a concentration reduction unit, and a terminal solidification unit. [0003] At present, the terminal curing technologies adopted at home and abroad mainly include: evaporative crystallization drying, direct injection flue crystallization drying, bypass flue crystallization drying, and hot air crystallization drying. [0004] Evaporation and crystallization drying: The evaporative crystallization pr...

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Problems solved by technology

[0006] (1) After the desulfurization wastewater evaporates, highly corrosive chlorides cannot be completely collected by the electrostatic precipitator, causing them to accumulate on the desulfurization tower and subsequent equipment, causing severe corrosion, and significantly increasing the frequency and cost of equipment maintenance;

[0007] (2) Materials such as heavy metals in desulfurization wastewater are enriched in fly ash, which greatly affects the reuse of fly ash and the safety of users

[0008] (3) After the wastewater is atomized, it will cause severe corrosion and scaling to the flue, electrostatic precipitator and downstream equipment, which will affect the long-term stable operation of the equipment. For example, the fouling of the electrode plate of the electrostatic precipitator will reduce the dust removal efficiency and even affect the electrostatic precipitator. normal operation

[0009] (4) The atomizing nozzle and the flue are severely worn, coupled with the corrosion of high-concentration chloride, the equipment fails quickly

[0010] (5) The process mainly relies on the electrostatic precipitator to remove the evaporation crystallization products. The substances that the electrostatic precipitator cannot remove will return to the desulfurization tower with the flue gas, and will be enriched continuously, increasing the load of the desulfurization tower, and causing PM2.5 and mercury Emissions are easy to exceed the standard

[0012] Hot air crystallization drying: requires a lot of steam, high energy consumption, unusable products, difficult to handle

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