A process for zero-discharge treatment of waste water from thermal power plants

Abstract

The invention relates to a process for zero emission treatment of wastewater in a thermal power plant. Waste water subjected to calcium ion and solid suspended matter removing enters a low-temperaturemulti-effect evaporation unit for evaporation; the low-temperature multi-effect evaporation unit communicates with a circulating pump; the circulating pump communicates with a water side inlet of a flue heat exchanger; a water side outlet of the flue heat exchanger communicates with a steam-water separator; a steam outlet of the steam-water separator communicates with a shell side steam inlet ofa first-effect heater of the low-temperature multi-effect evaporation unit; an shell side water outlet of the first-effect heater communicates with the circulating pump; a water outlet of a last-effect steam-water separator of the low-temperature multi-effect evaporation unit communicates with an inlet of a concentrated water tank; an outlet of the concentrated water tank communicates with an atomizing device; a compressed air unit communicates with the atomizing device; the atomizing device is arranged on a flue between an air pre-heater and an electrostatic dust collector; a shell side air inlet of a flue heat exchanger communicates with a flue behind the electrostatic dust remover; and a shell side air outlet of the flue heat exchanger communicates with a flue in front of a wet desulfurization device. The process provided by the invention can be applied to treatment of waste water of a thermal power plant.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a process for zero-discharge treatment of wastewater from thermal power plants. Background technique [0002] Thermal power accounts for about 80% of my country's installed power generation capacity, which has exceeded 1 billion kilowatts. Thermal power units are mainly coal-fired. With the substantial increase in installed capacity, the coal consumption ratio of thermal power has gradually increased. As a low-grade fossil energy, coal has high ash and sulfur content. About 90% of SO2 emissions in my country come from coal burning, and acid deposition pollution endangers the ecosystem and public health. With the increasingly stringent national environmental protection policies, most of the thermal power units in service and newly built thermal power units are equipped with flue gas desulfurization devices to ensure that the boiler flue gas discharges up ...

AI Technical Summary

Problems solved by technology

The treatment process uses membrane concentration, which consumes a lot of energy and costs

[0006] To sum up, there is currently no one with reasonable structure design, low operating cost, high operating stability, which can effectively remove high salinity (salt content 15000mg / L ~ 110000mg / L), heavy metal ions and suspended solids in wastewater Desulfurization wastewater treatment device with equal pollution factors

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