Salt-containing wastewater treatment system and method applying ejector to provide power and vacuum variable frequency pump to stabilize pressure

Abstract

The invention discloses a salt-containing wastewater treatment system and method applying an ejector to provide power and a vacuum variable frequency pump to stabilize pressure, and belongs to the field of salt-containing wastewater treatment. The device mainly comprises a feeding water tank, a spraying chamber, an evaporator, a heat exchange coil, a crystallization device, a gas-liquid separator, a compressor and a vacuum variable frequency pump. Aiming at the defects that a traditional multi-effect evaporator is high in energy consumption and not environmentally friendly when being used for treating high-concentration salt-containing wastewater, the evaporator is designed to recover secondary steam as a heat source to be re-fed into a cavity for evaporation, fresh steam does not need to be additionally produced, and salt-containing wastewater is efficiently recovered. Compared with the prior art, the vacuum variable frequency pump is used for stabilizing the pressure in the evaporator cavity, and the working frequency is adjusted according to the pressure state in the cavity; the ejector is used for replacing a water circulating pump to eject a concentrated solution, the ejector does not need electric power equipment, and the working energy consumption of the system is reduced; high-temperature condensate water is recycled to preheat fed materials, so that the use of an electric heater is reduced; and through the two-stage spraying system, the evaporation efficiency is improved, and the system complexity is reduced.

Description

technical field [0001] The invention relates to a saline wastewater treatment system and method using an ejector to provide power and a vacuum frequency conversion pump to stabilize the pressure, belonging to the field of saline wastewater treatment. Background technique [0002] High-salt wastewater contains refractory organic matter and complex and highly corrosive inorganic salts. Direct discharge will lead to an increase in the salinity of the water and seriously endanger the survival of aquatic animals and plants. Tensions will eventually endanger human life and health. The use of traditional multi-effect evaporation technology to treat saline wastewater requires continuous production of fresh steam, and a large amount of secondary steam is wasted, resulting in increased system energy consumption. Therefore, how to deal with saline wastewater in an energy-saving and low-carbon way is of great significance. The principle of mechanical vapor recompression crystallizatio...

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Problems solved by technology

The system is huge and the operation is complicated. When the system is running for the first time, fresh steam needs to be produced, and there is no recycling of high-temperature exhaust steam and high-temperature condensed water formed after evaporation.

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