Negative pressure ammonia distillation process and device for residual ammonia water in coking production

Abstract

The invention relates to a negative pressure ammonia distillation process and a negative pressure ammonia distillation device for residual ammonia water in coking production. A venturi tube is arranged at the ammonia steam inlet of a desulfurizing tower; and the bottom of an ammonia distillation tower is provided with an ammonia distillation wastewater / circulating ammonia water heat exchanger andan ammonia distillation wastewater circulating pump. The ammonia distillation wastewater / circulating ammonia water heat exchanger and the ammonia distillation wastewater circulating pump are started,so that heat of circulating ammonia water is brought in the ammonia distillation tower by ammonia distillation wastewater; when the temperature of the top of the ammonia distillation tower is between60 and 80 DEG C, a desulfurizing solution pipeline valve of the venturi tube is opened, and ammonia steam is sucked into the desulfurizing tower; meanwhile, a residual ammonia water pump and an ammonia distillation wastewater pump are started, the residual ammonia water enters the ammonia distillation tower through the heat exchanger, and the ammonia distillation wastewater at the bottom of the tower flows through the heat exchanger and an ammonia distillation wastewater cooler and is subjected to biochemical treatment. The process is simple, equipment has a reasonable structure and is convenient to install and adjust, energy consumption can be effectively reduced, and the ammonia distillation wastewater index is stabilized.

Description

technical field [0001] The invention relates to an auxiliary process technology in wastewater treatment in the coking industry, in particular to a negative pressure ammonia distillation process and device for residual ammonia water. Background technique [0002] In the production process of the coking industry, the moisture content of the mixed coal is about 8%, and the combined water is about 2%. The raw coal gas generated by the coke oven dry distillation contains a large amount of water vapor. Part of the circulating ammonia water used for spraying in the gas collection pipe, and the rest becomes surplus ammonia water. This part of surplus ammonia water becomes waste water in the production process of the coking industry. The remaining ammonia water contains 8-12g / L of ammonia, which must be treated by distilling ammonia to reach the standard before entering the biochemical system. Disposal and discharge after reaching the discharge standard. In the existing production t...

AI Technical Summary

Problems solved by technology

This process has the following defects: Although water vapor can further dilute the wastewater after directly entering the tower, the amount of wastewater increases, which increases the load of subsequent biochemical treatment; water vapor is used as a clean energy source, and the cost of desalinated water treatment is high, so it directly enters the tower to distill ammonia After that, the steam condensed water cannot be recovered, and the energy consumption is high

[0005] So far, no reports have been found on the use of negative pressure ammonia distillation in the coking industry

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