Negative-pressure ammonia distillation tower and ammonia distillation method

Abstract

The invention relates to a negative-pressure ammonia distillation tower and an ammonia distillation method. The negative-pressure ammonia distillation tower comprises a tower main body, a skirt, a tar outlet, a manhole, an ammonia distillation wastewater outlet, a conduction oil inlet, a conduction oil outlet, a reboiler, a full-flow baffle plate, a communicating pipe, a tray, an alkali liquor inlet, a raw material ammonia water inlet, an ammonia dephlegmator, a cooling water inlet, a cooling water outlet and an ammonia vapor outlet. The negative-pressure ammonia distillation tower is characterized in that the reboiler is arranged in the tower main body, the ammonia dephlegmator is arranged at the upper part of the tower main body, the raw material ammonia water inlet is located at the upper part of the tower main body, the alkali liquor inlet is located at the middle part of the tower main body, ammonia distillation wastewater in the downcommer of the bottommost tray is guided into the bottom layer of the tower by use of the communicating pipe, and the full-flow baffle plate is arranged at the bottom layer of the tower main body. The negative-pressure ammonia distillation tower has the advantages that the ammonia distillation tower works under negative pressure so that the solution boiling point is low and the distillation temperature can be reduced, and therefore, the energy consumption is reduced, besides, the anticorrosion process is optimized, the medium corrosion problem is solved and the material cost is saved, and furthermore, the reboiler is integrated in the ammonia distillation tower so that the ammonia distillation process can be simplified and the loss in the process can be reduced.

Description

technical field [0001] The invention relates to the field of coking residual ammonia water treatment, in particular to a built-in reboiler-type negative pressure residual ammonia water distillation device and ammonia distillation method. Background technique [0002] At present, steam stripping is generally used in coking plants to remove harmful impurities such as ammonia, phenol and COD. After treatment, the ammonia gas is discharged from the top of the ammonia distillation tower to the gas system, and the ammonia distillation wastewater at the bottom of the tower is sent to biochemical treatment. device. This kind of positive pressure steam distillation is operated at a high temperature of 90-110°C, which consumes a lot of energy and is severely corroded by the medium; at the same time, the heat exchange efficiency of the conventional shell-and-tube bottom reboiler and the top ammonia splitter is not high, and requires a large amount of energy consumption. The volume of ...

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Problems solved by technology

This kind of positive pressure steam distillation is operated at a high temperature of 90-110°C, which consumes a lot of energy and is severely corroded by the medium; at the same time, the heat exchange efficiency of the conventional shell-and-tube bottom reboiler and the top ammonia splitter is not high, and requires a large amount of energy consumption. The volume of steam and circulating water is large, especially the ammonia splitter is made of titanium, which is expensive, which leads to high investment and operation costs and high maintenance costs for ammonia distillation process equipment

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