Demister at urea hydrolysis reactor outlet

Abstract

The invention discloses a demister at a urea hydrolysis reactor outlet. The demister comprises a barrel as well as a cyclone demisting section and a mesh demisting section which are sequentially arranged in the barrel in a serial connection manner and separated by an annular baffle, wherein the lower end of the barrel extends into the urea hydrolysis reactor outlet, and a gas-phase outlet is formed in the upper end and fixed with the urea hydrolysis reactor outlet; a gas outlet end of the mesh demisting section is communicated with the gas-phase outlet, and a gas inlet end is connected with a gas discharge end of the cyclone demisting section; gas inlets of the cyclone demisting section are arranged on the side wall of the barrel, and a liquid discharge port in the lower end of the cyclone demisting section extends below the liquid level in a urea hydrolysis reactor. According to the demister, two stages of serially connected devices are adopted to perform demisting, the first stage is separation of large liquid drops through cyclone type demisting, and the second stage is separation of small drops through mesh demisting; gas flows from an outlet of the cyclone demisting section enter the mesh demisting section in a rotating flowing manner, so that lengths of the motion traces of the gas flows in the mesh demisting section are increased, the demisting effect of the mesh demisting section is improved, the better comprehensive demisting effect is realized, and the demisting capacity is higher.

Description

technical field [0001] The invention belongs to the technical field of flue gas denitrification, and relates to a demisting device at the outlet of a urea hydrolysis reactor. Background technique [0002] The preparation of ammonia by urea hydrolysis is a reducing agent preparation process in the SCR denitrification process of flue gas in thermal power plants. The principle is that the urea solution is hydrolyzed to generate ammonia and carbon dioxide under certain temperature and pressure in the hydrolysis reactor. The generated ammonia, carbon dioxide and part of the water vapor leave the hydrolysis reactor and are sent to the boiler flue for denitrification reaction. The internal space of the hydrolysis reactor is divided into the lower liquid phase space and the upper gas phase space. Due to the violent boiling of the liquid phase space, the vapor phase space is not only filled with reaction product ammonia, carbon dioxide and partially evaporated water vapor, but also ...

AI Technical Summary

Problems solved by technology

[0003] At present, the commonly used technology in the industry is to install a wire mesh demister at the outlet of the hydrolysis reactor product, such as figure 1 As shown, on the one hand, due to the large content of small droplets in the gas phase, the defogging effect is not ideal due to the limitation of the defogging ability of the wire mesh eliminator itself, and the defogging effect cannot be improved.

On the other hand, the current wire mesh demister adopts a built-in fixed structure, which is not easy to repair and replace after clogging

Images