A kind of urea supersaturated solution preparation and delivery system and its preparation delivery method

Abstract

The invention provides a preparation and delivery system for a supersaturated urea solution. The system comprises a preparation tank, a heating and thermostatic device, a reinforced mixing loop and a delivery pipeline, wherein the top of the preparation tank is provided with a urea feed inlet, the sidewall of the preparation tank is provided with a water inlet and the reinforced mixing loop, the bottom of the preparation tank is communicated with the delivery pipeline, the heating and thermostatic device penetrates into the preparation tank and is arranged at the bottom of the preparation tank, an external heat source provides heating heat for the heating and thermostatic device, the reinforced mixing loop is provided with a mixing pump, the liquid inlet end of the mixing pump is communicated with the lower part of the preparation tank through a pipeline, and the liquid outlet end of the mixing pump is communicated with the preparation tank through a pipeline. A preparation and delivery method for the supersaturated urea solution comprises the following steps: 1) cleaning of the preparation and delivery system for the supersaturated urea solution; 2) preparation of the supersaturated urea solution; and 3) delivery of the supersaturated urea solution. The system and the method provided by invention can guarantee uniform mixing of a solid phase and a liquid phase and facilitate delivery; and fouling hardly occurs after running of a cleaning method.

Description

technical field [0001] The invention belongs to the technical field of urea solution preparation in chemical industry, and in particular relates to a urea supersaturated solution preparation and delivery system and a preparation and delivery method thereof. Background technique [0002] To reduce nitrogen oxides (NO X ) to air pollution, thermal power plants often use selective catalytic reduction (SCR) to remove NO from flue gas X , to achieve low pollution emissions. As a method of preparing reducing agent in the SCR flue gas denitrification process, the urea hydrolysis ammonia production process is gradually favored due to its high safety and economical efficiency. However, due to the solubility characteristics of urea and long-term design practices in production, the existing urea hydrolysis ammonia production process uses 40% to 60% urea solution as the incoming liquid of the hydrolysis reactor. According to the stoichiometric ratio of the urea hydrolysis reaction, o...

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Problems solved by technology

However, the preparation and transportation of urea supersaturated solution have special requirements for process design and equipment selection. The existing urea solution preparation and transportation system cannot meet the process requirements, and it is easy to be precipitated during the preparation and transportation process. Adhesion and blockage of urea affect its normal use and operation, so there is no preparation and delivery system for urea supersaturated solution

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