Model SNCR - Comprehensive Modernization of Power Boilers
Comprehensive modernization of power boilers in deep emission reductions of nitrogen oxides below 200 mg/Nm3 by using primary and selective non-catalytic reduction methods - SNCR. Ecoenergia introduces turnkey projects reducing emissions of nitrogen oxides.
Our offer includes all stages, processes and investment industries:
- pre-modernization measurements,
- technical advice on the selection of an optimal method for NOx emission reduction for a particular boiler,
- designs for all sectors,
- comprehensive implementation (delivery and installation),
- start-up and optimization of the combustion process,
- warranty and after-warranty services.
The offered SNCR installations are based on the technical solution of the German company Mehldau & Steinfath Umwelttechnik GmbH. Selective non-catalytic chemical process of NOx emission reduction uses the reductive properties of the reactants such as ammonia and urea.
The efficiency of the process is dependent on the temperature occurring at the point of injection of urea. The ideal thermal conditions are between 850 °C and 1100 °C. If the temperature in the combustion chamber is too high, radical oxidation of ammonium formed from urea in the NOx ocurs, that can cause an increase in the concentration of NOx in the exhaust. If the temperature is too low ammonium radicals do not react with the NOx, which may lead to penetration of ammonia (NH3) into the atmosphere as so called 'ammonium effect'. In addition, the NOx reduction will be incomplete if urea is not injected into the entire reaction zone.
Reagent prior to injection into the combustion chamber is already adequately prepared in the mixing and measuring module. This module contains all the necessary measuring and control devices for controlling the reactant stream and pressure, for atomizing air and water dilution is responsible for the preparation of an appropriate mixture supplied to the boiler. Reagent diluted with compressed air is fed to the injectors through a system of valves. Urea injection into the combustion chamber takes place at optimum temperatures falling between 850 °C and 1100 °C. Dilution water pressure and compressed air for atomization depends on the desired depth of penetration of exhaust gases by a factor drops and in most cases is between 0.35 to 0.40 MPa at the inlet to the injector. Air stream varies from 10 to 25% (by weight) of liquid flow. The active agent is deluted by demineralized water provided constantly by a pressure pump installed in the module.
A typical SNCR system consists of the following elements:
- unloading station,
- reservoir for the active substance (reducing NOx),
- active agent circulators (redundant),
- dilution water pump (if needed),
- mixing and measuring module,
- lance injector with dual nozzles,
- pipelines for the active substance, water and compressed air,
- valves to regulate and control liquids used,
- controller (PLC),
- Optional - acoustic temperature measurement.