Resin-cast desulphurization nozzle and manufacturing method thereof

Abstract

The invention discloses a resin-cast desulphurization nozzle which is used in flue gas desulphurization systems of a power plant and a large-scale or small and medium boiler and a manufacturing method thereof. The nozzle comprises a cone-shaped spiral nozzle head which is molded through resin casting, a nut and a close nipple which are connected into a whole body in a same axis, and the nozzle is hollow; and the whole desulphurization nozzle which is manufactured through resin casting has the advantages of one-time molding technology, normal temperature and pressure casting, good corrosion resistance, good wear resistance, small channel unblocked resistance, small contraction, aging resistance, high strength, strong operability of shapes, low manufacturing cost and long service life.

Description

technical field [0001] The invention relates to a desulfurization nozzle used in a flue gas desulfurization system on a power plant, a large or medium-sized boiler, in particular to a resin casting desulfurization nozzle and a manufacturing method thereof. Background technique [0002] At present, the country has implemented the emission standards of "Emission Standards of Air Pollutants for Thermal Power Plants" and "Emission Standards of Air Pollutants for Boilers" respectively for power plants, large boilers and small and medium-sized boilers. In order to achieve the purpose of desulfurization, wet flue gas is generally used in China. Desulfurization (FGD) technology uses desulfurization nozzles for spraying and washing, so the selection and use of desulfurization nozzles are key factors for the stability of the desulfurization system. However, most domestic manufacturers generally use polypropylene (PP), polyvinyl chloride (PVC), brass, pig iron, stainless steel, ceramic...

AI Technical Summary

Problems solved by technology

However, most domestic manufacturers generally use polypropylene (PP), polyvinyl chloride (PVC), brass, pig iron, stainless steel, ceramics, and silicon carbide to manufacture desulfurization nozzles, which exist in the environment of flue gas desulfurization systems. Many disadvantages: (1) The desulfurization nozzle is connected to the slurry pipeline, when Ca(OH) 2 The lye is sprayed from the nozzle by the power of the desulfurization pump, and after forming a mist or water film, with the long-term use of the circulating fluid, the concentration of impurities in the slurry increases, and the frictional resistance to the nozzle also increases; The sprinkler system is operated intermittently, and after a long time, it is easy for sediment to adhere to the nozzle and then fall off, which has caused serious consequences to the wear of the nozzle; polypropylene (PP) nozzles with poor wear resistance, Polyvinyl chloride (PVC) nozzles, and alloy steel nozzles with poor wear resistance such as brass nozzles (wear ratio 1), pig iron nozzles (wear ratio 1-2) and stainless steel nozzles (wear ratio 4-15) Lifespan is very short, less than half a year

(2) During the spraying process, wet flue gas is condensed at the outlet of the nozzle. Since the flue gas contains a large amount of CO 2 , SO 2 Such acid gas and water vapor will seriously corrode nozzles made of alloy steel such as brass nozzles, pig iron nozzles and stainless steel nozzles, and also accelerate the aging of plastic nozzles such as polypropylene (PP) nozzles and polyvinyl chloride (PVC) nozzles and embrittlement, seriously reducing the service life of the nozzle

(3) Some old boilers have low thermal efficiency and serious heat loss, which makes the exhaust gas temperature of the boiler exhaust gas reach 180-200°C for a long time. In the desulfurization tower, the nozzle is directly surrounded by the smoke temperature, and plastic nozzles such as polypropylene (PP) nozzles (temperature resistance less than 110°C) and polyvinyl chloride (PVC) nozzles (temperature resistance less than 60°C) will definitely be melted and deformed. Steel nozzles such as brass nozzles, pig iron nozzles and stainless steel nozzles are slowly oxidized and corroded due to fly ash coking

(4) Although ceramic nozzles and silicon carbide nozzles are hard but brittle, they have poor shock resistance during transportation and are easy to be twisted if they are not careful during installation.

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