Research Of The New Boiler Water Treatment Agent

Boilers as an important energy transfer equipment can be used in many fields, such as coal-fired power plant, petroleum chemical industry, industrial production and daily life. Each boiler safety accident may cause casualties or property of heavy losses. At present, boiler accidents due to water quality problems caused by the scale and corrosion account for 50%. Therefore, developing a highly efficient and green scale of boiler water treatment agent with scale-inhibitor and inhibition erosion abilities becomes very important.A water soluble copolymer water treatment agent has been investigated and developed in this paper. It is mainly made of phosphor acid, ester group, carboxylic group, sulfonic group and ether group. It not only restrain carbonate and phosphate, but also stabiliz zinc and dispersing ferric salt. Meanwhile, it can inhibitate corrosion and has low phosphorus concentraint.In this paper, sulfonic group, ester group, ether group and phosphorous carboxylic group was introduced into copolymer through IA, SAS, DMI and AGE respectively, which can strengthen its corrosion inhibitation property. The studied copolymer used water as solvent, sodium persulfate and sodium hypophosphite as initiator, and IA as the main raw material.The effect of monomer ratio, monomer composition, NaS2O8 amount, reaction temper ature and reaction time on copolymer properties was discussed in this paper.. The exp erimental results show that the optimum synthetic conditions are as follows:(IA):(DMI): (SAS):(AGE)=1:0.26:0.26:0.26; the amount of reducing agent accounted for 15%; the a mount of initiating agent accounted for 8%; the optimum adding and reaction time are 120min and 20min.Effects of water-quality on the inhibition efficiency of copolymer was also investigated by scale inhibition test. The results show that the copolymer is suitable for soft water, weak alkaline and moderate temperature of water system. The best application conditions are the copolymer concentration of 15 mg/L～20 mg/L, PH 8.0～9.0, calcium ion concentration of 100mg/L～300mg/LThe comparison experiment between several comercial water treatment agents and copolymer developed in this paper shows that the copolymer have better functions of restraining carbonate and phosphate, stabilizing zinc and dispersing ferric salt than others. The Fourier projective groups proved that the functional groups of copolymer agreed with that got by theoretical analysis, i.e. phosphor acid, ester group, carboxylic group.The effects of copolymer water treatment agent on boilers material were analyzed by optical microscope, scanning electron microscopy, energy spectrum analysis and X-ray diffraction analysis and other testing methods. The results show that the descaling and corrosion performance of this water treatment agent fully meet the requirements. In the mean time, the water treatment agent has no harmful effect on the boiler material.