Limit Characteristic Of The Scale Inhibitor Effect Studies

In this thesis the limited carbonate hardness method and static scale inhibition areused to evaluate scale inhibition efficiency of POCA, HEDP, PBTCA, HPMA,T-225, ATMP in different temperatures, hardness and alkalinity.According to the test of the low temperature, PBTCA, ATMP and POCA have the lowefficiency scale inhibition in 30℃contrast with HEDP in 20℃, HPMA and T-225 haslow scale inhibition efficiency in this temperature scope. The result of the experiment showthat the limited carbonate hardness method is simple, quick and effective in mediumtemperature and estimate the sequence of scale inhibition efficiency: PBTCA＞ATMP＞HEDP＞POCA＞HPMA＞T-225. In the high temperature, T-225, PBTCA, HEDP,ATMP, POCA and HPMA have low scale inhibition efficiency after a particulartemperature as follows: 90℃, 185℃, 250℃, 185℃, 130℃, 300℃.Keeping the dosage of HCO₃^- in 10mmol/L, The result showed when C(Ca²⁺)＜20mmol/L, the scale inhibition of PBTCA maintains to 60%, the limited hardness of POCA iswell, but HEDP, HPMA, T-225 and ATMP can't tolerance high hardness. Keeping thedosage of Ca²⁺ in 8mmol/L, the result showed when C(HCO₃^-)＜20 mmol/L, the scaleinhibition of PBTCA maintain to 50%, HPMA and T-225 have good scale inhibition inlimited rigidity with C(HCO₃^-)＜10 mmol/L. When 10mmol/L＜HCO₃^-＜18mmol/L, thechange of the scale inhibition of POCA is smoothly, and When HCO₃^-＞10mmol/L andHCO₃^-＞15mmol/L, the scale inhibition of POCA is separately better than HEDP andATMP. The scale inhibition of HEDP, ATMP reduce quickly in high alkalinity.