Corrosion Inhibitor Efficiency
Calculate the efficiency of a corrosion inhibitor, η = (CR₀ − CR_inh) ÷ CR₀ × 100%, comparing the corrosion rate without inhibitor (CR₀) with the rate in its presence (CR_inh). The result, in %, measures how much the inhibitor slowed corrosion — the standard indicator to evaluate and compare inhibitors in laboratory tests (mass loss, polarization or impedance). Effective inhibitors form protective films on the surface and reach efficiencies above 90%. It is widely used in boiler water treatment, cooling systems and well acidizing. Enter the corrosion rates without and with inhibitor.
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Eficiência de inibidor de corrosão
Um inibidor de corrosão é uma substância que, adicionada em pequena concentração ao meio, reduz drasticamente a velocidade de corrosão de um metal — geralmente formando um filme protetor adsorvido na superfície que bloqueia as reações anódica, catódica ou ambas. Para avaliar e comparar inibidores, mede-se a eficiência de inibição: η = (TC₀ − TC_inib) ÷ TC₀ × 100%, comparando a taxa de corrosão sem o inibidor (TC₀) com a taxa na presença dele (TC_inib). Uma eficiência de 80% significa que o inibidor cortou a corrosão para um quinto do valor original. As taxas de corrosão usadas no cálculo podem vir de diferentes técnicas — ensaios de perda de massa, medidas de resistência de polarização (LPR) ou espectroscopia de impedância eletroquímica —, e a eficiência costuma ser levantada em função da concentração do inibidor para encontrar a dose ótima (acima dela, mais produto pouco acrescenta). Inibidores de boa performance superam 90–95% de eficiência. Eles são amplamente usados no tratamento de água de caldeiras e torres de resfriamento, em sistemas de petróleo e gás, na acidificação de poços (onde protegem a coluna durante a injeção de ácido) e em decapagem de metais. Informe as taxas de corrosão sem e com inibidor.
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Chlorine Demand
Calculate the chlorine demand of a water, demand = applied dose − chlorine residual, subtracting the measured chlorine residual (mg/L) from the applied chlorine dose (mg/L). The result, in mg/L, is the chlorine consumed by organic matter, ammonia, iron, manganese and other reducers before free chlorine remains for disinfection. Knowing the demand is essential to dose chlorine correctly and keep an adequate residual in the network without waste or underdosing. Enter the applied dose and the measured residual.
Hydraulic Retention Time (HRT)
Calculate the hydraulic retention time (HRT) of a reactor or tank, HRT = volume ÷ flow, dividing the working volume (m³) by the influent flow (m³/h). The result, in hours, is the average time the liquid stays in the unit and is decisive in designing clarifiers, anaerobic reactors, lagoons and aeration tanks: short times prevent reactions or settling from completing, while long times raise cost and footprint. Enter the working volume and the inlet flow.
Corrosion Rate (Mass Loss)
Calculate the corrosion rate by the mass-loss method, CR = 87.6 × W ÷ (D × A × t), from the mass loss W (mg), the material density D (g/cm³), the exposed area A (cm²) and the exposure time t (hours). The result, in mm/year, is the average speed at which the metal is consumed by corrosion — the key parameter to predict the service life of structures, piping and equipment and to set the corrosion allowance in design. Rates below 0.1 mm/year are usually acceptable. Enter the mass loss, density, area and time.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.