H2SH-18-C flender doo Helical gear Reduction Box H2

Flender/Flender Gear Units/Helical gear Reduction Box H2

/ wh ich is 3% less than the baseline measured average value of 0.3 mgN/. 5.7.2 Low to Medium Investment Measures Automated Aeration Control This measure involves full automation of aeration contro as outlined in Section 5.6.1. The analysis is for the following modifications: Optimal process operation as outlined in Section 5.6.1 above Installation of aerator VFDs Installation of PLCs and associated cont rol systems to implement feedback cascade ammonia DO control utilising the already installed ammonia and DO sensors Aerators to be controlled by combinat ion of VFDs and weir level adjustment 5-2 The model predicted aeration energy consumption and cost savings as well as final effluent quality when these measures are implemented are given in Table 5-1. Also included are the 2 baseline values for comparison. Table 5-1: JP Marais WWTP Model Predicted Parameters fo Implementing Automated Aeration Control (with ammonia based aeration control) Aeration Energy Parameter Units Baseline Automated Aeration Control FB Cascade NH 4+/DO Consumption MWh/yr 2,4 1,9 Consumption Saving MWh/yr 5 % Consumption Saving % 2 Consumption Cost /yr 2,2,4 1,8,7 Consumption Cost Saving /yr 4,6 % Consumption Cost Saving % 2 Demand Saving kW 5 Final Effluent Quality FSA mgN/ 1 3.5 Ortho mgP/ 0.3 0.1 Nitrate/Nitrite mgN/ 1 3 Model predicted values in Table 5-1 indicate that implementing advanced process control (with ammonia based aeration control) utilizing the existing aeration equipment results in: Potentially 2% savings in power consumption an costs. Demand savings of 5 kW is also realised as result of savings in consumption Average final effluent nitrate/nitrite concentr ation of 3mgN/; 5% below permit limit of 6 mgN/. Average Ortho concentration of 0.1 mgP/; 6% below the baseline measured value and 6 times less than the permit limit of 0.6 mgP/ Model predicted final effluent Ortho and nitrate/nitrite concen