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<br />Facility Audit Report 13 <br />San Leandro WWTF <br />is recommended, as it will maintain an almost constant airflow even if the discharge pressure <br />fluctuates, and will require minimal capital cost. A high efficiency blower will not produce <br />significant savings, and few are available at this size. The estimated power demand is 3.6 KW, <br />or 31,900 kWh annually. <br />Table 3.2.1.1.1 – Energy Usage Summary for Process Air Retrofit Options <br /> <br /> <br />The majority of energy cost savings result from reducing energy (kWh) charges, not demand <br />(KW) charges. However, we do anticipate a minor reduction in peak demand charges for the <br />recommended retrofit, as reflected in Table 3.2.1.1. At the highest baseline process airflows, <br />process air continued to be vented to the offline basin to supply its diffusers, adding to the total <br />blower airflow, and peak power demand. This airflow will be supplied much more efficiently at <br />low pressure if the low pressure blower recommendation is followed. The baseline maximum <br />demand from the blower system was estimated at 169 KW, averaged over the year. The <br />corresponding post retrofit demand estimate is 159 KW, the result of the 400 SCFM reduction in <br />peak airflow for the main blowers, less the added demand of the proposed low pressure PD <br />blower. <br />3.2.1.2 Scope of Effort to Improve Performance <br />A single high efficiency turbo blower was determined to be the most cost effective EEM for the <br />process air supply. One of the existing Lamson multistage blowers would be replaced by a high <br />efficiency blower capable of operation below 3000 SCFM. The new blower is expected to use <br />the existing Lamson power supply with minimal modifications. Its controls will have to be <br />integrated with the remaining Lamson blowers, allowing the turbo blower to operate at the <br />lowest airflow demands, then using the Lamsons exclusively above the capacity of the turbo <br />blower. For the occasional flow demands below the minimum of the turbo blower, excess air <br />will need to be vented. <br />The low pressure air supply to the offline basin will require new piping to intercept the two <br />existing basin air supply manifolds. Figure 3.2.1.2.1 shows the overall air supply schematic. <br />The low pressure supply lines from the PD blower are expected to be 3” diameter, and could be <br />tapped into the existing basin supply lines below the control and isolation valves. Manual valves <br />would be included on each low pressure supply branch to direct the low pressure airflow to the <br />offline basin. <br /> <br />ABS1 - 93 HP, 1 - 200 HP 524,000 <br />APG Neuros1 - 100 HP 536,000 <br />Universal EE-PAC2 - 60 HP 539,000 <br />Blower MakeBlower Rated HP <br />Annual <br />Process Air <br />Energy, <br />KWh