. You have a boiler that produces 50,000 Ib/hr of 235 psig steam at 600F. The...

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. You have a boiler that produces 50,000 Ib/hr of 235 psig steam at 600°F. The unit operates 8,600 hours per year with a fuel cost of $3.00/MMBTU. Make-up water is provided at 60°F, the DA operates at 12 psig, and the feedwater temperature is 246°F. Measurements indicate that the blowdown rate is 2.5% of the feedwater flow. Currently, blowdown is flashed to atmospheric pressure, flash vapor vented to the roof, and the remaining liquid at 212°F quenched to 140°F with make-up water because of sewer regulations. Water conservation is a huge corporate focus right now. Water from the city costs $10 per 1,000 gallons. You come up with the idea of installing blowdown heat recovery by flashing the blowdown to 15 psig, and then feeding the flash steam into the deaerator. The proposed flash vessel, piping, and controls will cost $25,000 to install. a. Compute the current energy lost due to blowdown and fuel cost per year, b. Find the amount of quench water needed to meet sewer regulations . You have a boiler that produces 50,000 Ib/hr of 235 psig steam at 600°F. The unit operates 8,600 hours per year with a fuel cost of $3.00/MMBTU. Make-up water is provided at 60°F, the DA operates at 12 psig, and the feedwater temperature is 246°F. Measurements indicate that the blowdown rate is 2.5% of the feedwater flow. Currently, blowdown is flashed to atmospheric pressure, flash vapor vented to the roof, and the remaining liquid at 212°F quenched to 140°F with make-up water because of sewer regulations. Water conservation is a huge corporate focus right now. Water from the city costs $10 per 1,000 gallons. You come up with the idea of installing blowdown heat recovery by flashing the blowdown to 15 psig, and then feeding the flash steam into the deaerator. The proposed flash vessel, piping, and controls will cost $25,000 to install. a. Compute the current energy lost due to blowdown and fuel cost per year, b. Find the amount of quench water needed to meet sewer regulations

Answer rating: 100% (QA)

mass flow rate of steam M 50000lbhr mass of water lost during blowdown m 25 of M 5000025... View the full answer