3.7 A process requires pure water which can be produced satisfactorily either by distillation or by ion exchange using activated resins.The cost of installation for a distillation unit is $8000 with operating costs of $1.00 per 1000 gal of water produced. The ion-exchange installation costs $2.00 per galon per hour feed rate, and suitable resins cost $1.00 per pound. After operating the ion-exchange system to produce pure water for 1 hour it is necessary to regenerate the resins for 20 minutes before pure water can be obtained again. resin needs may be considered as 1 pound per 10,000 gallons of treated water, and operating costs are $0.40 per 1000 gallons. Based on present worth, determine which installation is more economical for a water duty of 1,000gal/h. Assume 8400 h/year operation and 10 year life for both interet at 12 percent.