Consider a process with six sinks and five sources (Sorin and Bedard 1999). The process data are given in Tables 3-7 and 3-8. Fresh water is used in the sinks and it is desired to replace as much fresh water as possible using direct-recycle of process sources. Determine the target for minimum usage of fresh water and waste discharge after direct-recycle. How many material recycle pinch points are there? What is their significance? TABLE 3-7 SINK INFORMATION FOR PROBLEM 3.1 (SORIN AND BEDARD 1999) Sink 12345 I 2 3 5 Flow (tonnes/h) 120 80 80 140 80 195 1 2 Flow (tonnes/h) 120 80 140 80 195 TABLE 3-8 SOURCE INFORMATION FOR PROBLEM 3.1 (SORIN AND BEDARD 1999) Sources Maximum Inlet Concentration (ppm) Flow (tonnes/h) 0 50 50 140 50 100 80 70 170 240 Concentration (ppm) 100 140 180 230 250 Maximum inlet Concentration (ppm) 20 Load (kg/h) TABLE 3-9 SINK DATA FOR PROBLEM 3-2 (POLLEY AND POLLEY (2000)) Sinks 50 100 200 0 4 19,6 13.6 46.8 Load (kg/h) 12 11.2 25.2 18.4 48.75 Load (kg/h) 1 5 8 14