My filament is not round



Hy friends. I am facing a problem. I have a medium sized abs filament production unit pf capacity 4kg/hour. I have a hot water tank with hot water at 65 degree Celsius and length of tank is 5 feet. My extruder ejects the melted abs at temperature of 170 dgree. After all this arrangement my filament is still not round. Any body have trusted literature on the extrusion perimeter for abs filament and required hot water temperature and tank length? Please guide me